System for electrode localization using ultrasound

• US 6,216,027 B1
• Filed: 12/16/1997
• Issued: 04/10/2001
• Est. Priority Date: 08/01/1997
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Cardiac Pathways Corp. (Boston Scientific Corporation)
• Inventors: Willis, N. Parker, Brisken, Axel, Zeng, Jinglin, Hurd, Marsha
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): SHAW, SHAWNA JEANNINE
• Application Number:
  US08/991,556
• Time in Patent Office: 1,211 Days
• Field of Search: 600/424, 600/374, 600/437, 600/462, 600/439, 128/899, 128/920, 128/922, 607/122
• US Class Current: 600/424
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00113 with foam
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2063 Acoustic tracking systems, e.g. using ultrasound
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6855 with a distal curved tip
• CPC Class Codes: A61B 5/6856 with a distal loop
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 : Details of catheter construction
• CPC Class Codes: A61B 8/543 : involving acquisition triggered by a physiological signal
• CPC Class Codes: A61N 2007/0078 : with multiple treatment transducers

Abstract

The present invention is a device localization system that uses one or more ultrasound reference catheters to establish a fixed three-dimensional coordinate system within a patient'"'"'s heart using principles of triangulation. The coordinate system is represented graphically in three-dimensions on a video monitor and aids the clinician in guiding other medical devices, which are provided with ultrasound transducers, through the body to locations at which they are needed to perform clinical procedures. In one embodiment of a system according to the present invention, the system is used in the heart to help the physician guide mapping catheters for measuring electrical activity, and ablation catheters for ablating selected regions of cardiac tissue, to desired locations within the heart.

Claims

1. A method of establishing anatomical landmarks within a living body, comprising the steps of:

(a) providing a reference catheter having a plurality of ultrasound reference transducers, each reference transducer capable of transmitting and receiving ultrasound signals;

(b) providing a marking catheter having an ultrasound target transducer;

(c) positioning the reference catheter and the marking catheter within the living body and positioning the distal tip of the marking transducer adjacent to an anatomical structure within the body;

(d) causing a plurality of the transducers to emit ultrasound signals for receipt by others of the transducers, including causing reference transducers to receive ultrasound signals emitted by others of the reference transducers;

(e) measuring the elapsed time between transmission of each ultrasound signal emitted in step (d) and its receipt by others of the transducers, and using the measured elapsed times to determine the relative distances between the transducers;

using distances determined in step (e), establishing the three-dimensional arrangement of the reference transducers to establish a coordinate system within the body, and determining the location of the target transducer relative to the coordinate system;

(g) deriving the location of the anatomical landmark using the location of the target transducer determined in step (f); and

(h) displaying the three-dimensional position of the anatomical landmark relative to the coordinate system on a graphical display.

2. The method of claim 1, wherein step (d) includes causing a plurality of the reference transducers to emit ultrasound signals for receipt by others of the reference transducers.

3. The method of claim 2 wherein the anatomical landmark is a known anatomical structure found in human hearts.

4. The method of claim 3, further including the steps of:

(i) repositioning the marking catheter to a second position adjacent to a second anatomical structure found in human hearts;

(j) re-determining the location of the target transducer relative to the coordinate system and deriving the location of the second anatomical structure from the determined location of the target transducer; and

(k) displaying the three-dimensional position of the second anatomical structure relative to the coordinate system on the graphical display.

5. A method of tracking the position of a target catheter within a chamber of a living heart having a cardiac cycle, comprising the steps of:

(a) positioning a target catheter within a chamber of the heart, the target catheter having at least one ultrasonic target transducer mounted thereon;

(b) positioning a plurality of catheter-mounted ultrasonic reference transducers for ultrasonic communication with the target transducer;

(c) causing the transducers to transmit and/or receive ultrasound signals and recording the elapsed time between the transmission of signals from each one of the transmitting transducers and the receipt of the signals by the receiving transducers, including causing reference transducers to receive ultrasound signals emitted by others of the reference transducers;

(d) determining the location of at least a portion of the target catheter with respect to the reference transducers based on the recorded times;

(e) monitoring the cardiac cycle; and

(f) displaying an image on a graphical display representing the location of at least a portion of the target catheter during a selected portion of the cardiac cycle, the selected portion being less than the entirety of the cardiac cycle.

7. The method of claim 5 further including the step of storing data representing the location of the target catheter determined in step (d) for only the selected portion of the cardiac cycle.

8. The method of claim 5, wherein the method further includes the step of storing data representing the location of the target catheter determined in step (d) for more than the selected portion of the cardiac cycle and wherein step (f) includes displaying the image representing the location of at least a portion of the target catheter for only the selected portion of the cardiac cycle.

9. The method of claim 5, wherein steps (c) and (d) are performed throughout the entirety of the cardiac cycle.

6. The method of claim further comprising the step of:

(g) storing data representing the location of the target catheter determined in step (d);

(h) manipulating a medical device having a plurality of ultrasound transducers thereon within the heart chamber;

(i) during step (h), determining the location of the medical device with respect to the reference transducers and displaying an image representing the three-dimensional location of at least a portion of the medical device on the graphical display; and

(j) navigating the medical device within the chamber while observing the images generated in steps (f) and (i).

14. The method of claim 6 wherein steps (c) and (d) are performed throughout the entirety of the cardiac cycle.

10. A method of tracking the position of a target catheter within a living body having a respiratory cycle, comprising the steps of:

(a) positioning a target catheter within the living body, the target catheter having at least one ultrasonic target transducer mounted thereon;

(b) positioning a plurality of catheter-mounted ultrasonic reference transducers for ultrasonic communication with the target transducer;

(c) causing the transducers to transmit and/or receive ultrasound signals. including causing reference transducers to receive ultrasound signals emitted by others of the reference transducers, and recording the elapsed time between the transmission of signals from each one of the transmitting transducers and the receipt of the signals by the receiving transducers;

(d) determining the location of the target catheter with respect to the reference transducers based on the recorded times;

(e) monitoring the respiratory cycle; and

(f) displaying an image on a graphical display representing the location of at least a portion of the target catheter during a selected portion of the respiratory cycle, the selected portion being less than the entirety of the respiratory cycle.

11. The method of claim 10, further comprising the step of:

(g) storing data representing the location of the target catheter determined in step (d);

(h) manipulating a medical device having a plurality of ultrasound transducers thereon within the living body;

(i) during step (h), determining the location of the medical device with respect to the reference transducers and displaying an image representing the three-dimensional location of at least a portion of the medical device on the graphical display; and

(j) navigating the medical device within the chamber while observing the images generated in steps (f) and (i).

12. The method of claim 10 further including the step of storing data representing the location of the target catheter determined in step (d) for only the selected portion of the respiratory cycle.

13. The method of claim 10 wherein the method further includes the step of storing data representing the location of the target catheter determined in step (d) for more than the selected portion, of the respiratory cycle and wherein step (f) includes displaying the image representing the location of at least a portion of the target catheter for only the selected portion of the respiratory cycle.

15. A system for displaying position data corresponding to a location within a human heart, comprising:

a catheter positionable within a chamber of the heart, the catheter having at least one ultrasonic target transducer mounted thereon;

a plurality of catheter-mounted ultrasonic reference transducers positionable within the human body for ultrasonic communication with the target transducer;

a controller coupled to the transducers for causing the transducers to generate and/or receive ultrasound signals, including for causing reference transducers to receive ultrasound signals emitted by other reference transducers;

a processor coupled to the transducers for recording the elapsed time at which the signals from each emitting one of the transducers are received by the receiving ones of the transducers, the processor programmed to determine the location of the target catheter transducers with respect to the reference transducers based on the recorded times, and for generating location data representing a location associated with the target catheter;

a storage location for electronically storing the location data representing the location associated with the target catheter;

a graphical display for displaying an image representing the location data for a selected portion of a physiological cycle on a graphical display.

16. The system of claim 15 wherein the physiological cycle is the cardiac cycle.

17. The system of claim 15 wherein the physiological cycle is the respiratory cycle.

18. The system of claim 15 wherein the location associated with the target catheter includes at least a portion of the target catheter.

19. The system of claim 18 wherein the target catheter includes a distal tip and the location associated with the target catheter includes at least the distal tip of the target catheter.

20. The system of claim 15 wherein the location associated with the target catheter includes a location adjacent to the target catheter.

21. The system of claim 15, wherein the system is further for navigating a medical device to the location and wherein:

the system further comprises a medical device having a plurality of ultrasound transducers thereon, the medical device positionable within the heart chamber;

wherein the processor is further for generating additional data representing the three-dimensional position of at least a portion of the medical device relative to the reference transducers; and

wherein the graphical display is for simultaneously displaying the image data and the additional image data for facilitating navigation of the medical device to the target location.

22. The system of claim 15, wherein:

the processor is programmed to determine the location of the target catheter transducers throughout the entirety of a physiological cycle; and

the graphical display is for displaying an image representing the location data for the selected portion of the physiological cycle, the selected portion being less than the entirety of thy physiological cycle.

23. A method for cardiac mapping and electrode localization, comprising the steps of:

(a) positioning a mapping catheter within a chamber of the heart, the mapping catheter having an ultrasonic transducer and a plurality of electrodes thereon;

(b) positioning a plurality of catheter-mounted ultrasonic reference transducers for ultrasonic communication with the target transducer;

(c) causing the transducers to transmit and/or receive ultrasound signals, and recording the elapsed time between the transmission of signals from each one of the transmitting transducers and the receipt of the signals by the receiving transducers;

(d) during the entirety of a cardiac phase, determining the relative three-dimensional arrangement of the transducers based on the recorded times and deriving the relative three-dimensional locations of the electrodes based on the relative three-dimensional arrangement of the transducers;

(e) during the same cardiac phase, measuring electrical activity in the heart using a plurality of the electrodes; and

(f) electronically storing data corresponding to the electrical activity measured in step (e), the three-dimensional positions of the electrodes determined in step (d).

24. The method of claim 23 wherein the reference transducers positioned in step (b) are provided on the mapping catheter.

25. The method of claim 23, further comprising the step of selectively displaying images representing the data stored in step (f).

26. A method of tracking and visually displaying the position of a target catheter within a living body, comprising the steps of:

(a) determining the location in three-dimensional space of an anatomical landmark in the body using a reference catheter positioned within the body, the reference catheter including a plurality of ultrasound reference transducers each capable of transmitting and receiving ultrasound signals, the determining step including causing reference transducers to receive ultrasound signals transmitted by other reference transducers;

(b) displaying the location of the landmark on a graphical display; and

(c) manipulating a target catheter within the body while determining the three-dimensional position of the target catheter relative to the reference catheter and, after displaying the location of the landmark, displaying the three-dimensional position of at least a portion of the target catheter with respect to the landmark on the graphical display.

27. The method of claim 26 wherein the landmark is at least a portion of the coronary sinus.

28. The method of claim 26 wherein the landmark is at least a portion of the right ventricular apex.

29. The method of claim 26 wherein step (a) includes the step of using the reference catheter to establish a three-dimensional coordinate system within the body.

30. The method of claim 29 wherein step (a) includes:

(i) positioning the reference catheter at an anatomical landmark in the body;

(ii) causing a plurality of the transducers to transmit ultrasound signals for receipt by others of the transducers;

(iii) measuring the elapsed time between transmission and receipt of each ultrasound signal emitted in step (ii);

(iv) using the measured elapsed times to determine the relative distances between the transducers;

(v) using distances determined in step (iv), establishing the three-dimensional arrangement of a plurality of the transducers to establish the coordinate system and determining the location of the landmark relative to the coordinate system.

31. The method of claim 29, wherein the target catheter has ultrasound transducers thereon and wherein step (c) includes:

(i) causing a plurality of the transducers to transmit ultrasound signals for receipt by others of the transducers;

(ii) measuring the elapsed time between transmission and receipt of each ultrasound signal emitted in step (i);

(iii) using the measured elapsed times to determine the relative distances between the transducers;

(iv) using distances determined in step (iii), establishing the three-dimensional arrangement of a plurality of the transducers to establish the coordinate system, and determining the position of the target catheter relative to the coordinate system.

32. The method of claim 29 wherein the target catheter has ultrasound transducers thereon and wherein steps (a) and (c) include:

(i) positioning the reference catheter at an anatomical landmark in the body;

(ii) causing a plurality of the transducers to transmit ultrasound signals for receipt by others of the transducers;

(iii) measuring the elapsed time between transmission and receipt of each ultrasound signal emitted in step (ii);

(iv) using the measured elapsed times to determine the relative distances between the transducers;

(v) using distances determined in step (iv), establishing the three-dimensional arrangement of a plurality of the transducers to establish the coordinate system, and determining the location of the landmark and the position of the target transducer relative to the coordinate system.

33. The method of claim 26, wherein the target catheter includes at least one electrode and wherein step (c) includes determining the three-dimensional position of the electrode relative to the reference catheter and showing the electrode position on the graphical display.

34. The method of claim 33, wherein:

the method further comprises the step of

(d) using the electrode on the target catheter to create a lesion within the body; and

wherein step (c) includes displaying the three-dimensional position of the electrode on the graphical display to represent formation of a lesion at the electrode position.

35. The method of claim 33, wherein:

the method further comprises the step of

(d) using the electrode on the target catheter to measure electrical activity within the body; and

wherein step (c) includes displaying the three-dimensional position of the electrode to identify the electrode position as one at which electrical activity has been measured.

36. The method of claim 35, wherein step (c) includes visually representing a characteristic of the measured electrical activity at the electrode position.

37. The method of claim 33 in the target catheter includes a plurality of electrodes and wherein step (c) includes determining and displaying the positions of a plurality of the electrodes.

38. The method of claim 37, wherein:

the method further comprises the step of

(d) using a plurality of the electrodes on the target catheter to measure electrical activity within the body; and

step (c) includes visually representing a characteristic of the measured electrical activity at the three-dimensional positions of the electrodes relative to the reference catheter.

39. The method of claim 26, wherein the method is for tracking and visually displaying the position of a target catheter within the heart of a living body having a physiological cycle, and wherein:

the method includes the step of

(d) monitoring a physiological cycle; and

wherein

step (a) includes the step of displaying an image on the graphical display representing the three-dimensional location of the anatomical landmark during a selected portion of the physiological cycle.

40. The method of claim 39, wherein step (c) includes displaying an image representing the three-dimensional position of at least a portion of the target catheter during the selected portion of the physiological cycle.

41. The method of claim 39, wherein the target catheter includes at least one electrode and wherein step (c) includes determining and displaying an image representing the three-dimensional position of the electrode.

42. The method of claim 41 wherein:

the method further includes the step of

(d) using the electrode on the target catheter to measure electrical activity within the heart; and

step (c) includes determining and displaying an image representing the three-dimensional position of the electrode during step (d) and during the select portion of the physiological cycle to visually identify the position as one at which electrical activity has been measured.

43. The method of claim 42 wherein step (c) includes visually representing a characteristic of the measured electrical activity at the electrode position.

44. The method of claim 43 wherein the target catheter includes a plurality of electrodes, wherein step (d) includes using a plurality of the electrodes on the target catheter to measure electrical activity within the heart, and wherein step (c) further includes determining and displaying images representing the three-dimensional positions of the electrodes during step (d) to visually identify the positions as ones at which electrical activity has been measured.

45. The method of claim 44 wherein step (c) includes visually representing a characteristic of the measured electrical activity at the electrode positions to create a map of measured electrical activity.

46. The method of claim 45 wherein the map is an isochronal map.

47. The method of claim 45 wherein the map is an isopotential map.

48. The method of claim 45 wherein the method further includes the steps of.

(e) moving an ablation electrode within the heart to a region of the map selected for ablation, while determining the three-dimensional position of the ablation electrode relative to the reference catheter and displaying the three-dimensional position of the ablation electrode on the graphical display;

(f) using an ablation electrode to create a lesion within the heart; and

(g) determining and displaying an image representing the three-dimensional position of the electrode during lesion formation to visually represent the presence of a lesion at the position.

49. The method of claim 41 wherein:

the method further includes the step of

(d) using the electrode on the target catheter to create a lesion within the heart; and

step (c) includes determining and displaying an image representing the three-dimensional position of the electrode during lesion formation to visually represent the presence of a lesion at the position.

50. The method of claim 41 wherein step (c) includes displaying the electrode position for the select portion of the physiological cycle.

51. The method of claim 39 wherein the physiological cycle is the cardiac cycle.

52. The method of claim 39 wherein the physiological cycle is the respiratory cycle.

53. The method of claim 26 wherein the anatomical landmark is a known anatomical structure found in human hearts.