WO2006010310A1

WO2006010310A1 - Apparatus and method for non-invasive monitoring of blood components using pulsewave impedance spectra

Info

Publication number: WO2006010310A1
Application number: PCT/CN2005/000803
Authority: WO
Inventors: Gang Li; Zongwu Lu; Ling Lin
Original assignee: Tian Jin University
Priority date: 2004-07-27
Filing date: 2005-06-08
Publication date: 2006-02-02
Also published as: CN1297229C; CN1596826A

Abstract

Apparatus and method for non-invasive monitoring of glucose and other components in blood by using pulsewave impedance spectra are disclosed. The apparatus comprises of a main control unit, as well as a sweeping constant current source, a measuring unit, a display and alarm unit, a memory unit and a communication interface, all being connected with the main control unit. A pair of exciting electrodes and a pair of measuring electrodes are set in the sweeping constant current source and the measuring unit, respectively. The main control unit supplies for the entire system controlling and deals with the data of the dynamic pulsewave impedance spectra, thereby calculating the concentration of the glucose and other components in blood.

Description

Non-invasive detection device for pulse impedance spectrum blood sugar or other blood components and detection method thereof

The invention relates to a detecting device for detecting non-invasive blood sugar or other blood components and a detecting method thereof, in particular to a non-invasive measurement of blood sugar or other blood components by measuring body surface electrical impedance and its change with pulse wave. Detection device and detection method thereof. Background technique

Diabetes is a chronic metabolic disease that is caused by heredity, insufficient insulin secretion, or low insulin function. The disease initially manifests itself in elevated blood sugar levels, which in turn harm other organs and systems of the body, causing serious complications such as kidney failure, blindness, heart disease, peripheral uterine bleeding, gangrene and even resection. Diabetes has become a serious threat to human health.

In 2000, there were 180 million people with diabetes in the world, and 3.2 million people died of diabetes and its complications. It is estimated that the number of patients with diabetes in the world will reach 370 million in 2030, and the number of diabetic patients in China will reach 42 million, ranking second in the world. The expenditure for treating diabetes will become a heavy burden for society and families. At present, there is no medical method for completely eradicating diabetes. Therefore, it is crucial to monitor blood glucose concentration and adjust the dosage of hypoglycemic drugs in time to prevent and reduce the occurrence of complications. The existing detection methods require blood samples to be taken, and biochemical and optical instruments are used for analysis. Not only is the operation cumbersome, it causes pain to the patient, but also the risk of infecting other diseases, which limits the frequency and range of use of blood glucose detection. Non-invasive blood glucose testing technology not only enables real-time, continuous, safe and painless self-monitoring of blood glucose levels, but also does not require consumables, which can reduce testing costs and bring revolutionary progress to the prevention and treatment of diabetes. The more people are valued.

In recent years, with the gradual deepening of various technical basic theoretical research and the increasing enrichment of experimental results, the screening of several technologies with the most promising prospects has been basically completed. They can be divided into three categories: optical radiation technology, bioimpedance technology. And body fluid collection techniques.

Optical radiation techniques include mid-infrared spectroscopy, far-infrared spectroscopy, optical rotation, and light scattering coefficient methods. Among them, near-infrared spectroscopy is the most studied. The basic principle of the optical radiation method is to apply a certain wave of long light energy to a specific part of the human body. By measuring changes in parameters such as absorption, reflection, scattering, and polarization of light energy, the relationship between blood components such as blood sugar and these parameters is established. Calculate the concentration of blood sugar. These methods have attractive research and commercial prospects, as well as many major technical challenges that need to be addressed. The most prominent problem is that the spectroscopic devices used for detection must be recalibrated frequently. 'Multi-person instruments require specific multi-parametric prediction models for each subject due to differences in water, fat, muscle, skin, bone and other components. Even with the same subject, frequent changes in the above components with physiological processes make frequent calibrations inevitable, and each calibration process is lengthy and traumatic, usually taking 1-2 hours and requiring Continue to take blood tests.

Body fluid collection methods include iontophoresis and interstitial fluid transdermal collection. The iontophoresis method is to apply a weak current to the surface of the skin, and there will be bodily fluids in the vicinity of the electrode. The concentration of glucose in these body fluids is related to blood glucose concentration, measurement The concentration of glucose in the exudate can be used to derive the amount of glucose in the blood. Interstitial fluid transdermal collection is the collection of interstitial fluid from the surface of the skin using microneedle, chemical or laser methods, and then measuring the glucose concentration of these fluids. The shortcoming of these two methods is that the body fluid collection time is more than 20 minutes, and the change of blood glucose concentration cannot be reflected in real time; the second is that the skin has certain damage.

Bioimpedance technology is a detection technology that extracts biomedical information related to human physiological and pathological conditions by utilizing the electrical properties and changes of biological tissues and organs. 9 Bioelectrical impedance technology is extracted from the functional changes of tissues and organs. The electrical property information has unique discriminating power for blood, gas, body fluids and different tissue components and their changes, so bioimpedance measurement technology can be used to achieve non-invasive measurement of blood sugar and other components.

Impedance refers to the total hindrance of a substance to an alternating current passing through it. When this alternating current is applied to the blood, an inorganic solute like glucose absorbs electromagnetic energy, causing an increase in impedance, the magnitude of which is related to the glucose concentration. The effect of glucose on blood impedance at different frequencies is also different. Therefore, by measuring the impedance of blood and appropriately selecting a plurality of frequencies, the blood glucose concentration can be accurately obtained. Pendragon's A. Caduf f, etc., swept the impedance of the arm in the frequency range of 0.1-MHz in the l-200MHz frequency range, and compared with the measured blood glucose concentration, developed an impedance spectrum blood glucose monitor that can be worn. Monitor blood sugar changes in real time on your wrist. U.S. Patent No. 6,157,482 (H. R. Elden et al.) discloses a blood glucose personal monitor that uses a frequency of 20 kHz to give a blood glucose concentration of G = 0.31 X impedance modulus + 0. 24X phase angle, the measurement site is the forearm.

The impedance method blood glucose non-invasive measurement method has low instrument cost, high measurement accuracy, and short time required. In addition, if the frequency is appropriately selected, the concentration of a plurality of points such as cholesterol can be simultaneously detected. Therefore, impedance spectrum measurement has a broad development prospect for non-invasive blood glucose testing.

Human impedance is also affected by many factors such as skin, blood circulation, blood electrolytes and other components. These factors are called individual differences. Due to the existence of individual differences, the impedance spectrum non-invasive blood glucose monitoring has a large deviation, and the signal-to-noise ratio and sensitivity are difficult to improve. Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the existing impedance method blood glucose or other blood non-invasive detection technology, and provide a non-invasive detection device for blood sugar or other blood components with small error, signal to noise ratio and high sensitivity; Another object of the invention is to provide a non-invasive detection method for blood glucose or other blood components with low error, signal to noise ratio and high sensitivity.

In order to solve the above technical problem, the non-invasive detecting device for blood pressure or other blood components of the pulse impedance spectrum of the present invention is composed of a main control unit and a frequency sweeping constant recording source, a measuring unit, a display alarm unit and a storage unit connected to the main control unit; The swept constant current source is provided with a pair of excitation electrodes, and the sweep constant current source is used to generate a weak alternating current with a constant frequency amplitude, and the excitation electrode is fed into the human body through the test; The unit is provided with a pair of measuring electrodes for picking up the amplitude of the impedance pulse wave at different frequencies and feeding it to the main control unit; the main control unit is for controlling the entire measuring system for the dynamic pulse wave impedance Processing spectral data, thereby calculating the concentration of blood glucose and other blood components, and feeding the data to said display alarm unit and said storage unit; said display alarm unit receiving The storage unit is used to store monitoring data.

The excitation electrode is a ring electrode or an electrocardiographic monitoring electrode.

The measuring electrode is a ring electrode or an electrocardiographic monitoring electrode. .

The main control unit is a microprocessor or a microcontroller or a microcomputer.

The memory unit is a solid state memory flash chip.

The communication interface is a USB communication interface or an RS232 communication interface for transmitting stored blood glucose or other blood component data to other devices or devices.

In order to solve the above technical problems, the pulse impedance spectrum of the present invention is a non-invasive detection method for blood glucose or other blood components, which comprises the following steps:

Place the excitation electrode on the person's arm, finger, torso or lower limb, and apply a weak alternating current with a constant frequency adjustable amplitude to the human body;

The measuring electrode is placed between the excitation electrodes to pick up the voltage signal between the two sections; the dynamic pulse wave impedance spectrum is obtained by measuring the amplitude of the impedance pulse wave at different frequencies:

A3⁄4,i' = 0,l,2,3,„"N , where: ·/; indicates different excitation frequencies, resulting in an arterial impedance spectrum mainly due to arterial blood pulsation; frequency of one of the selected signals ^/q As the reference frequency, calculate:

AZ _f

' Λ7" , , , ■ '

The ratio is only related to the resistivity of the blood, and is independent of external factors such as skin, condition, and electrode polarization voltage, eliminating the influence of individual differences; by determining the relationship between blood resistivity and blood components: :^" ^ ² ^ ³ ,...^ , where e^ ³ ' is the concentration of blood sugar and other blood components, and the concentration of blood sugar or other blood components can be obtained.

Compared with the prior art, the present invention has the following beneficial effects: The present invention realizes a method and a device for non-invasive measurement of blood sugar or other blood components by measuring changes in body surface electrical impedance with pulse wave, thereby quelling the influence of individual differences and reducing Measurement error, improved signal-to-noise ratio and sensitivity, non-invasive, real-time, continuous self-monitoring of blood glucose and other blood components. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of the system of the present invention.

Figure 2 is the original lithium waveform of the dynamic pulse wave impedance spectrum.

Reference numerals: 1 display alarm unit 2 main control unit 3 storage unit '4 communication interface

5 swept constant current source 6 body to be tested · 7 measuring unit 8 excitation electrode 9 measuring resistance detailed description

The invention is described in detail below with reference to the embodiments.

As shown in FIG. 1, the non-invasive detecting device for blood pressure or other blood components of the pulse impedance spectrum of the present invention is composed of a main control unit 2 and a swept constant current source 5 connected to the main control unit 2, a measuring unit 7, and an alarm unit 1 The storage unit 3 and the communication interface 4 are configured. The swept constant current source 5 is provided with a pair of excitation electrodes 8, and the excitation electrode 8 is a ring electrode or an electrocardiographic monitoring electrode. The swept constant current source 5 is used to generate a weak alternating current having a constant frequency amplitude and is fed into the human body through the excitation electrode 8. The measuring unit 7 is provided with a pair of measuring electrodes 9, and the measuring electrode 9 is a ring-shaped electrode or an electrocardiographic monitoring electrode. The measuring electrode 9 is used for picking up the amplitude of the impedance pulse wave at different frequencies, and is converted into the main control unit 2 by the analog/digital converter built in the measuring unit. The main control unit 2 can be a microprocessor, a micro control or a microcomputer, and the main control unit 2 is used to control the entire measurement system, and process the dynamic pulse wave impedance spectrum data, thereby calculating the concentration of blood sugar and other blood components. And send data to display alarm unit 1 and storage unit 3. The display alarm unit 1 receives and displays the blood component data sent from the main control unit 2, and issues an alarm signal when the blood glucose or other blood components exceed the standard. The storage unit 3 is composed of a solid state memory and a control circuit, the solid state memory uses a flash chip, and the storage unit 3 is used to store monitoring data. The communication interface 4 is a USB, RS232 or other communication interface, and the communication interface 4 is used to transmit stored blood glucose or other blood component data to other devices or devices.

The principle of the detecting device of the invention is as follows: The swept constant current source generates a weak alternating current with a constant frequency adjustable amplitude, which is applied to the human body through a pair of excitation electrodes; the electrode adopts a ring electrode or an electrocardiographic monitoring electrode, and the placement portion can be The arm, the finger, the torso or the lower limb; the measuring electrode is placed between the excitation electrodes to pick up the voltage signal between the two sections; the measuring unit amplifies and filters the voltage signal to obtain the impedance pulse wave at different frequencies, and is subjected to A/D conversion. After being sent to the main control unit; the present invention defines the corresponding impedance pulse wave amplitude at these different frequencies as the dynamic pulse wave impedance spectrum. The main control unit processes the impedance pulse data to obtain a dynamic pulse wave impedance spectrum:

AZ _fi , i = 0,1, 2,3,..., N (l) ; indicates different excitation frequencies. Selected frequency /. As the reference frequency, the ratio is:

It is only related to the electrical resistivity of the blood. There is a definite relationship between blood resistivity and blood component:

p = p(c _l ,c ₂₎ c ₃ ,...c _i ) (3)

P is the blood resistivity, ^c^c^c,. is the concentration of different blood components. The relationship between blood resistivity and blood glucose or other various components can be determined in advance by a large number of experimental measurements and certain data processing methods. Figure 2 is a schematic diagram of the impedance pulse wave at a certain frequency, where ΔΖ represents the amplitude of the pulse wave and ₇ is the fundamental impedance of the human body. The main control unit calculates the concentration of the blood glucose or other components according to the measured pulse wave impedance spectrum data and the curves, and sends the data to the display alarm unit and the storage unit; the display alarm unit receives and displays the transmission from the main control unit. Blood sugar or other blood component data. If the concentration of blood sugar or other blood components exceeds the standard, an alarm signal is issued; the storage unit is composed of a solid-state memory and a control circuit, and can store blood glucose or other blood component concentration data for a period of time; the communication interface realizes communication between the main control unit and the microcomputer, and will store The data in the unit is transferred to the microcomputer for further analysis and processing.

The pulse impedance spectrum of the present invention is a non-invasive detection method for blood sugar or other blood components, comprising the steps of: placing an excitation electrode on a person's arm, finger, torso or lower limb, and applying a weak alternating current having a constant frequency adjustable amplitude to the human body. ;

The measuring electrode is placed between the excitation electrodes to pick up the voltage signal between the two sections; the dynamic pulse wave impedance spectrum is obtained by measuring the amplitude of the impedance pulse wave at different frequencies: '

A3⁄4, _Z ' = ( ₅ 2'3"'"N , where: indicates different excitation frequencies, resulting in an arterial impedance spectrum mainly due to arterial blood pulsation; selecting the frequency ^{/c of} one of the signals as the reference frequency, :

AZ,

t = ~ J = 1,2,3

1 A7 』

The ratio is only related to the resistivity of the blood, and is independent of external factors such as skin, condition, and electrode polarization, eliminating the effects of individual differences;

By determining the relationship between blood resistivity and blood components: P ⁼ P^ 2^ -Ci), where ^c " ^c " ^c ""' ^c i is the concentration of blood sugar and other blood components, and you can get blood sugar or The concentration of other blood components.

The invention realizes the detection device and the detection method for non-invasive measurement of blood sugar or other blood components by measuring the surface electrical impedance and the change of the pulse wave, thereby eliminating the influence of individual differences, reducing the measurement error, improving the signal to noise ratio and Sensitivity, non-invasive, real-time, continuous self-monitoring of blood glucose and many other blood components.

Claims

Rights request

A pulse-impedance spectrum non-invasive detection device for blood glucose or other blood components, which is constituted by a main control unit and a swept constant current source, a measuring unit, a display alarm unit and a storage unit connected to the main control unit. The swept constant current source is provided with a pair of excitation electrodes, and the sweep constant current source is used to generate a weak alternating current with a constant frequency variable amplitude, and is fed into the human body through the excitation electrode; The unit is provided with a pair of measuring electrodes for picking up the amplitude of the impedance pulse wave at different frequencies and feeding it to the main control unit; the main control unit is for controlling the entire measuring system for the dynamic pulse wave impedance Processing the spectral data, thereby calculating the concentration of blood glucose and other blood components, and feeding the data to the display alarm unit and the storage unit; the display alarm unit receives and displays the blood sent by the main control unit The component data, an alarm signal is issued when blood glucose or other blood components exceed the standard; and the storage unit is configured to store monitoring data.

A non-invasive detecting device for blood glucose or other blood components according to claim 1, wherein the excitation electrode is a ring electrode or a '1 electric monitoring electrode.

The non-invasive detecting device for blood pressure or other blood components of a pulse impedance spectrum according to claim 1, wherein the measuring electrode is a ring electrode or an electrocardiographic monitoring electrode.

4. A non-invasive detection device for blood pressure or other blood components of a pulse impedance spectrum according to claim 1, wherein said main control unit is a microprocessor or a controller or a microcomputer.

5. A non-invasive detection device for blood glucose or other blood components of a pulse impedance spectrum according to claim 1, wherein said memory unit is a solid state memory flash chip.

6. A non-invasive detection device for blood glucose or other blood components according to claim 1, wherein the communication interface is a USB communication interface or an RS232 communication interface for storing blood glucose or Other blood component data is transmitted to other devices or devices

7. A non-invasive detection method for blood pressure or other blood components of a pulse impedance spectrum, the method comprising the steps of _: placing an excitation electrode on a person's arm, finger, torso or lower limb, and applying a frequency adjustable amplitude to the human body Constant weak alternating current; placing the measuring electrode between the excitation electrodes to pick up the voltage signal between the two sections; obtaining the dynamic pulse wave impedance spectrum = 0,1 ₅ 2 by measuring the amplitude of the impedance pulse wave at different frequencies 3,...,N, where: indicates different excitation frequencies, resulting in an arterial impedance spectrum mainly due to arterial blood pulsation; selected frequency /. As the reference frequency, calculate: = l, 2, 3...N, whose value is only related to the resistivity of the blood, and to the skin, condition,

Irrespective of external factors such as electrode polarization voltage, eliminating the effects of individual differences; by determining the relationship between blood resistivity and blood component: ? = /7(£^ ₂ , ,... ), where is blood glucose and The concentration of other blood components gives the concentration of blood sugar or other blood components.