Catheter tracking system and method

• US 5,938,602 A
• Filed: 06/03/1997
• Issued: 08/17/1999
• Est. Priority Date: 06/11/1996
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Inventors: Lloyd, Peter Gregory
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US08/867,878
• Time in Patent Office: 805 Days
• Field of Search: 600/424, 600/407, 600/437, 607/122, 128/899
• US Class Current: 600/424
• CPC Class Codes: A61B 2017/00044 Sensing electrocardiography, i.e. ECG
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2018/00392 Transmyocardial revascularisation
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2063 Acoustic tracking systems, e.g. using ultrasound
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61B 2090/062 penetration depth
• CPC Class Codes: A61B 2090/0811 for the position of a particular part of an instrument with respect to the rest of the instrument, e.g. position of the anvil of a stapling instrument
• CPC Class Codes: A61B 2090/0818 Redundant systems, e.g. using two independent measuring systems and comparing the signals
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 2090/3929 Active markers
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: G01S 5/22 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/28 takes precedence

Abstract

A catheter tracking system for tracking and monitoring a position of a catheter head within the human or animal body includes a self-referencing catheter. The self-referencing catheter includes an inner core, an outer sheath having a plurality of sensors and a cage for fixing the outer sheath at a predetermined position. The sensors receive signals generated by the transducer so as to produce measurement signals in accordance with a time of propagation of the signals for determining the position of the head relative to the outer sheath.

Claims

1. A self-referencing catheter for a catheter tracking system, the catheter comprising:

an outer sheath member;

deployable fixing means mounted on the outer sheath member for fixing the outer sheath member at a predetermined position within a body into which the catheter is inserted;

an inner core member slidably mounted within the outer sheath member, the inner core member having a head portion formed thereon which carries transducer means for generating signals; and

sensing means located on the deployable fixing means for receiving signals from the transducer means and for producing measurement signals indicative of the location of the head portion with respect to the deployable fixing means in accordance with time propagation of signals generated by the transducer means and received by the sensing means.

2. A catheter as claimed in claim 1, wherein the head portion further comprises a measurement sensor for sensing electrical signals in a heart.

3. A catheter as claimed in claim 2, wherein the head portion further comprises means for treating adjacent tissue in-situ.

4. A catheter as claimed in claim 1, wherein the deployable fixing means comprises an extendible cage.

5. A catheter as claimed in claim 1, wherein the sensing means comprises a plurality of sensors arranged in an array.

6. A catheter as claimed in claim 1, wherein the transducer means comprises a plurality of transducers arranged in an array.

7. A catheter as claimed in claim 1, wherein the head portion of the catheter is provided with inner core member comprises an array of transducers for determining an inclination angle of the said head portion with respect to the deployable fixing means.

8. A catheter as claimed in claim 1, further comprising signal processing means for processing the signals received.

9. A catheter as claimed in claim 1, wherein the transducer means comprises at least one acoustic transducer which generates acoustic signals, and wherein the sensing means comprises at least one acoustic sensor for receiving the acoustic signals generated.

10. A catheter as claimed in claim 9, wherein the acoustic signals are ultrasonic signals.

11. A self-referencing catheter comprising:

an outer sheath member;

deployable fixing means mounted on the outer sheath member for fixing the outer sheath member at a predetermined position within a body into which the catheter is inserted;

transducer means located on the outer sheath for generating signals; and

an inner core member slidably mounted within the outer sheath member, the inner core member having a head portion formed thereon which carries sensing means for receiving signals from the transducer means and for producing measurement signals indicative of the location of the head portion with respect to the deployable fixing means in accordance with time propagation of signals generated by the transducer means and received by the sensing means.

12. A catheter as claimed in claim 11, wherein the head portion of the inner core member comprises an array of sensors for determining an inclination angle of the head portion with respect to the deployable fixing means.

13. A catheter as claimed in claim 11, wherein the head portion further comprises a measurement sensor for sensing electrical signals in a heart.

14. A catheter as claimed in claim 11, wherein the head portion further comprises means for treating adjacent tissue in-situ.

15. A catheter as claimed in claim 11, wherein the deployable fixing means comprises an extendible cage.

16. A catheter as claimed in claim 11, wherein the sensing means comprises a plurality of sensors arranged in an array.

17. A catheter as claimed in claim 11, wherein the transducer means comprises a plurality of transducers arranged in an array.

18. A catheter as claimed in claim 11, further comprising signal processing means for processing the received signals.

19. A catheter as claimed in claim 11, wherein the transducer means comprises at least one acoustic transducer which generates acoustic signals and wherein the sensing means comprises at least one acoustic sensor for receiving the acoustic signals generated.

20. A catheter as claimed in claim 19, wherein the acoustic signals are ultrasonic signals.

21. A method for tracking a catheter comprising an outer sheath member, deployable fixing means mounted on the outer sheath member for fixing the outer sheath member at a predetermined position within a body into which the catheter is inserted, an inner core member slidably mounted within the outer sheath member, the inner core member having a head portion formed thereon which carries transducer means for generating signals, and sensing means located on the deployable fixing means for receiving signals from the transducer means and for producing measurement signals indicative of the location of the head portion with respect to the deployable fixing means in accordance with time propagation of signals generated by the transducer means and received by the sensing means, the method comprising the steps of:

placing the outer sheath member at a predetermined position within the body;

deploying the deployable fixing means to fix the catheter in the predetermined position;

moving the head portion of the inner core member into a position within the body to be detected;

generating signals from the transducer means carried by the head portion of the inner core member;

transmitting the generated signals;

receiving the generated signals at the sensing means on the deployable fixing means;

determining a propagation time for the signals between the transducer means and the sensing means; and

calculating the position of the head portion relative to the deployable fixing means using the propagation time determined.

22. A method as claimed in claim 21, wherein the transducer means comprises at least one acoustic transducer which generates acoustic signals and the sensing means comprises at least one acoustic sensor for receiving the acoustic signals generated.

23. A method as claimed in claim 21, wherein said outer sheath member is positioned and fixed in a blood vessel.

24. A method for tracking a catheter comprising an outer sheath member, deployable fixing means mounted on the outer sheath member for fixing the outer sheath member at a predetermined position within a body into which the catheter is inserted, transducer means located on the outer sheath for generating signals, and an inner core member slidably mounted within the outer sheath member, the inner core member having a head portion formed thereon which carries sensing means for receiving signals from the transducer means and for producing measurement signals indicative of the location of the head portion with respect to the deployable fixing means in accordance with time propagation of signals generated by the transducer means and received by the sensing means, the method comprising the steps of:

placing the outer sheath member at a predetermined position within the body;

deploying the deployable fixing means to fix the catheter in the predetermined position;

moving the head portion of the inner core member into a position within the body to be detected;

generating signals from the transducer means located on the outer sheath;

transmitting the generated signals;

receiving the generated signals at the sensing means on the head portion of the inner core member;

determining a propagation time for the signals between the transducer means and the sensing means; and

calculating the position of the head portion relative to the deployable fixing means using the propagation time determined.

25. A method as claimed in claim 24, wherein the transducer means comprises at least one acoustic transducer which generates acoustic signals and wherein the sensing means comprises at least one acoustic sensor for receiving the acoustic signals generated.

26. A method as claimed in claim 24, wherein the outer sheath member is positioned and fixed in a blood vessel.