High resolution ultrasonic imaging apparatus and method

• US 5,456,256 A
• Filed: 11/04/1993
• Issued: 10/10/1995
• Est. Priority Date: 11/04/1993
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Ultra-Scan Corporation (Qualcomm, Inc.)
• Inventors: Schneider, Mark C., Gojevic, Stephen M., Keeney, Frank W., Leszczynski, Nicholas G., Drakes, Russell J., Wobschall, Darold C., Schneider, John K.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US08/147,027
• Time in Patent Office: 705 Days
• Field of Search: 128/660.04, 128/660.07, 128/660.08, 128/660.09, 128/662.03, 128/663.01, 128/660.06, 128/653.1, 382/4, 382/5
• US Class Current: 600/445
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames
• CPC Class Codes: A61B 8/4218 characterised by articulated arms
• CPC Class Codes: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G10K 11/352 by moving the transducer

Abstract

An ultrasonic imaging system and method for imaging human or animal tissue having a surface and including a probe including a platen for supporting the human or animal tissue for imaging the same, a transducer positioned closely adjacent the supporting means for providing an output ultrasonic beam directed on the surface so that the size of the beam at its focal point is as small as possible to maximize the resolution of the system and a mechanism for moving the transducer in two directions so as to provide a two dimensional scan of the surface by the ultrasonic beam. There is also provided a scan controller operatively connected to the probe for controlling the mechanism to provide the scan of the surface and a signal processor operatively connected to the probe for receiving signals produced in response to the scan of the surface and for processing the signals. In a form of mechanism wherein an oscillatory motor moves the transducer to direct the ultrasonic beam along an arcuate path, there is provided an encoder operatively associated with the motor for providing information on the amount of angular rotation provided by the motor. There is also provided an oscillatory flexible liquid impervious seal between the motor shaft and a liquid filled region containing the transducer in a manner causing minimal drag on the motor. The system and method can be employed in fingerprint scanning and processing, and in biometric identification and verification systems wherein the imaging system is utilized in combination with a record member containing a recorded biometric image and a processor for performing comparisons.

Claims

1. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same over the area of an image plane;

b) transducer means for providing an output ultrasonic beam; and

c) means for positioning said transducer means closely adjacent said supporting means in a manner directing said ultrasonic beam on said surface in a direction always substantially perpendicular to said image plane and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system in a plane substantially perpendicular to the direction of said beam.

2. A probe according to claim 1, wherein said means for defining said surface comprises platen means of a material having an acoustic impedance substantially matching the acoustic impedance of the tissue being imaged.

3. A probe according to claim 1, wherein said means for defining said surface comprises platen means in the form of a body of material having an acoustic impedance substantially matching the acoustic impedance of the tissue being imaged and having sufficient mechanical strength to support the tissue without deflection or deformation, said body being provided with a coating thereon of material which improves mechanical coupling of said body to the tissue being imaged while maintaining the matching of acoustic impedance.

4. A probe according to claim 1, wherein said positioning means comprises:

a) first means for moving said transducer means to direct said beam along said surface in a first direction;

b) second means for moving said transducer means to direct said beam along said surface in a second direction; and

c) said first and second directions being along said image plane.

5. A probe according to claim 4, wherein said first means comprises motor means for oscillating said transducer means in an arcuate path along said surface.

6. A probe according to claim 5, wherein said second means comprises motive means for moving said transducer means in a linear path along said surface.

7. A probe according to claim 6, wherein said motive means includes means for guiding said transducer means along said linear path coinciding with a radius of said arcuate path.

8. A probe according to claim 5, further including encoder means operatively connected to said motor means for providing information on the amount of angular rotation provided by said motor means.

9. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same over the area of an image plane;

b) transducer means for providing an output ultrasonic beam in a direction always substantially perpendicular to said image plane;

c) motor means having an output shaft for providing oscillatory output motion;

d) means for coupling said output shaft to said transducer means so that in response to oscillation of said shaft said output ultrasonic beam is directed in an arcuate path along said surface in a direction substantially parallel to said image plane; and

e) motive means for moving said transducer means in a manner such that said output ultrasonic beam is directed in a linear path along said surface in a direction substantially parallel to said image plane and in a radial direction relative to said arcuate path.

10. A probe according to claim 9, further including encoder means operatively coupled to said output shaft of said motor means for providing information on the amount of angular rotation provided by said motor means.

11. A probe according to claim 10, wherein said encoder means comprises optical encoder means for providing an output pulse for a given amount of angular rotation of said output shaft of said motor means.

12. A probe according to claim 11, wherein the angular resolution of said optical encoder means and a dimension of said coupling means are related in a manner such that an output pulse from said optical encoder means corresponds to a given amount of movement of said ultrasonic beam along said arcuate path independent of the velocity of said motor means.

13. A probe according to claim 9, further including position sensor means operatively associated with said means for moving said transducer means to direct said beam in said linear path for establishing a starting and reference position.

14. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for positioning said transducer means closely adjacent said supporting means in a manner directing said ultrasonic beam on said surface and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system, said positioning means comprising first means for moving said transducer means to direct said beam along said surface in a first direction and second means for moving said transducer means to direct said beam along said surface in a second direction, said first means comprising motor means for oscillating said transducer means in an arcuate path along said surface;

d) means for providing a liquid-filled region between said transducer means and said surface; and

e) means for providing a rotational and oscillatory flexible liquid impervious seal between said motor means and said means providing said liquid-filled region.

15. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) motor means having an output shaft for providing oscillatory output motion;

d) means for coupling said output shaft to said transducer means so that in response to oscillation of said shaft said output ultrasonic beam is directed in an arcuate path along said surface;

e) means for moving said transducer means in a manner such that said output ultrasonic beam is directed in a linear path along said surface and in a radial direction relative to said arcuate path;

f) means for providing a liquid-filled region between said transducer means and said surface; and

g) means for providing a rotational and oscillatory flexible liquid impervious seal between said output shaft of said motor means and said means providing said liquid-filled region in a manner causing minimal drag on said motor means.

16. A probe according to claim 15, wherein said means providing said liquid-filled region includes a wall having an aperture through which said output shaft extends and wherein said seal providing means is attached to said wall and to said output shaft.

17. A probe according to claim 16, wherein said seal providing means is in the form of a bladder having openings at opposite ends and positively attached adjacent said ends to said shaft and to said wall.

18. A probe according to claim 17, wherein said bladder is stretchable and attached in a manner allowing it to be loose between the attachment locations to provide limited rotary oscillatory motion with minimal drag on said motor means.

19. A probe according to claim 17, wherein said bladder is of relatively thin latex material and is adhesively attached to said shaft and said wall.

20. A method for ultrasonic imaging of human or animal tissue having a surface comprising the steps of:

a) defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) providing an ultrasonic energy beam;

c) directing said ultrasonic beam in an arcuate path along said surface;

d) directing said ultrasonic beam in a linear path along said surface and in a radial direction relative to said arcuate path;

e) linearizing the scanned image resulting from said step of directing said ultrasonic beam in an arcuate path; and

f) said step of linearizing comprising storing the data as scanned wherein each row of stored data points represents an arc of the image and calculating the new position for each pixel in the image band on the dimensions of the scanned arc.

21. A method for ultrasonic imaging of human or animal tissue having a surface comprising the steps of:

a) defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same over the area of an image plane;

b) providing an ultrasonic energy beam in a direction always substantially perpendicular to said image plane;

c) directing said ultrasonic beam in an arcuate path along said surface in a Direction substantially parallel to said image plane;

d) directing said ultrasonic beam in a linear path along said surface in a direction substantially parallel to said image plane and in a radial direction relative to said arcuate path; and

e) providing timing for the date points resulting from scanning the surface along said arcuate path.

22. A method according to claim 21, wherein said timing is provided by energizing said ultrasonic beam at regular intervals along said arcuate path.

23. An ultrasonic imaging system for imaging human or animal tissue having a surface comprising:

a) probe means including means for defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system and motive means for moving said transducer means in two directions so as to provide a two dimensional scan of said surface by said ultrasonic beam;

b) scan controller means operatively connected to said probe means for controlling said motive means to provide said scan of said surface;

c) signal processor means operatively connected to said probe means for receiving signals produced in response to said scan of said surface and for processing said signals.

24. A system according to claim 23, further including data buffer means connected to said signal processor means for storing data resulting from said processing of said signals.

25. A system according to claim 24, further including processor means operatively connected to said data buffer means so that said imaging system can scan said surface at a relatively fast rate independent of the rate at which said processor means reads data from said data buffer means.

26. A system according to claim 23, wherein said scan controller means comprises:

a) means for providing command signals for controlling said motive means;

b) means for receiving positional information from said motive means; and

c) means for providing timing and control signals for said system.

27. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for supporting said transducer means;

d) means for storing mechanical energy;

e) motive means operatively coupled to said supporting means and to said energy storing means for transferring stored energy to said supporting means in a controlled manner to move said supporting means and with it said transducer means along a linear path; and

f) motion conversion means drivenly coupled to said motive means and drivingly coupled to said transducer means for moving said transducer means along a path cross-wise relative to said linear path in response to operation of said motive means.

28. A probe according to claim 27, wherein said motion conversion means includes means for converting linear motion from said motive means into oscillatory motion of said transducer means along an arcuate path extending cross-wise relative to said linear path.

29. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for supporting said transducer means;

d) means for storing mechanical energy;

e) motive means operatively coupled to said supporting means and to said energy storing means for transferring stored energy to said supporting means in a controlled manner to move said supporting means and with it said transducer means along a linear path;

f) motion conversion means drivenly coupled to said motive means and drivingly coupled to said transducer means for moving said transducer means along a path cross-wise relative to said linear path in response to operation of said motive means;

g) said means for storing mechanical energy comprising spring means and tensioning means operatively coupled to said spring means for extending said spring means to store energy therein; and

h) said motive means comprising damper means operatively associated with said spring means for controlling the release of energy stored in said spring means and force conversion means for converting the release of stored energy in said spring means to linear motion of said supporting means.

30. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for supporting said transducer means;

d) means for storing mechanical energy;

e) motive means operatively coupled to said supporting means and to said energy storing means for transferring stored energy to said supporting means in a controlled manner to move said supporting means and with it said transducer means along a linear path;

f) motion conversion means drivenly coupled to said motive means and drivingly coupled to said transducer means for moving said transducer means along a path cross-wise relative to said linear path in response to operation of said motive means;

g) said motion conversion means comprising rack means fixed in relation to said supporting means and pinion means carried by said supporting means so that upon linear movement of said supporting means said pinion is rotated.

31. A probe according to claim 30, further including means for converting rotary motion of said pinion means into oscillatory motion of said transducer means along an arcuate path extending cross-wise relative to said linear path of said supporting means.

32. A biometric verification system comprising:

a) an ultrasonic imaging system for imaging human or animal tissue and providing output signals representing a scanned biometric image;

b) a record member having storage means containing a recorded biometric image;

c) processor means having a first input for receiving output signals from said ultrasonic imaging system and a second input for receiving a signal representation of said recorded image to determine if a match exists between said scanned and recorded images; and

d) means for providing a wireless communication link between said processor means and said ultrasonic imaging system and said record member.

33. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

c) arranging said transducer elements in a linear array for scanning said surface in a first direction;

d) moving said array of transducer elements in a second direction substantially perpendicular to said first direction;

e) energizing said transducer elements;

f) receiving signals produced in response to scanning of the surface;

g) imposing a spherical time delay curvature across the array during energizing of the transducer elements so that the ultrasonic beams can be converged and focused.

34. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

c) arranging said transducer elements in a linear array for scanning said surface in first direction;

d) moving said array of transducer elements in a second direction substantially perpendicular to said first direction;

e) energizing said transducer elements;

f) differentially delaying the energizing of said transducer elements in an appropriate fashion across the array;

g) imposing a spherical time delay curvature across the array during energizing of the transducer elements;

h) so that the ultrasonic beams from said transducer elements are swept and focused during scanning of the surface; and

i) receiving signals produced in response to scanning of the surface.

35. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) arranging said array of transducer elements in a two dimensional array extending over the area of the surface to be scanned;

c) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

d) energizing said transducer elements;

e) imposing a spherical time delay curvature across the array during energizing of the transducer elements so that the ultrasonic beams can be converged and focused; and

i) receiving signals produced in response to scanning of the surface.

36. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) arranging said array of transducer elements in a two dimensional array extending over the area of the surface to be scanned;

c) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

d) energizing said transducer elements;

e) differentially delaying the energizing of said transducer elements in an appropriate fashion across the array;

f) imposing a spherical time delay curvature across the array during energizing of the transducer elements;

g) so that the ultrasonic beams from said transducer elements are swept and focused during scanning of the surface; and

h) receiving signals produced in response to scanning of the surface.

37. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

c) said step of supporting said human or animal tissue comprising rolling the finger of a subject on a flat platen from side-to-side so that the finger is scanned from one edge of the fingernail to the other edge of the fingernail;

d) energizing said transducer elements; and

e) receiving signals produced in response to scanning of the surface.

38. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

c) energizing said transducer elements;

d) receiving signals produced in response to scanning of the surface; and

e) said step of supporting said human or animal tissue comprising placing the finger of a subject in a curved platen wherein said array of transducer elements is arranged in one direction along the curvature of the platen and moved in another direction along the longitudinal axis of the platen so that the finger is scanned from one edge of the fingernail to the other edge of the fingernail.

39. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers;

c) energizing said transducer elements;

d) receiving signals produced in response to scanning of the surface; and

e) said step of supporting said human or animal tissue comprising placing the finger of a subject in a curved platen wherein said array of transducer elements is arranged in two dimensions over the surface of the platen so that the finger is scanned from one edge of the fingernail to the other edge of the fingernail.

40. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for providing a liquid-filled region between said transducer means and said surface; and

d) means for positioning said transducer means in said liquid-filed region and closely adjacent said supporting means in a manner directing said ultrasonic beam on said surface and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system.

41. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for positioning said transducer means closely adjacent said supporting means in a manner directing said ultrasonic beam on said surface and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system;

d) said means for defining said surface comprising platen means in the form of a body of material having an acoustic impedance substantially matching the acoustic impedance of the tissue being imaged and having sufficient mechanical strength to support the tissue without deflection or deformation, said body being provided with a coating thereon of material on the surface of the body which contacts the tissue which improves mechanical coupling of said body to the tissue being imaged while maintaining the matching of acoustic impedance.

42. A probe for an ultrasonic imaging system for providing an output ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) transducer means for providing an output ultrasonic beam;

c) means for positioning said transducer means closely adjacent said supporting means in a manner directing said ultrasonic beam on said surface and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system;

d) said positioning means including motor means having an output shaft for providing oscillatory motion to move said transducer means for scanning said surface;

e) means for providing a liquid-filled region between said transducer means and said surface; and

f) means for providing an rotary oscillatory flexible liquid impervious seal between said output shaft of said motor means and said means providing said liquid-filled region in a manner causing minimal drag on said motor means.

43. A probe according to claim 42, wherein said means providing said liquid-filled region includes a wall having an aperture through which said output shaft extends and wherein said seal providing means is attached to said wall and to said output shaft.

44. A probe according to claim 43, wherein said seal providing means is in the form of a bladder having openings at opposite ends and positively attached adjacent said ends to said shaft and to said wall.

45. A probe according to claim 44, wherein said bladder is stretchable and attached in a manner allowing it to be loose between the attachment locations to provide limited rotary oscillatory motion with minimal drag on said motor means.

46. A probe according to claim 44, wherein said bladder is of relatively thin latex material and is adhesively attached to said shaft and said wall.

47. A method for ultrasonic imaging of human or animal tissue having a surface comprising the steps of:

a) utilizing an ultrasonic beam to perform an ultrasonic scan in three dimensions over a fixed area of the surface to provide a return signal; and

b) applying a high resolution range gate to said return signal to allow propagation of only that portion of the return signal from the immediate underside of the epidermis of the tissue;

c) so that an image is generated in a plane substantially perpendicular to the direction of propagation of the ultrasonic beam.

48. A method according to claim 47, wherein said step of performing an ultrasonic scan is with ultrasonic energy having a frequency of about 30 MHz.

49. A method according to claim 47, wherein said return signal is processed to provide a peak signal and wherein said high resolution range gate is applied to said peak signal.

50. A method for ultrasonic imaging of human or animal tissue having a surface comprising the steps of:

a) utilizing an ultrasonic beam to perform an ultrasonic scan in three dimensions over a fixed area of the surface to provide a return signal; and

b) applying a high resolution range gate to said return signal to allow propagation of only that portion of the return signal from a predetermined location beneath the surface of the tissue;

c) so that an image is generated in a plane substantially perpendicular to the direction of propagation of the ultrasonic beam.

51. A method according to claim 50, wherein said step of performing an ultrasonic scan is with ultrasonic energy having a frequency of about 15 MHz.

52. A method according to claim 50, wherein an ultrasonic scan is performed in a manner such that only the scatter return is received for imaging.

53. A method for ultrasonic imaging of human or animal tissue having a surface comprising the steps of:

a) defining said surface in a manner rigidly supporting said human or animal tissue for imaging the same over the area of an image plane;

b) providing an ultrasonic energy beam in a direction always substantially perpendicular to said image plane;

c) directing said ultrasonic beam in an arcuate path along said surface in a direction substantially parallel to said image plane; and

d) directing said ultrasonic beam in a linear path along said surface in a direction substantially parallel to said image plane and in a radial direction relative to said arcuate path.

54. A method according to claim 53 further including linearizing the scanned image resulting from said step of directing said ultrasonic beam in an arcuate path.

55. A method according to claim 54, wherein said step of linearizing comprises altering the position of each pixel in the imaging to compensate for the arc motion of the ultrasonic beam.

56. A method according to claim 53, wherein said return signal is processed to provide a peak signal and wherein said high resolution range gate is applied to said peak signal.

57. A probe for an ultrasonic imaging system for providing an output ultrasonic beam for scanning the finger of a subject, said probe comprising:

a) curved supporting means for rigidly supporting the finger for scanning from one edge of the fingernail to the other edge thereof, said supporting means having a longitudinal axis and supporting the finger with said longitudinal axis being substantially parallel to the longitudinal axis of the finger;

b) transducer means for providing an output ultrasonic beam, said transducer means comprising a plurality of transducers in spaced-apart relation in a direction along the longitudinal axis of said supporting means;

c) means for moving said transducer means along a first path substantially radially about said longitudinal axis of said supporting means so that said ultrasonic beam is directed along a path from one edge of the fingernail to the other; and

d) means for moving said transducer means along a second path substantially parallel to the longitudinal axis of said supporting means so that said ultrasonic beam is directed along a path substantially parallel to the longitudinal axis of the finger.

58. A probe for an ultrasonic imaging system for providing an ultrasonic beam to scan human or animal tissue having a surface, said probe comprising:

a) means for defining said surface in a manner supporting said human or animal tissue for imaging the same;

b) a plurality of transducer means, each providing an output ultrasonic beam;

c) means for supporting said transducer means in spaced relation along a transducer path;

d) first motive means operatively connected to said supporting means for moving said transducer means along a first scanning path along said surface so that said transducer path is in registry with said first scanning path and each of the ultrasonic beams from said plurality of transducer means is directed along a portion of said first scanning path in a manner such that the sum of the portions scanned equals the total length of said scanning path; and

e) second motive means for moving said plurality of transducer means along a second scanning path along said surface.

59. A probe according to claim 58, wherein said plurality of transducer means are equally spaced along said transducer path.

60. A probe according to claim 58, wherein the portions of said first scanning path along which said ultrasonic beams are directed are equal and in sum equal the total length of said first scanning path.

61. A probe according to claim 58, wherein said transducer path and said first scanning path are arcuate and have a common radius.

62. A probe according to claim 61, wherein said first motive means provides oscillatory motion about an axis located at the common radius of said transducer path and said first scanning path.

63. A probe according to claim 61, wherein said second motive means provides linear motion in a radial direction relative said arcuate paths.

64. A biometric identification system comprising:

a) an ultrasonic imaging system for imaging human or animal tissue having a surface and comprising probe means including means for defining said surface in a manner supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system and motive means for moving said transducer means in two directions so as to provide a two dimensional scan of said surface by said ultrasonic beam, said imaging system further comprising scan controller means operatively connected to said probe means for controlling said motive means to provide said scan of said surface and signal processor means operatively connected to said probe means for receiving signals produced in response to said scan of said surface and for processing said signals to provide an output;

b) means for storing a database of previously stored images; and

c) system processor means having inputs coupled to said database storage means and to the output of said processor means for comparing a scanned image from said ultrasonic imaging system to the previously stored images in said database storage means to determine if a match exists.

65. A system according to claim 64, further including data buffer means connected between the output of said signal processor means and said system processor means so that said ultrasonic imaging system can scan said surface at a relatively fast rate independent of the rate at which said system processor means reads data from said data buffer means.

66. A system according to claim 64, in combination with another ultrasonic imaging system, database storage means and system processor means together with local area network means for connecting said first-named system processor means and said another system processor means together.

67. A system according to claim 64, further including means for providing a wireless communication link between said ultrasonic imaging system and said system processor means.

68. A biometric verification system comprising:

a) an ultrasonic imaging system for imaging human or animal tissue and providing output signals representing a scanned biometric image;

b) a record member physically separate from said imaging system and having storage means containing a recorded biometric image, said record member being sufficiently small in size and light in weight so as to be portable and said record member being in a form so that it can be carried on a person;

c) processor means having a first input for receiving output signals from said ultrasonic imaging system and a second input for receiving a signal representation of said recorded image from said record member to determine if a match exists between said scanned and recorded images.

69. A biometric verification system according to claim 68, wherein said record member and said processor means are physically separate.

70. A biometric verification system according to claim 68, wherein said record member and said processor means are physically integrated.

71. A biometric verification system according to claim 68, wherein said ultrasonic imaging system comprises:

a) probe means including means for defining a surface in a manner supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system and motive means for moving said transducer means in two directions so as to provide a two dimensional scan of said surface by said ultrasonic beam;

b) scan controller means operatively connected to said probe means for controlling said motive means to provide said scan of said surface; and

c) signal processor means operatively connected to said probe means for receiving signals produced in response to said scan of said surface and for processing said signals to provide an output.

72. A probe for an ultrasonic imaging system for providing an output ultrasonic beam for scanning the finger of a subject, said probe comprising:

a) curved supporting means for rigidly supporting the finger for scanning from one edge of the fingernail to the other edge thereof, said supporting means having a longitudinal axis and supporting the finger with said longitudinal axis being substantially parallel to the longitudinal axis of the finger;

b) transducer means for providing an output ultrasonic beam;

c) means for moving said transducer means along a first path substantially radially about said longitudinal axis of said supporting means so that said ultrasonic beam is directed along a path from one edge of the fingernail to the other; and

d) means for moving said transducer means linearly along a second path substantially parallel to the longitudinal axis of said supporting means so that said ultrasonic beam is directed along a path substantially parallel to the longitudinal axis of the finger.

73. A probe according to claim 72, wherein said supporting means is substantially semicylindrical in cross-sectional shape and wherein said first path is an arcuate path having an arc length of about 180 degrees.

74. A probe according to claim 72, further including means for positioning said transducer means closely adjacent said supporting means in a manner directing said ultrasonic beam on the finger and so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system.

75. A probe according to claim 72, wherein said supporting means has a curved surface adapted to contact the finger and has longitudinally extending edges approximately in registry with the edges of the fingernail.

76. An ultrasonic imaging system for imaging human or animal tissue having a surface comprising:

a) transducer means comprising a plurality of transducer elements each providing an output ultrasonic beam, said transducer elements being arranged in an array;

b) means for rigidly supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducer elements; and

c) means for energizing said transducer elements and for receiving signals produced in response to scanning of the surface.

77. A system according to claim 76, wherein said array of transducer elements comprises a linear array extending in a first direction relative to the surface and further including means for moving said array in a second direction substantially perpendicular to said first direction.

78. A system according to claim 76, wherein said array of transducer elements comprises a two dimensional array extending over the area of the surface to be scanned and further including means for electronically steering the ultrasonic beams from said array of transducer elements.

79. An ultrasonic imaging system for imaging human or animal tissue having a surface comprising:

a) transducer means comprising a plurality of transducer elements each providing an output ultrasonic beam, said transducer elements being arranged in an array;

b) means for rigidly supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducer elements; and

c) means for energizing said transducer elements and for receiving signals produced in response to scanning of the surface, said means for energizing and receiving comprising pulser/receiver means operatively connected to each of said transducer elements for energizing said transducer elements and for receiving return echo signals and multiplexer means operatively connected to said pulser/receiver means for reading signals received from each of said pulser/receiver means.

80. A system according to claim 79, further including peak detector means operatively connected to said multiplexer means for providing a signal containing image information.

81. An ultrasonic imaging system for imaging human or animal tissue having a surface comprising:

a) transducer means comprising a plurality of transducer elements each providing an output ultrasonic beam, said transducer elements being arranged in a two dimensional array extending over the area of the surface to be scanned;

b) means for supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducer elements; and

c) means for energizing said transducer elements and for receiving signals produced in response to scanning of the surface, said means for energizing and receiving comprising a plurality of pulser/receiver means, one for each of said transducer elements, operatively connected to corresponding ones of said transducer elements, each of said pulser/receiver means energizing a corresponding one of said transducer elements and receiving return echo signals, and a plurality of programmable delay lines, one for each of said transducer elements, operatively connected to corresponding ones of said pulser/receiver means, said delay lines differentially delaying the energization of said transducer elements in a manner providing sweeping and steering of the ultrasonic beams from said transducer elements.

82. A system according to claim 81 further including:

a) multiplexer means operatively connected to said pulser/receiver means for reading signals received from each of said pulser/receiver means;

b) timing and control means operatively connected to said multiplexer means and to said programmable delay lines for providing timing and control signals to said multiplexer means and to said programmable delay lines; and

c) peak detection means operatively connected to said multiplexer means for peak detecting the output of said multiplexer means to provide a signal containing image information.

83. An ultrasonic imaging method for imaging human or animal tissue having a surface comprising:

a) providing a plurality of ultrasonic transducer elements arranged in an array and each providing an output ultrasonic beam;

b) rigidly supporting said human or animal tissue so that the surface thereof can be scanned by the ultrasonic beams from said array of transducers; and

c) energizing said transducer elements; and

d) receiving signals produced in response to scanning of the surface.

84. A method according to claim 83, further including processing the received signals to provide image information.

85. A method according to claim 83, including:

a) arranging said transducer elements in a linear array for scanning said surface in first direction; and

b) moving said array of transducer elements in a second direction substantially perpendicular to said first direction.

86. A method according to claim 85, further including differentially delaying the energizing of said transducer elements in an appropriate fashion across the array so that the ultrasonic beams from said transducers can be electronically steered.

87. A method according to claim 83 including arranging said array of transducer elements in a two dimensional array extending over the area of the surface to be scanned.

88. A method according to claim 87, further including differentially delaying the energizing of said transducer elements in an appropriate fashion across the array so that the ultrasonic beams from said transducers can be electrically steered.

89. A biometric identification system comprising:

a) an ultrasonic imaging system for imaging human or animal tissue having a surface and comprising probe means including means for defining said surface in a manner supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system, said imaging system further comprising control means operatively connected to said probe means for controlling scanning of said surface by said transducer means and signal processor means operatively connected to said probe means for receiving signals produced in response to said scanning of said surface and for processing said signals to provide an output;

b) means for storing a database of previously stored images; and

c) system processor means having inputs coupled to said database storage means and to the output of said processor means for comparing a scanned image from said ultrasonic imaging system to the previously stored images in said database storage means to determine if a match exists.

90. A system according to claim 89, further including data buffer means connected between the output of said signal processor means and said system processor means so that said ultrasonic imaging system can scan said surface at a relatively fast rate independent of the rate at which said system processor means reads data from said data buffer means.

91. A system according to claim 89, in combination with another ultrasonic imaging system, database storage means and system processor means together with local area network means for connecting said first-named system processor means and said another system processor means together.

92. A system according to claim 89, further including means for providing a wireless communication link between said ultrasonic imaging system and said system processor means.

93. A biometric identification system comprising:

a) a first ultrasonic imaging system for imaging human or animal tissue having a surface and comprising probe means including means for defining said surface in a manner supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system, said imaging system further comprising control means operatively connected to said probe means for controlling scanning of said surface by said transducer means and signal processor means operatively connected to said probe means for receiving signals produced in response to said scanning of said surface and for processing said signals to provide an output;

b) first means for storing a database of previously stored images;

c) first system processor means having inputs coupled to said database storage means and to the output of said processor means for comparing a scanned image from said ultrasonic imaging system to the previously stored images in said database storage means to determine if a match exists;

d) a second ultrasonic imaging system providing an output;

e) second means for storing a database of previously stored images;

f) second system processor means having inputs coupled to said second database storage means and to the output of said second ultrasonic imaging system for comparing a scanned image from the output of said second ultrasonic imaging system to the previously stored images in said second database storage means to determine if a match exists; and

g) local area network means for connecting said first and second system processor means together.

94. A biometric identification system comprising:

a) an ultrasonic imaging system for imaging human or animal tissue having a surface and comprising probe means including means for defining said surface in a manner supporting said human or animal tissue for imaging the same, transducer means positioned closely adjacent said supporting means for providing an output ultrasonic beam directed on said surface so that the size of said beam at its focal point is as small as possible to maximize the resolution of said system, said imaging system further comprising control means operatively connected to said probe means for controlling scanning of said surface by said transducer means and signal processor means operatively connected to said probe means for receiving signals produced in response to said scanning of said surface and for processing said signals to provide an output;

b) means for storing a database of previously stored images;

c) system processor means having inputs coupled to said database storage means and to the output of said processor means for comparing a scanned image from said ultrasonic imaging system to the previously stored images in said database storage means to determine if a match exists; and

d) means for providing a wireless communication link between said ultrasonic imaging system and said system processor means.