Flexible communication and control protocol for a wireless sensor and microstimulator network

• US 7,593,776 B2
• Filed: 07/03/2007
• Issued: 09/22/2009
• Est. Priority Date: 07/05/2006
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Weissberg, Jack, Rodriguez, Nuria, Loeb, Gerald E.
• Primary Examiner(s): Layno; Carl H
• Assistant Examiner(s): PATEL, NATASHA
• Application Number:
  US11/773,322
• Publication Number:
  US 20080140154A1
• Time in Patent Office: 812 Days
• Field of Search: 607/30, 607/36, 607/48, 607/60, 600/300, 375/222, 375/519
• US Class Current: 607/60
• CPC Class Codes: A61N 1/36003 of motor muscles, e.g. for walking assistance
• CPC Class Codes: A61N 1/36057 adapted for stimulating afferent nerves
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient

Abstract

A novel system and method for restoring functional movement of a paralyzed limb(s) or a prosthetic device. Stimulating one or more muscles of a patient using an implanted neuromuscular implants and sensing the response of the stimulated muscle by the implants, wherein the sensing the response is not limited to data related to patient'"'"'s movement intention, the posture, muscle extension, M-Wave and EMG. A communication and control protocol to operate the system safely and efficiently, use of forward and reverse telemetry channels having a limited bandwidth capacity, and minimizing the adverse consequences caused by errors in data transmission and intermittent loss of power to the implants. Adjusting stimulation rates and phases of the stimulator in order to achieve an efficient control of muscle force while minimizing fatigue and therefore providing for smooth movements and dynamic increase of the strength in patient'"'"'s muscle contraction.

Claims

1. A microstimulator implant controller for restoring functional movement in one or more muscles of a patient'"'"'s body, the controller comprising:

a. a processor configured to receive input parameters, to initialize one or more implants that are installed within a patient'"'"'s body with initialization data based on the input parameters, and to control various processes in the one or more implants by transmitting dynamic data,

wherein the initialization data include a unique identification data for each of the one or more implants and data required to enable the one or more implants to perform one or more actions,

wherein the initialization data further include data defining a sequence of actions to be performed by the one or more implants in a frame; and

wherein the actions include stimulation of one or more muscles within the patient'"'"'s body;

b. a transmitter configured to transmit the initialization data to the one or more implants by forward telemetry transmission;

wherein the transmitter is further configured to transmit a frame sync signal to the one or more implants in order to trigger a start of a new frame;

wherein the transmitter is further configured to transmit one or more internal sync signals to the one or more implants after the frame sync signal is transmitted in order to trigger one or more actions to be performed by the one or more implants according to the initialization data defining a sequence of actions in the frame; and

c. a receiver configured to receive back the transmitted initialization data from the one or more implants by reverse telemetry transmission, wherein the receiving back the transmitted initialization data is an indication to the processor that the initialization data has been received accordingly by the one or more implants;

wherein the receiver is further configured to receive M-waves measured by the one or more implants in response to the muscle stimulation; and

wherein the receiver is further configured to receive electromyogram (EMG) data detected by the one or more implants.

2. The controller of claim 1, wherein the transmitted initialization data further comprising predetermined time slots for the one or more implants'"'"' forward and reverse transmission so that collisions between the transmissions are avoided.

3. The controller of claim 2, wherein the processor is further configured to initialize up to 20 implants.

4. The controller of claim 1 wherein the received initialization data by the processor is an indication that the unique identification transmitted to the implant has been matched to a unique identification data that is stored in the implant.

5. The controller of claim 2, wherein the processor is further configured to reinitialize the one or more implants in the event of implants power dropping below a predetermined level.

6. The controller of claim 2, wherein the processor reinitializes the one or more implants when the reverse telemetry data has not been received within the predetermined time slot.

7. The controller of claim 1, wherein the forward telemetry is via a frequency-shift keyed (FSK) signal and wherein the data is Manchester-encoded.

8. The controller of claim 1, wherein the reverse telemetry received from the implant via an on-off keyed (OOK) bursts in the implant.

9. The controller of claim 1, wherein the processor is further configured to control frame duration and timing for the one or more internal Sync signals transmitted in each frame.

10. The controller of claim 9, wherein the processor is further configured to encode by Manchester violation the frame onset and the timing of the one or more internal Sync signals.

11. The controller of claim 1, wherein the receiver is configured to receive from one or more implants the electrical fields generated by one or more implants, wherein the generated electrical fields are the product of the implant delivering electrical current pulses.

12. The controller of claim 1, wherein the processor is further configured to dynamically adjust the stimulation data of the one or more implants based on the received data from the one or more implants.

13. The controller of claim 1, wherein the received EMG data corresponds to the patient'"'"'s residual voluntary movement of a muscle.

14. The controller of claim 1, wherein the transmitted initialization data further include mask data in order to prevent changing of certain values in the one or more implants according to dynamic data received subsequently.

15. The controller of claim 14, wherein the mask data delimit the range of stimulation values by setting a bit in the register of the one or more implants to remain unchanged.

16. The controller of claim 1, wherein the receiver is further configured to receive positional data from the one or more of the implants.

17. The controller of claim 16, wherein based on the positional data the processor is further configured to derive the coordinates of the one or more implants relative to positions of a plurality of coils installed external to patient'"'"'s body.

18. The controller of claim 16, wherein the positional data is gravitational data.

19. The controller of claim 1, wherein the receiver is further configured to receive the M-waves measured by the one or more implants in response to the muscle stimulation.

20. The controller of claim 19, wherein the processor is further configured to trigger a spindle window after detection of the M-waves stops.

21. The controller of claim 20, wherein the receiver is further configured to receive the electromyogram (EMG) data measured and integrated by the one or more implants after the spindle window is triggered.

22. The controller of claim 1, wherein the controller is further configured to stimulate the muscle twice after a new frame is started.

23. A microstimulator implant for restoring functional movement in muscle of a patient'"'"'s body, the implant comprising:

a) a memory unit configured to store a unique identification data assigned to the implant;

b) a receiver configured to wirelessly receive initialization data from an external controller by forward telemetry, wherein the initialization data including a unique identification data and data required to program the implants registers with one or more actions;

c) a processor configured to receive and process the received initialization data, wherein the processing including comparing of the received unique identification data with the stored identification data;

d) a transmitter configured to transmit the received initializing data back to the external controller by telemetry if the received and the stored unique identification data match;

e) a pair of electrodes configured to stimulate a muscle within the patient'"'"'s body based on the programmed registers of the implant;

wherein the electrodes are further configured to sense electromyogram (EMO) potentials corresponding to the patient'"'"'s voluntary movement; and

f) at least one sensor configured to detect signals from the stimulated muscle;

and wherein the transmitter is further configured to transmit the data corresponding to the detected signals to the external controller;

wherein the sensor is further configured to detect M-waves in response to muscle stimulation.

24. The implant of claim 23, wherein the registers are any one of LIFO register, programmable register, Sync Mask register, Dynamic register or stimulation parameter register.

25. The implant of claim 23, wherein the registers are configured to go through a reset operation in the event power dropping in the implant below a critical level.

26. The implant of claim 23, wherein the sensor is any one of electrical, magnetic or mechanical sensors.

27. The implant of claim 23, wherein the electrodes are further configured to send data by reverse telemetry.

28. The implant of claim 23, wherein the implant further comprising a sensor that is configured to sense electrical fields generated by one or more other implants.

29. The implant of claim 23, wherein the implant is further comprising a sensor that is configured to sense the implant'"'"'s position.

30. The implant of claim 23, wherein the implant is further comprising a sensor that is configured to detect acceleration.

31. The implant of claim 23, wherein the initialization data further comprising predetermined time slots designated for the implants forward and reverse transmission so that collisions between the transmissions are avoided.

32. The implant of claim 31, wherein the implant is configured to be reinitialized when the reverse telemetry data has not been received within the predetermined time slot.

33. The implant of claim 27, wherein the reverse telemetry is via an on-off keyed (OOK) bursts in the implant.

34. The implant of claim 23, wherein the initialization data further include data defining a sequence of actions to be performed by the one or more implants in a frame.

35. The implant of claim 34, wherein the receiver is further configured to receive a frame sync signal from the external controller in order to trigger a start of a new frame.

36. The implant of claim 35, wherein the receiver is further configured to receive an internal sync signal from the external controller in order to trigger one or more actions to be performed by the implant within the frame.

37. The implant of claim 34, wherein the initialization data further include data corresponding to duration of the frame.

38. The implant of claim 36, wherein the received frame Sync and the Internal Sync are Manchester violation encoded.

39. The implant of claim 23, wherein the stimulation parameter is dynamically changed by the external controller.

40. The implant of claim 23, wherein the received initialization data further include mask data in order to prevent changing of certain values in the implant according to dynamic data received subsequently.

41. The implant of claim 40, wherein the mask data delimit the range of stimulation values by setting a bit in register of the implant to remain unchanged.

42. The implant of claim 23, wherein the implant further comprising a sensor that is configured to receive positional data from one or more other implants.

43. The implant of claim 42, wherein the positional data is gravitational data.

44. The implant of claim 23, wherein the processor is further configured to integrate the M-waves measured by the one or more implants in response to the muscle stimulation.

45. The implant of claim 44, wherein the processor is further configured to integrate the electromyogram (EMG) data measured by the one or more implants.

46. The implant of claim 23, wherein the electrodes are further configured to stimulate the muscle twice.

47. A neuromuscular implant system for restoring functional movement in one or more muscles of a patient'"'"'s body, the system comprising:

a) a control unit located external to the patient'"'"'s body configured to initialize one or more implants with initialization data, transmitting the initialization data by forward telemetry to each of the one or more implants, wherein the initialization data include one or more muscle stimulation data, timing data, and a unique implant identification data;

wherein the control unit is further configured to verify the proper receipt of the initialization data by the one or more implants by receiving the transmitted initialization data back from the one or more implants;

wherein the control unit is further configured to receive M-waves measured by the one or more implants in response to the muscle stimulation;

wherein the control unit is further configured to receive electromyogram (EMG) data detected by the one or more implants; and

b) one or more implants having a stored unique identification data installed within the patient'"'"'s body, configured to receive the initialization data and to electrically stimulate one or more muscles within the patient'"'"'s body, to detect signals generated by the one or more stimulated muscles, and to send by reverse telemetry the detected signal to the external control unit.

48. The system of claim 47, wherein the one or more implants are configured to be initialized by the control unit prior to the stimulation of the one or more muscle.

49. The system of claim 47, wherein the one or more implants are further configured to match the sent identification code from the control unit with their stored identification data.

50. The system of claim 47, wherein the one or more implants are further configured to send back the initialization data within a predetermined time.

51. The system of claim 47, wherein the implant is configured to sense posture and/or movement data.

52. The system of claim 50, wherein the one or more implants are configured to be reinitialized when the reverse telemetry data has not been received by the external control unit within the predetermined time slot.

53. The system of claim 47, wherein the transmitted initialization data further comprising predetermined time slots for the one or more implants'"'"' forward and reverse transmission so that collisions between the transmissions are avoided.

54. The system of claim 47, wherein the control unit is further configured to initialize up to 20 implants.

55. The system of claim 47, wherein the one or more implant are configured to transmit the received initialization data back to the external control unit when the unique identification data transmitted by the control unit has been matched to the stored unique identification data of the one or more implants.

56. The system of claim 47, wherein the control unit is further configured to reinitialize the one or more implants in the event of implants power dropping below a predetermined level.

57. The system of claim 47, wherein the control unit reinitializes the one or more implants when the reverse telemetry data from the one or more implants has not been received within the predetermined time slot.

58. The system of claim 47, wherein the forward telemetry is via a frequency-shift keyed (FSK) signal and wherein the data is Manchester-encoded.

59. The system of claim 47, wherein the reverse telemetry received from the implant via an on-off keyed (OOK) bursts in the implant.

60. The system of claim 47, wherein the initialization data further include data defining a sequence of actions to be performed by the one or more implants in a frame.

61. The system of claim 60, wherein the control unit is further configured to transmit a frame sync signal to the one or more implants in order to trigger a start of a new frame.

62. The system of claim 60, wherein the control unit further configured to transmit one or more internal sync signals to the one or more implants in order to trigger one or more actions to be performed by the one or more implants according in each frame.

63. The system of claim 62, wherein the control unit is further configured to control frame duration and the timing for the one or more internal Sync signals transmitted in each frame.

64. The system of claim 63, wherein the control unit is further configured to encode by Manchester violation the frame onset and the timing of the one or more internal Sync signals.

65. The system of claim 47, wherein the one or more implants are configured to detect the electrical fields generated by different one or more implants, wherein the generated electrical fields are the product of the other implants delivering electrical current pulses.

66. The system of claim 47, wherein the control unit is further configured to dynamically adjust the stimulation data of the one or more implants based on the received data from the one or more implants.

67. The system of claim 47, wherein the received EMG data corresponds to the patient'"'"'s residual voluntary movement of a muscle.

68. The system of claim 47, wherein the transmitted initialization data by the control unit further include mask data in order to prevent changing of certain values in the one or more implants according to dynamic data received subsequently.

69. The system of claim 68, wherein the mask data delimit the range of stimulation values by setting a bit in register of the one or more implants to remain unchanged.

70. The system of claim 47, wherein the control unit is further configured to receive positional data from the one or more of the implants.

71. The system of claim 70, wherein the control unit based on the received positional data is further configured to derive the coordinates of the one or more implants relative to positions of a plurality of coils installed external to patient'"'"'s body.

72. The system of claim 70, wherein the positional data is gravitational data.

73. The implant of claim 47, wherein the one or more implants are further comprising a sensor that is configured to detect acceleration.

74. The system of claim 47, wherein the control unit is further configured to receive the M-waves measured by the one or more implants in response to the muscle stimulation.

75. The system of claim 47, wherein the control unit is further configured to trigger a spindle window after detection of the M-waves stops.

76. The system of claim 75, wherein the control unit is further configured to receive the electromyogram (EMG) data measured and integrated by the one or more implants after the spindle window is triggered.

77. The system of claim 47, wherein the implant is further configured to stimulate the muscle twice.

78. The system of claim 47, wherein the implant is further configured to collocate stimulation and sensing functions in the same implant.