SYSTEMS AND METHODS FOR POSITIONING IMPLANTED DEVICES IN A PATIENT

• US 20120083856A1
• Filed: 09/30/2010
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Nevro Corporation
• Original Assignee: Nevro Corporation
• Inventors: Thacker, James R., Parker, Jon, Chitre, Yougandh
• Granted Patent: US 8,965,482 B2
• Time in Patent Office: Days
• US Class Current: 607/46
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/062 penetration depth
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 5/066 Superposing sensor position on an image of the patient, e.g. obtained by ultrasound or x-ray imaging
• CPC Class Codes: A61B 5/407 Evaluating the spinal cord A61B5/4896 takes precedence
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36128 Control systems
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37241 providing test stimulations

Abstract

Systems and methods for positioning implanted devices in a patient are disclosed. A method in accordance with a particular embodiment includes, for each of a plurality of patients, receiving a target location from which to deliver a modulation signal to the patient'"'"'s spinal cord. The method further includes implanting a signal delivery device within a vertebral foramen of each patient, and positioning an electrical contact carried by the signal delivery device to be within ±5 mm. of the target location, without the use of fluoroscopy. The method can still further include, for each of the plurality of patients, activating the electrical contact to modulate neural activity at the spinal cord. In further particular embodiments, RF signals, ultrasound, magnetic fields, and/or other techniques are used to locate the signal delivery device.

Claims

1. A method for treating multiple patients, comprising:

for each of a plurality of patients, receiving a target location from which to deliver a modulation signal to the patient'"'"'s spinal cord;

for each of the plurality of patients, implanting a signal delivery device within a vertebral foramen of the patient, and positioning an electrical contact carried by the signal delivery device to be within ±

5 mm. of the target location, without the use of fluoroscopy; and

for each of the plurality of patients, activating the electrical contact to modulate neural activity at the spinal cord.

2. The method of claim 1 wherein modulating neural activity includes reducing patient pain.

3. The method of claim 1 wherein implanting the signal delivery device includes positioning the electrical contact at a location within ±

5 mm. of the target location in both a lateral direction and a rostral/caudal direction.

4. The method of claim 1 wherein implanting the signal delivery device includes positioning the electrical contact at a location within ±

5 mm. of the target location in each of a lateral direction, a rostral/caudal direction, and a dorsal/ventral direction.

5. The method of claim 1 wherein the signal delivery device is part of a signal delivery system, and wherein the method further comprises:

transmitting a locator signal from the signal delivery system;

detecting the locator signal from a position external to the patient;

based at least in part on detecting the locator signal, adjusting a position of the signal delivery device.

6. The method of claim 5 wherein transmitting the locator signal includes transmitting the locator signal from the signal delivery device.

7. The method of claim 6 wherein transmitting the locator signal includes transmitting the locator signal from the electrical contact.

8. The method of claim 5 wherein transmitting the locator signal includes transmitting the locator signal from a portion of the signal delivery device other than the electrical contact.

9. The method of claim 5 wherein implanting signal delivery device includes implanting the signal delivery device with a removable implanting tool, and wherein transmitting the locator signal includes transmitting the locator signal from the implanting tool.

10. The method of claim 1 wherein transmitting the locator signal includes transmitting an electromagnetic signal.

11. The method of claim 10 wherein transmitting the locator signal includes transmitting an RF signal.

12. The method of claim 10 wherein transmitting the locator signal includes transmitting a magnetic signal.

13. The method of claim 1 wherein positioning the electrical contact includes positioning the electrical contact based at least in part on an ultrasound signal.

14. The method of claim 13, further comprising transmitting an ultrasound signal from the within the patient and detecting the ultrasound signal from a position external to the patient.

15. The method of claim 13, further comprising emitting an ultrasound signal from external to the patient and detecting reflections of the ultrasound signal from a position external to the patient.

16. A method for treating a patient, comprising:

implanting an implantable signal delivery system beneath the patient'"'"'s skin and into a vertebral foramen of at least one of the patient'"'"'s vertebra, the signal delivery system including a signal delivery device having at least one electrical contact;

emitting a locator signal from the signal delivery system;

detecting the locator signal from a position external to the patient;

based at least in part on detecting the locator signal, adjusting a position of the signal delivery device relative to the patient'"'"'s spinal cord; and

directing a therapy signal from the electrical contact.

17. The method of claim 16 wherein directing the therapy signal includes directing the therapy signal to treat pain in the patient.

18. The method of claim 16 wherein the signal delivery system includes a signal delivery device and an implanting tool carrying the signal delivery device, and wherein emitting the locator signal includes emitting the locator signal from the implanting tool.19

19. The method of claim 18 wherein the implanting tool includes a stylet slideably and releasably received in an aperture of the signal delivery device.

20. The method of claim 16 wherein the signal delivery system includes a signal delivery device and an implanting tool carrying the signal delivery device, and wherein emitting the locator signal includes emitting the locator signal from the signal delivery device.

21. The method of claim 16 wherein emitting the locator signal includes emitting the locator signal from the signal delivery device.

22. The method of claim 21 wherein emitting the locator signal includes emitting the locator signal from the electrical contact.

23. The method of claim 16 wherein emitting a locator signal includes emitting an RF signal.

24. The method of claim 16 wherein emitting a locator signal includes generating and emitting an ultrasound signal.

25. The method of claim 16 wherein detecting the locator signal includes detecting the locator signal at a plurality of signal detectors external to the patient.

26. The method of claim 25, further comprising interpolating results obtained from the plurality of signal detectors to identify an estimated position of the signal delivery device.

27. The method of claim 16 wherein detecting the locator signal includes detecting the locator signal with an array of signal detectors releasably carried by the patient.

28. The method of claim 16, further comprising releasably attaching at least one locator signal detector to the patient'"'"'s skin.

29. The method of claim 16, further comprising presenting a display indicating an estimated location of the signal delivery device, based at least in part on the detected locator signal.

30. The method of claim 29 wherein presenting a display includes illuminating elements of a display grid positioned external to the patient.

31. The method of claim 16, further comprising detecting a location of the signal delivery device based at least in part on detecting the locator signal.

32. The method of claim 31 wherein detecting a location includes detecting a lateral location and a rostral/caudal location.

33. The method of claim 31 wherein detecting a location includes detecting a dorsal/ventral location.

34. The method of claim 33 wherein detecting a dorsal/ventral location includes comparing a length of the signal delivery system inserted into the patient with a length of the signal delivery system corresponding to the detected locator signal.

35. The method of claim 16, further comprising:

detecting the locator signal at a plurality of locations via an array of signal detectors; and

presenting a display indicating relative signal strength received at the signal detectors.

36. The method of claim 16, further comprising:

viewing a display indicating relative signal strength received at an array of signal detectors;

viewing markings on the signal delivery system;

based on the markings, identifying a length of the signal delivery system inserted into the patient;

comparing the length of the signal delivery system inserted into the patient with a projected length of the signal delivery system indicated by the array of signal detectors; and

based on a difference between the length of the signal delivery system inserted into the patient and the projected length of the signal delivery system indicated by the array of signal detectors, identifying a ventral/dorsal location of the signal delivery system.

37. The method of claim 16, further comprising:

receiving a plurality of indications of the strength of the locator signal from a corresponding plurality of signal detectors positioned in an array external to the patient and forming a plane extending laterally and in a rostral/caudal direction;

based on the plurality of indications, identifying a projected length of an implanted portion of the signal delivery device, projected into the plane of the array;

receiving an indication of the actual length of the an implanted portion of the signal delivery device;

comparing the actual length with the projected length; and

based on a difference between the actual length and the projected length, providing an indication of a ventral/dorsal location of the signal delivery system.

38. A method for treating a patient, comprising:

placing a plurality of RF detectors on a patient'"'"'s skin, along the patient'"'"'s spine;

inserting a stylet and a lead body carried by the stylet beneath the patient'"'"'s skin and into a vertebral foramen of at least one of the patient'"'"'s vertebra, the lead body carrying a plurality of electrical contacts;

emitting an RF locator signal from the stylet;

detecting the RF locator signal at the RF detectors;

based at least in part on detecting the RF signal at the RF detectors, adjusting a lateral position of the lead relative to the patient'"'"'s midline;

removing the stylet from the lead body and the patient; and

directing a therapy signal from at least one of the electrical contacts carried by the lead body to neural tissue of the patient at a frequency of from about 3 kHz to about 50 kHz to treat chronic low back pain in the patient.

39. The method of claim 38, further comprising:

receiving a plurality of indications of the strength of the locator signal from a corresponding plurality of signal detectors positioned in an array external to the patient and forming a plane extending laterally and in a rostral/caudal direction;

based on the plurality of indications, identifying a projected length of an implanted portion of the signal delivery device, projected into the plane of the array;

receiving an indication of the actual length of the implanted portion of the signal delivery device;

comparing the actual length with the projected length; and

based on a difference between the actual length and the projected length, providing an indication of a ventral/dorsal location of the signal delivery system.

40. The method of claim 38, further comprising:

detecting the locator signal at a plurality of locations via an array of signal detectors; and

presenting a display based at least in part on relative signal strengths of the locator signal received at the signal detectors.

41. The method of claim 38, further comprising detecting a location of the signal delivery device based at least in part on detecting the locator signal.

42. The method of claim 41 wherein detecting a location includes detecting a lateral location and a rostral/caudal location.

43. The method of claim 41 wherein detecting a location includes detecting a dorsal/ventral location.

44. A patient treatment system, comprising:

a signal delivery system that includes a patient-implantable signal delivery device coupleable to a power source to deliver a neural modulation signal;

a signal transmission system carried by the signal delivery system to transmit a locator signal; and

an external signal detector that is movable relative to the signal delivery device and positionable to detect the locator signal wirelessly through the patient'"'"'s skin, the signal detector having a releasable fixation element positioned to releasably secure the signal detector to the patient'"'"'s skin.

45. The treatment system of claim 44 wherein the signal delivery system includes an implanting tool releasably carried by to the signal delivery device, and wherein the implanting tool includes a locator signal transmitter.

46. The treatment system of claim 45 wherein the signal delivery device has an aperture, and wherein the implanting tool includes a stylet slideably and releasably received in the aperture of the signal delivery device.

47. The treatment system of claim 44 wherein the external signal detector is one of a plurality of external signal receivers arranged in an array.

48. The treatment system of claim 44, further comprising a display device coupled to the signal detector, the display device having at least one display element operatively coupled to the signal detector to present an indication of a signal strength detected at the signal detector.

49. The treatment system of claim 48 wherein the display device is releasably attachable to the patient'"'"'s skin.

50. The treatment system of claim 48 wherein the display device includes a display screen positionable apart from the patient.

51. The treatment system of claim 44 wherein the signal transmission system includes an electromagnetic signal emitter.

52. The treatment system of claim 44 wherein the transmission system includes an RF signal emitter.

53. The treatment system of claim 44 wherein the transmission system includes a magnet.

54. The treatment system of claim 44 wherein the transmission system includes an ultrasound signal emitter.

55. The treatment system of claim 44 wherein the transmission system includes an ultrasound signal reflector.

56. The treatment system of claim 44, further comprising an insertion tracker operably coupleable to the signal delivery system to track a length of the signal delivery system inserted into the patient.

57. The treatment system of claim 56 wherein the insertion tracker includes an electromechanical device that is releasably engageable with the signal delivery system.

58. The treatment system of claim 56, further comprising a computer-readable medium containing instructions that when executed:

compare an first inserted length of the signal delivery device based on information received from the external signal detector with a second inserted length of the signal delivery device based on information received from the insertion tracker; and

provide an indication when the first and second inserted lengths differ by at least a threshold amount.

59. A patient treatment system, comprising:

a signal delivery system that includes;

a patient-implantable, elongated signal delivery lead having an axial opening;

a therapy contact carried by the signal delivery lead and coupleable to a signal generator to deliver a neural modulation signal; and

a stylet removably received in the axial opening;

a signal transmission system carried by the signal delivery system, the signal transmission system including a signal emitter carried by the stylet and coupleable to a power source;

an external signal detector configured to detect a locator signal emitted by the signal emitter, the signal detector being movable relative to the signal delivery device, the signal detector having an array of detection elements and a releasable fixation element positioned to releasably secure the signal detector to the patient'"'"'s skin; and

a display device operatively coupled to the signal detector to present an indication of individual signal strengths received at the corresponding individual signal detectors.

60. The system of claim 59 wherein the display device is releasably attachable to the patient'"'"'s skin.

61. The treatment system of claim 60 wherein the display device includes a display screen positionable apart from the patient.