Acoustic image system and method

• US 4,821,731 A
• Filed: 12/08/1987
• Issued: 04/18/1989
• Est. Priority Date: 04/25/1986
• Status: Expired due to Term

• Current Assignee: Surgical Navigation Technologies, Inc. (Medtronic Plc)
• Original Assignee: Intra-Sonix, Inc.
• Inventors: von Thuna, Peter, Martinelli, Michael A.
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US07/129,830
• Time in Patent Office: 497 Days
• Field of Search: 128/653, 128/654, 128/656, 128/660, 128/661
• US Class Current: 600/463
• 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 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/3784 both receiver and transmitter being in the instrument or receiver being also transmitter
• 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 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 5/062 using magnetic field
• 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 8/4254 using sensors mounted on the probe
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: G16H 30/20 for handling medical images, e.g. DICOM, HL7 or PACS
• CPC Class Codes: G16H 40/63 for local operation

Abstract

An apparatus and method is disclosed for imaging internal features of a living body at a preselected site so that the data can be imaged in a quick, efficient and reliable manner with high resolution. The apparatus includes a catheter having a longitudinal axis, a proximal end and a distal end such that the catheter is adapted to be partially inserted into said living body so that said distal end is positioned relative to the preselected site and imaging data relating to the internal features can be acoustically provided at said distal end by moving said distal end through a plurality of positions relative to the site and generating an acoustic signal when the distal end is at each of said positions. The acoustic energy responsive to each acoustic signal at each of the positions is sensed so as to create a set of data. The location, including the orientation of said distal end of said catheter is sensed at each of said positions. The sets of data and the respective positions from which each was obtained is related to one another so as to create an image of the internal features of the body.

Claims

1. Apparatus for sensing imaging information of the internal features of a living body at a preselected site, said apparatus comprising:

a catheter having a longitudinal axis, a proximal end and a distal end such that said catheter is adapted to be partially inserted into said living body so that said distal end is positioned relative to said preselected site so that said imaging information of said internal features can be acoustically sensed at said distal end;

image data sensing means, coupled to said catheter at said distal end, for acoustically sensing said imaging information of said body in the general direction of an image data sensing axis transverse to the longitudinal axis of said catheter at said distal end so that rotation of said catheter about said longitudinal axis rotates said image data sensing axis about said longitudinal axis; and

position sensing means for determining the spatial position of said image data sensing means within said body and the angular orientation of said image data sensing axis about said longitudinal axis with respect to said spatial position so that imaging information of said body sensed by said image data sensing means at each such spatial position and angular orientation can be related to a specific cylindrical coordinate position, and imaging information of said body for a plurality of said cylindrical coordinate positions can be spatially cross correlated.

2. Apparatus according to claim 1, wherein said image data sensing means includes transducer means for generating an acoustic signal in the general direction of said image data sensing axis into said body and receiving echo signals reflected by said body in the general direction of said imaging axis in response to said acoustic signal.

3. Apparatus according to claim 2, wherein said transducer means includes a transmitter transducer for generating said acoustic signal and a receiver transducer for receiving said echo signals.

4. Apparatus according to claim 2, wherein said transducer means includes (a) a single transducer operable in a transmitting mode for generating said acoustic signal and a receiving mode for receiving said echo signals, and (b) means for operating said transducer in either said transmitting or said receiving mode.

5. Apparatus according to claim 2, further including means for generating said acoustic signal as a burst of pulses.

6. Apparatus according to claim 2, further including means for generating said acoustic signal as a burst of pulses staggered with respect to one another.

7. Apparatus according to claim 1, wherein said position sensing means includes first means for determining the spatial location of said imaging means within said body and second means for determining said angular orientation.

8. Apparatus according to claim 7, wherein said first means includes (a) transducer means for generating an acoustic signal toward said distal end of said catheter, and (b) means, coupled to said catheter at said distal end, for sensing said acoustic signal.

9. Apparatus according to claim 8, wherein said transducer means for generating said acoustic signal includes means for generating said acoustic signal at a preselected frequency.

10. Apparatus according to claim 9, wherein said means for sensing said acoustic signal includes antenna means coupled to said catheter at said distal end fixed relative to said imaging axis for generating a position signal in response to and as a function of the acoustic signal.

11. Apparatus according to claim 7, wherein said second means includes (a) means for generating two magnetic fields in two respective planes generally transverse to one another and (b) means, coupled to said catheter at said distal end, for sensing said magnetic fields.

12. Apparatus according to claim 11, wherein said first means includes (a) transducer means for generating an acoustic signal toward said distal end of said catheter, and (b) means, coupled to said catheter at said distal end, for sensing said acoustic signal.

13. Apparatus according to claim 11, wherein said means for generating said two magnetic fields includes means for generating each of said magnetic fields at a predetermined frequency, and said means for sensing said magnetic fields includes antenna mean coupled to said catheter at said distal end and fixed relative to said imaging axis for generating a position signal in response to and as a function of the magnetic fields.

14. Apparatus according to claim 13, wherein said antenna means includes a wire loop secured to said catheter and dimensioned so as to sense said magnetic fields at each of said predetermined frequencies and oriented so as to lie substantially in a plane fixed relative to said image data sensing axis.

15. Apparatus according to claim 14, wherein said wire loop is oriented so as to substantially lie in a plane fixed relative to said image data sensing axis.

16. Apparatus according to claim 13 wherein said means for generating each of said magnetic field includes means for generating said magnetic fields at different frequencies from one another, and said position sensing means includes means for sensing said position signal at each of said predetermined frequencies.

17. Apparatus according to claim 13, wherein said means for generating each of said magnetic fields includes means for generating said magnetic fields at the same frequency but out of phase with one another.

18. Apparatus according to claim 17, wherein said position sensing means includes means for sensing said position signal at said frequency.

19. Apparatus according to claim 1, wherein said position sensing means includes means for compensating for rhythmic ambient motion.

20. Apparatus according to claim 19, wherein said position sensing means includes (a) means for generating at least two position signals as a function of the position of said image data sensing means within said body and the angular orientation of said image data sensing axis about said longitudinal axis, (b) means for generating at least two second signals as a function of the movement of said image data sensing means in response to said rhythmic ambient motion for at least one cycle, and (c) means for subtracting said second signals from the corresponding ones of said position signals during each subsequent cycle of said rhythmic ambient motion.

21. Apparatus according to claim 20, wherein the cycle of said rhythmic ambient motion is variable, and said means for subtracting said second signals from said corresponding position signals is adapted to correlate the values of said second signals at their respective times of said at least one cycle, with the values of said position signals at the same corresponding times of each of said subsequent cycles.

22. Apparatus according to claim 1, further including means for spatially correlating the imaging information of said body sensed at a plurality of said cylindrical coordinate positions.

23. Apparatus for imaging internal features of a living body at a preselected site, said apparatus comprising, in combination:

a catheter having a longitudinal axis, a proximal end and a distal end such that said catheter is adapted to be partially inserted into said living body so that said distal end is positioned relative to said preselected site and imaging data relating to said internal features can be acoustically provided at said distal end by moving said distal end through a plurality of positions relative to said site and generating an acoustic signal when said distal end is at each of said positions;

means for selectively generating said acoustic signal when said distal end is at each of said positions;

first sensing means for sensing acoustic energy in response to said acoustic signal at each of said positions;

second sensing means for sensing the location of said distal end of said catheter at each of said positions;

means, responsive to said first and second sensing means, for collecting a set of data derived from the acoustic energy sensed by said sensing means at each of said positions and corresponding information relative to the corresponding position from which each set of data is obtained so as to form a plurality of said sets corresponding to a plurality of said positions; and

means for relating the plurality of sets of data with respect to the plurality of positions from which the sets of data are obtained so that said plurality of sets of data can be used to create an image of said internal features at said site.

24. Apparatus according to claim 23, wherein said first and second sensing means includes transducer means for generating said acoustic signal in the general direction of an image data sensing axis into said body at each of said positions, and receiving echo signals reflected by said body in the general direction of said image data sensing axis in response to said acoustic signal.

25. Apparatus according to claim 24, wherein said transducer means includes a transmitter transducer for generating said acoustic signal and a receiver transducer for receiving said echo signals.

26. Apparatus according to claim 24, wherein said transducer means includes (a) a single transducer operable in a transmitting mode for generating said acoustic signal and a receiving mode for receiving said echo signals, and (b) means for operating said transducer in either said transmitting or said receiving mode.

27. Apparatus according to claim 24, further including means for generating said acoustic signal as a burst of pulses.

28. Apparatus according to claim 24, further including means for generating said acoustic signal as a burst of pulses staggered with respect to one another.

29. Apparatus according to claim 24, wherein said image data sensing axis is transverse to the longitudinal axis of said catheter at said distal end, and said second sensing means includes first means for determining the spatial location of said second sensing means within said body, and second means for determining the angular orientation of said image data sensing axis about said longitudinal axis at said distal end.

30. Apparatus according to claim 29, wherein said first means includes (a) transducer means for generating an acoustic signal toward said distal end of said catheter, and (b) means, coupled to said catheter at said distal end, for sensing said acoustic signal.

31. Apparatus according to claim 30, wherein said transducer means for generating said acoustic signal includes means for generating said acoustic signal at a preselected frequency.

32. Apparatus according to claim 31, wherein said means for sensing said acoustic signal includes antenna means coupled to said catheter at said distal end and fixed relative to said imaging axis for generating a position signal in response to and as a function of the acoustic signal.

33. Apparatus according to claim 29, wherein said second means includes (a) means for generating two magnetic fields in two respective planes generally transverse to one another and (b) means, coupled to said catheter at said distal end, for sensing said magnetic fields.

34. Apparatus according to claim 33, wherein said first means includes (a) transducer means for generating a second acoustic signal toward said distal end of said catheter, and (b) means, coupled to said catheter at said distal end, for sensing said second acoustic signal.

35. Apparatus according to claim 33 wherein said means for generating said magnetic fields includes means for generating each of said magnetic fields at a predetermined frequency, and said means for sensing said magnetic fields includes antenna means coupled to said catheter at said distal end and fixed relative to said imaging axis for generating a position signal in response to and as a function of the magnetic fields.

36. Apparatus according to claim 35, wherein said antenna means includes a wire loop secured to said catheter and dimensioned so as to sense said magnetic fields at each of said predetermined frequencies and oriented so as to lie substantially in a plane fixed relative to said image data sensing axis.

37. Apparatus according to claim 35, wherein said means for generating each of said magnetic fields including means for generating said magnetic fields at different frequencies from one another, and said position sensing means includes means for sensing said position signal at each of said predetermined frequencies.

38. Apparatus according to claim 35, wherein said means for generating each of said magnetic fields includes means for generating said magnetic fields at the same frequency but out of phase with one another.

39. Apparatus according to claim 38, wherein said position sensing means includes means for sensing said position signal at said frequency.

40. Apparatus according to claim 23, wherein said second sensing means includes means for compensating for rhythmic ambient motion.

41. Apparatus according to claim 40, wherein said second sensing means includes (a) means for generating at least two position signals as a function of the position and orientation of said distal end within said body, (b) means for generating at least two second signals as a function of the movement of said image data sensing means in response to said rhythmic ambient motion for at least one cycle, and (c) means for subtracting said second signals from the corresponding ones of said position signals during each subsequent cycle of said rhythmic ambient motion.

42. Apparatus according to claim 23, wherein said wire loop is oriented so as to substantially lie in a plane fixed relative to said image data sensing axis.

43. A method of imaging internal features of a living body at a preselected site, said method comprising the steps of:

(a) partially inserting a catheter into said body so that the distal end of said catheter is positioned relative to said preselected site so that data relating to an image of said internal features can be acoustically sensed at said distal end by moving said distal end through a plurality of positions;

(b) collecting a corresponding plurality of sets of data derived from acoustic signals generated from said distal end of said catheter as said distal end is moved through said plurality of positions; and

(c) relating the plurality of sets of data with respect to the plurality of positions from which the sets of data are obtained so that said plurality of sets of data can be used to create a coherent image of said internal features at said site.

44. A catheter assembly for use with a device for generating two magnetic fields in two respective planes generally transverse to one another, said assembly comprising:

a catheter including a longitudinal axis, a proximal portion and a distal portion such that said catheter is adapted to be partially inserted into a living body so that the distal portion is positioned relative to a preselected site;

means, positioned at said distal portion of said catheter, for (a) generating a beam of acoustic energy in a predetermined direction transverse to said longitudinal direction at said distal end so that the beam can be generated into said living body at said site, (b) sensing acoustic energy reflected by said body part along a image data sensing axis in response to said beam, and (c) generating an electrical signal in response to said and as a function of said sensed acoustic energy; and

antenna means, positioned at said distal end of said catheter and fixed relative to the direction of said image data sensing axis, for sensing said magnetic fields and for generating an electrical signal representative of the spatial angular orientation of the direction of said image data sensing axis about said longitudinal axis relative to said distal end.

45. A catheter assembly according to claim 44, wherein said antenna means includes a wire loop (1) positioned at said distal portion of said catheter (2) substantially disposed in a plane fixed relative to the direction of said image data sensing axis, and (3) dimensioned so as to sense said magnetic fields.

46. A catheter assembly according to claim 45, wherein said wire loop is positioned at said distal portion so that the direction of said image data sensing axis extends through said wire loop.

47. A catheter assembly according to claim 46, wherein said wire loop is substantially disposed in a plane extending substantially normal to the direction of said image data sensing axis.

48. A catheter assembly according to claim 44, further including means, coupled to said catheter, for generating an electrical signal representative of the spatial position of said distal portion of said catheter.