CHARACTERIZATION OF ELECTRICAL STIMULATION ELECTRODES USING POST-IMPLANT IMAGING

• US 20090196471A1
• Filed: 01/23/2009
• Published: 08/06/2009
• Est. Priority Date: 01/31/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Goetz, Steven M., Ng, Andrew, Dewing, Wende L.
• Granted Patent: US 8,160,328 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/30052 Implant; Prosthesis
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

In general, the disclosure is related to characterization of implanted electrical stimulation electrode arrays using post-implant imaging. The electrode arrays may be carried by implanted leads. Characterization of implanted electrode arrays may include identification of the type or types of leads implanted within a patient and/or determination of positions of the implanted leads or electrodes carried by the leads relative to one another or relative to anatomical structures within the patient. In addition, the disclosure relates to techniques for specifying or modifying patient therapy parameters based on the characterization of the implanted electrode arrays.

Claims

1. A method comprising:

analyzing, by an image processing device, an electronic image of an electrical stimulation electrode array implanted within a patient to identify one or more physical characteristics of the electrode array, wherein the electrode array includes one or more electrodes;

characterizing the array based on the identified physical characteristics; and

automatically generating an indication of the characterization of the array.

2. The method of claim 1, wherein the electrode array comprises one or more electrodes on an implanted lead, and wherein characterizing the array comprises determining a type of the lead.

3. The method of claim 2, wherein characterizing the lead further comprises:

comparing the identified physical characteristics to physical characteristics for different types of leads; and

determining the type of the lead based on the comparison,

wherein the physical characteristics include an electrode number characteristic, an electrode size characteristic, an intra-lead electrode spacing characteristic.

4. The method of claim 3, wherein the electrode size characteristic comprises a ratio of electrode length to electrode width, and wherein the intra-lead electrode spacing characteristic comprises a ratio of electrode length to intra-lead electrode spacing.

5. The method of claim 3, wherein the physical characteristics include an electrode shape characteristic.

6. The method of claim 3, wherein the electrode size characteristic comprises an electrode width, wherein calculating the electrode width comprises:

centering an observing rectangle within an electronic image of at least one of the one or more electrodes;

stretching the observing rectangle;

determining whether an overspill of the observing rectangle is greater than an overspill threshold value;

continuing to stretch the observing rectangle when the overspill is less than or equal to the overspill threshold value;

rotating the observing rectangle when the overspill is greater than the overspill threshold value;

repeating the determining of whether the overspill of the observing rectangle is greater than the overspill threshold value, stretching the observing rectangle when the overspill is less than or equal to the overspill threshold value, and rotating the observing rectangle when the overspill is greater than the overspill threshold value until the observing rectangle is fully rotated; and

approximating the electrode width based upon a width of the observing rectangle after the observing rectangle has been fully rotated.

7. The method of claim 6, wherein the observing rectangle comprises a length-to-width ratio of 3:

2.

8. The method of claim 6, wherein approximating the electrode width based upon a width of the observing rectangle comprises reducing the width of the observing rectangle based on the overspill threshold value.

9. The method of claim 1, wherein the electronic image includes an electronic image of a plurality of electrical stimulation electrode arrays on a plurality of leads implanted within the patient, and wherein:

analyzing comprises analyzing the image of the electrical stimulation leads to identify one or more physical characteristics of each of the leads, wherein each of the leads comprises one or more electrodes;

characterizing comprises characterizing the leads based on the identified physical characteristics; and

automatically generating comprises automatically generating indications of the characterizations of the leads.

10. The method of claim 9, wherein characterizing comprises determining a configuration of the plurality of leads, wherein the configuration includes the types of at least some of the leads, orientations of at least some of the leads within the patient, and relative positions of at least some of the electrodes.

11. The method of claim 10, wherein determining a configuration of the plurality of leads comprises:

determining a dimensional scale of pixels within the electronic image; and

determining actual relative positions of electrodes on the leads based on the pixels corresponding to the electrodes and the dimensional scale.

12. The method of claim 11, further comprising displaying a representation of the electrical stimulation leads in the image on a display associated with a programmer for an implantable electrical stimulation device, wherein the representation indicates the actual relative positions of the electrodes.

13. The method of claim 12, further comprising:

receiving user input specifying selection, as an electrode combination, of a plurality of the electrodes displayed in the representation of the electrical stimulation leads; and

receiving user input specifying one or more electrical stimulation parameters associated with electrical stimulation to be delivered by the implantable electrical stimulation device via the selected electrodes.

14. The method of claim 1, wherein automatically generating comprises automatically presenting the indication of the characterization of the electrode array on a display associated with a programmer for an implantable electrical stimulation device.

15. The method of claim 1, wherein the physical characteristics include a radio-opaque identification marker.

16. The method of claim 1, wherein the characterization includes an indication of at least one of orientation and rotation of the electrode array based on at least one of landmarks and fiducial elements.

17. The method of claim 1, further comprising verifying the characterization based on comparison of scales derived from different physical characteristics of the electrode array.

18. A device comprising:

an image analysis unit that analyzes an electronic image of an electrical stimulation electrode array implanted within a patient to identify one or more physical characteristics of the electrode array, wherein the electrode array includes one or more electrodes; and

a characterization unit that characterizes the electrode array based on the identified physical characteristics, and that automatically generates an indication of the characterization of the array.

19. The device of claim 18, wherein the electrode array comprises one or more electrodes on an implanted lead, wherein the characterization includes a type of the lead.

20. The device of claim 19, wherein the physical characteristics include an electrode number characteristic, an electrode size characteristic, and an intra-lead electrode spacing characteristic, and wherein the characterization unit compares the identified physical characteristics to physical characteristics for different types of leads, and determines the type of the lead based on the comparison.

21. The device of claim 20, wherein the physical characteristics include an electrode shape characteristic.

22. The device of claim 20, wherein the electrode size characteristic comprises a ratio of electrode length to electrode width, and wherein the intra-lead electrode spacing characteristic comprises a ratio of electrode length to intra-lead electrode spacing.

23. The device of claim 20, wherein the electrode size characteristic comprises an electrode width, wherein the image analysis unit calculates the electrode width by:

centering an observing rectangle within an electronic image of at least one of the one or more electrodes;

stretching the observing rectangle;

determining whether an overspill of the observing rectangle is greater than an overspill threshold value;

continuing to stretch the observing rectangle when the overspill is less than or equal to the overspill threshold value;

rotating the observing rectangle when the overspill is greater than the overspill threshold value;

repeating the determining of whether the overspill of the observing rectangle is greater than the overspill threshold value, stretching the observing rectangle when the overspill is less than or equal to the overspill threshold value, and rotating the observing rectangle when the overspill is greater than the overspill threshold value until the observing rectangle is fully rotated; and

approximating the electrode width based upon a width of the observing rectangle after the observing rectangle has been fully rotated.

24. The device of claim 23, wherein the observing rectangle comprises a length-to-width ratio of 3:

2.

25. The device of claim 23, wherein the image analysis unit approximates the electrode width based on a width of the observing rectangle by reducing the width of the observing rectangle based on the overspill threshold value.

26. The device of claim 18, wherein the electronic image includes an electronic image of a plurality of electrical stimulation electrode arrays on a plurality of leads implanted within the patient, and wherein:

the image analysis unit analyzes the image of the electrical stimulation leads to identify one or more physical characteristics of each of the leads, wherein each of the leads comprises one or more electrodes; and

the characterization unit characterizes the leads based on the identified physical characteristics, and generates indications of the characterizations of the leads.

27. The device of claim 26, wherein the characterization unit determines a configuration of the plurality of leads, wherein the configuration includes the types of at least some of each of the leads, orientations of at least some of the leads within the patient, and relative positions of at least some of the electrodes.

28. The device of claim 27, wherein the characterization unit determines a dimensional scale of pixels within the electronic image, and determines actual relative positions of electrodes on the leads based on the pixels corresponding to the electrodes and the dimensional scale.

29. The device of claim 28, wherein an output unit comprises a display that displays a representation of the electrical stimulation leads in the image, wherein the representation indicates the actual relative positions of the electrodes.

30. The device of claim 29, further comprising a user input device that receives user input specifying selection, as an electrode combination, of a plurality of the electrodes displayed in the representation of the electrical stimulation leads, and receives user input specifying one or more electrical stimulation parameters associated with electrical stimulation to be delivered by the implantable electrical stimulation device via the selected electrodes.

31. The device of claim 18, further comprising an output unit that displays the indication of the characterization of the electrode array.

32. The device of claim 18, wherein the physical characteristics include a radio-opaque identification marker.

33. The device of claim 18, wherein the characterization includes an indication of at least one of orientation and rotation of the electrode array based on at least one of landmarks and fiducial elements.

34. The device of claim 18, wherein the image analysis unit verifies the characterization based on comparison of scales derived from different physical characteristics of the electrode array.

35. A system comprising:

an image capture device that obtains an electronic image of an electrical stimulation electrode array implanted within a patient, wherein the array includes one or more electrodes;

an image analysis unit that analyzes the electronic image of the electrical stimulation electrode array to identify one or more physical characteristics of the lead;

a characterization unit that characterizes the array based on the identified physical characteristics, and that automatically generates an indication of the characterization of the array; and

a programmer for an electrical stimulation device coupled to the array.

36. The system of claim 35, wherein the image analysis unit and the characterization unit form part of the programmer.

37. The system of claim 35, wherein the electrode array comprises one or more electrodes on an implanted lead, and wherein the characterization of the array includes a type of the lead.

38. The system of claim 37, wherein the physical characteristics include an electrode number characteristic, an electrode size characteristic, and an intra-lead electrode spacing characteristic, and wherein the characterization unit compares the identified physical characteristics to physical characteristics for different types of leads, and determines the type of the lead based on the comparison.

39. The system of claim 38, wherein the physical characteristics include an electrode shape characteristic.

40. The system of claim 38, wherein the electrode size characteristic comprises a ratio of electrode length to electrode width, and wherein the intra-lead electrode spacing characteristic comprises a ratio of electrode length to intra-lead electrode spacing.

41. The system of claim 35, wherein the electronic image includes an electronic image of a plurality of electrical stimulation electrode arrays on a plurality of leads implanted within the patient, and wherein:

the image analysis unit analyzes the image of the electrical stimulation leads to identify one or more physical characteristics of each of the leads, wherein each of the leads comprises one or more electrodes; and

the characterization unit characterizes the leads based on the identified physical characteristics, and generates indications of the types of leads.

42. The system of claim 41, wherein the characterization unit determines a configuration of the plurality of leads, wherein the configuration includes the types of at least some of each of the leads, orientations of at least some of the leads within the patient, and relative positions of at least some of the electrodes.

43. The system of claim 42, wherein the characterization unit determines a dimensional scale of pixels within the electronic image, and determines actual relative positions of electrodes on the leads based on the pixels corresponding to the electrodes and the dimensional scale.

44. The system of claim 43, further comprising an output unit that that displays a representation of the electrical stimulation leads in the image, wherein the representation indicates the actual relative positions of the electrodes, wherein:

the programmer further comprises a user input device that receives user input specifying selection, as an electrode combination, of a plurality of the electrodes displayed in the representation of the electrical stimulation leads, and

the user input device receives user input specifying one or more electrical stimulation parameters associated with electrical stimulation to be delivered by the implantable electrical stimulation device via the selected electrodes.

45. The system of claim 35, wherein the image capture device comprises one of a fluoroscopic imaging, X-ray imaging, or magnetic resonance imaging (MRI) device.

46. The system of claim 35, wherein the physical characteristics include a radio-opaque identification marker.

47. The system of claim 35, wherein the characterization includes an indication of at least one of orientation and rotation of the electrode array based on at least one of landmarks and fiducial elements.

48. The system of claim 35, further comprising means for verifying the characterization based on comparison of scales derived from different physical characteristics of the electrode array.

49. A device comprising:

means for analyzing an electronic image of an electrical stimulation electrode array implanted within a patient to identify one or more physical characteristics of the electrode array, wherein the electrode array comprises one or more electrodes;

means for characterizing the array based on the identified physical characteristics; and

means for automatically generating an indication of the characterization of the array.

50. The device of claim 49, wherein the electrode array comprises one or more electrodes on an implanted lead, wherein the means for characterizing the array comprises means for determining a type of the lead.

54. The device of claim 49, wherein the electronic image includes an electronic image of a plurality of electrical stimulation electrode arrays on a plurality of leads implanted within the patient, and wherein:

the means for analyzing comprises means for analyzing the image of the electrical stimulation leads to identify one or more physical characteristics of each of the leads, wherein each of the leads comprises one or more electrodes;

the means for characterizing comprises means for characterizing the leads based on the identified physical characteristics; and

the means for automatically generating comprises means for automatically generating indications of the characterizations of the leads.

51. The device of 50, wherein the physical characteristics include an electrode number characteristic, an electrode size characteristic, and an intra-lead electrode spacing characteristic, the device further comprising:

means for comparing the identified physical characteristics to physical characteristics for different types of leads; and

means for determining the type of the lead based on the comparison.

52. The device of claim 51, wherein the physical characteristics include an electrode shape characteristic.

53. The device of claim 51, wherein the electrode size characteristic comprises a ratio of electrode length to electrode width, and wherein the intra-lead electrode spacing characteristic comprises a ratio of electrode length to intra-lead electrode spacing.

55. A computer-readable medium comprising instructions to cause a processor to:

analyze an electronic image of an electrical stimulation electrode array implanted within a patient to identify one or more physical characteristics of the electrode array, wherein the electrode array comprises one or more electrodes;

characterize the electrode array based on the identified physical characteristics; and

automatically generating an indication of the characterization of the electrode array.

56. The computer-readable medium of claim 55, wherein the electrode array comprises one or more electrodes on an implanted lead, and wherein the instructions cause the processor to determine a type of the lead.

59. The computer-readable medium of claim 55, wherein the electronic image includes an electronic image of a plurality of electrical stimulation electrode arrays on a plurality of leads implanted within the patient, and wherein the instructions cause the processor to:

analyze the image of the electrical stimulation leads to identify one or more physical characteristics of each of the leads, wherein each of the leads comprises one or more electrodes;

characterize the leads based on the identified physical characteristics; and

automatically generate indications of the characterizations of the leads.

57. The computer-readable medium of 56, wherein the physical characteristics include an electrode number characteristic, an electrode size characteristic, and an intra-lead electrode spacing characteristic, the instructions further causing the processor to:

compare the identified physical characteristics to physical characteristics for different types of leads; and

determining the type of the lead based on the comparison.

58. The computer-readable medium of claim 57, wherein the electrode size characteristic comprises a ratio of electrode length to electrode width, and wherein the intra-lead electrode spacing characteristic comprises a ratio of electrode length to intra-lead electrode spacing.