Granted Patent B2

US 6,962,587 · App. 09/916,235 · Granted Nov 8, 2005

Abstract

Claims (146)

1. A method for detecting and treating a tumor using tissue localized volumetric impedance measurements, the method comprising:

providing an impedance measurement apparatus including an impedance array having a plurality of resilient members being positionable in an elongated delivery device and being deployable with curvature, at least two of the plurality resilient members being a sensor member for determining impedance, where each sensor member is operatively connected to a separate energy source, at least one of said plurality of resilient members being an electrode operatively coupled to a energy source;

positioning the apparatus at a selected tissue site;

deploying the impedance array to define a sample volume;

utilizing the impedance array to make impedance measurements through a plurality of conductive pathways;

determining a tissue condition of the sample volume utilizing information from the impedance measurements; and

delivering energy from the energy delivery device to ablate or necrose at least a portion of the tumor.

2. The method of claim 1 , wherein tissue impedance measurements through the plurality of conductive pathways are made substantially simultaneously, sequentially or sweep sequentially.

3. The method of claim 1 , wherein the condition is at least one of a tumorous, a healthy, a hyperthermic, an injury, or a necrotic condition.

4. The method of claim 1 , further comprising:

combining or integrating at least a first and a second impedance measurement made along a first and a second conductive pathway of the plurality of conductive pathways.

5. The method of claim 1 , further comprising:

identifying a tissue type utilizing information from the impedance measurements.

6. The method of claim 1 , further comprising:

monitoring at least one of an ablation volume or a tumor volume at the tissue site utilizing information from the impedance measurements.

7. The method of claim 1 , further comprising:

substantially simultaneously monitoring a tumor volume and a developing ablation volume at the tissue site utilizing information from the impedance measurements.

8. The method of claim 1 , further comprising:

making the impedance measurements at a discrete frequency.

9. The method of claim 1 , further comprising:

making the impedance measurement at a frequency distinct from an RE ablation frequency.

10. The method of claim 1 , further comprising:

locating at least one of an ablation volume, an ablation boundary, a tumor volume, a tumor boundary or a healthy tissue ablative margin utilizing information from the impedance measurements.

11. The method of claim 1 , further comprising:

titrating an amount of ablative treatment or energy delivery at the tissue site utilizing information from the impedance measurements.

12. The method of claim 1 , further comprising:

configuring at least a portion of the plurality of conductive pathway to be substantially evenly distributed, spaced or aligned within the sample volume.

13. The method of claim 1 , further comprising:

sampling an impedance within a volume defined by plurality of conductive pathways.

14. The method of claim 13 , further comprising:

making a sweep sample of the impedance through the volume defined by plurality of conductive pathways.

15. The method of claim 1 , further comprising;

repetitively sampling impedance through at least a portion of the plurality of conductive pathways to monitor for temporal changes in the tissue condition.

16. The method of claim 1 , further comprising:

sampling a first impedance at a first time; sampling a second impedance at a later second time; and

comparing the first impedance to the second impedance or comparing a tissue condition of the first time to a tissue condition of the second time.

17. The method of claim 16 , further comprising:

making a treatment endpoint decision responsive to a comparison of the first impedance to the second impedance.

18. The method of claim 16 , further comprising:

adjusting an ablative therapy parameter or energy delivery parameter responsive to a comparison of the first impedance to the second impedance.

19. The method of claim 1 , wherein the plurality of conductive pathways defines a first and a second sample sector, the method further comprising:

sampling a first impedance within the first sample sector;

sampling a second impedance within the second sample sector; and

comparing the first impedance to the second impedance or comparing a tissue condition of the first sample sector to a tissue condition of the second sample sector.

20. The method of claim 1 , wherein at least one of the plurality of conductive pathways is configured to provide a reference impedance measurement; the method further comprising:

making a reference impedance measurement through the at least one conductive pathway.

21. The method of claim 1 , wherein the plurality of conductive pathways includes a first and a second conductive pathway.

22. The method of claim 21 , wherein the first and the second conductive pathways have a common origin.

23. The method of claim 21 , further comprising:

positioning the second conductive pathway at a selectable angle to the first conductive pathway to define the sample volume.

24. The method of claim 21 , further comprising:

sampling a first impedance through the first conductive pathway;

sampling a second impedance through the second conductive pathway; and

comparing the first impedance to the second impedance.

25. The method of claim 24 , further comprising:

determining a tissue condition of the sample volume utilizing the comparison of the first to the second impedance.

26. The method of claim 1 , further comprising:

measuring a complex impedance within the sample volume; and

utilizing real and imaginary components of the complex impedance to identify the tissue condition.

27. A method of detecting and treating a tumor comprising:

providing a tissue diagnosis and treatment apparatus for detecting and treating a tumor, the apparatus including an elongated delivery device, an impedance sensor array comprising a plurality of sensor members for determining impedance, where each sensor member is operatively connected to a separate energy source, and an energy delivery device, the;

introducing the apparatus into a target tissue site;

making a complex impedance measurement within a sample volume substantially defined by the impedance array;

utilizing the complex impedance measurement to determine a tissue condition of the sample volume;

positioning the energy delivery at the target tissue site; and

delivering energy from the energy delivery device to ablate or necrose at least a portion of the tumor.

28. The method of claim 27 , wherein the condition is at least one of a tumorous, a healthy, a hyperthermic, an injury, or a necrotic condition.

29. The method of claim 27 , further comprising:

identifying a tissue type utilizing information from the complex impedance measurement.

30. The method of claim 27 , further comprising:

monitoring at least one of an ablation volume or a tumor volume at the tissue site utilizing information from the complex impedance measurement.

31. The method of claim 27 , further comprising:

substantially simultaneously monitoring a tumor volume and a developing ablation volume at the tissue site utilizing information from the complex impedance measurement.

32. The method of claim 27 , further comprising:

making the complex impedance measurement at a discrete frequency.

33. The method of claim 27 , further comprising:

making the complex impedance measurement at a frequency distinct from an RF ablation frequency.

34. The method of claim 27 , further comprising:

locating at least one of an ablation volume, an ablation boundary, a tumor volume, a tumor boundary or a healthy tissue ablative margin at the tissue site utilizing information from the complex impedance measurement.

35. The method of claim 27 , further comprising:

titrating an amount of ablative treatment or energy delivery at the tissue site utilizing information from the complex impedance measurement.

36. The method of claim 27 , further comprising:

determining a treatment endpoint or regiment utilizing information from the complex impedance measurement.

37. The method of claim 27 , further comprising:

sampling a first impedance at a first time;

sampling a second impedance at a later second time; and

comparing the first impedance to the second impedance or comparing a tissue condition of the first time to a tissue condition of the second time.

38. The method of claim 37 , further comprising:

determining a treatment endpoint responsive to a comparison of the first impedance to the second impedance.

39. The method of claim 37 , further comprising:

adjusting an ablative therapy parameter or energy delivery parameter responsive to a comparison of the first impedance to the second impedance.

40. The method of claim 27 , further comprising:

signaling one of the tissue condition, an ablation condition or a treatment endpoint condition to one of a display, a monitoring device or an alarm.

41. The method of claim 27 , further comprising:

determining a real and an imaginary component of the impedance measurement; and

utilizing at least one of the real and the imaginary components to monitor or locate at least one of the sample volume, a tumor volume or an ablation volume.

42. The method of claim 41 , further comprising:

comparing the real and imaginary components of the impedance measurement to a database of real and imaginary values.

43. The method of claim 27 , further comprising:

determining a magnitude and a phase angle of the impedance measurement; and

utilizing at least one of the magnitude and the phase angle to monitor or locate at least one of the sample volume, a tumor volume or an ablation volume.

44. The method of claim 43 , further comprising:

comparing the magnitude and the phase angle of the impedance measurement to a database of magnitude and phase angle values.

45. The method of claim 27 , further comprising:

determining an impedance vector within the sample volume; and

utilizing the impedance vector to monitor or locate at least one of the sample volume, a tumor volume, a tumor boundary, an ablation volume or an ablation volume boundary.

46. The method of claim 27 , further comprising:

determining a locus of an impedance or the complex impedance within the sample volume.

47. The method of claim 27 , further comprising:

utilizing the locus to monitor, locate, image or display one of an ablation volume, a tumor volume or a tissue mass.

48. The method of claim 27 , further comprising:

making at least two of an intracellular, extracellular or capacitance measurement within the tissue volume; and

utilizing the at least two measurements to monitor at least of the tissue volume or an ablation volume.

49. The method of claim 27 , wherein the apparatus includes logic resources, the method further comprising:

adjusting one of a power, current, power duty cycle or fluid flow response to an input from the impedance array.

50. The method of claim 27 , further comprising:

making a first complex impedance measurement within a first portion of the sample volume and a second complex impedance measurement within a second portion of the sample volume; and

comparing a condition of the first sample volume portion to a condition of the second sample volume portion.

51. The method of claim 50 , further comprising:

determining a distinction or boundary between the first sample volume portion and the second sample volume portion.

52. The method of claim 50 , wherein the first and second impedance measurements are made substantially simultaneously.

53. The method of claim 50 , wherein the first sample volume portion is one of one of an ablated or injured tissue portion and the second sample volume portion is a non-ablated or healthy tissue portion.

54. The method of claim 27 , further comprising:

utilizing a reference or baseline signal to improve a signal to noise ratio sensitivity or resolution.

55. The method of claim 27 , further comprising:

positioning the impedance array to detect one of a tumor volume or a boundary of the tumor volume.

56. The method of claim 27 , further comprising:

processing an impedance signal using a transform function.

57. The method of claim 27 , wherein the logic resource include at least one of a processor, a microprocessor, a software module, a fuzzy logic module, a database, a histological database, a tissue database or a tumor database.

58. The method of claim 27 , further comprising:

generating an image of the sample volume utilizing information from at least one of the complex impedance measurement or a locus of impedance.

59. A method of detecting and treating a tumor utilizing volumetric complex impedance measurement, the method comprising:

providing a tissue diagnosis and treatment apparatus for detecting and treating a tumor, the apparatus including, an impedance sensor array comprising a plurality of sensor members for determining impedance, where each sensor member is operatively connected to a separate energy source;

introducing the apparatus into a target tissue site;

positioning the impedance array to define a sample volume;

making a complex impedance measurement within the sample volume; and

analyzing real and imaginary components of the complex impedance measurement to determine a tissue condition of the sample volume.

60. The method of claim 59 , further comprising:

identifying a tissue type utilizing information from the complex impedance measurement.

61. The method of claim 59 , further comprising:

utilizing information from the complex impedance measurement to monitor or locate at least one of an ablation volume, an ablation boundary or a tumor volume at the tissue site.

62. The method of claim 59 , further comprising:

substantially simultaneously monitoring a tumor volume and a developing ablation volume at the tissue site utilizing information from the complex measurement.

63. The method of claim 59 , further comprising:

titrating an amount of ablative treatment or energy delivery at the tissue site utilizing information from the complex impedance measurement.

64. The method of claim 59 , wherein the impedance array includes a sensor, the sensor having one of a resistance gradient configured to improve measurement of a complex impedance.

Assignments (8)