Systems, methods, and devices for controlling external devices by signals derived directly from the nervous system

• US 6,171,239 B1
• Filed: 08/17/1998
• Issued: 01/09/2001
• Est. Priority Date: 08/17/1998
• Status: Expired due to Term

• Current Assignee: Emory University
• Original Assignee: Emory University
• Inventors: Humphrey, Donald R.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): Ruddy, David M.
• Application Number:
  US09/135,249
• Time in Patent Office: 876 Days
• Field of Search: 600/372, 600/373, 600/377, 600/378, 600/383, 600/544, 600/545, 607/116, 607/117, 607/118, 607/62, 606/129, 606/130
• US Class Current: 600/372
• CPC Class Codes: A61B 5/375 using biofeedback
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/407 Evaluating the spinal cord A61B5/4896 takes precedence
• CPC Class Codes: A61F 2/54 Artificial arms or hands or parts thereof
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control

Abstract

A system and method control prostheses and other devices with signals received by sensors implanted directly in the brain or other parts of the nervous system of a subject/patient and transmitted to an external receiver. Included in the system are sensors in the form of bundles of small, insulated, flexible wires, configured in a parallel or twisted array, which are used to receive multicellular signals from small clusters of neurons. A new “calibration/adaptation” system is developed, in which the neural signals are cross-correlated with the parameters of a set of standardized or model movements as the subject/patient attempts to emulate the model movements, and on the basis of the correlations the neural signals that are best suited for control of the corresponding movement or movement parameter of the external device are selected. Periodic use of this calibration system compensates for or adapts to uncontrolled changes in neural signal parameters over time, and therefore results in re-selection of the optimal neural channels for better device control. Artificial neural nets are used for mapping the selected neural signals onto appropriate movements or control parameters of the external device.

Claims

1. A device for collecting multicellular signals directly from a central nervous system and transmitting the signals to an external receiver, comprising:

A) a plurality of electrodes formed in bundles of flexible wires with tips at staggered length aligned to be implanted in the central nervous system, each electrode for collecting multicellular signals from the central nervous system; and

B) a signal processing mechanism connected to the electrodes for multiplexing and transmitting the signals from the electrodes to the external receiver;

wherein the tips of the electrodes are sized to have a recording area greater than 400 μ

m² for collecting the multicellular signals from the central nervous system.

2. The device according to claim 1, wherein the number of the flexible wires in a bundle ranges from 3 to 10.

3. The device according to claim 1, wherein the diameter of the flexible wires is smaller than 50 μ

m.

4. The device according to claim 1, wherein the difference in length from one tip to its neighbor tip of the wires is variable.

5. The device according to claim 4, wherein the difference in length from one tip to its neighbor tip of the wires is about 0.3 to 0.6 mm.

6. The device according to claim 1, wherein the flexible wires in a bundle are made from noble metal.

7. The device according to claim 1, wherein the signal processing mechanism comprises:

A) an insulating substrate;

B) an array of electrode contact pads mounted on the substrate for receiving the electrodes, each electrode received individually by one of the electrode contact pads, and with the electrode contact pads being electrically isolated from each other at the substrate;

C) a microchip bonded in close contact with the substrate for receiving and multiplexing the signals from the electrodes; and

D) an electric connection to the microchip for relaying power to the microchip and transmitting the signals received at the microchip to the external receiver.

8. The device according to claim 7, wherein the electric connection is a hardware device.

9. The device according to claim 8, wherein the hardware device is a cable.

10. The device according to claim 7, wherein the electric connection is a wireless device.

11. The device according to claim 10, wherein the wireless device is a nonresonant wireless setup.

12. The device according to claim 11, wherein the nonresonant wireless setup comprises:

A) a first coil in connection with the microchip for relaying power to the microchip; and

B) a second coil in connection with the microchip for receiving and transmitting the multiplexed signals to the external receiver.

13. The device according to claim 10, wherein the wireless device is a resonant wireless setup.

14. The device according to claim 13, wherein the resonant wireless setup comprises:

A) a coil in connection with the microchip for relaying power to the microchip; and

B) a low pass filter in connection with the microchip for receiving and transmitting the multiplexed signals to the external receiver.

15. The device according to claim 7, wherein the microchip comprises signal processing integrated circuits.

16. An apparatus for recording multi-neuron signals directly from a central nervous system, comprising:

a plurality of sensors, wherein each sensor further comprises a bundle of noble metal wires with tips at staggered lengths and with the tips sized to have a recording area greater than 400 μ

m² so that each tip collects multicellular signals from the central nervous system.

17. An instrument for collecting multicellular signals directly from a central nervous system and transmitting the signals to an external receiver, comprising:

A) at least one sensor for receiving the signals, wherein the sensor comprises;

i) a bundle of wires of staggered lengths arranged in an array, wherein each wire has a tip for receiving multicellular signals from the central nervous system; and

ii) an optical cement bead through which the wires pass for holding the wires in position in a selected distance from the most distant wire tip; and

B) a signal processor connected to the sensor for multiplexing and transmitting the signals from the sensor to the external receiver;

wherein the signal processor conducts adaptive processing of the signals from the sensor so that the instrument responds to changes in the multicellular signals.

18. The instrument according to claim 17, wherein the selected distance is about 6-8 mm.

19. The instrument according to claim 17, wherein the wires are made from conductive materials.

20. The instrument according to claim 17, wherein the conductive materials are noble metal.

21. A channel display system for monitor recorded multicellular signals, comprising:

A) a device for recording multichannel neural signals directly from a central nervous system and broadcasting the signals, wherein the device has electrodes with staggered tips, each electrode is sized to have a surface area greater than 400 μ

m², and each electrode is for detecting multicellular signals;

B) an external receiver for receiving the multicellular signals;

C) electric connection means for connecting to an external receiver to relay the signals; and

D) a visual display for displaying the signals in a matrix, wherein each cell of the matrix represents a separate neural data channel.

22. The channel display system according to claim 21, wherein the visual display comprises an LED, wherein the intensity of illumination of the LED is a positive function of the level of neural signals fed from the related neural data channel.

23. The channel display system according to claim 21, wherein the visual display comprises a computer screen, wherein the color of each cell of the display matrix on the screen is coded according to the level of neural signals fed from the related neural data channel.

24. A system for collecting multicellular signals directly from a central nervous system and for transmitting processed signals to a device, comprising:

a sensor for detecting multicellular signals directly from the central nervous system, the sensor having a plurality of electrodes for being implanted near the central nervous system to allow for chronic detection of the multicellular signals, each electrode for detecting multicellular signals from the central nervous system; and

an interface for receiving the multicellular signals from the sensor, for processing the multicellular signals to generate processed signals, and for transmitting the processed signals to the device; and

the device for receiving the processed signals;

wherein the interface conducts adaptive processing of the multicellular signals so that the system responds to changes in the multicellular signals.

25. The system as set forth in claim 24, wherein the sensor is for being implanted into the brain.

26. The system as set forth in claim 24, wherein the device delivers the processed signals to a prosthetic device.

27. The system as set forth in claim 24, wherein the device delivers the processed signals to muscular tissue.

28. The system as set forth in claim 24, wherein the device is a prosthetic device.

29. The system as set forth in claim 24, wherein the electrodes of the sensor are formed of noble metal.

30. The system as set forth in claim 24, wherein the electrodes comprise wires and the sensor comprises a wire bundle.

31. The system as set forth in claim 24, wherein the electrodes are mounted to a substrate.

32. The system as set forth in claim 24, wherein the sensor is for being implanted into a skull and the interface is connected to the sensor through the skull.

33. The system as set forth in claim 24, wherein the sensor is for being implanted into a skull and the interface is located entirely external to the skull and is coupled to the sensor through a wireless connection.

34. The system as set forth in claim 24, wherein the interface processes the signals for controlling the device.

35. The system as set forth in claim 24, further comprising a movement calibration system for calibrating the multicellular signals with movement of the device.

36. The system as set forth in claim 24, wherein the interface includes a neural network.

37. The system as set forth in claim 36, wherein the neural network comprises an artificial neural network.

38. The system as set forth in claim 24, wherein the interface maps the multicellular signals onto an output parameter.

39. The system as set forth in claim 38, wherein the interface comprises a neural network.

40. The system as set forth in claim 24, wherein the interface shapes the processed signal for control of the device.

41. The system as set forth in claim 40, wherein the interface comprises a neural network.

42. The system as set forth in claim 41, wherein the interface further includes an interface controller for receiving an output of the neural network.