Catheter localization system and method for performing medical diagnostics

• US 6,226,546 B1
• Filed: 09/24/1998
• Issued: 05/01/2001
• Est. Priority Date: 09/24/1997
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Inventors: Evans, Richard John
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Lin, Jeoyuh
• Application Number:
  US09/159,457
• Time in Patent Office: 950 Days
• Field of Search: 600/437, 600/443, 600/448, 600/450, 600/463, 600/466, 600/461, 600/459, 600/471, 600/417, 607/115, 607/116, 606/130, 128/898, 128/899, 128/916
• US Class Current: 600/424
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/0841 for locating instruments
• 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 8/483 involving the acquisition of a 3D volume of data

Abstract

A catheter localization system for generating information appertaining to a three dimensional map of a part of a human or animal body from which three dimensional map a position of said catheter may be determined. The catheter localization system includes a catheter having a catheter head which is arranged in use to be conveyed through the human or animal body to a desired localization, a plurality of acoustic transducers disposed about said catheter head at predetermined localizations and a signal processing unit which operates to determine said three dimensional map of said part of a human or animal body consequent upon signals received by a plurality of acoustic transducers acting as acoustic receivers, which acoustic signals were generated by at least one of said plurality of acoustic transducers acting as an acoustic source.

Claims

1. A system for determining a position of a head of a catheter with reference to a body part of a human or animal body from mapping information appertaining to a three-dimensional map of said body, said system comprising a first plurality of acoustic transducers disposed about said catheter head in spaced apart relationship, which catheter head in use is positionable at a predetermined location in said body part, and a signal processing unit which operates to determine said three dimensional map of said body part, based upon a first set of measurement data appertaining to measured times of flight of acoustic signals generated by at least one of said first plurality of acoustic transducers acting as an acoustic signal source and received by said first plurality of acoustic transducers acting as acoustic receivers, said times of flight of said acoustic signals being representative of a distance traveled between said acoustic signal source and said acoustic receivers reflected from said body part.

2. The system as claimed in claim 1, wherein:

said catheter head is movable to at least one other predetermined location, for generating at least a second set of measurement data, representative of a plurality of distance measurements generated from measured times of flight of acoustic signals between at least one of said plurality of acoustic sensors acting as an acoustic signal source, and reflected via said body part; and

said signal processing unit determines said three dimensional map of said body part by matching said first and second sets of measurement data.

3. The system as claimed in claim 2, wherein said signal processing unit further operates to determine a location of the acoustic transducers on the catheter head with reference to a reference acoustic transducer from at least one of said first and said at least a second set of measurement data.

4. The system as claimed in claim 2, wherein said matching of said first and said at least a second set of measurement data is effected by at least one of an elastic networks, least squares fitting and point distribution modeling image processing algorithm.

5. The system as claimed in claim 2, wherein the signal processing unit further operates to determine a location of the catheter head with reference to at least one of the first and second sets of measurement data in combination with the map of the part of the body.

6. A catheter localization system as claimed in claim 2, said catheter head further comprising at least one other plurality of acoustic transducers disposed at a predetermined location on said catheter head, which at least one other plurality of acoustic transducers operates to generate at least one other set of measurement data, said other set of measurement data being representative of a plurality of distance measurements generated from measured times of flight of acoustic signals between at least one of said plurality of acoustic sensors acting as an acoustic signal source, reflected via said part of the body, and said signal processing unit operates to determine said three dimensional map of said part of the body by matching said first and said other sets of measurement data.

7. The system as claimed in claim 1, wherein:

said catheter head further comprises at least a second plurality of acoustic transducers disposed at predetermined locations on said catheter head, for generating at least a second set of measurement data representative of a plurality of distance measurements generated from measured times of flight of acoustic signals between at least one of said second plurality of acoustic sensors acting as an acoustic signal source, and reflected via said body part; and

said signal processing unit determines said three dimensional map of said body part by matching said first and second sets of measurement data.

8. The system as claimed in claim 7, wherein said signal processing unit further operates to determine a location of the acoustic transducers on the catheter head with reference to a reference acoustic transducer from at least one of said first and said at least a second set of measurement data.

9. The system as claimed in claim 7, wherein said matching of said first and said at least a second set of measurement data is effected by at least one of an elastic networks, least squares fitting and point distribution modeling image processing algorithm.

10. The system as claimed in claim 7, wherein the signal processing unit further operates to determine a location of the catheter head with reference to at least one of the first and second sets of measurement data in combination with the map of the part of the body.

11. The system as claimed in claim 1, further comprising a display unit which displays said mapping data representative of a three dimensional image of said part of the human or animal body and said catheter.

12. The system as claimed in claim 1, wherein said catheter head further includes a substantially blistered raised volume upon which said acoustic transducers are disposed, said raised volume providing an angular displacement of acoustic signals generated by said acoustic transducers.

17. The method as claimed in claim 10, further including the step of

determining a location of the catheter head with reference to at least one of the first and a second set of measurement data in combination with the map of the part of the body.

13. A method of determining a position of a catheter head within a part of a human or animal body comprising the steps of

generating acoustic signals from at least one of a plurality of acoustic transducers acting as an acoustic signal source, disposed on said catheter head,

receiving said acoustic signals with said plurality of acoustic transducers acting as acoustic receivers after said acoustic signals have been reflected from a wall of the body part,

determining a first set of measurement data appertaining to distances traveled by said acoustic signals from said at least one acoustic transducer acting as an acoustic signal sources to said plurality of acoustic transducers acting as acoustic receivers, and

determining mapping data representative of a three dimensional map of the part of the human or animal body.

14. The method as claimed in claim 13, further include the steps of

generating at least a second set of measurement data appertaining to distances traveled by said acoustic signals from said at least one acoustic transducer to said plurality of acoustic transducers, which at least a second set of measurement data is determined at a different location within said body part, and

matching said first said and said at least a second set of measurement data so as to facilitate generation of said three dimensional map.

15. The method as claimed in claim 14, wherein the step of matching said first set and said at least a second set of measurement data includes use of an elastic network, least squares fitting or point distribution model image processing algorithm.

16. A method of determining a position of a catheter head as claimed in claim 15, further including the step of determining a location of the catheter head with reference to at least one of the first and the other sets of measurement data in combination with the map of the part of the body.