WO2001054563A2

WO2001054563A2 - Method and apparatus for biopotential sensing and stimulation

Info

Publication number: WO2001054563A2
Application number: PCT/US2001/003140
Authority: WO
Inventors: Babak A. Taheri
Original assignee: Integrated Biosensing Technologies
Priority date: 2000-01-31
Filing date: 2001-01-31
Publication date: 2001-08-02
Also published as: AU2001256953A1; WO2001054563A3

Abstract

A biopotential sensor electrode (100) comprising at least one sensory component (104) coupled to a biopotential signal source (1208). The at least one sensory component comprises at least one layer of electrically conductive material (1202) and at least one dielectric layer (1204). At least one conditioning component (1110) is coupled to condition signals from the at least one sensory component. At least one interface (1104) is configured to transfer signals among the at least one conditioning component and external instrumentation. At least one power source (906) is coupled among the at least one sensory component, the at least one conditioning component and the at least one interface.

Description

METHOD AND APPARATUS FOR BIOPOTENTIAL SENSING AND STIMULATION

This invention relates to the field of biopotential sensors In particular, the invention relates to surface electrodes Typical biopotential sensing/stimulating systems are used to gather a growing variety of biopotential signal types or information from subjects or patients These sensmg/stimulatmg systems are also used to stimulate the patient with a known signal such that skin impedance and other information can be sensed from the subjects or patients Typical biopotential sensmg/stimulatmg systems include two types of subsystems, biopotential sensors and the associated external monitoring systems or instrumentation While the medical information capable of being extracted from this biopotential information has increased significantly with advances m medical science and technology, the usefulness of these systems remains as a limiting factor in patient treatment because of deficiencies of the typical biopotential sensmg/stimulatmg systems

Regarding the biopotential sensor/stimulator subsystem, biopotential sensors/stimulators can generally be categorized as being invasive or non-mvasive Invasive sensors are implanted surgically, and are used for accurate isolation of potential sources during sensing and/or delivery of a stimulating signal m to a specific target location The invasive sensors/stimulators can usually be applied to peripheral nervous systems (l e , axons or muscles) or to mtrocerebral sites as m brain research

Non-mvasive sensors/stimulators, also referred to as surface, skin, or scalp electrodes and/or sensors, are applied to the skin surface These electrodes are typically connected to the surface of the skm via an electrolyte or gel, hence they are also referred to as wet surface electrodes, or wet electrodes Wet surface electrodes are commercially available and are routinely used in the clinics and research labs The preference for wet surface electrodes is due in part to the relatively low manufacturing cost of wet electrodes, and historically proven technology Furthermore, the wet surface electrodes are passive devices that can be used for both sensing and stimulating, since all the necessary electronics and intelligence resides m the external monitoring systems or instruments

One class of surface electrodes does not use electrolytes These electrodes, referred to as active electrodes, employ an impedance transformation at the sensing site via active electronics The active electrodes are subdivided into two electrode types, dry electrodes and insulated electrodes The dry electrode has a metal in direct contact with the skm which is followed by an impedance converting amplifier The insulated electrode is capacitively coupled to the skin via a dielectric which is followed by an impedance converting amplifier Research results for active electrodes have demonstrated that both dry and insulated electrodes are comparable to wet electrodes for sensing or receivmg electrocardiogram (ECG or EKG) signals However, typical active dry and insulated electrodes do not exhibit the same consistency and signal to noise ratio (SNR) as the wet electrodes In addition, the typical non-mvasive active electrodes have been used for signal sensing purposes only and not stimulating While the research has focused on ECG signals, there are numerous other biopotential signal types to which the application of active electrodes would be desirable but has yet to be demonstrated

Efforts to realize active insulated electrodes have included significant research and development in the area of sensor dielectrics A number of materials have been investigated for thm-film capacitor fabrication in sensors of the active hybrid electrodes Some of the materials typically considered for use include silicon monoxide (SiO), silicon dioxide (Sι0₂), silicon nitπde (Sι₃N ), Diamond like Carbon (DLC), and tantalum pentoxide (Ta₂0₅). In practice, deposited dielectric films thinner than 500-700 Angstroms (A) have a fairly high pinhole density and the yields are poor Pinholes lead to resistive shorts between the electrodes (in the vicinity of each other) and increase the leakage current. Thick dielectric films, or films with a thickness greater than approximately 20,000 A also may exhibit problems because of the high mtemal stress levels found in these films High compressive forces cause the films to peel off; however, large tensile forces can be relieved by crazing, or the production of fine cracks in the film. These factors thus may limit the thickness of the dielectric mateπal to between 800 A and 10,000 A.

While both silicon monoxide and silicon dioxide are good insulators for electrical isolation, their behavior as a barrier to sodium ions (Na+) is poor. In addition, these two materials require high temperatures m order to form high quality films with few pinholes Tantalum pentoxide also can suffer from high-temperature deposition requirements and low breakdown voltage.

The insulated electrodes with dielectrics currently in use are not practical because of breakage, scratched surfaces, and inconsistency. Therefore, there is a need for an electrode dielectric mateπal having a number of specific properties The properties desired include, low reaction with sodium chloπde (NaCl) for biocompatibihty and sensor protection, low deposition temperature (approximately less than 500 degrees Celsius) to be compatible with electrode material, high dielectπc constant for obtaining a large capacitance m a small area, high dielectπc strength (resultmg in high breakdown voltage) for electrostatic protection; moderate leakage resistance for impedance matchmg to the amplifier; and, oxidation rate 30 times slower than that of silicon

Regarding electrode monitoπng subsystems, a typical electrode monitoring system consists of the following components: (1) an array of wet electrodes attached to the monitoπng environment; (2) electrode cables for couplmg each of the wet electrodes to instrumentation; (3) a cable converter box for receiving the electrode cables; and, (4) a monitoπng system connected to the cable converter box with a seπes of cables. The typical electrode signal path from the sensor to the monitoπng system is through unshielded cables of approximately 3 to 6 feet in length. These cables typically degrade the signal-to-noise-ratio (SNR) of the recording system and increase motion artifacts In addition, the cables confine the movement of the subject as well as impose a health hazard in monitoπng systems Consequently, there is a need for an electrode monitoπng system that does not require the patient to be wired to the monitoring system, a system that eliminates the need for electrode cables, the cable converter box, and the monitoπng cables

Wireless telemetry systems in general are classified as active or passive. Active telemetry systems are used for telemetry over longer distances Therefore, typical active telemetry systems require a power source m both transmitter and receiver sections The power source is pπmaπly used to operate active devices such as transistors that form the circuits for these systems. The factors that influence the distance of communications mclude the available power, frequency of operation, and antenna size.

Typical telemetry for monitoπng systems use either infrared red (IR) or radio-frequency (RF) links These systems consist of several wet electrodes mounted on a cap and connected via cables to a transmitter section. The transmitter section consists of transmitter circuitry, a power unit, IR light emitting diodes or a large antenna, voltage converters/multiplexers, and a microcontroller unit. Th; transmitter section requires very high bandwidth and additional signal processmg circuitry in order to provide ligitized and time multiplexed data for transmission. As such, the size and weight of the transmitter section m these telemetry systems prevents them from being mounted on the cap with or m the electrodes. Therefore, the transmitter section is placed on a belt strap which is attached to the subject. Thus, the cables along with the size, weight, and power consumption of the transmitter sectton limit the application of these systems. While a number of RF telemetry systems have been deployed, most have been discontinued for use m electrode monitoπng applications because of these limitations. Furthermore, IR telemetry systems have also found limited applications due to the size and poor SNR resultmg from signal attenuation due to light reflections, and the amount of light that couples into the detectors.

Recently, in the field of local area networking and telephony, wireless systems have been introduced that utilize RF and spread spectrum techniques. These systems in their current state are not suitable for use m electrode monitoπng systems without major modification, for a number of reasons. As an example, since these systems provide only a single transmitter channel, they would require additional signal processmg and multiplexing if used m an electrode monitoπng system. Furthermore, an increase in the number of electrodes would increase the power consumption, and thus the size of the transmitters, inhibiting then- use for high resolution electrode recording Thus, there is a need for a micro-telemetry system that eliminates cables that connect a subject to a monitoring system and is small in size and weight for ease of attachment and carrying.

The descπptions provided herein are exemplary and explanatory and are provided as examples of the claimed invention.

The accompanying drawings illustrate embodiments of the claimed invention. In the drawings: Figure 1 is a hybπd sensor electrode of an embodiment.

Figure 2 is the hybrid sensor electrode an alternate embodiment.

Figure 3 is a hybπd sensor electrode of another alternate embodiment.

Figure 4 is a wireless hybπd sensor electrode of an embodiment.

Figure 5 is a wireless hybrid sensor electrode of an alternate embodiment Figure 6 is a functional block diagram of a hybπd sensor electrode of an embodiment.

Figure 7 is a functional block diagram of an interface for a hybπd sensor electrode digital interface of an embodiment

Figure 8 is a functional block diagram of a hybnd sensor electrode of an alternate embodiment

Figure 9 is a block diagram of stimulation circuitry of a hybnd sensor electrode of an embodiment. Figure 10 is a schematic diagram of stimulation circuitry of a hybπd sensor electrode of an embodiment.

Figure 11 is a block diagram of sensor pick-up circuitry of a hybπd sensor electrode of an embodiment.

Figure 12 is a sensory element of a hybπd sensor electrode of an embodiment.

Figure 13 is an alternate sensory element or component of a hybπd sensor electrode of an embodiment. Figure 14 is a sensory element configuration of a hybπd sensor electrode of an embodiment.

Figure 15 is an alternate sensory element configuration of a hybπd sensor electrode of an embodiment.

Figure 16 is a functional block diagram of a hybπd sensor electrode array of an embodiment.

Figure 17 is a functional block diagram of an alternate hybπd sensor electrode array of an embodiment.

Figure 18 is a block diagram of a telemetry system of a hybπd sensor electrode of an embodiment. Figure 19 is a functional block diagram of a hybπd sensor telemetry electrode of an embodiment. Figure 20 is a functional block diε ram of a hybrid sensor telemetry electrode of an alternate embodiment.

Figure 21 is a functional block diεgram of a radio frequency (RF) powered or telemetry powered hybrid sensor telemetry electrode of an embodiment. Figure 22 is a hybrid sensor electrode of an embodiment having a telemetry system and a coil antenna.

Figure 23 is a hybrid sensor electrode of an embodiment with a flat antenna.

Figure 24 is a block diagram of integrated circuitry (IC) of a hybrid sensor electrode transmitter section of an embodiment using telemetry powering.

Figure 25 is a block diagram of integrated circuitry (IC) of a hybrid sensor electrode transmitter section of an embodiment using internal battery power.

Figure 26 is a flowchart of a method for collecting biopotential signals of an embodiment.

Figure 1 is a hybrid sensor electrode 100 of an embodiment. The hybrid sensor electrode 100 is a hybrid between dry electrodes and insulated electrodes and, unlike any of the typical dry or insulated electrodes, the hybrid sensor electrode houses the power source within the same package. This configuration minimizes interference noise, provides plug compatibility to the current monitoring systems, and reduces the possibility of accidental shocks that could arise from the monitoring system. This configuration also provides an improved signal to noise ratio (SNR), and allows for programmable signal gains of greater than two orders of magnitude using the active electronics integrated into the sensor electrode. Furthermore, the hybrid sensor electrode is scalable, wherein multiple sensing sites can be integrated onto a single substrate for built-in redundancy and performance as described herein.

The hybrid sensor electrode 100 includes, but is not limited to, a hybrid sensor substrate 102, a metallic sensory component 104 coupled between the skin, or sensing environment, and one side of the hybrid sensor substrate 102, sensory components and electronics 106 coupled to another side of the hybrid sensor substrate 102, an electronic connector/connection 108 to a battery substrate 110 housing one or two battery holders 112, and a package or housing 114. The housing 114 may be attached to a strap using mounting holes 116 or to the surface of the skin using adhesive tape. A wire or cable 118 transfers signals between the hybrid sensor electrode 100 and external instrumentation, but the embodiment is not so limited. While an embodiment uses batteries as a power source, solar cells or other power sources may be used.

Figure 2 is a hybrid sensor electrode 200 of an alternate embodiment. This hybrid sensor electrode includes, but is not limited to, a metallic sensory component 202 coupled between the sensing environment and one side of a hybrid sensor substrate 204, sensory components and electronics coupled to another side of the hybrid sensor substrate, an electronic connector/connection to a battery substrate housing battery holders 206, and a two-piece package 208. The metallic sensory component 202 includes a smooth flat surface for contact with the skin, but is not so limited. The package 208 includes a hybrid sensor housing and a housing cap, both removeably coupled to the hybrid sensor substrate. The package 208 may be attached to a strap using mounting holes or to the surface of the skin using adhesive tape. A wire or cable coupled through the wire ports 212 transfers signals between the hybrid sensor electrode 200 and external instrumentation, but the embodiment is not so limited. While an embodiment uses batteries 210 as a power source, solar cells or other power sources may be used. Furthermore, while an embodiment uses a permanent metallic sensory component, a disposable metallic sensory component may be used. Figure 3 is a side view of a hybπd sensor electrode 300 of another alternate embodiment. This alternate hybnd sensor electrode 300 mcludes a metallic sensory component 302 havmg a rough or bumped surface 304 This rough surface 304 provides for contact with the skm over hair, for example on the scalp, and can be a disposable component Figure 4 is a wireless hybnd sensor electrode 400 of an embodiment The wireless hybnd sensor electrode 400 includes, but is not limited to, a metallic sensory component 402 coupled to a hybπd sensor substrate 404 housmg sensory electronics and components 406 Wireless technology is integrated mto the sensor package using a transmitter substrate 408, transmitter electronics 410, and antenna components 412 to enable the telemetermg of both data and power Figure 5 is a wireless hybnd sensor electrode 500 of an alternate embodiment While the wireless hybnd sensor electrode 400 of Figure 4 mcludes a separate transmitter substrate 408 housing the transmitter electronics 410 and the antenna reference signal connector 412, the alternate embodiment 500 has the components of the transmitter 502 on the electrode holder substrate 504 and eliminates the transmitter substrate 408 Further alternative embodiments of the wireless hybπd sensor electrode descπbed herein utilize radio frequency (RF) poweπng to remotely provide power to the sensor electronics, thereby elmunatmg the batteπes as a power source

A hybrid sensor electrode package or housing of an embodiment compnses a mam housmg and a cover piece The cover piece locks mto the main housmg, but is not so limited A windowed hybnd sensor electrode package exposes a metallic sensory component on one side of the substrate to the environment, and isolates other components from the environment The package mtegrates the conditionmg circuitry and battery substrate with strap mounting holes The power source of this embodiment mcludes battenes that are held m place by holders on a separate substrate and connected electncally to the sensor substrate

An alternate embodiment of the hybπd sensor electrode package mcludes a package type compπsing a smgle piece housmg The single piece housmg allows for a disposable version of the hybnd sensor electrode by providing a housing that snap connects to a disposable sensor substrate The disposable version eliminates battery or sensor replacement

Figure 6 is a functional block diagram of a hybnd sensor electrode 600 of an embodiment The hybπd sensor electrode 600 includes an mterface 602 that receives signals from a sensor pick-up section 604 and provides signals to monitoπng/controlling instruments 606 The mterface 602 can be coupled to the monitormg/controllmg instruments 606 usmg cables or using a wireless mterface, but is not so limited The mterface 602 is coupled to sensory circuitry mcludmg stimulation circuitry 608, or sensor stimuli circuitry, sensory components 610, and conditionmg circuitry 604, or sensor pick-up circuitry The stimulation circuitry 608 and the conditioning circuitry 604 are coupled to a sensory component 610 that receives signals or data from the environment 612 that is being monitored The monitored environment 612 mcludes but is not limited to human skm and annual skm A power source 614 is coupled to each of the mterface 602, stimulation circuitry 608, sensory component 610, and conditionmg circuitry 604

The mterface 602 of an embodiment can be analog or digital Usmg an analog mterface, the mterface block mcludes a conductive wire and amplifier Usmg a digital mterface, the mterface block compnses several components mcludmg analog-to-digital (A/D) converters, memory, and a digital input/output mterface Figure 7 is a functional block diagram of a hybπd sensor electrode digital mterface 700 of an embodiment. The digital mterface 700 mcludes at least one analog-to-digital (A/D) converter 708, memory 710, protocol input/output (I/O) mterface units 702, and a state machme 706, but is not so limited. The mterface 700 can be realized usmg low power circuitry compnsing complementary metal-oxide semiconductor (CMOS) circuitry or SiGe/CMOS process circuitry, but is not so limited.

The I/O mterface unit 702 communicates with the monitoring and controlling instrumentation 704 usmg a custom digital protocol. The state machme 706, as the controller for the digital mterface 700, monitors and sequences the A/D converter 708, memory 710, and mterface units 702 The state machme 706 can partially reside in the memory 710, but is not so limited. The A/D converter 708 mcludes a 12-bit A/D realized m complementary metal-oxide semiconductor

(CMOS) technology with a low power design using successive approximation or delta-sigma modulation techniques, but is not so limited. The A/D converter 708 receives input from the analog sensor section and converts the signal to a 12 bit or larger bit digital word.

The memory device or memory 710 is used to store manufacturing data, and as a data buffer to the interface 700 and the instrument. The memory device 710 mcludes memory selected from a group mcludmg electrically erasable programmable read only memory (EEPROM), flash memory, or other types of non volatile memory. The memory device 710 may be integrated with or separated from the A/D converter circuitry 708.

Figure 8 is a functional block diagram of a hybrid sensor electrode 800 of an alternate embodunent. In this alternate embodunent, the hybrid sensor electrode 800 includes an interface 802 that receives signals from and provides signals to monitoring/controlling instruments 804. The interface 802 is coupled to sensory circuitry mcludmg sensory components 806 and conditionmg circuitry 808, or sensor pick-up circuitry. The mterface 802 couples biopotential signals received from the monitored environment 812 by the sensory component 806 through the conditionmg circuitry 808 to the monitormg/controllmg instruments or external instrumentation 804. A power source 810 is coupled to each of the mterface 802, sensory component 806, and conditionmg circuitry 808.

Figure 9 is a block diagram of stimulation cucuitry 900 of a hybπd sensor electrode of an embodiment The stimulation circuitry 900 is coupled to transfer signals between the mterface 902 and the sensory component 904. The stimulation circuitry 900 includes, but is not limited to, voltage/current (V/I) source circuitry 906, cuπent- to- voltage converter or transresistance (TRA) amplifier 908, and programmable generator circuitry 910. The programmable generator 910 is coupled between the mterface 902 and the cuπent source 906. The cunent source 906 is coupled to the sensor 904 and the TRA 908. The cunent source output 914 can be dynamically monitored by the TRA 908 in order to operate m a closed-loop control fashion for accuracy and reliability. The TRA output is coupled as feedback 912 to the interface.

Figure 10 is a schematic diagram of stimulation circuitry 1000 of a hybπd sensor electrode of an embodiment. An embodunent of the circuitry uses CMOS technology, but is not so limited. The programmable current source mcludes transistors M5 and M6 as references and transistors M7 to M 10 as current mirrors that establish a cunent threshold for transistors Ml to M4. The signal mputs to transistors Ml to M4 are labeled as A,B,C,and D respectively. These mput signals are used to add or turn off the respective transistors for summing cunent at the node labeled lout. The transistors Ml 1, Ml 2, and M13 form the TRA that converts the summed current to a voltage if a threshold (Ith) is exceeded, feedmg back to the irterface to turn off one or several of the Ml to M4 devices for lower cunent output. A portion of the lout cunent is delivered to the skm of a subject. The delivered cunent should not exceed 100 micro amps and it can be as low as 5 micro amps.

Figure 11 is a block diagram of sensor pick-up circuitry 1100 of a hybnd sensor electrode of an embodunent. The sensor pick-up circuitry 1100, or conditionmg circuitry, is coupled to transfer signals between the sensory component 1102 and the mterface 1104. The sensor pick-up circuitry 1100 mcludes, but is not limited to, impedance matchmg circuitry 1106, amplification/buffering circuitry 1108, and conditionmg circuitry 1110. The impedance matchmg circuitry 1106 provides charge balancmg for the sensing element, impedance matchmg to minimize loadmg with a feedback controlled amplifier that has low noise and low offset charactenstics. The amplification and buffering circuitry 1108 provides programmable gam control, a programmable filter for frequency band selection, and feedback control for minimization of noise and drift. The conditioning circuitry 1110 provides signal level shifters, output electronic static discharge protection, and input/output matchmg.

Figure 12 is a sensory element 1200 of a hybπd sensor electrode of an embodiment. The sensory element 1200 includes a first metallic contact 1202 coupled to a first side of a dielectric 1204 and a second metallic contact 1206 coupled to a second side of the dielectπc 1204 The first metallic contact 1202 is placed in the environment 1208 to be monitored The second metallic contact 1206 is coupled to other sensory elements and circuitry 1210.

The hybnd sensory element of an embodiment is a hybπd between dry electrodes and insulated electrodes as it provides metallic contact at both ends and allows means of stimulating the sensor environment in addition to sensing the signals from the environment. Like the dry electrodes, the sensor has a metallic or conductive matenal (e g., Gold, Stainless Steel) in contact with the skin. Similar to the msulated electrode, the couplmg to the skm is capacitive The capacitive couplmg to the skm in an embodiment of the hybπd sensor electrode is via a metallic contact with the skm followed by a dielectnc, a metallic mateπal followed by a dissimilar metallic material, then transimpedance amplifiers and circuits for signal conditionmg Figure 13 is an alternate sensory element or component 1300 of a hybnd sensor electrode of an embodiment. The sensory element 1300 includes a first metallic contact 1302 coupled to the environment to be sensed 1304. The first metallic contact 1302 is also coupled to a second metallic contact 1306 via a bond 1308. The bond 1308 includes, but is not limited to, a metallic bond, a metallic snap connector, and any other type of metallic contact that electrically couples the first metallic contact 1302 to the second metallic contact 1306 such that the first metallic contact 1302 is removable and disposable. The second metallic contact 1306 is coupled to one side of a dielectric 1310. Another side of the dielectnc 1310 is coupled to a third metallic contact 1312. The third metallic contact 1312 is coupled to a fourth metallic contact 1314 via another bond 1316. The fourth metallic contact 1314 couples to the hybπd sensor electrode circuitry 1318 and other sensory elements.

Figure 14 is a sensory element configuration 1400 of a hybπd sensor electrode of an embodiment. This sensory element configuration 1400 can be used with any of the sensor elements descπbed herein, but is not so limited. The sensory element 1400 mcludes a first metallic contact 1402 coupled to a first side of a dielectπc 1404 and a second metallic contact 1406 coupled to a second side of the dielectπc 1404. The first metallic contact 1402 is placed in the environment to be monitored 1408. The second metallic contact 1406 is coupled to protection circuitry 1410. The protection circuitry 1410 mcludes back-to-back diodes 1412 for high voltage protection, but is not so limited. The second metallic contact 1406 is coupled to a resistive element 1418 usmg a third metallic contact 1414 and a metallic t ond 1416 The resistive element 1418 is coupled to a low noise amplifier 1420 through a charge balancmg cunent source/sink 1422. The low noise amplifier 1420 mcludes feedback, but is not so limited

Regarding transduction/sensing mechanisms, the sensory element of an embodunent, when m contact with the surface of the body or the skm, or m close proximity to the environment of the surface of the body, forms a completed network that allows biopotentials (e g , ionic) or fields to be picked up from the surface of the skm and transfened to instruments for analysis and recordmg The functioning of the sensor can be descnbed as a network of electπcal circuit components such as amplifiers, resistors, capacitors and impedances The sensor, when in contact with the skm, provides a means of converting the ionic potential at the skm boundary to electncal potentials When m the vicinity of the skm, the sensor converts the electπcal field near the skm to electrical potential Consequently, the sensor serves as two integrated sensors that convert both ionic potentials and electnc fields to electncal potential such that it can be monitored and recorded by instruments to which it is coupled The sensor output provides the electπcal interface for utilizing four types of biopotential signals and for connecting to the associated electrocardiogram (EKG), electroencephalogram (EEG), electromyogram (EMG), and electro-oculogram (EOG) instrumentation without additional conditionmg

In the design of the hybπd sensor electrode of an embodiment, the effects of changmg skm impedance are minimized by introducing an electrode put impedance placed in seπes with the skm impedance that has a much larger magnitude (electrode-dominant impedance) This electrode mput impedance mcludes a sensor impedance in senes with the skm impedance coupled to the local amplifier input impedance and charge balancmg circuitry The local amplifier circuitry of an embodiment should have a very high mput impedance (greater than 1 tena ohm), low offset voltage (less than 200 microvolts), low noise (less than 1 microvolt root mean square (rms) per root hertz (Hz) at 1 Hz) and operate at voltages less than 3 volts (V) The charge balancmg circuitry should be able to leak or provide cunent to the amplifier and sensory element node cunents as low as 10 nano amperes and as high as 1 micro amperes The charge balancing circuitry minimizes direct cunent (DC) offset and motion artifacts caused by the motion of the subject and vanation of low frequency components of the biopotential

Figure 15 is an alternate sensory element configuration 1500 of a hybπd sensor electrode of an embodiment This sensory element configuration 1500 can be used with any of the sensor elements descπbed herem, but is not so limited The sensory element 1500 mcludes a first metallic contact 1504, placed m the envuronment to be monitored 1502, coupled to a second metallic contact 1506 using a metallic bond 1508 The second metallic contact 1506 is coupled to protection cucuitry 1510, for example back-to-back diodes The second metallic contact 1506 is coupled to a third metallic contact 1512 usmg a metallic bond 1514 The third metallic contact 1512 is coupled to a side of a dielectπc 1516 Another side of the dielectπc 1516 is coupled to common cathode diode circuitry 1518 and the mput of a low noise amplifier 1520 usmg a fourth metallic contact 1522 and a metallic bond 1524

The effects of changmg skm impedance are minimized m the hybπd sensor electrode by introducing an electrode mput impedance placed m seπes with the skm impedance The electrode mput impedance mcludes a sensor impedance in senes with the skm impedance coupled to the local amplifier mput impedance and charge balancmg circuitry The local amplifier circuitry of an embodunent has a very high mput impedance (equal to or greater than 1 tena ohm), low offset voltage (less than 200 microvolts), low noise (less than 1 microvolt rms per root hertz at 1 Hz) and operates at voltages less than 3 volts. The charge balancing circuitry of an embodiment leaks or provides cunent to the amplifier and sensory element node approximately in the range 10 nano amperes to 1 micro amperes. The charge balancing minimizes DC offset and motion artifacts caused by the motion of the subject and variation of low frequency components of the biopotential at the skin. In this embodiment, the charge balancing circuitry comprises a common cathode diode that further serves as protection against high voltages, and provides large input impedance.

Regarding the selection of electrode materials, a number of materials have been investigated for thin-film capacitor fabrication, where some of the commonly used materials include silicon monoxide (SiO), silicon dioxide (Si0₂), silicon nitride (Si₃N ), Diamond like Carbon (DLC), and tantalum pentoxide (Ta₂0₅). Tantalum pentoxide is used as the dielectric material of an electrode of an embodiment.

The properties of the dielectric material of an embodiment of the electrode include, but are not limited to: low reaction with sodium chloride (NaCl) for biocompatibility and sensor protection; low deposition temperature (less than 500 degrees Celsius) to be compatible with the electrode material (the melting point of aluminum is 660 degrees Celsius); high dielectric constant for obtaining a large capacitance in a small area; high dielectric strength (needing high breakdown voltage, or BV) for electrostatic protection; and, moderate leakage resistance for impedance matching to the amplifier. Considering these factors, silicon nitride (Si₃N ) is used as the dielectric material of an embodiment. Silicon nitride is an extremely good barrier to the diffusion of water and ions, particularly sodium (Na⁺) ions. Furthermore, silicon nitride oxidizes 30 times slower than silicon, adheres well to aluminum, and has a high dielectric constant. Moreover, silicon nitride can be deposited by plasma-enhanced chemical vapor deposition (PECVD), atmospheric-pressure chemical vapor deposition

(APCVD), and low pressure chemical vapor deposition (LPCVD), with each of these deposition techniques resulting in different nitride characteristics. Following selection of the dielectric, electrode, and substrate materials, dielectric film deposition conditions and thickness are optimized.

The hybrid sensor electrode of an embodiment is scalable, and this allows for the integration of multiple sensing sites onto a single substrate for built-in redundancy and performance. Figure 16 is a functional block diagram of a hybrid sensor electrode anay 1600 of an embodiment. The anay 1600 includes a number of hybrid sensor electrodes 1602 on a single substrate 1610, where the electrodes are coupled to the monitored environment 1604, but is not so limited. The monitored environment 1604 includes but is not limited to human skin and animal skin. The electrodes 1602 are coupled to a bidirectional multiplexer 1606 that provides for communications among the hybrid sensor electrodes 1602 and monitoring/controlling equipment or external instrumentation 1608.

The hybrid sensor electrode 1602 includes an interface 1620 that receives signals from and provides signals to monitoring/controlling instruments 1608 through the bidirectional multiplexer 1606. The bidirectional multiplexer 1606 can be coupled to the monitoring/controlling instruments 1608 using a wired interface, a wireless interface, or a combination wired/wireless interface, but is not so limited. The interface 1620 is coupled to sensory circuitry including stimulation circuitry 1622, or sensor stimuli circuitry, sensory components 1624, and conditioning circuitry 1626, or sensor pick-up circuitry. The interface 1620 of an embodiment couples signals from the interface 1620 through the stimulation circuitry 1622 and sensory component 1624 to the conditioning circuitry 1626 and back to the interface 1620. The stimulation circuitry 1622 and the conditioning circuitry 1626 are coupled to a sensory component 1624 that receives signals or data communications among the hybrid sensor electrodes 1602 and monitormg/controllmg equipment or external instrumentation 1608

The hybrid sensor electrode 1602 mcludes an mterface 1620 that receives signals from and provides signals to monitormg/controllmg instruments 1608 through the bidirectional multiplexer 1606 The bidirectional multiplexer 1606 can be coupled to the monitormg/controllmg instruments 1608 usmg a wired interface, a wireless interface, or a combination wired/wireless interface, but is not so limited The interface 1620 is coupled to sensory circuitry mcludmg stimulation circuitry 1622, or sensor stimuli circuitry, sensory components 1624, and conditionmg circuitry 1626, or sensor pick-up circuitry The mterface 1620 of an embodiment couples signals from the interface 1620 through the stimulation circuitry 1622 and sensory component 1624 to the conditioning circuitry 1626 and back to the mterface 1620 The stimulation circuitry

1622 and the conditionmg circuitry 1626 are coupled to a sensory component 1624 that receives signals or data from the environment 1604 that is being monitored A power source 1628 is coupled to each of the interface 1620, stimulation circuitry 1622, sensory component 1624, and conditionmg circuitry 1626 In an alternate embodiment, a single power source 1630 can be used to provide power to all of the hybrid sensor electrodes 1602 of the hybrid sensor electrode anay 1600

Figure 17 is a functional block diagram of an alternate hybπd sensor electrode anay 1700 of an embodiment The alternate anay 1700 includes a number of alternate hybrid sensor electrodes 1702 on a smgle substrate 1710, where the electrodes 1702 are coupled to the monitored environment 1704, but is not so limited The electrodes 1702 are coupled to a bidirectional multiplexer 1706 that provides for communications among the hybrid sensor electrodes 1702 and monitoring/controlling equipment 1708 The alternate hybrid sensor electrode 1702 includes an interface 1720 that receives signals from and provides signals to monitoring/controlling instruments 1708 through the bidirectional multiplexer 1706 The interface 1720 is coupled to sensory circuitry including sensory components 1722 and conditioning circuitry 1724, or sensor pickup circuitry A power source 1726 is coupled to each of the interface 1720, sensory component 1722, and conditioning circuitry 1724 In an alternate embodiment, a single power source 1728 can be used to provide power to all of the hybπd sensor electrodes 1702 of the hybrid sensor electrode anay 1700

The hybrid sensor electrode system of an embodiment provides a micro-telemetry system that eliminates any cables or wires used to connect the electrodes of a subject to a monitoring system As the micro- telemetry system is co-located with the electrode, and the electrode is attached to the subject, the size, weight, power consumption and bandwidth of the transmitter section are the key parameters in design of a telemetry system for electrode systems The transmitter section of an embodiment provides, but is not limited to, long term momtormg, low bandwidth and unproved SNR and power consumption, while not disturbing the normal physical processes of the subject

Figure 18 is a block diagram of a telemetry system 1800 of a hybrid sensor electrode of an embodiment Each electrode 1802 is configured with an embedded micro-transmitter 1804 and a power source 1806 that includes a battery, but is not so limited In an alternate embodunent, the electrode 1802 and the transmitter 1804 can share the power source 1806 The transmitter 1804 is coupled to the electrode 1802 and converts the electrode signals to radio frequency signals for transmission The transmitter 1804 has dimensions approximately in the range 5 to 20 millimeters (mm) long, 5 to 20 mm wide, and 1 to 5 mm high while weighing less than 100 milligram (mg) and usmg less and 100 milliwatts (mW) of discrete power, but is not so limited As each transmitter 1804 processes signals from a smgle electrode 1802, the bandwidth requirement for each channel is identical, allowing for repeatable and consistent SNR In addition, a reference link 1808 between each electrode 1802 allows all electrodes to be synchronized and referenced to a smgle potential This reference link can be provided by means of cunent injection to the surface of the skin by a master electrode that is received by all other electrodes (slave electrodes) The reference link 1808 can also be provided using telemetry from the receiver section Furthermore, the reference link 1808 can be provided usmg a wired link among the electrodes

The receiver section 1820 of an embodunent mcludes up to 8 antennas 1822 and receivers 1824, wherein each receiver 1824 processes telemetry signals from numerous electrodes 1802, but is not so limited A receiver section 1820 of an embodunent compπsing up to 8 channels is modularized and expandable to convert transmitted signals from up to 256 electrodes simultaneously The modularization allows for an increase or decrease in the number of electrodes without affecting system performance Furthermore, each channel has adequate bandwidth for distortion free telemetry plus appropriate filtering to maximize the SNR and to prevent aliasing in sampled-data monitoπng systems

The output signal 1826 from the receiver section 1820 is compatible with and interfaces with typical electrode monitoπng systems 1828 This compatibility is provided by the use of a receiver output section that is compatible in the following areas connector plug-in to fit in standard monitoring systems, signal levels and bandwidths not exceeding the cunent systems requirements, and, low output impedance to prevent signal attenuation Thus, the telemetry system of an embodiment allows for retrofit of current monitoring systems without modification Furthermore, the receiver section 1820 can be integrated with the monitoring system 1828

The couplmg among the electrodes 1802 and the monitoring system 1828 can include a network In an embodiment, the monitoring system can be coupled 1826 to the receiver section 1820 using network connections including wired, wireless, and combined wired and wireless connections In an alternate embodiment, the receivers 1824 of a receiver section can be located away from the controller 1830 and coupled to the controller 1830 using network connections mcludmg wired, wireless, and combined wired and wireless connections The controller 1830 can then be coupled 1826 to the monitoπng system 1828 usmg network connections including wired, wireless, and combined wired and wireless connections Figure 19 is a functional block diagram of a hybrid sensor telemetry electrode 1900 of an embodiment

The hybrid sensor telemetry electrode 1900 includes an mterface 1902 that couples signals between circuitry of the sensor electrode and monitoring and controlling instruments 1904 The interface 1902 is coupled to the monitoring and controlling instruments 1904 using a wireless interface or network, but is not so limited The interface 1902 is coupled to a data telemetry transmitter/receiver (transceiver) 1906 of the sensor electrode 1900, but is not so limited In one alternate embodiment the interface 1902 can be coupled to a transmitter In another alternate embodunent the mterface can be coupled to a receiver In yet another alternate embodiment, the interface can be separately coupled to a transmitter and a receiver

The transceiver 1906 is coupled to sensory circuitry mcludmg stimulation circuitry 1908, or sensor stimuli circuitry, sensory components 1920, and conditioning circuitry 1912, or sensor pick-up circuitry The stimulation circuitry 1908 and the conditionmg circuitry 1912 are coupled to a sensory component 1910 that receives signals or data from the env ronment 191t that is being monitored The monitored environment 1916 includes but is not limited to human .km and animal skm A power source 1914 is coupled to each of the transceiver 1906, stimulation circuit y 1908, sensory component 1910, and conditionmg circuitry 1912 Figure 20 is a functional b ck dirgram of a hybrid sensor telemetry electrode 2000 of an alternate embodiment In this alternate embodiment, the transceiver 2002 is coupled to sensory circuitry including sensory components 2004 and conditionmg circuitry 2006, or sensor pick-up circuitry The transceiver 2002 couples signals from the sensory component 2004 through the conditionmg circuitry 2006 to the interface 2008 A power source 2010 is coupled to each of the transceiver 2002, sensory component 2004, and conditionmg circuitry 2006

Further alternative embodiments of the hybrid sensor telemetry electrode use radio frequency (RF) powering to remotely provide power to the hybπd sensor circuitry, thereby eliminating the battery power source Figure 21 is a functional block diagram of a RF powered or telemetry powered hybrid sensor telemetry electrode 2100 of an embodiment The RF powered hybrid sensor telemetry electrode 2100 mcludes an mterface 2102 that couples signals between circuitry of the sensor electrode and monitoring and controlling instruments 2104 The mterface 2102 is coupled to the momtormg and controlling instruments 2104 usmg a wireless mterface or network, but is not so limited The interface 2102 is coupled to a data telemetry transmitter/receiver (transceiver) 2106 of the sensor electrode, but is not so limited

The transceiver 2106 is coupled to sensory circuitry mcludmg stimulation circuitry 2108, or sensor stimuli circuitry, sensory components 2110, and conditionmg circuitry 2112, or sensor pick-up circuitry The stimulation circuitry 2108 and the conditioning circuitry 2112 are coupled to a sensory component 2110 that receives signals or data from the environment 2114 that is being monitored A telemetry power source 2116 is coupled to each of the transceiver 2106, stimulation circuitry 2108, sensory component 2110, and conditioning circuitry 2112 Figure 22 is a hybrid sensor electrode 2200 of an embodiment having a telemetry system and a coil antenna 2202 The coil antenna 2202 is used to communicate with the electrode 2200 and to provide power to the electrode 2200, thereby eliminating batteries as an electrode power source

The transceiver section of a RF powered hybrid sensor telemetry electrode of an embodiment is coupled to an antenna that optimizes the performance of the link while providing reduced size, weight, and cost The antenna types are configured for use with frequencies in the range of 1 kHz to 6 GHz The antenna types used m a hybrid sensor electrode of an embodiment can be either a flat antenna, a spiral antenna, or an array antenna

Figure 23 is a hybrid sensor electrode 2300 of an embodiment with a flat antenna 2302 A flat antenna 2302 of an embodunent includes an air-core transmitter antenna used for transmitting and receiving in a 13 56 MHz system The dimensions of the flat antenna are approximately m the range 20 mm by 20 mm by 1 mm, but are not so limited The range of a system link using this antenna is approximately in the range 0 5 to 1 5 meters Alternate embodiments of the hybrid sensor electrode may use a spiral antenna or an anay antenna for transmitting and receivmg at higher frequencies A spiral antenna comprises a thick film spiral mductor embedded in a prmted circuit board A typical sensor electrode application may impose dimensional limitations on the sensor electrode package. For example, bulky transmitter sizes may not be ideal for head mounts durmg sleep studies due to patient discomfort Furthermore, heavy transmitters that often find use in high resolution electrode/EKG applications where tens of electrodes are placed on the subject could lead to patient discomfort Moreover, the size and weight of the transmitter section limits the telemetry application area In considering these transmitter section limitations, elimination of batteries as a sensor electrode power source would result in a reduction m the size and weight of the associated sensor electrode, with an associated increase in patient comfort This reduction m size and weight arises from the elimination of a typical battery that has parameters including a diameter of approximately 6 to 18 mm, a thickness of approximately 6 mm, a weight of approximately less than 100 mg, and, a life approximately in the range of one day to 6 months

The hybπd sensor electrode of an embodiment eliminates the requirement for a local battery by using remote poweπng, also refened to as telemetry powering, infrared (IR) powering, or RF powering The remote powering is provided over ranges m excess of one meter Thus, each receiver section will not only be able to communicate with eight transmitters section, but also will have the capability to remotely power the transmitters via the transmitter antenna

Figure 24 is a block diagram of integrated circuitry (IC) 2400 of a hybrid sensor electrode transmitter section of an embodiment using telemetry powering Figure 25 is a block diagram of integrated circuitry (IC) 2500 of a hybrid sensor electrode transmitter section of an embodiment using internal battery power These ICs 2400 and 2500 provide reduced size, weight, power, and cost with an associated benefit of higher levels of integrated functionality Furthermore, these ICs 2400 and 2500 provide the ability to inject low cunent to measure skin impedance, and to allow mtra-electrode communication for noise reduction and noise cancellation The ICs of an embodiment use 0 8 micrometer complementary metal-oxide semiconductor (CMOS) technology, but are not so limited

The ICs 2400 and 2500 are partitioned based on functionality, wherem the functional partitions include power management circuitry, power conditionmg circuitry, transmitter circuitry, and sensor conditioning circuitry, but are not so limited In an embodiment, each section of the IC can be tested separately and disabled from outside pins, allowing for full or partial utilization of the IC as needed For example, the remote power detection circuitry is part of the power conditioning section Provisions are made via additional bonding pads and power switching mechanisms wherein this circuitry can be disabled so that all other sections of the IC can be tested separately

In operation, with reference to Figure 24, a large alternating cunent (AC) signal is received by the dual-purpose coil antenna 2402 The AC signal is converted into a regulated direct current (DC) voltage, which supplies power to the local components Initially, the controller state machine 2404 momentarily closes switches Cl and C2, while switches C3 and C4 remain open This allows the incoming AC signal to be rectified and regulated into a DC voltage In an embodiment, the rectifier and regulator 2406 converts an AC signal to a DC signal and regulates the voltages for the entire IC The regulated DC voltage is stored for local DC distribution to the rest of the circuit

Prior to DC power distribution, the DC power management circuitry 2408 optimizes power consumption by prioritizing power to the components The power manager/controller 2408 supervises the instantaneous power on the bus, and determines which section of the circuit has pπoπty for utilizing the power Accordmg to a round robm mechanism, the power manager/controller 2408 turns segments of the circuit on or off to optimize power consumption

When the charge storage operation is completed, the controller state machme 2404 simultaneously opens Cl and C2, while closing C3 and C4 to allow electrode/EKG data to be transmitted The high voltage isolator 2410 prevents large signals that may perturb the dπver and transmitter circuitry 2412 The sensor output conditionmg circuit 2414 generates programmable pulsed cunent of 1 microamp (uA) to 100 uA m amplitude and delivers it to the sensor 2416 The sensor output conditioning circuitry 2414 amplifies, filters and biases the electrode/EKG signal to be sent to the transmitter The detection-controller circuitry 2418 determines whether the signal level is that of an electrode or EKG, and conditions the signal to prevent saturation of the transmitter circuitry Upon completion of data transmission, the process of remote powermg and data transmission is repeated

As a result of advances made in the areas of micromachining, integrated circuit technology, and printed wiπng board capabilities, the cost difference between active electrodes of an embodiment and wet surface electrodes is negligible Furthermore, the superior performance of the active electrodes of an embodunent allow for their use in new application areas that demand higher performance and a higher number of electrodes than their wet counterparts For example, long term (over 24 hours) recording and embedded telemetry are provided, and applications such as biofeedback (use of sensors and computers to improve or control deficiencies), sleep monitoring (analyzing sleep patterns and disorders), alertness monitoπng (monitoπng the mental awareness of a person), biocontrol games (mput and output form the biology to computer and video games), and biocontrol of computers are enabled

Figure 26 is a flowchart of a method for collecting biopotential signals of an embodiment Operation begins at step 2602, where at least one sensory component or element is capacitively coupled to a biopotential signal source Power is telemetered to and received by the sensory component, at step 2604 Biopotential signals and data are collected, at step 2606, and the collected signals and data are telemetered to external instrumentation, at step 2608

As can be seen, a method and apparatus for biopotential sensing and stimulation has been provided that can include a sensory component, a biopotential sensor electrode and a biopotential sensory electrode system In one embodiment, the sensory component includes a first layer of electrically conductive material coupled among a biopotential signal source and a dielectric layer A second layer of electrically conductive material is coupled among the dielectric layer, resistive elements, a charge balancmg cunent source and sink, and circuits of the associated biopotential electrode

In one embodiment, the biopotential sensor electrode includes the sensory component, conditioning components, an interface, and a power source The sensory component is coupled among the biopotential signal source and the conditionmg components The conditionmg components couple conditioned signals to the mterface, which is configured to transfer signals to external instrumentation The signal transfer occurs over wireless or wired connections Stimulation components may also be coupled among the sensory component and the interface to provide stimulation signals to the biopotential signal source The power source is coupled among the sensory component, the conditionmg components, and the mterface, and includes batteπes, solar cells, and telemetry power sources.

In one embodiment, the biopotential sensory electrode system includes at least one electrode anay. The electrode array mcludes the biopotential sensor electrodes and a receiver section that transfers biopotential signals among the biopotential signal source and external instrumentation and equipment. A reference link among the biopotential sensor electrodes of an anay is provided by a coupling that mcludes cunent injection to a surface of the biopotential signal source, or via a common wire to all electrodes.

In another embodiment, a biopotential sensor electrode is provided that includes at least one sensory component coupled to a biopotential signal source, the at least one sensory component comprising at least one layer of electrically conductive mateπal and at least one dielectric layer, at least one conditionmg component coupled to condition signals from the at least one sensory component, at least one mterface configured to transfer signals among the at least one conditioning component and external instrumentation, and at least one power source coupled among the at least one sensory component, the at least one conditioning component, and the at least one interface. In such biopotential sensor electrode, the at least one sensory component can include a dielectπc layer coupled between a first and a second layer of electrically conductive material, the first layer of electrically conductive material being coupled to the biopotential signal source and the second layer of electrically conductive material being coupled to the at least one conditioning component. Such second layer of electrically conductive material can be coupled to the at least one conditioning component using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, at least one resistive element, charge balancmg circuitry, and a feedback amplifier. Such at least one bond can be selected from a group consisting of a permanent metallic bond and at least one mating spπng snap connector button, the at least one mating spring snap connector button being disposable. Such first layer of electrically conductive material can be coupled to the dielectπc layer through a third layer of electrically conductive material and a first bond and the second layer of electrically conductive mateπal can be coupled to the dielectric layer through a fourth layer of electrically conductive material and a second bond Such first bond and second bond can be selected from a group consisting of a permanent metallic bond and at least one mating spπng snap connector button, such one side of the at least one mating sprmg snap connector button being disposable Such first layer of electrically conductive material can be coupled to the biopotential signal source using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, and at least one metal layer and such second layer of electrically conductive material can be coupled to the at least one conditioning component using at least one component selected from a group consisting of charge balancing circuitry and at least one bond Such at least one bond can be selected from a group consisting of a permanent metallic bond and at least one matmg spring snap connector button, one side of the at least one mating spπng snap connector button being disposable.

In such biopotential sensor electrode, the at least one sensory component can include a dielectπc layer coupled between the biopotential signal source and an electrically conductive layer, the electrically conductive layer being coupled to the at least one conditioning component. Such biopotential sensor electrode can mclude at least one stimulation component coupled among the at least one mterface and the at least one sensory component, the at least one stimulation component providmg stimulation signals to a skm Such a least one stimulation component can include at least one component selected from a group consistmg of i t least one programmable cunent source, at least one programmable voltage source, at least one programmable g( nerator, at least one current-to-voltage converter, and at least one transresistance amplifier

In such biopotential sensor electrode, the at least one mterface transfers can signal among the at least one conditionmg component and the external instrumentation using at least one medium selected from a group consistmg of wires, cables, and buses Such biopotential sensor electrode can include at least one telemetry component coupled among the at least one conditionmg component, the at least one interface, and the at least one power source Such at least one telemetry component can mclude a telemetry receiver and transmitter, the at least one telemetry component transfenmg information and power among the biopotential sensor electrode and the external instrumentation At least one antenna can be coupled to the at least one telemetry component In such biopotential sensor electrode, the at least one power source includes a telemetry power component that produces power m response to telemetry signals received from the external instrumentation

In such biopotential sensor electrode, the at least one power source includes at least one power source selected from a group consistmg of at least one battery and at least one solar cell

In such biopotential sensor electrode, the at least one layer of electrically conductive material can mclude at least one material selected from a group consistmg of stainless steel, platinum, gold, and silver silver- chloπde

In such biopotential sensor electrode, the at least one dielectric layer can mclude at least one mateπal selected from a group consisting of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitride, silicon nitride, oxide, and aluminum dioxide In such biopotential sensor electrode, the at least one layer of electrically conductive material can have a surface texture selected from a group consistmg of smooth, rough, and bumped

In such biopotential sensor electrode, the at least one conditioning component can include at least one component selected from a group consisting of impedance matching circuitry, charge balancing circuitry, amplification and buffermg circuitry, programmable gam control circuitry, programmable filter circuitry, feedback control circuitry, and conditioning circuitry

Such biopotential sensor electrode can include at least one bidirectional multiplexer coupled to transfer signals among the at least one interface and the external instrumentation

Such biopotential sensor electrode can include a housmg selected from a group consisting of a single piece housmg, a two-piece housmg, and a disposable housmg In such biopotential sensor electrode, the at least one interface can be selected from a group consisting of an analog interface and a digital interface

In such biopotential sensor electrode, the at least one interface can be a digital mterface comprising at least one analog-to-digital converter, at least one memory device, at least one input/output interface unit, and at least one state machine Such biopotential sensor electrode can comprise a substrate mcludmg at least one electrode anay, the at least one electrode anay mcludmg at least one other biopotential sensor electrode Such at least one power source can be shared among the at least one other biopotential sensor electrode

Such biopotential sensor electrode can include at least one reference link among at least one other biopotential sensor electrode, the at least one reference link allowmg the biopotential sensor electrode to be synchronized and referenced to a single potential, the at least one reference link being provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and cunent injection to a skm surface

In another embodiment, a biopotential sensor electrode is provided that includes at least one sensory component and at least one telemetry component, the at least one sensory component comprising at least one layer of electrically conductive material and at least one dielectric layer, the at least one sensory component bemg coupled among a biopotential signal source and the at least one telemetry component, the at least one telemetry component transfemng signals and power among the biopotential sensor electrode and external instrumentation In another embodiment, a method for collecting biopotential signals is provided that compπsmg receiving telemetered power signals at a biopotential sensor electrode, generating power in response to the telemetered power signals, receiving the biopotential signals via a couplmg with a skin surface and transferring the biopotential signals from the biopotential sensor electrode usmg at least one coupling comprising a wireless

In another embodiment, a computer readable medium containing executable instructions which, when executed m a processing system, causes the system to collect biopotential signals is provided The collection comprises the steps of receiving telemetered power signals at a biopotential sensor electrode, generating power m response to the telemetered power signals, receiving the biopotential signals via a coupling with a skin surface and transfemng the biopotential signals from the biopotential sensor electrode using at least one coupling comprising a wireless link

In another embodiment, an electromagnetic medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals is provided The collection comprises receiving telemetered power signals at a biopotential sensor electrode, generating power in response to the telemetered power signals, receivmg the biopotential signals via a coupling with a skin surface and transferring the biopotential signals from the biopotential sensor electrode using at least one coupling comprising a wireless link

In another embodiment, a biopotential sensor electrode is provided that includes at least one sensory means and at least one telemetry means, the at least one sensory means comprises at least one layer of electrically conductive material and at least one dielectric layer, the at least one sensory means is coupled among a biopotential signal source and the at least one telemetry means, the at least one telemetry means transfers signals and power among the biopotential sensor electrode and external instrumentation

In another embodiment, a biopotential sensor electrode is provided that comprises means for receiving telemetered power signals at a biopotential sensor electrode, means for generating power in response to the telemetered power signals, means for receiving the biopotential signals via a coupling with a skin surface and means for transferring the biopotential signals from the biopotential sensor electrode usmg at least one couplmg compπsmg a wireless link

In another embodunent, a biopotential electrode sensory component is provided that compπses a first layer of electrically conductive mateπal coupled among a biopotential signal source and a dielectπc layer, and a second layer of electπcally conductive mateπal coupled among the dielectric layer, at least one resistive element, at least one charge balancmg cunent source and sink and at least one biopotential electrode circuit

In such biopotential electrode sensory component, the biopotential signal source can be further coupled to the at least one biopotential electrode circuit usmg at least one component selected from a group consistmg of high voltage protection circuitry, at least one bond, at least one metal layer, and a feedback amplifier Such at least one bond can be selected from a group consistmg of a permanent metallic bond and a snap connector

In such biopotential electrode sensory component, the first layer of electrically conductive material can be coupled to the dielectric layer through a third layer of electrically conductive material and a first bond, the second layer of electrically conductive material can be coupled to the dielectric layer through a fourth layer of electπcally conductive material and a second bond Such first bond and such second bond can be selected from a group consisting of a permanent metallic bond and a snap connector

In such biopotential electrode sensory component, the dielectric layer can comprise at least one mateπal selected from a group consisting of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitride, silicon nitride, oxide, and alummum dioxide

In such biopotential electrode sensory component, the first layer and second layer of electrically conductive material can compπse at least one material selected from a group consistmg of stainless steel, platinum, gold, and silver silver-chloπde

In such biopotential electrode sensory component, the first layer of electrically conductive material has a surface texture selected from a group consistmg of smooth, rough, and bumped

Such biopotential electrode sensory component can further include an electrical coupling to at least one interface selected from a group consisting of an analog interface and a digital interface

Such biopotential electrode sensory component can further compπse an electrical coupling to at least one telemetry component, the at least one telemetry component transfemng biopotential signals and power among the biopotential electrode sensory component and external instrumentation

Such biopotential electrode sensory component can further comprise an electrical coupling to at least one reference link that allows at least one biopotential sensor electrode associated with the biopotential electrode sensory component to be synchronized and referenced to a single potential, the at least one reference link bemg provided by at least one couplmg selected from a group consisting of a wired link, a telemetry link, and cunent injection to a skm surface

In another embodunent, a biopotential electrode sensory component is provided that comprises a first layer of electπcally conductive material coupled among a biopotential signal source, a dielectπc layer, and voltage protection circuitry, and a second layer of electrically conductive mateπal coupled among the dielectric layer, at least one biopotential electrode circuit, and at least one charge balancmg circuit

Such biopotential electrode sensory component can include a third and fourth electπcally conductive layer coupled between the first layer of electπcally conductive material and the dielectric layer usmg at least one bond Such at least one bond can be selected from a group consistmg of a permanent metallic bond and a snap connector Such third layer and fourth layer of electπcally conductive material compπse at least one mateπal selected from a group consistmg of stainless steel, platmum, gold, and silver silver-chloπde

In such biopotential electrode sensory component, the biopotential signal source can be coupled to the at least one biopotential electrode circuit usmg a feedback amplifier

In such biopotential electrode sensory component, the dielectric layer compπses at least one material selected from a group consistmg of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitπde, silicon nitnde, oxide, and alummum dioxide

In such biopotential electrode sensory component, the first layer and second layer of electrically conductive material can comprise at least one material selected from a group consistmg of stainless steel, platinum, gold, and silver silver-chloπde

In such biopotential electrode sensory component, the first layer of electrically conductive mateπal can have a surface texture selected from a group consisting of smooth, rough, and bumped

Such biopotential electrode sensory component can further comprise an electrical couplmg to at least one interface selected from a group consisting of an analog interface and a digital interface

Such biopotential electrode sensory component can further compπse an electπcal coupling to at least one telemetry component, the at least one telemetry component transferring biopotential signals and power among the biopotential electrode sensory component and external instrumentation

Such biopotential electrode sensory component can further comprise an electπcal coupling to at least one reference link that allows at least one biopotential sensor electrode associated with the biopotential electrode sensory component to be synchronized and referenced to a single potential, the at least one reference link being provided by at least one coupling selected from a group consistmg of a wired link, a telemetry link, and cunent injection to a skin surface

In another embodiment, a method for collecting biopotential signals is provided that comprises coupling a sensory component to a skin surface, converting ionic potentials and electric fields received by the sensory component to electrical potentials, minimizing effects of changing skin impedance on the electrical potentials usmg a sensor impedance m seπes with a skin impedance, wherein a magnitude of the sensor impedance is greater than a magnitude of the skin impedance, minimizing direct cunent offset and motion artifacts of the electrical potentials using charge balancing and providing electrical potentials to external instrumentation

In another embodiment, a computer readable medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals is provided The collection comprises couplmg a sensory component to a skin surface, converting ionic potentials and electric fields received by the sensory component to electrical potentials, minimizing effects of changmg skm impedance on the electrical potentials usmg a sensor impedance m series with a skin impedance, wherein a magnitude of the sensor impedance is greater than a magnitude of the skin impedance, minimizing direct current offset and motion artifacts of the electrical potentials using charge balancing and providing electπcal potentials to external instrumentation In another embodiment, an electromagnetic medium contammg executable instructions which, when executed m a processmg system, cai ses the system to collect biopotential signals is provided The collection compπses couplmg a sensory comp >nent to a skin surface, converting ionic potentials and electπc fields received by the sensory component o electrical potentials, minimizing effects of changmg skm impedance on the electrical potentials usmg a sens ir impedance m series with a skm impedance, wherem a magnitude of the sensor impedance is greater than a

of the skm impedance, minimizing direct cunent offset and motion artifacts of the electrical potentials using charge balancmg and providmg electπcal potentials to external instrumentation

In another embodiment, a biopotential electrode sensory component is provided that includes means for coupling a sensory means to a skm surface, means for converting ionic potentials and electric fields received by the sensory means to electrical potentials, means for minimizing effects of changmg skm impedance on the electrical potentials usmg an impedance in series with a skm impedance, wherein a magnitude of the impedance is greater than a magnitude of the skm impedance, means for minimizing direct cunent offset and motion artifacts of the electrical potentials usmg charge balancing means and means for providmg electrical potentials to external instrumentation

In another embodiment, a biopotential sensor electrode system is provided that comprises at least one electrode array including at least one biopotential sensor electrode coupled to at least one telemetry component and at least one power source, the at least one biopotential sensor electrode including at least one sensory component coupled to a biopotential signal source, and at least one receiver section comprising at least one receiver, the at least one receiver section transfemng biopotential signals among the biopotential signal source and external instrumentation using the at least one telemetry component

In such biopotential sensor electrode system, the at least one sensory component can comprises at least one layer of electrically conductive mateπal and at least one dielectric layer, the at least one biopotential sensor electrode further comprising at least one conditioning component coupled to condition signals from the at least one sensory component, at least one interface configured to transfer signals among the at least one conditionmg component and external instrumentation and at least one power source coupled among the at least one sensory component, the at least one conditioning component, and the at least one interface Such biopotential sensor electrode system can further comprise at least one stimulation component coupled among the at least one interface and the at least one sensory component, the at least one stimulation component providing stimulation signals to the biopotential signal source, the at least one stimulation component compπsing at least one component selected from a group consistmg of at least one programmable cunent source, at least one programmable voltage source, at least one programmable generator, at least one cunent-to-voltage converter, and at least one transresistance amplifier Such biopotential sensor electrode system can further compπse at least one bidirectional multiplexer coupled to transfer signals among the at least one mterface and the external instrumentation Such at least one interface can be selected from a group consistmg of an analog interface and a digital interface

In such biopotential sensor electrode system, the at least one sensory component can compπse a dielectric layer coupled between a first and a second layer of electrically conductive material, the first layer of electπcally conductive material can be capacitively coupled to the biopotential signal source, and the second layer of electrically conductive material can be coupled to the at least one conditioning component Such second layer of electπcally conductive material can be coupled to the at least one conditionmg component using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, at least one resistive element, charge balancing circuitry, and a feedback amplifier Such at least one bond can be selected from a group consisting of a permanent metallic bond and a snap connector Such first layer of electπcally conductive material can be coupled to the dielectric layer through a third layer of electrically conductive material and a first bond, the second layer of electπcally conductive mateπal can be coupled to the dielectric layer through a fourth layer of electπcally conductive material and a second bond Such first bond and the second bond can be selected from a group consisting of a permanent metallic bond and a snap connector Such first layer of electrically conductive material can be coupled to the biopotential signal source using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, and at least one metal layer, and such second layer of electrically conductive material can be coupled to the at least one conditioning component using at least one component selected from a group consisting of charge balancmg circuitry and at least one bond Such at least one bond can be selected from a group consisting of a permanent metallic bond and a snap connector

In such biopotential sensor elecfrode system, the at least one telemetry component can comprise a telemetry receiver and transmitter and antenna, the at least one telemetry component transfemng information and power among the biopotential sensor electrode and the external instrumentation In such biopotential sensor electrode system, the at least one power source can compπse at least one power source selected from a group consisting of at least one battery, at least one solar cell, and a telemetry power component, the telemetry power component generating power m response to telemetry signals received from the external instrumentation

In such biopotential sensor electrode system, the at least one power source can be coupled among the at least one biopotential sensor electrode of the at least one electrode anay

In such biopotential sensor electrode system, the at least one power source can comprise a power source for each biopotential sensor electrode of the at least one electrode anay

Such biopotential sensor electrode system can further comprise at least one reference link among the at least one biopotential sensor electrode that allows the at least one biopotential sensor electrode to be synchronized and referenced to a smgle potential, the at least one reference link bemg provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and cunent injection to a skm surface

In such biopotential sensor electrode system, the at least one biopotential sensor electrode can be on a single substrate Such biopotential sensor electrode system can further comprise a network coupled among the at least one electrode array and the external instrumentation, the network comprising at least one network coupling selected from a group consisting of wired, wireless, and a combmation of wired and wireless

In another embodiment, a biopotential sensor electrode system is provided that comprises at least one electrode anay including at least one biopotential sensor electrode, the at least one biopotential sensor electrode compπsmg at least one signal transfer component and at least one sensory component coupled to a biopotential signal source, the at least one sensory component compπsmg a first layer of electπcally conductive mateπal coupled among a biopotential signal source and a dielectπc layer, a second layer of electπcally conductive mateπal coupled among the dielectπc layer, at least one resistive element, at least one charge balancmg current source and sink, and at least one biopotential electrode circuit, and at least one receiver section comprising at least one receiver, the at least one receiver section transferring biopotential signals among the signal transfer component and external instrumentation

Such biopotential sensor electrode system can further comprise at least one reference link among the at least one biopotential sensor electrode that allows the at least one biopotential sensor electrode to be synchronized and referenced to a single potential, the at least one reference link bemg provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and current injection to a skin surface

Such biopotential sensor electrode system can further comprise a network coupled among the at least one electrode array and the external instrumentation, the network compπsing at least one network coupling selected from a group consisting of wired, wireless, and a combmation of wired and wireless

In another embodiment, a biopotential sensor electrode system can be provided that comprises at least one electrode array mcludmg at least one biopotential sensor electrode, the at least one biopotential sensor electrode comprising at least one signal transfer component and at least one sensory component coupled to a biopotential signal source, the at least one sensory component comprising a first layer of electrically conductive material coupled among a biopotential signal source, a dielectric layer, and voltage protection circuitry, a second layer of electrically conductive material coupled among the dielectric layer, at least one biopotential electrode circuit, and at least one charge balancing circuit, and at least one receiver section comprising at least one receiver, the at least one receiver section transfemng biopotential signals among the signal transfer component and external instrumentation Such biopotential sensor electrode system can further comprise at least one reference link among the at least one biopotential sensor electrode that allows the at least one biopotential sensor electrode to be synchronized and referenced to a single potential, the at least one reference link bemg provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and cunent injection to a skin surface Such biopotential sensor electrode system can further comprise a network coupled among the at least one electrode array and the external instrumentation, the network comprising at least one network coupling selected from a group consistmg of wired, wireless, and a combmation of wired and wireless

In another embodiment, a method for collecting biopotential signals is provided that comprises transfemng telemetry signals among at least one sensor electrode and external instrumentation, the telemetry signals comprising power signals and biopotential signals, generating power for the sensor electrode in response to the power signals, receivmg and conditioning biopotential signals from a skm surface at the sensor electrode, providmg stimulation signals to the skm surface, and receivmg telemetered conditioned biopotential signals at the external instrumentation In another embodiment, a computer readable medium containing executable instructions which, when executed in a processmg system, causes the system to collect biopotential signals is provided The collection compπses transfemng telemetry signals among at least one sensor electrode and external instrumentation, the telemetry signals compnsmg power signals and biopotential signals, generating power for the sensor electrode m response to the power signals, receivmg and conditionmg biopotential signals from a skin surface at the sensor electrode, providmg stimulation signals to the skin surface, and receiving telemetered conditioned biopotential signals at the external instrumentation

In another embodiment, an electromagnetic medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals is provided The collection compπses transfemng telemetry signals among at least one sensor elecfrode and external instrumentation, the telemetry signals compnsmg power signals and biopotential signals, generating power for the sensor electrode in response to the power signals, receiving and conditionmg biopotential signals from a skin surface at the sensor electrode, providing stimulation signals to the skin surface, and receivmg telemetered conditioned biopotential signals at the external instrumentation In another embodiment, a biopotential sensor electrode system is provided that comprises means for transferring telemetry signals among at least one sensor means and external instrumentation, the telemetry signals comprising power signals and biopotential signals, means for generating power for the sensor elecfrode in response to the power signals, means for receiving and conditioning biopotential signals from a skin surface at the sensor electrode, means for providing stimulation signals to the skm surface, and means for receiving telemetered conditioned biopotential signals at the external instrumentation

The foregoing description of various embodiments of the claimed invention is presented for purposes of illustration and descπption It is not intended to limit the claimed invention to the precise forms disclosed Many modifications and equivalent anangements may be apparent

Claims

What is claimed is:

1 A biopotential sensor electr _)de, compnsmg at least one sensory compoi ent coupled to a biopotential signal source, the at least one sensory component compπsmg at least one yer of electrically conductive mateπal and at least one dielectπc layer, at least one conditionmg component coupled to condition signals from the at least one sensory component, at least one interface configured to transfer signals among the at least one conditioning component and external instrumentation, and at least one power source coupled among the at least one sensory component, the at least one conditioning component, and the at least one mterface

2 The biopotential sensor electrode of claim 1, wherein the at least one sensory component comprises a dielectric layer coupled between a first and a second layer of elecfrically conductive material, wherein the first layer of electrically conductive material is coupled to the biopotential signal source, and wherein the second layer of electrically conductive material is coupled to the at least one conditionmg component

3 The biopotential sensor electrode of claim 2, wherein the second layer of electrically conductive material is coupled to the at least one conditioning component using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, at least one resistive element, charge balancmg circuitry, and a feedback amplifier

4 The biopotential sensor electrode of claim 3, wherein the at least one bond is selected from a group consisting of a permanent metallic bond and at least one mating sprmg snap connector button, wherein one side of the at least one mating spπng snap connector button is disposable

5 The biopotential sensor electrode of claim 2, wherein the first layer of electrically conductive material is coupled to the dielectric layer through a third layer of electrically conductive material and a first bond, wherein the second layer of electrically conductive mateπal is coupled to the dielectric layer through a fourth layer of electrically conductive material and a second bond

6 The biopotential sensor electrode of claim 4, wherein the first bond and the second bond are selected from a group consisting of a permanent metallic bond and at least one mating spring snap connector button, wherein one side of the at least one matmg spring snap connector button is disposable

7 The biopotential sensor electrode of claim 2, wherein the first layer of electπcally conductive material is coupled to the biopotential signal source using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, and at least one metal layer, and wherein the second layer of elecfrically conductive mateπal is coupled to the at least one conditionmg component using at least one component selected from a group consistmg of charge balancmg circuitry and at least one bond

8 The biopotential sensor electrode of claim 5, wherem the at least one bond is selected from a group consisting of a permanent metallic bond and at least one mating sprmg snap connector button, wherein one side of the at least one matmg sprmg snap connector button is disposable

9 The biopotential sensor elecfrode of claim 1, wherein the at least one sensory component comprises a dielectric layer coupled between the biopotential signal source and an electrically conductive layer, wherein the electrically conductive layer is coupled to the at least one conditionmg component

10 The biopotential sensor electrode of claim 1, further comprising at least one stimulation component coupled among the at least one interface and the at least one sensory component, wherem the at least one stimulation component provides stimulation signals to a skin

11 The biopotential sensor electrode of claim 10, wherein the at least one stimulation component comprises at least one component selected from a group consisting of at least one programmable cunent source, at least one programmable voltage source, at least one programmable generator, at least one cunent-to-voltage converter, and at least one fransresistance amplifier

12 The biopotential sensor elecfrode of claim 1 , wherem the at least one interface transfers signals among the at least one conditioning component and the external instrumentation using at least one medium selected from a group consisting of wires, cables, and buses

13 The biopotential sensor electrode of claim 1, further comprising at least one telemetry component coupled among the at least one conditionmg component, the at least one interface, and the at least one power source

14 The biopotential sensor electrode of claim 13, wherem the at least one telemetry component comprises a telemetry receiver and transmitter, wherem the at least one telemetry component transfers information and power among the biopotential sensor electrode and the external instrumentation

15 The biopotential sensor electrode of claim 14, further comprising at least one antenna coupled to the at least one telemetry component

16 The biopotential sensor electrode of claim 1 , wherein the at least one power source comprises a telemetry power component that produces power m response to telemetry signals received from the external instrumentation

17 The biopotential sensor electrode of claim 1, wherem the at least one power source compπses at least one power source selected from a group consisting of at least one battery and at least one solar cell

18 The biopotential sensor electrode of claim 1 , wherem the at least one layer of electπcally conductive mateπal compπses at least one material selected from a group consistmg of stamless steel, platinum, gold, and silver silver-chloπde

19 The biopotential sensor electrode of claim 1, wherem the at least one dielectnc layer comprises at least one material selected from a group consistmg of Diamond Like Carbon (DLC) mateπal, tantalum pentoxide, nitride, silicon nitride, oxide, and aluminum dioxide

20 The biopotential sensor electrode of claim 1 , wherem the at least one layer of electrically conductive material has a surface texture selected from a group consistmg of smooth, rough, and bumped

21 The biopotential sensor elecfrode of claim 1, wherein the at least one conditioning component comprises at least one component selected from a group consistmg of impedance matching circuitry, charge balancing circuitry, amplification and buffermg circuitry, programmable gain control circuitry, programmable filter circuitry, feedback control circuitry, and conditioning circuitry

22 The biopotential sensor electrode of claim 1, further comprising at least one bidirectional multiplexer coupled to transfer signals among the at least one interface and the external instrumentation

23 The biopotential sensor electrode of claim 1, further comprising a housing selected from a group consisting of a smgle piece housing, a two-piece housing, and a disposable housing

24 The biopotential sensor electrode of claim 1, wherein the at least one interface is selected from a group consisting of an analog mterface and a digital interface

25 The biopotential sensor electrode of claim 1, wherein the at least one interface is a digital interface comprising at least one analog-to-digital converter, at least one memory device, at least one input/output interface unit, and at least one state machine

26 The biopotential sensor electrode of claim 1 , further comprising a substrate including at least one electrode anay, wherein the at least one electrode anay comprises at least one other biopotential sensor electrode

27 The biopotential sensor electrode of claim 26, wherein the at least one power source is shared among the at least one other biopotential sensor electrode

28 The biopotential sensor electrode of claim 1, further comprising at least one reference link among at least one other biopotential sensor electrode, wherein the at least one reference link allows the biopotential sensor electrode to be synchronized and referenced to a smgle potential, wherem the at least one reference link is provided by at least one couplmg selected from a group consistmg of a wired link, a telemetry link, and current injection to a skm surface.

29. A biopotential sensor electrode, compnsmg at least one sensory component and at least one telemetry component, wherein the at least one sensory component comprises at least one layer of electrically conductive material and at least one dielectric layer, wherem the at least one sensory component is coupled among a biopotential signal source and the at least one telemetry component, wherem the at least one telemetry component transfers signals and power among the biopotential sensor electrode and external instrumentation

30 A method for collecting biopotential signals, compnsmg: receivmg telemetered power signals at a biopotential sensor electrode; generatmg power m response to the telemetered power signals, receivmg the biopotential signals via a coupling with a skm surface; and transfemng the biopotential signals from the biopotential sensor electrode using at least one couplmg comprising a wireless link

31 A computer readable medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals, the collection comprising receivmg telemetered power signals at a biopotential sensor electrode; generating power m response to the telemetered power signals, receiving the biopotential signals via a coupling with a skin surface; and transferring the biopotential signals from the biopotential sensor electrode using at least one couplmg comprising a wireless link

32. An electromagnetic medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals, the collection compnsmg receiving telemetered power signals at a biopotential sensor electrode, generating power m response to the telemetered power signals; receivmg the biopotential signals via a coupling with a skm surface, and transfemng the biopotential signals from the biopotential sensor electrode using at least one coupling compnsmg a wireless link.

33. A biopotential sensor electrode, compπsing at least one sensory means and at least one telemetry means, wherem the at least one sensory means comprises at least one layer of electrically conductive material and at least one dielectric layer, wherein the at least one sensory means is coupled among a biopotential signal source and the at least one telemetry means, wherem the at least one telemetry means transfers signals and power among the biopotential sensor electrode and external instrumentation.

34. A biopotential sensor electrode, comprising: means for receiving telemf tered power signals at a biopotential sensor electrode; means for generating powt r in response to the telemetered power signals; means for receiving the biopotential signals via a coupling with a skin surface; and means for transferring the biopotential signals from the biopotential sensor elecfrode using at least one coupling comprising a wireless link.

35. A biopotential electrode sensory component, comprising: a first layer of electrically conductive material coupled among a biopotential signal source and a dielectric layer; and a second layer of electrically conductive material coupled among the dielectric layer, at least one resistive element, at least one charge balancing cunent source and sink, and at least one biopotential electrode circuit.

36. The biopotential electrode sensory component of claim 35, wherein the biopotential signal source is further coupled to the at least one biopotential electrode circuit using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, and a feedback amplifier.

37. The biopotential elecfrode sensory component of claim 36, wherein the at least one bond is selected from a group consisting of a permanent metallic bond and a snap connector.

38. The biopotential electrode sensory component of claim 35, wherein the first layer of electrically conductive material is coupled to the dielectric layer through a third layer of elecfrically conductive material and a first bond, wherein the second layer of elecfrically conductive material is coupled to the dielectric layer through a fourth layer of elecfrically conductive material and a second bond.

39. The biopotential elecfrode sensory component of claim 38, wherein the first bond and the second bond are selected from a group consisting of a permanent metallic bond and a snap connector.

40. The biopotential electrode sensory component of claim 35, wherein the dielectric layer comprises at least one material selected from a group consisting of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitride, silicon nitride, oxide, and aluminum dioxide.

41. The biopotential electrode sensory component of claim 35, wherein the first layer and second layer of electrically conductive material comprise at least one material selected from a group consisting of stainless steel, platinum, gold, and silver silver-chloride.

42 The biopotential elecfrode sensory component of claim 35, wherem the first layer of electrically conductive material has a surface texture selected from a group consistmg of smooth, rough, and bumped

43 The biopotential electrode sensory component of claim 35, further comprising an electπcal coupling to at least one mterface selected from a group consisting of an analog interface and a digital interface

44 The biopotential electrode sensory component of claim 35, further comprising an electrical coupling to at least one telemetry component, wherem the at least one telemetry component transfers biopotential signals and power among the biopotential elecfrode sensory component and external instrumentation

45 The biopotential electrode sensory component of claim 35, further comprising an electrical coupling to at least one reference link that allows at least one biopotential sensor electrode associated with the biopotential elecfrode sensory component to be synchronized and referenced to a single potential, wherem the at least one reference link is provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and current injection to a skin surface

46 A biopotential electrode sensory component, comprising a first layer of electπcally conductive material coupled among a biopotential signal source, a dielectric layer, and voltage protection circuitry, a second layer of electπcally conductive material coupled among the dielectπc layer, at least one biopotential electrode circuit, and at least one charge balancing circuit

47 The biopotential electrode sensory component of claim 46, wherein a third and fourth electrically conductive layer are coupled between the first layer of electrically conductive mateπal and the dielectric layer using at least one bond

48 The biopotential electrode sensory component of claim 47, wherein the at least one bond is selected from a group consisting of a permanent metallic bond and a snap connector

49 The biopotential electrode sensory component of claim 46, wherein the biopotential signal source is further coupled to the at least one biopotential electrode circuit using a feedback amplifier

50 The biopotential electrode sensory component of claim 46, wherem the dielectπc layer comprises at least one mateπal selected from a group consisting of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitride, silicon nitride, oxide, and aluminum dioxide

51 The biopotential electrode sensory component of claim 46, wherem the first layer and second layer of electrically conductive material comprise at least one mateπal selected from a group consistmg of stamless steel, platmum, gold, and silver silver-chloride

52 The biopotential electrode sensory component of claim 47, wherem the third layer and fourth layer of electrically conductive material compπse at least one material selected from a group consisting of stamless steel, platinum, gold, and silver silver-chloride

53 The biopotential electrode sensory component of claim 46, wherem the first layer of electrically conductive material has a surface texture selected from a group consistmg of smooth, rough, and bumped

54 The biopotential electrode sensory component of claim 46, further compπsing an electrical coupling to at least one interface selected from a group consisting of an analog interface and a digital interface

55 The biopotential electrode sensory component of claim 46, further comprising an electrical coupling to at least one telemetry component, wherein the at least one telemetry component transfers biopotential signals and power among the biopotential electrode sensory component and external instrumentation

56 The biopotential electrode sensory component of claim 46, further comprising an electπcal couplmg to at least one reference link that allows at least one biopotential sensor elecfrode associated with the biopotential electrode sensory component to be synchronized and referenced to a single potential, wherein the at least one reference link is provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and current injection to a skin surface

57 A method for collecting biopotential signals, comprising couplmg a sensory component to a skin surface, converting ionic potentials and electric fields received by the sensory component to electrical potentials, minimizing effects of changing skin impedance on the electrical potentials using a sensor impedance m series with a skm impedance, wherein a magnitude of the sensor impedance is greater than a magnitude of the skin impedance, minimizing direct cunent offset and motion artifacts of the electπcal potentials using charge balancing, and providmg electrical potentials to external instrumentation

58 A computer readable medium containing executable instructions which, when executed m a processing system, causes the system to collect biopotential signals, the collection compπsmg couplmg a sensory component to a skm surface, converting ionic potentials and electnc fields received by the sensory component to electπcal potentials, minimizing effects of changmg skm impedance on the electπcal potentials usmg a sensor impedance m seπes with a skm impedance, wherem a magnitude of the sensor impedance is greater than a magnitude of the skm impedance, minimizing direct cunent offset and motion artifacts of the electrical potentials using charge balancing, and providmg electrical potentials to external instrumentation

59 An electromagnetic medium contaming executable instructions which, when executed in a processing system, causes the system to collect biopotential signals, the collection comprising couplmg a sensory component to a skm surface, converting ionic potentials and electric fields received by the sensory component to electrical potentials, minimizing effects of changing skin impedance on the electrical potentials using a sensor impedance in series with a skm impedance, wherein a magnitude of the sensor impedance is greater than a magnitude of the skin impedance, minimizing direct cunent offset and motion artifacts of the electrical potentials using charge balancing, and providmg electrical potentials to external instrumentation

60 A biopotential electrode sensory component, comprising means for couplmg a sensory means to a skm surface, means for converting ionic potentials and electric fields received by the sensory means to electrical potentials, means for minimizing effects of changing skm impedance on the electrical potentials usi/ig an impedance in series with a skin impedance, wherein a magnitude of the impedance is greater than a magnitude of the skin impedance, means for minimizing direct cunent offset and motion artifacts of the electπcal potentials using charge balancmg means, and means for providing electrical potentials to external instrumentation

61 A biopotential sensor electrode system, comprising at least one electrode anay including at least one biopotential sensor electrode coupled to at least one telemetry component and at least one pov/er source, wherein the at least one biopotential sensor electrode includes at least one sensory component coupled to a biopotential signal source, and at least one receiver sectior compπsmg at least one receiver, the at least one receiver section transferring biopotential signals amc ng the biopotential signal source and external instrumentation usmg the at least one telemetry component

62 The biopotential s sor r lectrode system of claim 61 , wherem the at least one sensory component comprises at least one layei of electπcally conductive material and at least one dielectric layer, wherein the at least one biopotential sensor electrode further compπses at least one conditionmg component coupled to condition signals from the at least one sensory component, at least one interface configured to transfer signals among the at least one conditioning component and external instrumentation, and at least one power source coupled among the at least one sensory component, the at least one conditioning component, and the at least one mterface

63 The biopotential sensor electrode system of claim 61, wherem the at least one sensory component comprises a dielectric layer coupled between a first and a second layer of electrically conductive material, wherem the first layer of electrically conductive material is capacitively coupled to the biopotential signal source, and wherem the second layer of electrically conductive material is coupled to the at least one conditioning component

64 The biopotential sensor electrode system of claim 63, wherein the second layer of elecfrically conductive material is coupled to the at least one conditioning component using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, at least one resistive element, charge balancmg circuitry, and a feedback amplifier

65 The biopotential sensor electrode system of claim 64, wherem the at least one bond is selected from a group consisting of a permanent metallic bond and a snap connector

66 The biopotential sensor electrode system of claim 63, wherein the first layer of electπcally conductive mateπal is coupled to the dielectric layer through a third layer of electrically conductive mateπal and a first bond, wherein the second layer of electrically conductive material is coupled to the dielectπc layer through a fourth layer of electrically conductive material and a second bond

67 The biopotential sensor electrode system of claim 66, where the first bond and the second bond are selected from a group consisting of a permanent metallic bond and a snap connector

68 The biopotential sensor electrode system of claim 66, wherein the first layer of electrically conductive material is coupled to the biopotential signal source usmg at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, and at least one metal layer, and wherein the second layer of electrically conductive material is coupled to the at least one conditionmg component usmg at least one component selected from a group consistmg of charge balancmg circuitry and at least one bond

69 The biopotential sensor electrode system of claim 68, wherem the at least one bond is selected from a group consisting of a permanent metallic bond and a snap connector

70 The biopotential sensor electrode system of claim 62, further comprising at least one stimulation component coupled among the at least one mterface and the at least one sensory component, wherein the at least one stimulation component provides stimulation signals to the biopotential signal source, wherem the at least one stimulation component comprises at least one component selected from a group consistmg of at least one programmable cunent source, at least one programmable voltage source, at least one programmable generator, at least one cunent- to- voltage converter, and at least one transresistance amplifier

71 The biopotential sensor elecfrode system of claim 61, wherem the at least one telemetry component comprises a telemetry receiver and transmitter and antenna, wherem the at least one telemetry component transfers information and power among the biopotential sensor electrode and the external instrumentation

72 The biopotential sensor electrode system of claim 61 , wherein the at least one power source comprises at least one power source selected from a group consisting of at least one battery, at least one solar cell, and a telemetry power component, wherein the telemetry power component generates power in response to telemetry signals received from the external instrumentation

73 The biopotential sensor electrode system of claim 61, wherem the at least one power source is coupled among the at least one biopotential sensor electrode of the at least one electrode array

74 The biopotential sensor electrode system of claim 61, wherein the at least one power source comprises a power source for each biopotential sensor electrode of the at least one elecfrode anay

75 The biopotential sensor electrode system of claim 62, further compπsing at least one bidirectional multiplexer coupled to transfer signals among the at least one interface and the external instrumentation

76 The biopotential sensor electrode system of claim 62, wherein the at least one interface is selected from a group consisting of an analog interface and a digital interface

77 The biopotential sensor electrode system of claim 61, further compπsing at least one reference link among the at least one biopotential sensor elecfrode that allows the at least one biopotential sensor electrode to be synchronized and referenced to a single potential, wherem the at least one reference link is provided by at least one couplmg selected from a group consistmg of a wired link, a telemetry link, and cunent injection to a skm surface.

78. The biopotential sensor electrode system of claim 61, wherein the at least one biopotential sensor electrode is on a single substrate.

79. The biopotential sensor elecfrode system of claim 61 , further compπsmg a network coupled among the at least one elecfrode array and the external mstmmentation, wherem the network comprises at least one network couplmg selected from a group consistmg of wired, wireless, and a combmation of wired and wireless.

80. A biopotential sensor electrode system, comprising at least one electrode anay including at least one biopotential sensor electrode, wherem the at least one biopotential sensor elecfrode comprises at least one signal transfer component and at least one sensory component coupled to a biopotential signal source, wherem the at least one sensory component comprises, a first layer of electrically conductive material coupled among a biopotential signal source and a dielectric layer; a second layer of electrically conductive material coupled among the dielectric layer, at least one resistive element, at least one charge balancing cunent source and sink, and at least one biopotential electrode circuit; and at least one receiver section compπsing at least one receiver, the at least one receiver section transfemng biopotential signals among the signal transfer component and external instrumentation.

81 The biopotential sensor electrode system of claim 80, further comprising at least one reference link among the at least one biopotential sensor electrode that allows the at least one biopotential sensor elecfrode to be synchronized and referenced to a single potential, wherein the at least one reference link is provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and current injection to a skm surface

82. The biopotential sensor elecfrode system of claim 80, further compnsmg a network coupled among the at least one electrode anay and the external mstmmentation, wherem the network compπses at least one network coupling selected from a group consistmg of wired, wireless, and a combmation of wired and wireless.

83 A biopotential sensor electrode system, compnsmg' at least one electrode anay including at least one biopotential sensor elecfrode, wherem the at least one biopotential sensor elecfrode comprises at least one signal transfer component and at least one sensory component coupled to a biopotential signal source, wherem the at least one sensory component comprises, a first layer of electπcally conductive material coupled among a biopotential signal source, a dielectπc layer, and voltage protection circuitry, a second layer of electπcally conductive mateπal coupled among the dielectπc layer, at least one biopotential electrode circuit, and at least one charge balancing circuit, and at least one receiver section compπsmg at least one receiver, the at least one receiver section transferring biopotential signals among the signal transfer component and external instrumentation

84 The biopotential sensor electrode system of claim 83, further compπsmg at least one reference link among the at least one biopotential sensor electrode that allows the at least one biopotential sensor elecfrode to be synchronized and referenced to a smgle potential, wherem the at least one reference link is provided by at least one coupling selected from a group consistmg of a wired link, a telemetry link, and cunent injection to a skm surface

85 The biopotential sensor electrode system of claim 83, further comprising a network coupled among the at least one electrode anay and the external instrumentation, wherem the network compπses at least one network couplmg selected from a group consisting of wired, wireless, and a combination of wired and wireless

86 A method for collecting biopotential signals, compnsmg transferring telemetry signals among at least one sensor electrode and external instrumentation, wherein the telemetry signals compπse power signals and biopotential signals, generating power for the sensor electrode in response to the power signals, receiving and conditionmg biopotential signals from a skm surface at the sensor electrode, providmg stimulation signals to the skin surface, and receiving elemetered conditioned biopotential signals at the external mstmmentation

87 A computer readable medium containing executable instructions which, when executed in a processing system, causes the system to collect biopotential signals, the collection comprising transfemng telemetry signals among at least one sensor elecfrode and external instrumentation, wherein the telemetry signals compπse power signals and biopotential signals, generating power for the sensor elecfrode m response to the power signals, receiving and conditioning biopotential signals from a skin surface at the sensor electrode, providmg stimulation signals to the skm surface, and receiving telemetered conditioned biopotential signals at the external instrumentation

88. An electromagnetic medium containing executable instructions which, when executed in a processing system, causes the syster 1 to collect biopotential signals, the collection comprising: transferring telemetry sign; Is among at least one sensor electrode and external instmmentation, wherein the telemetry signals compi ise power signals and biopotential signals; generating power for the sensor elecfrode in response to the power signals; receiving and conditioning biopotential signals from a skin surface at the sensor elecfrode; providing stimulation signals to the skin surface; and receiving telemetered conditioned biopotential signals at the external instmmentation.

89. A biopotential sensor elecfrode system, comprising: means for transferring telemetry signals among at least one sensor means and external instmmentation, wherein the telemetry signals comprise power signals and biopotential signals; means for generating power for the sensor elecfrode in response to the power signals; means for receiving and conditioning biopotential signals from a skin surface at the sensor electrode; means for providing stimulation signals to the skin surface; and means for receiving telemetered conditioned biopotential signals at the external instmmentation.