Breast cancer detection

• US 20020183645A1
• Filed: 04/04/2002
• Published: 12/05/2002
• Est. Priority Date: 04/04/2001
• Status: Active Grant

• Current Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Original Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Inventors: Nachaliel, Ehud
• Granted Patent: US 7,409,243 B2
• Time in Patent Office: Days
• US Class Current: 600/547
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0536 Impedance imaging, e.g. by tomography

Abstract

Apparatus for breast examination, comprising:

a sensing unit including a probe capable of sensing electrical signals from a surface of a breast, including at least a portion of the nipple thereof;

a processor operative to generate, based on sensed signals from only the nipple of the breast, optionally adjusted by values outside the breast, a malignancy score relating to the need of additional testing of the breast; and

a display operative to indicate at least the range of the malignancy score.

Claims

1. Apparatus for breast examination, comprising:

a sensing unit including a probe capable of sensing electrical signals from a surface of a breast, including at least a portion of the nipple thereof,

a processor operative to generate, based on sensed signals from only the nipple of the breast, optionally adjusted by values outside the breast, a malignancy score relating to the need of additional testing of the breast; and

a display operative to indicate at least the range of the malignancy score.

2. Apparatus according to claim 1, wherein the processor is operative to determine the malignancy score as a function of an electrical parameter of the breast.

3. Apparatus according to claim 2, wherein the electrical parameter comprises an electrical parameter determined directly from the sensed signals.

4. Apparatus according to claim 2, wherein the electrical parameter comprises an electrical parameter of inner tissue of the breast.

5. Apparatus according to claim 2, wherein the processor is adapted to determine the malignancy score as a binary function of the electrical parameter of the breast.

6. Apparatus according to claim 1, wherein the malignancy score comprises a binary malignancy score.

7. Apparatus according to claim 1, wherein the processor is adapted to generate an impedance based image of the breast and the malignancy score is determined from a nipple portion of the image.

8. Apparatus according to claim 1, wherein the malignancy score is operative to indicate a need for additional tests on the average for more than twice the percentage in the population of malignant breasts.

9. Apparatus according to claim 8, wherein the malignancy score is adapted to indicate a need for additional tests on the average for more than ten times the percentage in the population of malignant breasts.

10. Apparatus according to claim 9, wherein the malignancy score is adapted to indicate a need for additional tests on the average for about 5% or more of the examined patients.

11. Apparatus according to claim 1 wherein the probe comprises a multi-element probe operative to produce an image of the breast, including the nipple and the processor is operative to delineate areas of the nipple and areas outside the nipple.

12. Apparatus according to claim 1 wherein the probe comprises a hole or depression suitable for fitting the tip of the nipple therein.

13. Apparatus according to claim 1 wherein an outer periphery of the probe is within an outer edge of the nipple.

14. Apparatus according to claim 12 wherein the outer periphery of the probe is within 1 cm of the center of the hole or depression.

15. Apparatus according to claim 12 wherein the outer periphery of the probe is within 1.5 cm of the center of the hole or depression.

16. Apparatus according to claim 12 and including a plurality of different probes, adapted for matching different sized nipples.

17. Apparatus according to claim 1 wherein the probe comprises an outer guard ring and an inner sensing electrode.

18. Apparatus according to claim 1 wherein the probe comprises a single sensing electrode having an outer dimension of less than 1 cm.

19. Apparatus according to claim 1, wherein the probe comprises a multi-element probe.

20. Apparatus according to claim 1, wherein the probe comprises a marking of a position to be placed on the nipple.

21. Apparatus according to claim 1, wherein the sensor comprises at least one sensing element adapted to be placed on a surface of the body other than the breast.

22. Apparatus according to claim 21 wherein the processor utilizes signals from said sensing element to adjust the values of said signals from the breast portion utilized in determining said score.

24. Apparatus according to claim 23 wherein the sensing unit comprises a surface probe.

25. Apparatus according to claim 24, wherein the surface probe comprises a multi-element probe.

26. Apparatus according to claim 24, wherein the surface probe comprises a marking of a position to be placed on the nipple.

27. Apparatus according to claim 24, wherein the surface probe comprises a hole or depression adapted to receive the nipple.

28. Apparatus according to claim 24, wherein the surface probe comprises at least one sensing element adapted to be placed on a surface remote from the breast.

29. Apparatus according to claim 28, wherein the processor utilizes signals from said sensing element to adjust the values of said signals from the breast portion utilized in determining said score.

30. Apparatus according to claim 23, wherein the score is a binary score.

23. Apparatus for breast examination, comprising:

a sensing unit capable of sensing electrical signals from a breast, including at least a portion of the nipple thereof;

a processor adapted to determine the extent of said nipple portion and to generate, responsive to sensed signals from the determined portion, a malignancy score relating to the need of additional testing of the breast; and

a human output interface adapted to provide the malignancy score to a user.

31. A method of determining internal tissue impedance of a body portion of a subject, through a skin layer having a surface impedance, comprising:

applying, to the subject, one or more electrical stimulus signals;

measuring a group of one or more electrical signals responsive to each of the one or more applied stimulus signals, by a surface probe placed on a surface of the body portion, said measured signals being affected by the tissue and surface impedance; and

determining an impedance of the internal tissue in which the effects of the surface impedance on the measured electrical signals are at least partially neutralized, from at least one of the measured signals.

32. A method according to claim 31, wherein determining the impedance of the internal tissue comprises estimating an impedance of the skin layer responsive to a value of at least one of the measured signals, and determining the impedance of the internal tissue, responsive to the estimated surface impedance and at least one of the measured signals.

33. A method according to claim 32, wherein estimating the surface impedance comprises estimating based on a comparison of an imaginary portion of an admittance determined from the measured signals of at least one of the applied signals, to a model thereof.

34. A method according to claim 33, wherein estimating the surface impedance comprises estimating based on a comparison of an imaginary portion of an admittance determined from the measured signals of at least two of the applied signals, to a model thereof.

35. A method according to claim 32, wherein determining the impedance of the internal tissue comprises determining based on a comparison of a real portion of an admittance determined from the measured signals of at least one of the applied signals, to a model thereof.

36. A method according to claim 33, wherein determining the impedance of the internal tissue comprises determining based on measured signals of different applied signals than those used in estimating the impedance of the surface.

37. A method according to claim 31, wherein applying the one or more stimulus signals comprises applying a plurality of signals with different frequencies.

38. A method according to claim 37, wherein estimating the surface impedance comprises estimating responsive to measured signals from a plurality of groups generated responsive to stimulus signals with different frequencies.

39. A method according to claim 31, wherein applying the one or more stimulus signals comprises sequentially applying a plurality of signals while the probe is urged against the breast with different pressure levels.

40. A method according to claim 31, wherein applying the one or more stimulus signals comprises applying a plurality of signals from different positions.

41. A method according to claim 31, wherein estimating the surface impedance comprises estimating responsive to a cupping effect of a map, formed of a plurality of measured signals of one of the groups of measured signals.

42. A method according to claim 31, wherein determining the impedance of the internal tissue comprises solving a set of equations to simultaneously determine the internal tissue impedance and the surface impedance.

43. A method according to claim 31, wherein applying the one or more electrical stimulus signals comprises applying signals with frequencies of up to 5000 Hz.

44. A method according to claim 31, wherein the surface probe comprises a two-dimensional array of sensing elements.

45. A method according to claim 44, wherein the surface probe comprises a rectangular sensing surface.

46. A method according to claim 44, wherein the surface probe comprises a circular sensing surface.

47. A method according to claim 44, wherein measuring the group of one or more electrical signals comprises measuring while substantially all the elements of the surface probe are held at an equipotential.

48. A method according to claim 44, wherein measuring the group of one or more electrical signals comprises measuring at any specific time from fewer than all the elements of the surface probe while the remaining elements of the surface probe are held floating.

49. A method according to claim 31, wherein the surface probe comprises a single element probe.

50. A method according to claim 31, wherein measuring the signals comprises determining measured impedance values and determining the impedance of the internal tissue comprises fitting at least some of the measured impedance values into a model of the measured impedance which is a function of the surface impedance and the internal tissue impedance.

51. A method according to claim 50, wherein fitting at least some of the measured values into the model comprises fitting into a model which depends on the real and imaginary impedance of the skin layer.

52. A method according to claim 51, wherein the model depends only on the frequency of the applied signals, the real and imaginary impedance of the skin layer and the true internal tissue impedance.

53. A method according to claim 51, wherein the model depends on at least two parameters additional to the frequency of the applied signals, the real and imaginary impedance of the skin layer and the real internal tissue impedance.

54. A method according to claim 31, comprising passing the values of at least one of the acquired groups of signals through a low pass spatial filter.

55. A method according to claim 31, wherein determining the impedance comprises determining a ratio between an impedance of a skin layer on the body portion and an inner tissue layer of the body portion.

56. A method according to claim 31, wherein determining the impedance comprises comparing the image to a plurality of library images having respective impedance image values.

57. A method according to claim 31 and including providing a score indicative of the probability of cancer.

58. A method according to claim 57 wherein the score is a binary score.

60. A method according to claim 59, wherein estimating the indicator frequency comprises fitting a plurality of the impedance measurements into a parabolic model and estimating responsive to a coefficient of the parabola.

61. A method according to claim 59, comprising providing a malignant indication if the indicator frequency is greater than a predetermined threshold.

59. A method of determining an indicator of a body tissue, comprising:

sensing impedance measurements by a surface probe responsive to stimulus signals at a plurality of different frequencies; and

estimating an indicator frequency at which one of the imaginary admittance component and the real admittance component of the impedance measurements has a local maximum, based on said sensed measurements.

62. A method of impedance imaging of a body portion of a subject, comprising:

applying, to the subject, one or more electrical stimulus signals;

generating a multi-element impedance image of the body portion responsive to each of the one or more applied stimulus signals, by a surface probe placed on a surface of the body portion; and

determining at least one characteristic of a cupping effect of the multi-element impedance image.

63. A method according to claim 62 and including:

providing an indication of malignancy responsive to the at least one characteristic of the cupping effect.

64. An impedance probe adapted for measuring impedance of in vivo human tissue, comprising an electrode having a depression or hole in the center thereof such that a surface of the electrode is in the form of an annulus.

65. An impedance probe according to claim 64 wherein the annulus has an outer diameter of less than 2 cm.

66. An impedance probe according to claim 64 wherein the annulus has an outer diameter of between 2 cm and 2.5 cm.

67. An impedance probe according to claim 64 wherein the annulus has an outer diameter of between 2.5 and 3 cm.

68. An impedance probe set comprising a plurality of probes each comprising an electrode having a hole or depression therein suitable for receiving a tip of a nipple of a breast and having varying outer dimensions allowing matching of the outer dimension to a size smaller than a diameter of an areola of a nipple of a particular breast.