System and method for providing a sense of feel in a prosthetic or sensory impaired limb

• US 6,500,210 B1
• Filed: 12/10/1996
• Issued: 12/31/2002
• Est. Priority Date: 09/08/1992
• Status: Expired due to Fees

• Current Assignee: Novacare Orthotics & Prosthetics East, Inc.
• Original Assignee: Seattle Systems Incorporated
• Inventors: Ortega, Giovani M., Sabolich, John A., Schwabe, G. Blaine IV
• Primary Examiner(s): Willse, David H.
• Application Number:
  US08/763,012
• Time in Patent Office: 2,212 Days
• Field of Search: 623/24, 623/25, 623/27, 623/57, 600/592, 414/5, 731/72, 737/69, 737/71, 737/72, 738/654
• US Class Current: 623/24
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61F 2/583 Hands; Wrist joints
• CPC Class Codes: A61F 2/586 Fingers
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/68 Operating or control means
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2/80 Sockets, e.g. of suction type
• CPC Class Codes: A61F 2002/5058 having means for restoring the perception of senses
• CPC Class Codes: A61F 2002/5061 the sense of touch
• CPC Class Codes: A61F 2002/5063 the feeling of temperature, i.e. of warmth or cold
• CPC Class Codes: A61F 2002/543 Lower arms or forearms
• CPC Class Codes: A61F 2002/587 Thumbs
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6621 Toes
• CPC Class Codes: A61F 2002/6642 Heels
• CPC Class Codes: A61F 2002/665 Soles
• CPC Class Codes: A61F 2002/6657 having a plate-like or strip-like spring element, e.g. an energy-storing cantilever spring keel
• CPC Class Codes: A61F 2002/6827 Feedback system for providing user sensation, e.g. by force, contact or position
• CPC Class Codes: A61F 2002/704 : computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 : Electromagnetic data transfer for implantable prostheses A61F2250/0002
• CPC Class Codes: A61F 2002/7635 : for measuring force, pressure or mechanical tension

Abstract

An apparatus for providing a person with stimuli corresponding to an external operation on a sensor of a prosthetic device used in conjunction with a prosthetic or sensory impaired limb. A lower limb prosthesis includes sensors located in a prosthetic foot, contacts in the socket producing stimuli felt on the residual limb, and an electronic unit to adjust and control the magnitude of the stimuli. The sensors are either inductance-based or resistance-based. An upper limb prosthesis comprises a pressure sensor located in the thumb of a prosthetic hand, a vibrating motor generating sensations felt in the residual limb and an electronic circuit to control the vibrating motor and to adjust the intensity of the vibrations. An apparatus for a sensory impaired limb providing a sense of feel to a remote but unimpaired body part are constructed in a similar manner.

Claims

1. A method for providing sensory perceptions in a sensor system of a prosthetic device, the method comprising:

sensing an external operation magnitude from a plurality of sensor groups, each sensor group sensing a fraction of the external operation magnitude;

generating a plurality of sensory inputs from the sensor groups in response to the external operation;

generating an electrical input signal with a magnitude;

controlling the electrical input signal with the plurality of sensory inputs to create a plurality of sensory output signals collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical input signal magnitude, each sensory output signal having a fraction of the stimulus magnitude corresponding to the fraction of the external operation magnitude sensed by one of the sensor groups; and

transmitting each of the sensory output signals to a designated one of a plurality of contacts through a designated one of a plurality of channels;

wherein the plurality of contacts comprises a non-floating ground contact and a floating ground contact, and wherein the method further comprises creating a potential difference between the floating ground contact and the non-floating ground contact and creating a partial circuit path from the non-floating ground contact through a residual limb and then to the floating ground contact.

2. A method for providing sensory perceptions in a sensor system of a prosthetic device, the method comprising:

sensing an external operation magnitude from a plurality of sensor groups, each sensor group sensing a fraction of the external operation magnitude;

generating a plurality of sensory inputs from the sensor groups in response to the external operation, wherein the plurality of sensory inputs are in a plurality of sensory input signals;

generating an electrical input signal with a magnitude;

controlling the electrical input signal with the plurality of sensory inputs to create a plurality of sensory output signals collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical input signal magnitude, each sensory output signal having a fraction of the stimulus magnitude corresponding to the fraction of the external operation magnitude sensed by one of the sensor groups; and

transmitting each of the sensory output signals to a designated one of each of a plurality of contacts through a designated one of a plurality of channels;

wherein controlling the output comprises;

processing the sensory input signals to create a plurality of control signals; and

controlling the electrical input signal with the control signals by applying the control signals to the electrical input signal to create the plurality of sensory output signals;

wherein the controlling the output step comprises digitally processing the electrical input signal with the plurality of sensory input signals;

wherein processing the sensory input signals comprises;

counting frequency pulse data in the sensory input signals within a discrete time frame; and

processing the frequency pulse data to determine the fraction of the stimulus magnitude to be generated in each of the sensory output signals.

3. A method for providing sensory perceptions in a sensor system of a prosthetic device, the method comprising:

sensing an external operation magnitude from a plurality of sensor groups, each sensor group sensing a fraction of the external operation magnitude;

generating a plurality of sensory inputs from the sensor groups in response to the external operation, wherein the plurality of sensory inputs are in a plurality of sensory input signals;

generating an electrical input signal with a magnitude;

controlling the electrical input signal with the plurality of sensory inputs to create a plurality of sensory output signals collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical input signal magnitude, each sensory output signal having a fraction of the stimulus magnitude corresponding to the fraction of the external operation magnitude sensed by one of the sensor groups; and

transmitting each of the sensory output signals to a designated one of each of a plurality of contacts through a designated one of a plurality of channels;

wherein controlling the output comprises;

processing the sensory input signals to create a plurality of control signals; and

controlling the electrical input signal with the control signals by applying the control signals to the electrical input signal to create the plurality of sensory output signals;

wherein the controlling the output step comprises digitally processing the electrical input signal with the plurality of sensory input signals;

wherein processing the sensory input signals comprises;

counting frequency pulse data in the sensory input signals within a discrete time frame; and

processing the frequency pulse data to determine the fraction of the stimulus magnitude to be generated in each of the sensory output signals;

wherein receiving the sensory input signals into a frequency counter comprises;

counting the frequency pulse data in the sensory input signals as binary values in a binary counter within a discrete time frame; and

storing the binary values for a delay time before transmitting the binary values.

4. A sensory feedback system for use with a prosthetic device comprising:

a power source adapted to transmit an electrical input signal;

a plurality of sensors each operable to create a sensory input in response to an external operation thereon;

a plurality of contacts each adapted to receive a sensory output signal;

a plurality of channels each connected to one of the plurality of contacts and adapted to carry one of the sensory output signals to the contact to which it is connected; and

a control and processing center adapted to receive the electrical input signal from the power source and to receive the sensory inputs from the sensors, to create the sensory output signals by processing the sensory inputs to create processed input signals and applying each of the processed input signals to the electrical input signal so that each sensory output signal has a particular stimulus with a particular stimulus level that corresponds to a particular processed input signal, and to transmit the sensory output signals to the contacts through the channels.

5. The sensory feedback system of claim 4 wherein the sensors comprise an inductance-based pressure sensor.

6. The sensory feedback system of claim 5 wherein the inductance-based pressure sensor is comprised of an inductance-based coil pressure sensor.

7. The sensory feedback system of claim 4 wherein the sensors comprise a resistance-based pressure sensor.

8. The sensory feedback system of claim 4 wherein the sensors comprise resistance-based pressure sensors having an electrical resistance, wherein the external operation comprises pressure, and wherein:

the control and processing center is adapted to deactivate the power source in response to resistance in each resistance-based pressure sensor which is greater than a selected level of electrical resistance and to activate the power source in response to resistance in any of the resistance-based pressure sensors which is less than the selected level of electrical resistance.

9. The sensory feedback system of claim 4 wherein the electrical input signal has a frequency and the sensory output signals have a frequency corresponding to the electrical input signal frequency, and wherein the sensory feedback system further comprises a frequency controller adapted to modify the frequency of the electrical input signal, thereby causing the frequency of the sensory output signals to be modified.

10. The sensory feedback system of claim 4 wherein one of the contacts comprises a floating ground contact.

11. The sensory feedback system of claim 4 wherein the control and processing center comprises an analog circuit.

12. The sensory feedback system of claim 11 wherein the electrical input signal has a magnitude and wherein the analog circuit comprises:

an oscillating circuit adapted to receive the electrical input signal from the power source and to oscillate the electrical input signal;

a transformer circuit adapted to receive the electrical input signal from the oscillator circuit and to increase the magnitude of a voltage; and

a trigger circuit adapted to receive the electrical input signal from the transformer circuit and to apply each of the sensory inputs to the electrical input signal to create the sensory output signals.

13. The sensory feedback system of claim 4 wherein the control and processing center comprises an integrated circuit.

14. The sensory feedback system of claim 12 wherein each of the sensory output signals has a stimulus, and wherein the control and processing center comprises:

a processing center adapted to receive the sensory inputs from the sensors and to process the sensory inputs to create a plurality of control signals, each of the plurality of control signals designated to define the stimulus of one of the sensory output signals; and

an isolator adapted to receive the plurality of control signals and to receive the electrical input signal, to apply the control signals to the electrical input signal to create the sensory output signals, and to transmit each of the sensory output signals through a designated one of the channels to a designated one of the contacts.

15. The sensory feedback system of claim 14 wherein the isolator is adapted to modify the frequency of the electrical input signal.

16. The sensory feedback system of claim 4 wherein the control and processing center comprises:

a frequency counter adapted to receive the sensory inputs within a designated time frame;

a process converter adapted to receive from the frequency counter the sensory inputs and to process the sensory inputs to create a plurality of control signals; and

an isolator adapted to control an output of the electrical input signal, the isolator adapted to receive the electrical input signal from the power source, to receive the control signals from the process converter, and to apply the control signals to the electrical input signal to create the sensory output signals.

17. The sensory feedback system of claim 16 wherein the power source transmits an electrical power signal, and wherein the system further comprises:

a sensor controller adapted to receive the electrical power signal from the power source, to transmit the electrical power signal to the sensors, to receive the sensory inputs from the sensors as sensory input signals, and to transmit the sensory input signals to the process converter via the frequency counter.

18. The sensory feedback system of claim 17 wherein the process converter is adapted to select a designated one of the sensors to receive the electrical power signal and to generate a process control signal identifying the designated sensor, and wherein the sensor controller comprises:

an oscillator adapted to receive the electrical power signal and to oscillate the electrical power signal; and

a multiplexer adapted to receive the oscillating electrical power signal from the oscillator, to receive a process control signal from the process converter, and, in response, to transmit the oscillating electrical power signal to the designated sensor.

19. The sensory feedback system of claim 17 wherein the power source comprises:

a battery adapted to transmit the electrical power signal and the electrical input signal, the electrical input signal having a magnitude; and

a transformer circuit adapted to receive the electrical input signal, to oscillate the electrical input signal, to modify the magnitude of the electrical input signal, and to transmit the modified oscillating electrical input signal to the isolator.

20. The sensory feedback system of claim 19 wherein the process converter comprises:

a processor having a processing program and adapted to receive the sensory input signals from the frequency counter and to process the sensory input signals with the processing program to create intermediate control signals; and

a converter adapted to receive the intermediate control signals from the processor, to translate the intermediate control signals into control signals that can be received and processed by the isolator, and to transmit the control signals to the isolator.

21. The sensory feedback system of claim 20 wherein:

the converter comprises a digital potentiometer adapted to transmit each of the intermediate control signals, each intermediate control signal having a designated voltage magnitude; and

the isolator comprises an optical isolator adapted to receive the intermediate control signals and to convert the designated voltage magnitude of each intermediate control signal into a corresponding resistance value, to receive the electrical input signal, and to apply each of the resistance values to the electrical input signal to create the sensory output signals.

22. The sensory feedback system of claim 20 further comprising an option controller adapted to control a maximum magnitude and a minimum magnitude of a stimulus of the sensory output signals.

23. A sensory feedback system for a prosthetic device comprising:

a power source adapted to transmit an electrical power signal and an electrical input signal;

a control and processing center adapted to receive the electrical input signal and to transmit a plurality of sensory output signals;

a plurality of contacts each adapted to receive a designated one of the sensory output signals;

a plurality of inductance-based pressure sensors each adapted to receive the electrical power signal, to change the electrical power signal to a sensory input signal representing pressure applied thereto, and to transmit the sensory input signal therefrom; and

a sensor controller adapted to route the electrical power signal to each inductance-based pressure sensor and to return the sensory input signal from each inductance-based pressure sensor to the control and processing center;

wherein the control and processing center is further adapted to process the sensory input signals and the electrical input signal to create a plurality of sensory output signals each representing the pressure applied to at least one of the inductance-based pressure sensors, and to transmit the sensory output signals to the contacts.

24. The sensory feedback system of claim 23 wherein the control and processing center selects a designated one of the sensors to receive the electrical input signal and transmits a processor control signal designating the sensor and wherein the sensor controller comprises:

an oscillator adapted to receive the electrical power signal and to oscillate the electrical power signal; and

a multiplexer adapted to receive the oscillating electrical power signal from the oscillator, to receive the processor control signal from the control and processing center, and to transmit the oscillating electrical power signal to the designated sensor.

25. The sensory feedback system of claim 23 wherein the control and processing center is adapted to control the output of the electrical input signal by processing the sensory input signals to create a plurality of control signals and applying the control signals to the electrical input signal to create the sensory output signals.

26. The sensory feedback system of claim 25 wherein the electrical input signal has a voltage magnitude and wherein the control and processing system is adapted to apply the control signals to the electrical input signal to define a current magnitude in each of the sensory output signals.

27. The sensory feedback system of claim 25 wherein the electrical power signal has a frequency and wherein the control and processing center is adapted to control the frequency of the electrical power signal.

28. The sensory feedback system of claim 25 wherein one of the contacts is a floating ground contact adapted to return at least one of the sensory output signals to the control and processing center.

29. The sensory feedback system of claim 25 further comprising a sensor unit adapted to be fitted to a foot wherein the sensor unit comprises the sensors.

30. The sensory feedback system of claim 29 wherein the sensor unit comprises a foam rubber layer.

31. The sensory feedback system of claim 30 wherein the foam rubber layer comprises cellular urethane.

32. The sensory feedback system of claim 31 wherein the cellular urethane has a durometer value in a range of ten to thirty.

33. The sensory feedback system of claim 32 wherein the cellular urethane has a durometer value of approximately fifteen.

34. The sensory feedback system of claim 29 wherein the sensor unit further comprises a foil layer.

35. The sensory feedback system of claim 25 further comprising a prosthesis adapted to be fitted to a residual limb of an amputee wherein the prosthesis comprises the sensors.

36. The sensory feedback system of claim 35 further comprising a sensor unit which contains the sensors.

37. The sensory feedback system of claim 35 wherein the sensor unit comprises a foam rubber layer.

38. The sensory feedback system of claim 37 wherein the foam rubber layer comprises cellular urethane.

39. The sensory feedback system of claim 38 wherein the cellular urethane has a durometer value in a range of ten to thirty.

40. The sensory feedback system of claim 39 wherein the cellular urethane has a durometer value of approximately fifteen.

41. The sensory feedback system of claim 35 wherein the sensor unit further comprises a foil layer.

42. The sensory feedback system of claim 25 wherein the inductance-based pressure sensors comprise a front inductance-based pressure sensor and a back inductance-based pressure sensor, wherein the front pressure is applied to the front inductance based pressure sensor and the back pressure is applied to the back inductance based pressure sensor, and wherein the control and processing center is adapted to transmit sensory output signals to the contacts when the front pressure is not equal to the back pressure.

43. The sensory feedback system of claim 25 wherein the control and processing center comprises:

a frequency counter adapted to receive data in the sensory input signals within a designated time frame;

a process converter adapted to receive the data from the sensory input signals from the frequency counter and to process the data to create a plurality of control signals; and

an isolator operable to control the output of the electrical input signal, the isolator adapted to receive the electrical input signal from the power source, to receive the control signals from the process converter, and to apply the control signals to the electrical input signal to create the sensory output signals.

44. The sensory feedback system of claim 43 wherein the power source transmits an electrical power signal, wherein the process converter selects a designated one of the sensors to receive the electrical input signal, and wherein the sensor controller comprises:

an oscillator adapted to receive the electrical power signal and to oscillate the electrical power signal; and

a multiplexer adapted to receive the oscillating electrical power signal from the oscillator and to transmit the oscillating electrical power signal to the designated sensor.

45. The sensory feedback system of claim 44 wherein the power source comprises:

a battery adapted to transmit the electrical power signal and the electrical input signal, the electrical input signal having a magnitude; and

a transformer circuit adapted to receive the electrical input signal, to oscillate the electrical input signal, to modify the magnitude of the electrical input signal, and to transmit the electrical input signal to the isolator.

46. The sensory feedback system of claim 45 wherein the process converter comprises:

a processor having a processing program and adapted to receive from the frequency counter the data from the sensory input signals and to process data with the processing program to create intermediate control signals; and

a converter adapted to receive the intermediate control signals from the processor, to translate the intermediate control signals into control signals that can be received and processed by the isolator, and to transmit the control signals to the isolator.

47. The sensory feedback system of claim 46 wherein:

the converter comprises a digital potentiometer, the digital potentiometer transmitting each of the intermediate control signals, each intermediate control signal having a designated voltage magnitude; and

the isolator comprises an optical isolator, the optical isolator adapted to receive the intermediate control signals and to convert each of the intermediate control signals having the designated voltage magnitude to a corresponding resistance value, to receive the electrical input signal, and to apply each of the resistance values to the electrical input signal to create the sensory output signals.

48. The sensory feedback system of claim 47 wherein the electrical input signal has a frequency and wherein the converter is adapted modify the frequency of the electrical input signal.

49. The sensory feedback system of claim 47 further comprising an option controller adapted to control a maximum magnitude and a minimum magnitude of a stimulus in the sensory output signals.

50. The sensory feedback system of claim 47 wherein one of the contacts is a floating ground contact.

51. The sensory feedback system of claim 23 wherein the control and processing center is adapted to transmit the sensory output signals to the contacts after the pressure applied to the inductance-based pressure sensors exceeds a pressure threshold.

52. The sensory feedback system of claim 23 wherein the control and processing center is adapted to transmit the sensory output signals to the contacts after pressure is applied to the inductance-based pressure sensors for a time exceeding a time threshold.

53. The sensory feedback system of claim 23 wherein:

the inductance-based pressure sensors comprise a front inductance-based pressure sensor and a back inductance-based pressure sensor;

the contacts comprise a front contact and a back contact, wherein the pressure comprises a total pressure comprising a front pressure and a back pressure;

the front pressure is applied to the front inductance based pressure sensor and the back pressure is applied to the back inductance based pressure sensor;

the control and processing center is adapted to transmit a front sensory output signal and a back sensory output signal collectively having a total magnitude; and

the control and processing center is adapted to transmit the front sensory output signal to the front contact having a stimulus with a stimulus magnitude having a proportion of the total magnitude corresponding to a proportion of the front pressure with respect to the total pressure and to transmit the back sensory output signal to the back contact having a stimulus with a stimulus magnitude having a proportion of the total magnitude corresponding to a proportion of the back pressure with respect to the total pressure.