US20110028989A1 - Navigation using sensed physiological data as feedback - Google Patents

Navigation using sensed physiological data as feedback Download PDF

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US20110028989A1
US20110028989A1 US12/773,443 US77344310A US2011028989A1 US 20110028989 A1 US20110028989 A1 US 20110028989A1 US 77344310 A US77344310 A US 77344310A US 2011028989 A1 US2011028989 A1 US 2011028989A1
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physiological property
location
sensed physiological
medical device
navigation system
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Rogers C. Ritter
Raju R. Viswanathan
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Stereotaxis Inc
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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/02Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026Measuring blood flow
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B34/00Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
    • A61B34/70Manipulators specially adapted for use in surgery
    • A61B34/73Manipulators for magnetic surgery
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/02Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026Measuring blood flow
    • A61B5/0275Measuring blood flow using tracers, e.g. dye dilution
    • A61B5/028Measuring blood flow using tracers, e.g. dye dilution by thermo-dilution
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/06Devices, other than using radiation, for detecting or locating foreign bodies ; determining position of probes within or on the body of the patient
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/06Devices, other than using radiation, for detecting or locating foreign bodies ; determining position of probes within or on the body of the patient
    • A61B5/061Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body
    • A61B5/062Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body using magnetic field
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/06Devices, other than using radiation, for detecting or locating foreign bodies ; determining position of probes within or on the body of the patient
    • A61B5/065Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/06Devices, other than using radiation, for detecting or locating foreign bodies ; determining position of probes within or on the body of the patient
    • A61B5/065Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
    • A61B5/068Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe using impedance sensors
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/25Bioelectric electrodes therefor
    • A61B5/279Bioelectric electrodes therefor specially adapted for particular uses
    • A61B5/28Bioelectric electrodes therefor specially adapted for particular uses for electrocardiography [ECG]
    • A61B5/283Invasive
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/06Measuring blood flow
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/12Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00017Electrical control of surgical instruments
    • A61B2017/00022Sensing or detecting at the treatment site
    • A61B2017/00039Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
    • A61B2017/00044Sensing electrocardiography, i.e. ECG
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B34/00Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
    • A61B34/20Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
    • A61B2034/2046Tracking techniques
    • A61B2034/2051Electromagnetic tracking systems
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/316Modalities, i.e. specific diagnostic methods
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/316Modalities, i.e. specific diagnostic methods
    • A61B5/318Heart-related electrical modalities, e.g. electrocardiography [ECG]
    • A61B5/339Displays specially adapted therefor
    • A61B5/341Vectorcardiography [VCG]
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/06Measuring instruments not otherwise provided for

Definitions

  • Cardiac arrhythmias are a form of cardiac disease where the electrical activity of the heart is disrupted, often due to the takeover of signal generation by abnormal excitation nodes.
  • Cardiac arrhythmia may be treated through minimally invasive interventions such as catheter ablation, where catheters navigate a set of electrodes (often 3-8 electrodes) intravascularly into the relevant chambers of the heart, and monitor electrical signal activation times and propagation to thereby identify location points of focal arrhythmias, for example Supraventricular Tachycardia (e.g., SVT).
  • An electro-physiological study is performed to record the activation sequence at target locations of the heart, to determine the arrhythmia mechanism. Such mapping may then be used to identify location points within the heart that are part of the tachycardia or arrhythmia mechanism, but not part of the normal cardiac conduction system.
  • Such location points are then rendered electrically inactive by ablating the point, typically by Radio Frequency ablation.
  • the electrophysiological study may also record blood flow velocity, to determine areas of disrupted blood flow caused by poorly coordinated pumping of the heart chambers. Where the heart valve chambers are fluttering, vortices will occur at certain regions while other regions will have streamline blood flow.
  • the electrophysiological catheter is useful in assisting in the diagnosis and treatment of such conditions. Recent advancements have also resulted in automated remote navigation systems that can drive catheter placement with a great deal of precision, more specifically magnetic navigation systems.
  • a system for treatment of arrhythmia that comprises an electrophysiological catheter having at least one electrode for sensing intra-cardiac wave front activation signals on a tissue surface, a navigation system for guiding the distal end of the catheter to a number of locations for sensing intra-cardiac activation signals along the wall of a subject body's heart, and an ECG recording system for recording the local intra-cardiac signal data for each of the locations.
  • the system further comprises a computer for determining the direction of propagation of the wave front with respect to time from the intra-cardiac activation signals corresponding to the location points. From the direction of propagation of the wave front, the computer may calculate a new location point in the direction of the source of the wave front for advancing the catheter to, where intra-cardiac activation data may be used with at least two of the prior locations for further evaluation of the wave front direction.
  • a method for determining the movements of the catheter towards a focal arrhythmia for ablation.
  • a method is provided in combination with a navigation system, a localization system, and an algorithm for directing the movement of the catheter. The method comprises navigating the distal end of the catheter to sense intra-cardiac activation signals at a number of locations on the wall of a subject body's heart, recording the local intra-cardiac signal data for the minimum number of locations, and determining the direction of propagation of the wave from with respect to time from the location points using the algorithm.
  • the method further comprises calculating a new location point in the direction of the source of the wave front using the algorithm, for use with at least two of the prior locations for further evaluation of the wave front direction, iteratively repeating the step of determining the direction of propagation to obtain the earliest activation location of the wave front, and responsively navigating the distal tip of the catheter to the earliest activation location for providing medical treatment.
  • a means for determining patterns of disrupted blood flow caused by poorly coordinated pumping of heart chambers.
  • the means for determining blood flow comprises a fluid velocity sensing means located on the tip of the electrophysiological catheter, for use in diagnosis and treatment of arrhythmia.
  • the one or more fluid velocity sensors are capable of measuring temperature changes across a region of the sensor to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the temperature change.
  • the one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip.
  • one or more Doppler fluid velocity sensing means are located on the tip of the electrophysiological catheter.
  • the one or more Doppler fluid velocity sensing means comprise a transmitter for transmitting a high frequency sound wave into the fluid, and an antenna that detects a frequency shift of the reflected wave from the fluid particles to determine the fluid velocity.
  • the one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip.
  • a preferred embodiment of a method for controlling the navigation of a medical device within a subject body to sense an electrophysiological property is also provided.
  • the method may be used to navigate a medical device comprising one or more physiological sensing means to a plurality of regions within a subject body, for sensing the value or relative change in value of a sensed physiological property such as an electrical signal, conductivity, temperature, or fluid velocity and direction as previously disclosed.
  • the method of controlling a remote navigation system to navigate a medical device in an operating region in a subject comprises operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location.
  • the method operates the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property value, and uses the sensor to sense the physiological property in each location.
  • the method automatically determines the location of a local extreme value of the sensed physiological property, and may be selectively used to locate a maximum value of the sensed physiological property or a minimum of the sensed physiological property.
  • FIG. 1 is a cut away view of a heart showing a re-entry circuit within the right atria and a possible target area for ablation to render the re-entry mechanism inactive;
  • FIG. 2 is an illustration of the difference in phase of ECG signals at points P 1 and p 2 ;
  • FIG. 3 is an illustration of a number of location points of intra-cardiac activity having phase signal differences, and a corresponding direction of wave front propagation.
  • FIG. 4 is a side view of one embodiment of an electrophysiological catheter having a fluid velocity sensing means according to the principles of the present invention.
  • Embodiments of the systems and methods of the present invention are provided that comprise various electrophysiological sensors disposed on the tip of a catheter for sensing and recording local activity of tissues or fluid flow within the body.
  • the various embodiments of the present invention are capable of measuring local electrical activity, temperature, fluid velocity and fluid flow direction in a local area within a subject body using a minimal number of devices.
  • a system and method are provided for measuring and recording various points in a region of a patient's heart for mapping electrophysiological activity of the tissue, and for determining a target location for catheter ablation to correct an arrhythmia mechanism.
  • the arrhythmia mechanism of an atrioventricular re-entry tachycardias may be established where an electrical wave front occurs within the heart that generates a re-entry circuit.
  • an example of a re-entry circuit is generally shown as a circular electrical pathway 22 within the right atrium around the inferior vena cava 24 and superior vena cava 26 .
  • a possible target 28 for atrial ablation could be near the isthmus between the tricuspid valve 30 and the inferior vena cava 24 . Ablation would render the location electrically inactive, and would interrupt the electrical pathway of the re-entry circuit.
  • Atrioventricular Nodal Re-entry Tachycardia is another arrhythmia mechanism that is established where both a fast and slow conduction pathways into the atrioventricular node exist. Atrial flutter and Focal Atrial Tachycardia are yet further re-entry mechanisms in which the passage of the activation wave front around the atrium establishes re-polarization of the ventricle before the wave front completes one circuit.
  • the present invention provides a method for evaluating such various arrhythmia mechanisms and determining the source or focal point of the arrhythmia to be treated.
  • the method described herein involves using a single catheter to measure and record intracardiac electrical activity in a small local region, identify the direction of signal propagation of the wave front of intracardiac activity from these measurements, and navigate the catheter in the appropriate direction towards the source of the wave front. Once identified, such electrical signal sources that are not part of the normal cardiac conduction system can be removed by catheter ablation techniques such as Radio Frequency (RF) ablation, where electrical energy is delivered through the tip electrode of the catheter in order to locally destroy abnormal tissue.
  • RF Radio Frequency
  • a system for treatment of arrhythmia comprises a catheter having at least one electrode for sensing intra-cardiac wave front activation signals on a tissue surface, and a navigation system for guiding the distal end of the catheter to a minimum number of locations to sense intra-cardiac activation signals along the endocardial wall of a subject's heart.
  • Navigation of the catheter may be performed by a magnetic navigation system or any other navigation system suitable for guiding a catheter within a subject body.
  • An ElectroPhysiology ECG recording system is used for recording the location the local intra-cardiac electrical signal data corresponding to the minimum number of locations.
  • a localization system is used to record catheter tip location data together with intra-cardiac electrical signal data.
  • the system may also include a fluoroscopic imaging system for obtaining images and location points of the catheter within the body during the surgical procedure.
  • fluoro-localization is used to record three dimensional catheter tip location data by manually marking on corresponding points in at least two fluoro images.
  • the catheter may be a magnetically navigable catheter, which may be advanced through the vasculature in a selected direction by pushing the proximal end of the catheter, and by deflecting the distal end of the catheter by an applied magnetic field to gain entry to a vessel branch.
  • the distal end of the catheter may comprise a radio-opaque material useful for viewing in an X-ray or fluoroscopic imaging system, and one or more magnetic elements which can be deflected to align with an applied magnetic field external to the subject body of a patient.
  • One such navigation system for example, is the Stereotaxis NiobeTM magnetic navigation system, which can apply an external magnetic field of about 0.08 Tesla within the subject in any direction in order to suitably orient or steer the catheter.
  • other actuation schemes such as mechanical, electrostrictive, hydraulic or other methods could be used to steer or deflect the catheter in order to navigate it.
  • the system further comprises a computer for determining the regional direction of propagation of the wave front from the intra-cardiac signal data corresponding to the location points. By determining the direction of propagation of the wave front, the computer calculates a new location for advancing the catheter in the direction of the source of the wave front, where intra-cardiac signal data may be used with at least two of the prior locations for further evaluation and adjustment of the estimated wave front direction.
  • the computer may execute an algorithm for iteratively repeating the above progression to determine the earliest activation location or source of the wave front, and responsively navigating the distal tip of the catheter to the earliest activation location for medical treatment.
  • the preferred embodiment further comprises a method for determining the point of earliest activation of a local wave front associated with focal atrial tachycardia.
  • the method includes the step of determining the direction of propagation of the wave front from an analysis of signal delays or signal arrival times in the intra-cardiac signal data corresponding to the location points.
  • the method calculates a new location for advancing the catheter in the direction of the source of the wave front, where intra-cardiac signal data may be used with at least two of the prior locations for further evaluation or estimation of the wave front propagation direction.
  • the method repeats the iterative progression to determine the earliest activation location of the wave front and to responsively navigate the distal tip of the catheter to the earliest intra-cardiac activation location for medical treatment.
  • the system and method may automatically determine the location of a focal point of arrhythmia or atrial tachycardia re-entry mechanism where unpolarized intra-cardiac activation is initiated, and may automatically advance the catheter to the location for ablation treatment.
  • the method may also be used to perform an electrophysiological study for generating an electro-anatomical map of the heart tissue.
  • Such atrial tachycardia re-entry or other cardiac arrhythmia mechanisms are established by lines of conduction that can be visualized using mapping systems that can characterize and predict focal points.
  • the catheter tip is positioned at three locations on the wall of the heart chamber and the electrical signals recorded at each of these locations.
  • the locations are preferably mutually separated by separations in the range 5 mm-20 mm and more preferably in the range 5 mm-15 mm.
  • An ECG system (ideally outputting data to the navigation system) records local intracardiac signal data at each of these locations p 1 , p 2 and p 3 .
  • the ECG data is recorded for about 3-20 cycles to determine the periodicity T of the signal.
  • the position ⁇ right arrow over (X) ⁇ p 1 can be determined, for example by fluoro-localization.
  • the catheter is then moved to location p 3 , and its position ⁇ right arrow over (X) ⁇ p 3 is determined, for example by fluro-localization.
  • the electrical signal is recorded, and its phase difference b′ is determined.
  • p 1 is the point of earliest activation, i.e., a′ and b′ (phase differences at the other 2 points with respect to p 1 ) are both positive, and are hereinafter referred to as a and b instead of a′ and b′.
  • the triangle formed by points p 1 , ( 40 ), p 2 , ( 42 ), and p 3 ( 44 ) is shown in FIG. 3 .
  • Isochrones (contours of equal propagation time) within this triangle represent the local wave front; the direction of propagation is normal to this wave front. Referring to FIG.
  • x -> 0 x -> 1 + a b ⁇ ( x -> 3 - x -> 1 )
  • Equations (4), and (5) can be solved for ⁇ and ⁇ , and thus ⁇ right arrow over (n) ⁇ can be determined (pick the sign of ⁇ right arrow over (n) ⁇ such that ⁇ right arrow over (n) ⁇ points towards ⁇ right arrow over (x) ⁇ 1 , or such that n has positive dot product with the vector (x 1 ⁇ (x 0 +x 2 )/2)).
  • ⁇ right arrow over (y) ⁇ ′ 1 is defined as a new target for the catheter; because the wall surface is curved, target navigation of the catheter (with suitable control actuations applied) will actually take the tip to a location ⁇ right arrow over (y) ⁇ ′ 1 .
  • a new triangle O 2 is fowled by the points ⁇ right arrow over (y) ⁇ ′ 1 and the 2 points (from triangle O 1 ) that are closest to it.
  • the process is iteratively repeated to get a new local propagation direction in triangle O 2 , as long as the activation time at point ⁇ right arrow over (y) ⁇ ′ 1 is earlier than that of the other 2 points in O 2 . If the activation time at ⁇ right arrow over (y) ⁇ ′ 1 is later than that of at least one of the other 2 points, a reduced step is taken:
  • the focal point of the arrhythmia may thus be found and the catheter will have been placed there.
  • Ablative therapy may be performed to eliminate the source of the arrhythmia.
  • these methods may be generalized to multi-focal arrhythmias by looking for double periodicities and other signal features, such that multiple isochrones may be tracked locally to arrive at multiple foci.
  • more than one catheter may be used in combination for diagnosis and navigation.
  • the remote navigation system could be used with a localization system with location feedback, or with a registered pre-operative or other anatomical data.
  • a suitably modified stepping point ⁇ right arrow over (y) ⁇ ′ 1 etc. may be directly defined on the (curved) heart surfaces so that a stepped path is defined on the curved surface, minimizing the need for repeated fluoro localization.
  • catheter tip location could be estimated or evaluated from a knowledge of actuation control variables from the navigation system and a computational device model that predicts tip location based on the actuation controls. Varying levels of automation thus are possible depending a system integration and availability of anatomical and/or catheter location data.
  • a low voltage signal may be applied to the at least one electrode, and the current conducted through the tissue may be measured and recorded for enabling mapping of conductivity of a tissue surface.
  • the catheter or medical device may be navigated to bring the electrode successively into a plurality of locations in a predetermined pattern, to sense the conductivity of each location. At least once thereafter, the medical device may be navigated to bring the electrode successively into further locations in a predetermined pattern relative to at least one location selected from the immediately preceding plurality of locations.
  • An algorithm may be used to automatically operate the navigation system to bring the sensor to a series of locations in a predetermined pattern, to guide the medical device to a local extreme of a sensed conductivity, such as an area of minimum electrical conductivity.
  • Such an algorithm may utilized the method disclosed above for automatically navigating the medical device in a predetermined pattern to locate a region having a local extreme.
  • an electrophysiological catheter 20 that further comprises one or more fluid velocity sensing means disposed on the tip of the catheter.
  • the catheter 20 comprises a tubular element 22 having a proximal end and a distal end 24 .
  • the distal end of the catheter comprises at least one magnetically responsive element 26 for enabling navigation of the distal end, and also comprises one or more electrodes 28 .
  • One or more fluid velocity sensing means 30 may be utilized for sensing relative changes in velocity of a fluid flowing across the sensing means.
  • the one or more fluid velocity sensors are capable of measuring temperature changes across a region of the sensor to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the temperature change.
  • the one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip.
  • the current conducted through the tissue may be measured and recorded for enabling mapping of conductivity of a tissue surface.
  • the fluid velocity sensing means comprises a micro-machined structure having a heater that measures temperature drop across a region to determine the relative change in fluid velocity across the heater. Such a device need not be calibrated for absolute velocity in this application, but instead would determine relative values at appropriate locations within the subject body.
  • the heater comprises a homogeniously heated segmented heater having a plurality of heated segments forming a generally square shape, for enabling the detection of a relative temperature difference between corresponding segments. The plurality of segments provide for determining the flow direction corresponding to the sensed fluid velocity across the heater.
  • the catheter or medical device may be navigated to bring the fluid velocity sensing means successively into a plurality of locations in a predetermined pattern, to sense the fluid velocity at each location. At least once thereafter, the medical device may be navigated to bring the fluid velocity sensing means successively into further locations in a predetermined pattern relative to at least one location selected from the immediately preceding plurality of locations.
  • An algorithm may be used to automatically operate the navigation system to bring the fluid velocity sensing means to a series of locations in a predetermined pattern, to guide the medical device to a local extreme of a sensed fluid velocity, such as an area of minimum fluid velocity or a vortices in the blood flow.
  • the fluid velocity sensing means could also be used to sense local maximums of fluid velocity such as regions of streamline blood flow through the chambers of the heart.
  • the mapping of such velocity data is useful in assisting in the diagnosis of medical conditions such as cardiac arrhythmia.
  • the algorithm utilized may employ the method disclosed above for automatically navigating the medical device in a predetermined pattern to locate a region having a local extreme.
  • This embodiment comprising a fluid sensing means may also be used to sense the temperature of a location as well.
  • the homogeniously heated segmented heater establishes a base temperature, which may be increased or decreased by the surrounding tissues it comes into contact with.
  • the above sensing means is capable of sensing a temperature drop across the surface as well as changes in absolute temperature of the homogeniously heated sensor.
  • This sensing means may also be used to sense relative changes in temperature from location to location.
  • an electrophysiological catheter that further comprises one or more Doppler fluid velocity sensing means disposed on the tip of the catheter, for sensing relative changes in fluid velocity across the sensing means.
  • the one or more Doppler fluid velocity sensing means are capable of measuring frequency shifts in a wave signal to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the sensing means.
  • the one or more Doppler fluid velocity sensing means comprise a transmitter for transmitting a high frequency sound wave into the fluid, and an antenna that detects a frequency shift of the reflected wave from the fluid particles to determine the fluid velocity. Electrical connections for the micro-transmitter and antenna may be disposed within the catheter or medical device to provide for measuring and recording of the sensed fluid velocity.
  • the one or more Doppler fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip. By orienting one or more fluid velocity sensing means of this type on the tip of the catheter, the component of direction of the fluid velocity relative to the catheter could be determined.
  • a preferred embodiment of a method of controlling the navigation of a medical device within a subject body to sense an electrophysiological property is also provided.
  • the method may be used to navigate a medical device comprising one or more physiological sensing means to a plurality of regions within a subject body, for sensing the value or relative change in value of a sensed physiological property such as an electrical signal, conductivity, temperature, or fluid velocity and direction as previously disclosed.
  • the method of controlling a remote navigation system to navigate a medical device in an operating region in a subject comprises operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location.
  • the method operates the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property value, and uses the sensor to sense the physiological property in each location.
  • the method automatically determines the location of a local extreme value of the sensed physiological property, and may be selectively used to locate a maximum value of the sensed physiological property or a minimum of the sensed physiological property.
  • a medical device for sensing a physiological property may be capable of sensing more than one property, and may be employed to sense any one of a magnitude of an electrical signal, a conductivity, a temperature, a fluid flow rate or a fluid velocity, or a range of motion of a surface.

Abstract

A method for controlling a remote navigation system to navigate a medical device in an operating region in a subject is provided, comprising operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location. At least once thereafter, the method operates the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property value, and uses the sensor to sense the physiological property in each location. The method automatically determines the location of a local extreme value of the sensed physiological property, and may be selectively used to locate a maximum value of the sensed physiological property or a minimum of the sensed physiological property. The method may be utilized for sensing one or more physiological properties such as a magnitude of an electrical signal, a conductivity, a temperature, a fluid flow rate or a fluid velocity, or a range of motion of a surface.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application claims the benefit of U.S. provisional patent application Ser. No. 60/642,853 filed Jan. 11, 2005, the entire disclosure of which is incorporated herein by reference.
  • BACKGROUND OF THE INVENTION
  • Cardiac arrhythmias are a form of cardiac disease where the electrical activity of the heart is disrupted, often due to the takeover of signal generation by abnormal excitation nodes.
  • Cardiac arrhythmia may be treated through minimally invasive interventions such as catheter ablation, where catheters navigate a set of electrodes (often 3-8 electrodes) intravascularly into the relevant chambers of the heart, and monitor electrical signal activation times and propagation to thereby identify location points of focal arrhythmias, for example Supraventricular Tachycardia (e.g., SVT). An electro-physiological study is performed to record the activation sequence at target locations of the heart, to determine the arrhythmia mechanism. Such mapping may then be used to identify location points within the heart that are part of the tachycardia or arrhythmia mechanism, but not part of the normal cardiac conduction system. Such location points are then rendered electrically inactive by ablating the point, typically by Radio Frequency ablation. The electrophysiological study may also record blood flow velocity, to determine areas of disrupted blood flow caused by poorly coordinated pumping of the heart chambers. Where the heart valve chambers are fluttering, vortices will occur at certain regions while other regions will have streamline blood flow. The electrophysiological catheter is useful in assisting in the diagnosis and treatment of such conditions. Recent advancements have also resulted in automated remote navigation systems that can drive catheter placement with a great deal of precision, more specifically magnetic navigation systems.
  • SUMMARY OF THE INVENTION
  • Embodiments of the systems and methods of the present invention advance the art of remote surgical navigation by combining diagnosis with navigation and therapy, using a minimal number of devices. In one embodiment of the present invention, a system is provided for treatment of arrhythmia that comprises an electrophysiological catheter having at least one electrode for sensing intra-cardiac wave front activation signals on a tissue surface, a navigation system for guiding the distal end of the catheter to a number of locations for sensing intra-cardiac activation signals along the wall of a subject body's heart, and an ECG recording system for recording the local intra-cardiac signal data for each of the locations. The system further comprises a computer for determining the direction of propagation of the wave front with respect to time from the intra-cardiac activation signals corresponding to the location points. From the direction of propagation of the wave front, the computer may calculate a new location point in the direction of the source of the wave front for advancing the catheter to, where intra-cardiac activation data may be used with at least two of the prior locations for further evaluation of the wave front direction.
  • In one aspect of the present invention, a method is provided for determining the movements of the catheter towards a focal arrhythmia for ablation. A method is provided in combination with a navigation system, a localization system, and an algorithm for directing the movement of the catheter. The method comprises navigating the distal end of the catheter to sense intra-cardiac activation signals at a number of locations on the wall of a subject body's heart, recording the local intra-cardiac signal data for the minimum number of locations, and determining the direction of propagation of the wave from with respect to time from the location points using the algorithm. The method further comprises calculating a new location point in the direction of the source of the wave front using the algorithm, for use with at least two of the prior locations for further evaluation of the wave front direction, iteratively repeating the step of determining the direction of propagation to obtain the earliest activation location of the wave front, and responsively navigating the distal tip of the catheter to the earliest activation location for providing medical treatment.
  • In another aspect of the present invention, a means is provided for determining patterns of disrupted blood flow caused by poorly coordinated pumping of heart chambers. The means for determining blood flow comprises a fluid velocity sensing means located on the tip of the electrophysiological catheter, for use in diagnosis and treatment of arrhythmia. In one embodiment of the present invention, the one or more fluid velocity sensors are capable of measuring temperature changes across a region of the sensor to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the temperature change. The one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip. In another embodiment of the present invention, one or more Doppler fluid velocity sensing means are located on the tip of the electrophysiological catheter. The one or more Doppler fluid velocity sensing means comprise a transmitter for transmitting a high frequency sound wave into the fluid, and an antenna that detects a frequency shift of the reflected wave from the fluid particles to determine the fluid velocity. In both embodiments, the one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip.
  • In yet another aspect of the present invention, a preferred embodiment of a method for controlling the navigation of a medical device within a subject body to sense an electrophysiological property is also provided. The method may be used to navigate a medical device comprising one or more physiological sensing means to a plurality of regions within a subject body, for sensing the value or relative change in value of a sensed physiological property such as an electrical signal, conductivity, temperature, or fluid velocity and direction as previously disclosed. The method of controlling a remote navigation system to navigate a medical device in an operating region in a subject comprises operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location. At least once thereafter, the method operates the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property value, and uses the sensor to sense the physiological property in each location. The method automatically determines the location of a local extreme value of the sensed physiological property, and may be selectively used to locate a maximum value of the sensed physiological property or a minimum of the sensed physiological property.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a cut away view of a heart showing a re-entry circuit within the right atria and a possible target area for ablation to render the re-entry mechanism inactive;
  • FIG. 2 is an illustration of the difference in phase of ECG signals at points P1 and p2; and
  • FIG. 3 is an illustration of a number of location points of intra-cardiac activity having phase signal differences, and a corresponding direction of wave front propagation.
  • FIG. 4 is a side view of one embodiment of an electrophysiological catheter having a fluid velocity sensing means according to the principles of the present invention.
  • DETAILED DESCRIPTION OF THE INVENTION
  • Embodiments of the systems and methods of the present invention are provided that comprise various electrophysiological sensors disposed on the tip of a catheter for sensing and recording local activity of tissues or fluid flow within the body. The various embodiments of the present invention are capable of measuring local electrical activity, temperature, fluid velocity and fluid flow direction in a local area within a subject body using a minimal number of devices.
  • In a preferred embodiment of the present invention, a system and method are provided for measuring and recording various points in a region of a patient's heart for mapping electrophysiological activity of the tissue, and for determining a target location for catheter ablation to correct an arrhythmia mechanism. The arrhythmia mechanism of an atrioventricular re-entry tachycardias may be established where an electrical wave front occurs within the heart that generates a re-entry circuit. In the cutaway of a heart 20 in FIG. 1, an example of a re-entry circuit is generally shown as a circular electrical pathway 22 within the right atrium around the inferior vena cava 24 and superior vena cava 26. A possible target 28 for atrial ablation, for example, could be near the isthmus between the tricuspid valve 30 and the inferior vena cava 24. Ablation would render the location electrically inactive, and would interrupt the electrical pathway of the re-entry circuit. Atrioventricular Nodal Re-entry Tachycardia is another arrhythmia mechanism that is established where both a fast and slow conduction pathways into the atrioventricular node exist. Atrial flutter and Focal Atrial Tachycardia are yet further re-entry mechanisms in which the passage of the activation wave front around the atrium establishes re-polarization of the ventricle before the wave front completes one circuit. The present invention provides a method for evaluating such various arrhythmia mechanisms and determining the source or focal point of the arrhythmia to be treated. The method described herein involves using a single catheter to measure and record intracardiac electrical activity in a small local region, identify the direction of signal propagation of the wave front of intracardiac activity from these measurements, and navigate the catheter in the appropriate direction towards the source of the wave front. Once identified, such electrical signal sources that are not part of the normal cardiac conduction system can be removed by catheter ablation techniques such as Radio Frequency (RF) ablation, where electrical energy is delivered through the tip electrode of the catheter in order to locally destroy abnormal tissue.
  • In one preferred embodiment in accordance with the present invention, a system for treatment of arrhythmia is provided that comprises a catheter having at least one electrode for sensing intra-cardiac wave front activation signals on a tissue surface, and a navigation system for guiding the distal end of the catheter to a minimum number of locations to sense intra-cardiac activation signals along the endocardial wall of a subject's heart. Navigation of the catheter may be performed by a magnetic navigation system or any other navigation system suitable for guiding a catheter within a subject body. An ElectroPhysiology ECG recording system is used for recording the location the local intra-cardiac electrical signal data corresponding to the minimum number of locations. In one preferred embodiment, a localization system is used to record catheter tip location data together with intra-cardiac electrical signal data. The system may also include a fluoroscopic imaging system for obtaining images and location points of the catheter within the body during the surgical procedure. In an alternate embodiment, fluoro-localization is used to record three dimensional catheter tip location data by manually marking on corresponding points in at least two fluoro images.
  • In a preferred embodiment, the catheter may be a magnetically navigable catheter, which may be advanced through the vasculature in a selected direction by pushing the proximal end of the catheter, and by deflecting the distal end of the catheter by an applied magnetic field to gain entry to a vessel branch. The distal end of the catheter may comprise a radio-opaque material useful for viewing in an X-ray or fluoroscopic imaging system, and one or more magnetic elements which can be deflected to align with an applied magnetic field external to the subject body of a patient. One such navigation system, for example, is the Stereotaxis Niobe™ magnetic navigation system, which can apply an external magnetic field of about 0.08 Tesla within the subject in any direction in order to suitably orient or steer the catheter. In alternate embodiments, other actuation schemes such as mechanical, electrostrictive, hydraulic or other methods could be used to steer or deflect the catheter in order to navigate it.
  • The system further comprises a computer for determining the regional direction of propagation of the wave front from the intra-cardiac signal data corresponding to the location points. By determining the direction of propagation of the wave front, the computer calculates a new location for advancing the catheter in the direction of the source of the wave front, where intra-cardiac signal data may be used with at least two of the prior locations for further evaluation and adjustment of the estimated wave front direction. The computer may execute an algorithm for iteratively repeating the above progression to determine the earliest activation location or source of the wave front, and responsively navigating the distal tip of the catheter to the earliest activation location for medical treatment.
  • The preferred embodiment further comprises a method for determining the point of earliest activation of a local wave front associated with focal atrial tachycardia. The method includes the step of determining the direction of propagation of the wave front from an analysis of signal delays or signal arrival times in the intra-cardiac signal data corresponding to the location points. By determining the direction of the propagation of the wave front, the method calculates a new location for advancing the catheter in the direction of the source of the wave front, where intra-cardiac signal data may be used with at least two of the prior locations for further evaluation or estimation of the wave front propagation direction. The method repeats the iterative progression to determine the earliest activation location of the wave front and to responsively navigate the distal tip of the catheter to the earliest intra-cardiac activation location for medical treatment.
  • The system and method may automatically determine the location of a focal point of arrhythmia or atrial tachycardia re-entry mechanism where unpolarized intra-cardiac activation is initiated, and may automatically advance the catheter to the location for ablation treatment. The method may also be used to perform an electrophysiological study for generating an electro-anatomical map of the heart tissue. Such atrial tachycardia re-entry or other cardiac arrhythmia mechanisms are established by lines of conduction that can be visualized using mapping systems that can characterize and predict focal points. The advantages of the methods used in the present invention to evaluate measured local intracardiac activation data and to responsively determine the propagation of the wave front of intracardiac activation for moving the mapping/ablation catheter to a desired location for ablation will become apparent from the following detailed description of the method.
  • Step 1
  • The catheter tip is positioned at three locations on the wall of the heart chamber and the electrical signals recorded at each of these locations. The locations are preferably mutually separated by separations in the range 5 mm-20 mm and more preferably in the range 5 mm-15 mm. An ECG system (ideally outputting data to the navigation system) records local intracardiac signal data at each of these locations p1, p2 and p3. At p1 the ECG data is recorded for about 3-20 cycles to determine the periodicity T of the signal. The position {right arrow over (X)}p1 can be determined, for example by fluoro-localization.
  • Step 2
  • The catheter is moved to location p2, and its position {right arrow over (X)}p2 is determined, for example by fluoro-localization. The electrical signal is recorded and its phase difference with respect to the signal at p1 is measured. FIG. 2 illustrates the phase difference 32 of signals at p1, and p2. If the signal (peak) at p2 is measured at time τ, Δ2=(τ−NT) where N is the largest integer such that Δ2 is positive. If Δ2>T/2, define a′=−(T−Δ2), else define a′=Δ2; a′ is the phase difference at p2.
  • The catheter is then moved to location p3, and its position {right arrow over (X)}p3 is determined, for example by fluro-localization. The electrical signal is recorded, and its phase difference b′ is determined.
  • Step 3
  • The points are relabeled as needed such that p1, is the point of earliest activation, i.e., a′ and b′ (phase differences at the other 2 points with respect to p1) are both positive, and are hereinafter referred to as a and b instead of a′ and b′.
  • The triangle formed by points p1, (40), p2, (42), and p3 (44) is shown in FIG. 3. The three triangle points p1, (t=0), p2, (t=a), and p3 (t=b) all have associated time or propagation delays relative to the other points. This is a small (local) triangle, and therefore the time (propagation) delays within this triangle may be linearly interpolated with little error. Isochrones (contours of equal propagation time) within this triangle represent the local wave front; the direction of propagation is normal to this wave front. Referring to FIG. 3, where b>a (no loss of generality), the isochrone passing through point {right arrow over (X)}2 (42) is the dotted line 48, intersecting edge x1−x3 of the triangle at a point {right arrow over (X)}0 (46), such that
  • x -> 0 = x -> 1 + a b ( x -> 3 - x -> 1 )
  • (since propagation delays are linearly interpolated within the triangle). The vector {right arrow over (l)}=({right arrow over (x)}0−{right arrow over (x)}2) is therefore along the isochronal direction {right arrow over (n)} (or at equal time propagation). Since the propagation direction 50 must be perpendicular to this,

  • {right arrow over (n)}·{right arrow over (l)}=o, or {right arrow over (n)}·({right arrow over (X)} 0 −{right arrow over (X)} x)=o  (1)

  • Therefore,

  • {right arrow over (n)}=α{right arrow over (u)} 1 +β{right arrow over (u)} 2  (2)
  • where
  • u -> 2 = ( χ -> 1 - χ -> s ) χ -> 1 - χ -> 2 and u -> 2 = ( χ -> 3 - χ -> x ) χ -> 3 - χ -> 2 ( 3 )
  • {right arrow over (n)} is a unit vector, so we have

  • α22+2αβ cos θ=1  (4)
  • where cos o {right arrow over (u)}1·{right arrow over (u)}2.
    From equations (1) and (2):

  • {right arrow over (n)}·({right arrow over (X)} o −{right arrow over (X)} x=0 or

  • {right arrow over (u)} 1 +β{right arrow over (u)} 2)·[b({right arrow over (x)} 1 −{right arrow over (x)} x)+a({right arrow over (x)} 3 −{right arrow over (x)} 1)]=0

  • or

  • α[b{right arrow over (u)} 1·({right arrow over (x)} 1 −{right arrow over (x)} 2)+α{right arrow over (u)} 1·({right arrow over (x)} 3 −{right arrow over (x)} 1)]+β[b{right arrow over (u)} 2·({right arrow over (x)} 1 −{right arrow over (x)} 2)+α{right arrow over (u)} 2·({right arrow over (x)} 3 −{right arrow over (x)} 1)]  (5)
  • Equations (4), and (5), can be solved for α and β, and thus {right arrow over (n)} can be determined (pick the sign of {right arrow over (n)} such that {right arrow over (n)} points towards {right arrow over (x)}1, or such that n has positive dot product with the vector (x1−(x0+x2)/2)).
  • Step 4
  • Once {right arrow over (n)} (the local reverse propagation direction) is determined, starting at {right arrow over (x)}1 a new point {right arrow over (y)}′1=A{right arrow over (n)}+{right arrow over (x)}1 is defined where A is a step size in the range 5 mm-20 mm. {right arrow over (y)}′1 is defined as a new target for the catheter; because the wall surface is curved, target navigation of the catheter (with suitable control actuations applied) will actually take the tip to a location {right arrow over (y)}′1. A new triangle O2 is fowled by the points {right arrow over (y)}′1 and the 2 points (from triangle O1) that are closest to it. The process is iteratively repeated to get a new local propagation direction in triangle O2, as long as the activation time at point {right arrow over (y)}′1 is earlier than that of the other 2 points in O2. If the activation time at {right arrow over (y)}′1 is later than that of at least one of the other 2 points, a reduced step is taken:
  • Define z -> 1 = A 2 n -> + x -> 1
  • and navigate the catheter to a (real) wall location {right arrow over (z)}1 etc.
  • Step 5
  • In a relatively small number of steps/iteration, the focal point of the arrhythmia may thus be found and the catheter will have been placed there. Ablative therapy may be performed to eliminate the source of the arrhythmia.
  • It is worth noting that these methods may be generalized to multi-focal arrhythmias by looking for double periodicities and other signal features, such that multiple isochrones may be tracked locally to arrive at multiple foci. Likewise more than one catheter may be used in combination for diagnosis and navigation. The remote navigation system could be used with a localization system with location feedback, or with a registered pre-operative or other anatomical data. In the latter case, a suitably modified stepping point {right arrow over (y)}′1 etc. may be directly defined on the (curved) heart surfaces so that a stepped path is defined on the curved surface, minimizing the need for repeated fluoro localization. Although fluoro-localization has been described in the example detailed above, in the case where real-time location data is available from a device localization system, fluro-localization is not needed, again minimizing the need for repeated user interaction. In an alternate embodiment, catheter tip location could be estimated or evaluated from a knowledge of actuation control variables from the navigation system and a computational device model that predicts tip location based on the actuation controls. Varying levels of automation thus are possible depending a system integration and availability of anatomical and/or catheter location data.
  • It should be noted that the above preferred embodiment useful for sensing electrical activity may also employed to sense conductivity. A low voltage signal may be applied to the at least one electrode, and the current conducted through the tissue may be measured and recorded for enabling mapping of conductivity of a tissue surface. The catheter or medical device may be navigated to bring the electrode successively into a plurality of locations in a predetermined pattern, to sense the conductivity of each location. At least once thereafter, the medical device may be navigated to bring the electrode successively into further locations in a predetermined pattern relative to at least one location selected from the immediately preceding plurality of locations. An algorithm may be used to automatically operate the navigation system to bring the sensor to a series of locations in a predetermined pattern, to guide the medical device to a local extreme of a sensed conductivity, such as an area of minimum electrical conductivity. Such an algorithm may utilized the method disclosed above for automatically navigating the medical device in a predetermined pattern to locate a region having a local extreme.
  • In another embodiment of the present invention, an electrophysiological catheter 20 is provided that further comprises one or more fluid velocity sensing means disposed on the tip of the catheter. As shown in FIG. 4, the catheter 20 comprises a tubular element 22 having a proximal end and a distal end 24. The distal end of the catheter comprises at least one magnetically responsive element 26 for enabling navigation of the distal end, and also comprises one or more electrodes 28. One or more fluid velocity sensing means 30 may be utilized for sensing relative changes in velocity of a fluid flowing across the sensing means. The one or more fluid velocity sensors are capable of measuring temperature changes across a region of the sensor to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the temperature change. The one or more fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip. The current conducted through the tissue may be measured and recorded for enabling mapping of conductivity of a tissue surface. The fluid velocity sensing means comprises a micro-machined structure having a heater that measures temperature drop across a region to determine the relative change in fluid velocity across the heater. Such a device need not be calibrated for absolute velocity in this application, but instead would determine relative values at appropriate locations within the subject body. The heater comprises a homogeniously heated segmented heater having a plurality of heated segments forming a generally square shape, for enabling the detection of a relative temperature difference between corresponding segments. The plurality of segments provide for determining the flow direction corresponding to the sensed fluid velocity across the heater. By orienting one or more fluid velocity sensing means of this type on the tip of the catheter, the component of direction of the fluid velocity relative to the catheter could be determined.
  • The catheter or medical device may be navigated to bring the fluid velocity sensing means successively into a plurality of locations in a predetermined pattern, to sense the fluid velocity at each location. At least once thereafter, the medical device may be navigated to bring the fluid velocity sensing means successively into further locations in a predetermined pattern relative to at least one location selected from the immediately preceding plurality of locations. An algorithm may be used to automatically operate the navigation system to bring the fluid velocity sensing means to a series of locations in a predetermined pattern, to guide the medical device to a local extreme of a sensed fluid velocity, such as an area of minimum fluid velocity or a vortices in the blood flow. The fluid velocity sensing means could also be used to sense local maximums of fluid velocity such as regions of streamline blood flow through the chambers of the heart. The mapping of such velocity data is useful in assisting in the diagnosis of medical conditions such as cardiac arrhythmia. The algorithm utilized may employ the method disclosed above for automatically navigating the medical device in a predetermined pattern to locate a region having a local extreme.
  • This embodiment comprising a fluid sensing means may also be used to sense the temperature of a location as well. The homogeniously heated segmented heater establishes a base temperature, which may be increased or decreased by the surrounding tissues it comes into contact with. Thus, the above sensing means is capable of sensing a temperature drop across the surface as well as changes in absolute temperature of the homogeniously heated sensor. This sensing means may also be used to sense relative changes in temperature from location to location.
  • In yet another embodiment of the present invention, an electrophysiological catheter is provided that further comprises one or more Doppler fluid velocity sensing means disposed on the tip of the catheter, for sensing relative changes in fluid velocity across the sensing means. The one or more Doppler fluid velocity sensing means are capable of measuring frequency shifts in a wave signal to determine relative changes in fluid velocity, as well as alignment of the fluid flow direction with respect to the sensing means. The one or more Doppler fluid velocity sensing means comprise a transmitter for transmitting a high frequency sound wave into the fluid, and an antenna that detects a frequency shift of the reflected wave from the fluid particles to determine the fluid velocity. Electrical connections for the micro-transmitter and antenna may be disposed within the catheter or medical device to provide for measuring and recording of the sensed fluid velocity. The one or more Doppler fluid velocity sensors are oriented relative to the catheter so as to provide for determining the component of direction of the fluid velocity relative to the catheter tip. By orienting one or more fluid velocity sensing means of this type on the tip of the catheter, the component of direction of the fluid velocity relative to the catheter could be determined.
  • A preferred embodiment of a method of controlling the navigation of a medical device within a subject body to sense an electrophysiological property is also provided. The method may be used to navigate a medical device comprising one or more physiological sensing means to a plurality of regions within a subject body, for sensing the value or relative change in value of a sensed physiological property such as an electrical signal, conductivity, temperature, or fluid velocity and direction as previously disclosed. The method of controlling a remote navigation system to navigate a medical device in an operating region in a subject comprises operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location. At least once thereafter, the method operates the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property value, and uses the sensor to sense the physiological property in each location. The method automatically determines the location of a local extreme value of the sensed physiological property, and may be selectively used to locate a maximum value of the sensed physiological property or a minimum of the sensed physiological property. Some embodiments of a medical device for sensing a physiological property may be capable of sensing more than one property, and may be employed to sense any one of a magnitude of an electrical signal, a conductivity, a temperature, a fluid flow rate or a fluid velocity, or a range of motion of a surface.

Claims (16)

1. A method of controlling a remote navigation system to navigate a medical device in an operating region in a subject, the method comprising:
operating the remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location;
at least once thereafter, operating the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed physiological property, and using the sensor to sense the physiological property in each location.
2. A method of controlling a remote navigation system to navigate a medical device in an operating region in a subject, the method comprising: automatically successively operating the navigation system to bring a sensor carried on a medical device to a position determined by an algorithm using at least one previously sensed physiological value and corresponding location as an input, and sensing the physiological property in the location.
3. The method according to claim 1 wherein the sensed physiological property is the magnitude of an electrical signal.
4. The method according to claim 1 wherein the sensed physiological property is the timing of an electrical signal.
5. The method according to claim 1 wherein the sensed physiological property is temperature.
6. The method according to claim 1 wherein the sensed physiological property is range of motion of a surface.
7. The method according to claim 1 wherein the sensed physiological property is conductivity.
8. The method according to claim 1 wherein the sensed physiological property is a flow rate.
9. The method according to claim 1 wherein the sensed physiological property is a fluid velocity.
10. A method of automatically finding the location of a local extreme of a sensed physiological property, the method comprising:
operating a remote navigation system to bring a sensor carried on a medical device successively into a plurality of locations in a predetermined pattern, and using the sensor to sense a physiological property of the subject in each location;
at least once thereafter, operating the remote navigation system to bring a sensor carried on a medical device successively into a series of locations in a predetermined pattern relative to at least one location selected from the predetermined pattern in the immediately preceding step based upon the sensed value physiological property, and using the sensor to sense the physiological property in each location to identify the local extreme of the sensed physiological property.
11. The method according to claim 10 wherein the local extreme of the sensed physiological property is a maximum of the sensed physiological property.
12. The method according to claim 10 wherein the local extreme of the sensed physiological property is a minimum of the sensed physiological property.
13. A method of automatically finding the location of a local extreme of a sensed physiological property in an operating region in a subject, the method comprising: automatically successively operating a remote navigation system to bring a sensor carried on a medical device to a position determined by an algorithm using at least one previously sensed physiological value and corresponding location as an input, and sensing the physiological property in the location.
14. The method according to claim 13 wherein the local extreme of the sensed physiological property is a maximum of the sensed physiological property.
15. The method according to claim 13 wherein the local extreme of the sensed physiological property is a minimum of the sensed physiological property.
16. A method of controlling a remote navigation system capable of remotely navigating the distal end of a medical device to a selected location.
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110130718A1 (en) * 2009-05-25 2011-06-02 Kidd Brian L Remote Manipulator Device
US20120173217A1 (en) * 2010-12-30 2012-07-05 Heimbecher Reed R Catheter configuration interface and related system
WO2012151301A1 (en) * 2011-05-02 2012-11-08 Topera, Inc. System and method for targeting heart rhythm disorders using shaped ablation
US8308628B2 (en) 2009-11-02 2012-11-13 Pulse Therapeutics, Inc. Magnetic-based systems for treating occluded vessels
US20130023788A1 (en) * 2011-07-18 2013-01-24 Gostout Christopher J Gastrointestinal biopsy devices
US9883878B2 (en) 2012-05-15 2018-02-06 Pulse Therapeutics, Inc. Magnetic-based systems and methods for manipulation of magnetic particles
US11918315B2 (en) 2018-05-03 2024-03-05 Pulse Therapeutics, Inc. Determination of structure and traversal of occlusions using magnetic particles

Families Citing this family (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6702804B1 (en) 1999-10-04 2004-03-09 Stereotaxis, Inc. Method for safely and efficiently navigating magnetic devices in the body
US7313429B2 (en) 2002-01-23 2007-12-25 Stereotaxis, Inc. Rotating and pivoting magnet for magnetic navigation
US7635342B2 (en) * 2001-05-06 2009-12-22 Stereotaxis, Inc. System and methods for medical device advancement and rotation
US7248914B2 (en) 2002-06-28 2007-07-24 Stereotaxis, Inc. Method of navigating medical devices in the presence of radiopaque material
US7389778B2 (en) 2003-05-02 2008-06-24 Stereotaxis, Inc. Variable magnetic moment MR navigation
EP1846894A4 (en) 2004-12-20 2009-10-21 Stereotaxis Inc Contact over torque with three dimensional anatomical data
US7708696B2 (en) 2005-01-11 2010-05-04 Stereotaxis, Inc. Navigation using sensed physiological data as feedback
US7756308B2 (en) 2005-02-07 2010-07-13 Stereotaxis, Inc. Registration of three dimensional image data to 2D-image-derived data
US8597193B2 (en) 2005-05-06 2013-12-03 Vasonova, Inc. Apparatus and method for endovascular device guiding and positioning using physiological parameters
US9204819B2 (en) 2005-05-06 2015-12-08 Vasonova, Inc. Endovenous access and guidance system utilizing non-image based ultrasound
US20090118612A1 (en) 2005-05-06 2009-05-07 Sorin Grunwald Apparatus and Method for Vascular Access
US9314222B2 (en) 2005-07-07 2016-04-19 Stereotaxis, Inc. Operation of a remote medical navigation system using ultrasound image
EP1907041B1 (en) * 2005-07-11 2019-02-20 Catheter Precision, Inc. Remotely controlled catheter insertion system
US7769444B2 (en) 2005-07-11 2010-08-03 Stereotaxis, Inc. Method of treating cardiac arrhythmias
US7818076B2 (en) 2005-07-26 2010-10-19 Stereotaxis, Inc. Method and apparatus for multi-system remote surgical navigation from a single control center
US7495537B2 (en) 2005-08-10 2009-02-24 Stereotaxis, Inc. Method and apparatus for dynamic magnetic field control using multiple magnets
US7792563B2 (en) * 2006-03-16 2010-09-07 Massachusetts Institute Of Technology Method and apparatus for the guided ablative therapy of fast ventricular arrhythmia
WO2008003059A2 (en) 2006-06-28 2008-01-03 Stereotaxis, Inc. Electrostriction devices and methods for assisted magnetic navigation
US7961924B2 (en) 2006-08-21 2011-06-14 Stereotaxis, Inc. Method of three-dimensional device localization using single-plane imaging
US7747960B2 (en) 2006-09-06 2010-06-29 Stereotaxis, Inc. Control for, and method of, operating at least two medical systems
US8244824B2 (en) 2006-09-06 2012-08-14 Stereotaxis, Inc. Coordinated control for multiple computer-controlled medical systems
US8242972B2 (en) 2006-09-06 2012-08-14 Stereotaxis, Inc. System state driven display for medical procedures
US8273081B2 (en) 2006-09-08 2012-09-25 Stereotaxis, Inc. Impedance-based cardiac therapy planning method with a remote surgical navigation system
US8135185B2 (en) 2006-10-20 2012-03-13 Stereotaxis, Inc. Location and display of occluded portions of vessels on 3-D angiographic images
US20080312673A1 (en) * 2007-06-05 2008-12-18 Viswanathan Raju R Method and apparatus for CTO crossing
US8024024B2 (en) 2007-06-27 2011-09-20 Stereotaxis, Inc. Remote control of medical devices using real time location data
EP2205145A4 (en) 2007-07-06 2013-06-19 Stereotaxis Inc Management of live remote medical display
WO2009061860A1 (en) 2007-11-05 2009-05-14 Stereotaxis, Inc. Magnetically guided energy delivery apparatus
JP5478511B2 (en) 2008-01-16 2014-04-23 カセター・ロボティクス・インコーポレーテッド Remote control catheter insertion system
EP2637568B1 (en) 2010-11-08 2017-04-12 Vasonova, Inc. Endovascular navigation system
US9345447B2 (en) 2012-05-07 2016-05-24 Vasonova, Inc. Right atrium indicator
US9533121B2 (en) 2013-02-26 2017-01-03 Catheter Precision, Inc. Components and methods for accommodating guidewire catheters on a catheter controller system
GB2528423A (en) 2013-05-24 2016-01-20 Medyria Ag Flow sensor arrangement and method for using a flow sensor arrangement
US9993614B2 (en) 2013-08-27 2018-06-12 Catheter Precision, Inc. Components for multiple axis control of a catheter in a catheter positioning system
US9724493B2 (en) 2013-08-27 2017-08-08 Catheter Precision, Inc. Components and methods for balancing a catheter controller system with a counterweight
US9999751B2 (en) 2013-09-06 2018-06-19 Catheter Precision, Inc. Adjustable nose cone for a catheter positioning system
US9750577B2 (en) 2013-09-06 2017-09-05 Catheter Precision, Inc. Single hand operated remote controller for remote catheter positioning system
US9795764B2 (en) 2013-09-27 2017-10-24 Catheter Precision, Inc. Remote catheter positioning system with hoop drive assembly
US9700698B2 (en) 2013-09-27 2017-07-11 Catheter Precision, Inc. Components and methods for a catheter positioning system with a spreader and track
US10349212B2 (en) * 2015-09-18 2019-07-09 Qualcomm Incorporated Using intrabody signal propagation to infer wearable device location on the body for sensor optimization and configuration
US10302817B2 (en) 2016-04-06 2019-05-28 StormSensor Inc. Distributed systems for stormwater monitoring and reporting
US10292025B2 (en) * 2016-04-06 2019-05-14 Stormsensor Inc Sensor devices and networks for remotely acquiring stormwater data
US11638576B2 (en) * 2016-11-11 2023-05-02 Philips Image Guided Therapy Corporation Wireless intraluminal imaging device and associated devices, systems, and methods
EP3600061A1 (en) * 2017-03-31 2020-02-05 Koninklijke Philips N.V. Intravascular flow and pressure measurements

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7708696B2 (en) * 2005-01-11 2010-05-04 Stereotaxis, Inc. Navigation using sensed physiological data as feedback

Family Cites Families (115)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5657755A (en) * 1993-03-11 1997-08-19 Desai; Jawahar M. Apparatus and method for cardiac ablation
IL116699A (en) * 1996-01-08 2001-09-13 Biosense Ltd Method of constructing cardiac map
US5654864A (en) 1994-07-25 1997-08-05 University Of Virginia Patent Foundation Control method for magnetic stereotaxis system
US6015414A (en) * 1997-08-29 2000-01-18 Stereotaxis, Inc. Method and apparatus for magnetically controlling motion direction of a mechanically pushed catheter
US6128174A (en) 1997-08-29 2000-10-03 Stereotaxis, Inc. Method and apparatus for rapidly changing a magnetic field produced by electromagnets
US7066924B1 (en) * 1997-11-12 2006-06-27 Stereotaxis, Inc. Method of and apparatus for navigating medical devices in body lumens by a guide wire with a magnetic tip
US6157853A (en) 1997-11-12 2000-12-05 Stereotaxis, Inc. Method and apparatus using shaped field of repositionable magnet to guide implant
US6014580A (en) * 1997-11-12 2000-01-11 Stereotaxis, Inc. Device and method for specifying magnetic field for surgical applications
US6459924B1 (en) 1997-11-12 2002-10-01 Stereotaxis, Inc. Articulated magnetic guidance systems and devices and methods for using same for magnetically-assisted surgery
US6212419B1 (en) * 1997-11-12 2001-04-03 Walter M. Blume Method and apparatus using shaped field of repositionable magnet to guide implant
WO1999024097A1 (en) 1997-11-12 1999-05-20 Stereotaxis, Inc. Intracranial bolt and method of placing and using an intracranial bolt to position a medical device
US6505062B1 (en) * 1998-02-09 2003-01-07 Stereotaxis, Inc. Method for locating magnetic implant by source field
US6315709B1 (en) 1998-08-07 2001-11-13 Stereotaxis, Inc. Magnetic vascular defect treatment system
WO2000007641A2 (en) * 1998-08-07 2000-02-17 Stereotaxis, Inc. Method and apparatus for magnetically controlling catheters in body lumens and cavities
US20040030244A1 (en) 1999-08-06 2004-02-12 Garibaldi Jeffrey M. Method and apparatus for magnetically controlling catheters in body lumens and cavities
US6385472B1 (en) * 1999-09-10 2002-05-07 Stereotaxis, Inc. Magnetically navigable telescoping catheter and method of navigating telescoping catheter
EP1119299A1 (en) * 1998-10-02 2001-08-01 Stereotaxis, Inc. Magnetically navigable and/or controllable device for removing material from body lumens and cavities
US6428551B1 (en) 1999-03-30 2002-08-06 Stereotaxis, Inc. Magnetically navigable and/or controllable device for removing material from body lumens and cavities
US6241671B1 (en) 1998-11-03 2001-06-05 Stereotaxis, Inc. Open field system for magnetic surgery
US6330467B1 (en) 1999-02-04 2001-12-11 Stereotaxis, Inc. Efficient magnet system for magnetically-assisted surgery
US6296604B1 (en) 1999-03-17 2001-10-02 Stereotaxis, Inc. Methods of and compositions for treating vascular defects
US6148823A (en) 1999-03-17 2000-11-21 Stereotaxis, Inc. Method of and system for controlling magnetic elements in the body using a gapped toroid magnet
US6375606B1 (en) * 1999-03-17 2002-04-23 Stereotaxis, Inc. Methods of and apparatus for treating vascular defects
US6911026B1 (en) * 1999-07-12 2005-06-28 Stereotaxis, Inc. Magnetically guided atherectomy
US6902528B1 (en) * 1999-04-14 2005-06-07 Stereotaxis, Inc. Method and apparatus for magnetically controlling endoscopes in body lumens and cavities
US6292678B1 (en) * 1999-05-13 2001-09-18 Stereotaxis, Inc. Method of magnetically navigating medical devices with magnetic fields and gradients, and medical devices adapted therefor
AU3885801A (en) * 1999-09-20 2001-04-24 Stereotaxis, Inc. Magnetically guided myocardial treatment system
US6298257B1 (en) 1999-09-22 2001-10-02 Sterotaxis, Inc. Cardiac methods and system
US6975197B2 (en) 2002-01-23 2005-12-13 Stereotaxis, Inc. Rotating and pivoting magnet for magnetic navigation
US7313429B2 (en) * 2002-01-23 2007-12-25 Stereotaxis, Inc. Rotating and pivoting magnet for magnetic navigation
US7019610B2 (en) * 2002-01-23 2006-03-28 Stereotaxis, Inc. Magnetic navigation system
US6702804B1 (en) * 1999-10-04 2004-03-09 Stereotaxis, Inc. Method for safely and efficiently navigating magnetic devices in the body
US6401723B1 (en) * 2000-02-16 2002-06-11 Stereotaxis, Inc. Magnetic medical devices with changeable magnetic moments and method of navigating magnetic medical devices with changeable magnetic moments
US6940379B2 (en) * 2000-04-11 2005-09-06 Stereotaxis, Inc. Magnets with varying magnetization direction and method of making such magnets
US6527782B2 (en) * 2000-06-07 2003-03-04 Sterotaxis, Inc. Guide for medical devices
WO2002007794A2 (en) 2000-07-24 2002-01-31 Stereotaxis, Inc. Magnetically navigated pacing leads, and methods for delivering medical devices
US6524303B1 (en) * 2000-09-08 2003-02-25 Stereotaxis, Inc. Variable stiffness magnetic catheter
US6537196B1 (en) * 2000-10-24 2003-03-25 Stereotaxis, Inc. Magnet assembly with variable field directions and methods of magnetically navigating medical objects
US7026515B2 (en) * 2000-11-09 2006-04-11 Mitsui Chemicals, Inc. Optically active amine derivatives and preparation process therefor
US20030009094A1 (en) 2000-11-15 2003-01-09 Segner Garland L. Electrophysiology catheter
US6662034B2 (en) 2000-11-15 2003-12-09 Stereotaxis, Inc. Magnetically guidable electrophysiology catheter
US6677752B1 (en) * 2000-11-20 2004-01-13 Stereotaxis, Inc. Close-in shielding system for magnetic medical treatment instruments
US6352363B1 (en) * 2001-01-16 2002-03-05 Stereotaxis, Inc. Shielded x-ray source, method of shielding an x-ray source, and magnetic surgical system with shielded x-ray source
US20020103430A1 (en) 2001-01-29 2002-08-01 Hastings Roger N. Catheter navigation within an MR imaging device
ATE412372T1 (en) 2001-05-06 2008-11-15 Stereotaxis Inc CATHETER ADVANCEMENT SYSTEM
US7635342B2 (en) * 2001-05-06 2009-12-22 Stereotaxis, Inc. System and methods for medical device advancement and rotation
US7020512B2 (en) * 2002-01-14 2006-03-28 Stereotaxis, Inc. Method of localizing medical devices
US7161453B2 (en) * 2002-01-23 2007-01-09 Stereotaxis, Inc. Rotating and pivoting magnet for magnetic navigation
US6968846B2 (en) 2002-03-07 2005-11-29 Stereotaxis, Inc. Method and apparatus for refinably accurate localization of devices and instruments in scattering environments
US8721655B2 (en) * 2002-04-10 2014-05-13 Stereotaxis, Inc. Efficient closed loop feedback navigation
US20050256398A1 (en) 2004-05-12 2005-11-17 Hastings Roger N Systems and methods for interventional medicine
US7008418B2 (en) * 2002-05-09 2006-03-07 Stereotaxis, Inc. Magnetically assisted pulmonary vein isolation
US7248914B2 (en) 2002-06-28 2007-07-24 Stereotaxis, Inc. Method of navigating medical devices in the presence of radiopaque material
US7189198B2 (en) * 2002-07-03 2007-03-13 Stereotaxis, Inc. Magnetically guidable carriers and methods for the targeted magnetic delivery of substances in the body
US7769427B2 (en) * 2002-07-16 2010-08-03 Magnetics, Inc. Apparatus and method for catheter guidance control and imaging
US20040157082A1 (en) 2002-07-22 2004-08-12 Ritter Rogers C. Coated magnetically responsive particles, and embolic materials using coated magnetically responsive particles
US7630752B2 (en) * 2002-08-06 2009-12-08 Stereotaxis, Inc. Remote control of medical devices using a virtual device interface
US20040186376A1 (en) 2002-09-30 2004-09-23 Hogg Bevil J. Method and apparatus for improved surgical navigation employing electronic identification with automatically actuated flexible medical devices
EP1576625A3 (en) 2002-11-07 2005-10-26 Stereotaxis, Inc. Method of making a compound magnet
WO2004045387A2 (en) 2002-11-18 2004-06-03 Stereotaxis, Inc. Magnetically navigable balloon catheters
AU2003297241A1 (en) * 2002-12-18 2004-07-22 Scimed Life Systems, Inc. Catheter based sensing for intraluminal procedures
US20040133130A1 (en) 2003-01-06 2004-07-08 Ferry Steven J. Magnetically navigable medical guidewire
US7774046B2 (en) 2003-03-13 2010-08-10 Stereotaxis, Inc. Magnetic navigation system
US7305263B2 (en) 2003-03-13 2007-12-04 Stereotaxis, Inc. Magnetic navigation system and magnet system therefor
US8162920B2 (en) 2003-04-24 2012-04-24 Stereotaxis, Inc. Magnetic navigation of medical devices in magnetic fields
US7389778B2 (en) * 2003-05-02 2008-06-24 Stereotaxis, Inc. Variable magnetic moment MR navigation
US6980843B2 (en) 2003-05-21 2005-12-27 Stereotaxis, Inc. Electrophysiology catheter
US20050065435A1 (en) * 2003-07-22 2005-03-24 John Rauch User interface for remote control of medical devices
US7092759B2 (en) * 2003-07-30 2006-08-15 Medtronic, Inc. Method of optimizing cardiac resynchronization therapy using sensor signals of septal wall motion
US20050119687A1 (en) * 2003-09-08 2005-06-02 Dacey Ralph G.Jr. Methods of, and materials for, treating vascular defects with magnetically controllable hydrogels
US20050113812A1 (en) * 2003-09-16 2005-05-26 Viswanathan Raju R. User interface for remote control of medical devices
US7280863B2 (en) * 2003-10-20 2007-10-09 Magnetecs, Inc. System and method for radar-assisted catheter guidance and control
US20050182315A1 (en) 2003-11-07 2005-08-18 Ritter Rogers C. Magnetic resonance imaging and magnetic navigation systems and methods
US8046049B2 (en) * 2004-02-23 2011-10-25 Biosense Webster, Inc. Robotically guided catheter
US20060041181A1 (en) * 2004-06-04 2006-02-23 Viswanathan Raju R User interface for remote control of medical devices
WO2006005012A2 (en) * 2004-06-29 2006-01-12 Stereotaxis, Inc. Navigation of remotely actuable medical device using control variable and length
US20060036163A1 (en) * 2004-07-19 2006-02-16 Viswanathan Raju R Method of, and apparatus for, controlling medical navigation systems
US20060144407A1 (en) 2004-07-20 2006-07-06 Anthony Aliberto Magnetic navigation manipulation apparatus
US20060144408A1 (en) 2004-07-23 2006-07-06 Ferry Steven J Micro-catheter device and method of using same
US7627361B2 (en) * 2004-08-24 2009-12-01 Stereotaxis, Inc. Methods and apparatus for steering medical device in body lumens
US7555331B2 (en) * 2004-08-26 2009-06-30 Stereotaxis, Inc. Method for surgical navigation utilizing scale-invariant registration between a navigation system and a localization system
US7815580B2 (en) * 2004-09-07 2010-10-19 Stereotaxis, Inc. Magnetic guidewire for lesion crossing
US7831294B2 (en) * 2004-10-07 2010-11-09 Stereotaxis, Inc. System and method of surgical imagining with anatomical overlay for navigation of surgical devices
US7983733B2 (en) * 2004-10-26 2011-07-19 Stereotaxis, Inc. Surgical navigation using a three-dimensional user interface
US7190819B2 (en) * 2004-10-29 2007-03-13 Stereotaxis, Inc. Image-based medical device localization
US20060094956A1 (en) * 2004-10-29 2006-05-04 Viswanathan Raju R Restricted navigation controller for, and methods of controlling, a remote navigation system
EP1846894A4 (en) 2004-12-20 2009-10-21 Stereotaxis Inc Contact over torque with three dimensional anatomical data
US8348858B2 (en) 2005-01-05 2013-01-08 Stereotaxis, Inc. Stent delivery guide wire
US20070032746A1 (en) * 2005-01-10 2007-02-08 Stereotaxis, Inc. Guide wire with magnetically adjustable bent tip and method for using the same
US20070062546A1 (en) * 2005-06-02 2007-03-22 Viswanathan Raju R Electrophysiology catheter and system for gentle and firm wall contact
US20070060992A1 (en) * 2005-06-02 2007-03-15 Carlo Pappone Methods and devices for mapping the ventricle for pacing lead placement and therapy delivery
US20070021744A1 (en) * 2005-07-07 2007-01-25 Creighton Francis M Iv Apparatus and method for performing ablation with imaging feedback
US20070038065A1 (en) * 2005-07-07 2007-02-15 Creighton Francis M Iv Operation of a remote medical navigation system using ultrasound image
US7603905B2 (en) * 2005-07-08 2009-10-20 Stereotaxis, Inc. Magnetic navigation and imaging system
US7769444B2 (en) * 2005-07-11 2010-08-03 Stereotaxis, Inc. Method of treating cardiac arrhythmias
US7690619B2 (en) * 2005-07-12 2010-04-06 Stereotaxis, Inc. Apparatus for pivotally orienting a projection device
US20070016131A1 (en) * 2005-07-12 2007-01-18 Munger Gareth T Flexible magnets for navigable medical devices
US7416335B2 (en) * 2005-07-15 2008-08-26 Sterotaxis, Inc. Magnetically shielded x-ray tube
US8192374B2 (en) * 2005-07-18 2012-06-05 Stereotaxis, Inc. Estimation of contact force by a medical device
US20070060829A1 (en) * 2005-07-21 2007-03-15 Carlo Pappone Method of finding the source of and treating cardiac arrhythmias
US20070062547A1 (en) * 2005-07-21 2007-03-22 Carlo Pappone Systems for and methods of tissue ablation
US20070043455A1 (en) * 2005-07-26 2007-02-22 Viswanathan Raju R Apparatus and methods for automated sequential movement control for operation of a remote navigation system
US20070060962A1 (en) * 2005-07-26 2007-03-15 Carlo Pappone Apparatus and methods for cardiac resynchronization therapy and cardiac contractility modulation
US20070040670A1 (en) * 2005-07-26 2007-02-22 Viswanathan Raju R System and network for remote medical procedures
US7818076B2 (en) 2005-07-26 2010-10-19 Stereotaxis, Inc. Method and apparatus for multi-system remote surgical navigation from a single control center
US20070060916A1 (en) * 2005-07-26 2007-03-15 Carlo Pappone System and network for remote medical procedures
US7495537B2 (en) * 2005-08-10 2009-02-24 Stereotaxis, Inc. Method and apparatus for dynamic magnetic field control using multiple magnets
US20070049909A1 (en) * 2005-08-26 2007-03-01 Munger Gareth T Magnetically enabled optical ablation device
US20070055124A1 (en) * 2005-09-01 2007-03-08 Viswanathan Raju R Method and system for optimizing left-heart lead placement
US7662126B2 (en) * 2005-09-02 2010-02-16 Stereotaxis, Inc. Ultrasonic disbursement of magnetically delivered substances
US20070167720A1 (en) 2005-12-06 2007-07-19 Viswanathan Raju R Smart card control of medical devices
US20070149946A1 (en) 2005-12-07 2007-06-28 Viswanathan Raju R Advancer system for coaxial medical devices
US20070161882A1 (en) 2006-01-06 2007-07-12 Carlo Pappone Electrophysiology catheter and system for gentle and firm wall contact
US20070197899A1 (en) 2006-01-17 2007-08-23 Ritter Rogers C Apparatus and method for magnetic navigation using boost magnets
US20070197906A1 (en) 2006-01-24 2007-08-23 Ritter Rogers C Magnetic field shape-adjustable medical device and method of using the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7708696B2 (en) * 2005-01-11 2010-05-04 Stereotaxis, Inc. Navigation using sensed physiological data as feedback

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110130718A1 (en) * 2009-05-25 2011-06-02 Kidd Brian L Remote Manipulator Device
US10537713B2 (en) 2009-05-25 2020-01-21 Stereotaxis, Inc. Remote manipulator device
US9339664B2 (en) 2009-11-02 2016-05-17 Pulse Therapetics, Inc. Control of magnetic rotors to treat therapeutic targets
US10159734B2 (en) 2009-11-02 2018-12-25 Pulse Therapeutics, Inc. Magnetic particle control and visualization
US8313422B2 (en) 2009-11-02 2012-11-20 Pulse Therapeutics, Inc. Magnetic-based methods for treating vessel obstructions
US11612655B2 (en) 2009-11-02 2023-03-28 Pulse Therapeutics, Inc. Magnetic particle control and visualization
US8529428B2 (en) 2009-11-02 2013-09-10 Pulse Therapeutics, Inc. Methods of controlling magnetic nanoparticles to improve vascular flow
US8308628B2 (en) 2009-11-02 2012-11-13 Pulse Therapeutics, Inc. Magnetic-based systems for treating occluded vessels
US8715150B2 (en) 2009-11-02 2014-05-06 Pulse Therapeutics, Inc. Devices for controlling magnetic nanoparticles to treat fluid obstructions
US8926491B2 (en) 2009-11-02 2015-01-06 Pulse Therapeutics, Inc. Controlling magnetic nanoparticles to increase vascular flow
US11000589B2 (en) 2009-11-02 2021-05-11 Pulse Therapeutics, Inc. Magnetic particle control and visualization
US9345498B2 (en) 2009-11-02 2016-05-24 Pulse Therapeutics, Inc. Methods of controlling magnetic nanoparticles to improve vascular flow
US10813997B2 (en) 2009-11-02 2020-10-27 Pulse Therapeutics, Inc. Devices for controlling magnetic nanoparticles to treat fluid obstructions
US10029008B2 (en) 2009-11-02 2018-07-24 Pulse Therapeutics, Inc. Therapeutic magnetic control systems and contrast agents
US8708902B2 (en) * 2010-12-30 2014-04-29 St. Jude Medical, Atrial Fibrillation Division, Inc. Catheter configuration interface and related system
US20120173217A1 (en) * 2010-12-30 2012-07-05 Heimbecher Reed R Catheter configuration interface and related system
WO2012151301A1 (en) * 2011-05-02 2012-11-08 Topera, Inc. System and method for targeting heart rhythm disorders using shaped ablation
US20130023788A1 (en) * 2011-07-18 2013-01-24 Gostout Christopher J Gastrointestinal biopsy devices
US10646241B2 (en) 2012-05-15 2020-05-12 Pulse Therapeutics, Inc. Detection of fluidic current generated by rotating magnetic particles
US9883878B2 (en) 2012-05-15 2018-02-06 Pulse Therapeutics, Inc. Magnetic-based systems and methods for manipulation of magnetic particles
US11918315B2 (en) 2018-05-03 2024-03-05 Pulse Therapeutics, Inc. Determination of structure and traversal of occlusions using magnetic particles

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