Control system and method for controlling an actuated prosthesis

• US 20040049290A1
• Filed: 06/20/2003
• Published: 03/11/2004
• Est. Priority Date: 08/22/2002
• Status: Active Grant

• Current Assignee: Victhom Laboratory Inc (Ergoresearch Ltd.)
• Original Assignee: Victhom Human Bionics Inc. (Ergoresearch Ltd.)
• Inventors: Bedard, Stephane
• Granted Patent: US 7,147,667 B2
• Time in Patent Office: Days
• US Class Current: 623/24
• CPC Class Codes: A61F 2/644 of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2/6607 Ankle joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer
• CPC Class Codes: A61F 2002/762 for measuring dimensions, e.g. a distance
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• CPC Class Codes: A61F 2002/763 for measuring spatial position, e.g. global positioning system [GPS]
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/7645 for measuring torque, e.g. hinge or turning moment, moment of force
• CPC Class Codes: A61F 2002/7685 located on natural or sound-site limbs, e.g. comparison measuring means

Abstract

The method and the control system are used for determining a portion of locomotion and a phase of locomotion portion in view of controlling an actuated prosthesis in real time. Accordingly, the method comprises receiving a data signal from a plurality of main artificial proprioceptors, obtaining a first and a second derivative signal for each data signal, obtaining a third derivative signal for at least one of the data signals, using a set of a first state machines to select one state among a plurality of possible states for each artificial proprioceptor with the corresponding data and derivative signals, generating the phase of locomotion portion using the states of the main artificial proprioceptors; and using a second state machine to select the portion of locomotion among a plurality of possible portions of locomotion using events associated to the data signals. It is particularly well adapted for the control of an actuated leg prosthesis for above-knee amputees.

Claims

1. A method for determining a portion of locomotion and a phase of locomotion portion in view of controlling an actuated prosthesis in real time, the method comprising;

providing a plurality of main artificial proprioceptors;

receiving a data signal from each of the main artificial proprioceptors;

obtaining a first and a second derivative signal of at least some of the data signals;

obtaining a third derivative signal for at least one of the data signals;

using a set of a first state machines to select one state among a plurality of possible states for each main artificial proprioceptor with the corresponding data and derivative signals;

generating the phase of locomotion portion using the states of the main artificial proprioceptors; and

using a second state machine to select the portion of locomotion among a plurality of possible portions of locomotion using events associated to the data signals.

2. The method according to claim 1, further comprising:

pre-processing the data signals before obtaining the derivative signals.

3. The method according to claim 2, wherein the pre-processing comprises:

filtering the data signals; and

normalizing the data signals; and

binary formatting the data signals for adapting them to input specifications of the first state machines.

4. The method according to claim 3, where in the step of normalizing the data signals comprises:

converting the data signals using first conversion coefficients obtained during a zero-calibration procedure.

converting the data signals using second conversion coefficients obtainted during a weight-calibration procedure.

5. The method according to claim 1, wherein the main artificial proprioceptors include plantar pressure sensors, the method comprising:

sensing the plantar pressure at a plurality of locations, the data signals from the plantar pressure sensors being indicative of the plantar pressure at these locations.

6. The method according to claim 5, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including an angular position sensor provided between two movable parts of the prosthesis, the method comprising:

generating a data signal indicative of the angular position between the two movable parts, the data signal from the angular position sensor being used in at least one of the events in the second state machine.

7. The method according to claim 5, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including two angular velocity sensors, one being provided on a shank of a non-amputee l g and the other being on a residual limb, the Method comprising:

generating data signals indicative of th angular velocity measured at ach angular velocity sensor, the data signals from the angular velocity sensors being used in at least one of the events in the second state machine.

8. The method according to claim 5, wherein the plantar pressure is sensed for at least four locations, two of the locations being at a right foot and two of the locations being at a left foot.

9. The method according to claim 8, wherein one of the locations at the right foot and one at the left foot are at a calcaneus region, another one of th locations at the right foot and one at the left foot are at a metatarsophalangeal region.

10. The method according to claim 9, wherein the right and left plantar pressure sensors are provided in corresponding insoles.

11. The method according to claim 9, wherein one of the feet is an artificial foot, the other being a natural foot.

12. The method according to claim 9, wherein both feet are artificial feet.

13. The method according to claim 9, wherein the step of obtaining the third derivative signal for at least one of the data signals comprises:

obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneus region of the right foot; and

obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneous region of the left foot.

14. The method according to claim 13, further comprising:

calculating complementary signals from at least some of the data signals, the states of the main artificial proprioceptors being selected with data, complementary and derivative signals.

15. The method according to claim 14, wherein the step of calculating complementary signals comprises:

calculating a first complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the left foot;

calculating a second complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the right foot;

calculating a third complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot;

calculating a fourth complementary signal using the data signals indicative of the plantar pressure at the metatarsophalangeal region of the right foot and that of the left foot; and

calculating a fifth complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot, and the metatarsophalangeal region of the right foot and that of the left foot.

16. The method according to claim 1, wherein the step of generating the phase of locomotion portion using the states of the main artificial proprioceptors comprises:

appending binary lab Is representing the state of each main artificial proprioceptor to create a binary label representing the phas of locomotion portion.

17. The method according to claim 1, wherein the step of receiving the data signal from each of the main artificial proprioceptors comprises:

receiving at least some of the data signals from a wireless transmission.

18. A method for controlling an actuated prosthesis in real time, the method comprising:

providing a plurality of main artificial proprioceptors;

receiving a data signal from each of the main artificial proprioceptors;

obtaining a first and a second derivative signal for at least some of the data signals;

obtaining a third derivative signal for at least one of the data signals;

using a set of first state machines to select one state among a plurality of possible states for each main artificial proprioceptor with the corresponding data and derivative signals;

generating the phase of locomotion portion using the states of the main artificial proprioceptors;

using a second state machine to select the portion of locomotion among a plurality of possible portions of locomotion using events associated to the data signals;

calculating a locomotion speed value;

determining coefficient values from a lookup table using the phase of locomotion portion, the portion of locomotion and the locomotion speed value;

calculating at least one dynamic parameter value of the actuated prosthesis using the coefficient values from the lookup table and at least some of the data signals, and

converting the dynamic parameter value into an output signal to control th actuated prosthesis.

19. The method according to claim 18, wherein the step of determining coefficient values from the lookup table comprises using the phase of locomotion portion, the portion of locomotion, the locomotion speed value and the data signals, the data signals being in binary formatted.

20. The method according to claim 18, wherein the actuated prosthesis is an actuated leg prosthesis for above-knee amputees, the step of calculating at least one dynamic parameter value comprising;

calculating at least one torque value and angular position value.

21. The method according to claim 19, wherein the actuated prosth sis includes an actuator using electric power, the output signal being indicative of the electrical power to be supplied to the actuator.

22. The method according to claim 21, further comprising:

adjusting the output signal in response to at least one feedback signal received from the prosthesis.

23. The method according to claim 22, wherein there are at l ast a first and a second feedback signal, the first feedback signal being indicative of a relative angular position measured between two movable parts of a knee joint, and the second feedback signal being indicative of a torque value measured between the two movable parts.

24. The method according to claim 18, further comprising the initial step of.

processing experimental data to create the lookup table.

25. The method according to claim 18, further comprising:

pre-processing the data signals before obtaining the derivative signals.

26. The method according to claim 25, wherein the pre-processing comprises:

filtering the data signals;

normalizing the data signals; and

binary formatting the data signals for adapting them to input specifications of the first state machines.

27. The method according to claim 26, wherein the step of normalizing the data signals comprises.

converting the data signals using first conversion coefficients obtained during a zero-calibration procedure;

and

converting the data signals using second conversion coefficients obtained during a weight-calibration procedure.

28. The method according to claim 18, wher in the main artificial proprioceptors include plantar pressure sensors, the method comprising:

sensing the plantar pressure at a plurality of locations, the data signals being indicative of the plantar pressure at these locations.

29. The method according to claim 28, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including an angular position sensor provided between two movable parts of the prosthesis, the method comprising:

generating a data signal indicative of the angular position between the two movable parts, the data signal from the angular position sensor being used in at least one of the events in the second state machine.

30. The method according to claim 28, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including two angular velocity sensors, one being provided on a shank of a non-amputee leg and the other being on a residual limb, the method comprising:

generating data signals indicative of the angular velocity measured at each angular velocity sensor, the data signals from the angular velocity sensors being used in at least one of the events in the second stat machine.

31. The method according to claim 28, wherein the plantar pressure is sensed for at least four locations, two of the locations being at a right foot and two of the locations being at a left foot.

32. The method according to claim 31, wherein one of the locations at the right foot and one at the left foot are at a calcaneus region, anoth r one of the locations at the right foot and one at the l ft foot are at a metatarsophalangeal region.

33. The method according to claim 32, wherein the right and left plantar pressure sensors are provided in corresponding insoles.

34. The method according to claim 32, wherein one of the feet is an artificial foot, the other being a natural foot.

35. The method according to claim 32, wherein both feet are artificial feet.

36. The method according to claim 32, wherein the step of obtaining the third derivative signal for at least one of the data signals comprises:

obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneous region of the right foot; and

obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneous region of the left foot.

37. The method according to claim 36, further comprising:

calculating complementary signals from at least some of the data signals, the states of the main artificial proprioceptors being selected with data, complementary and derivative signals.

38. The method according to claim 37, wherein the step of calculating the complementary signals comprises;

calculating a first complem ntary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the left foot;

calculating a second complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the right foot;

calculating a third complementary signal using the data signals indicativ of the plantar pressure at the calcaneus region of the right foot and that of the left foot;

calculating a fourth complementary signal using the data signals indicative of the plantar pressure at the metatarsophalangeal region of the right foot and that of the left foot; and

calculating a fifth complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot, and the metatarsophalangeal region of the right foot and that of the left foot.

39. The method according to claim 18, wherein the step of generating the phase of locomotion portion using the states of the main artificial proprioceptors comprises:

appending binary labels representing the state of each main artificial proprioceptor to create a binary label representing the phase of locomotion portion.

40. The method according to claim 18, wherein the step of receiving th data signal from each of the main artificial proprioceptors comprises:

receiving at least some of the data signals from a wir less transmission.

41. A device for determining a portion of locomotion and a phase of locomotion portion in view of controlling an actuated prosthesis in real time using a plurality of main artificial proprioceptors, the device comprising:

a data signal input for each of the main artificial proprioceptors;

means for obtaining a first and a second derivative signal for at least some of the data signals;

means for obtaining a third derivative signal for at least one of the data signals;

a set of first state machines, the first state machines being used to select one state among a plurality of possible states for each artificial proprioceptor with the corresponding data and derivative signals;

means for generating the phase of locomotion portion using the states of the main artificial proprioceptors; and

a second state machine, the second state means being used to select th portion of locomotion among a plurality of possible portions of locomotion using events associated to the data signals.

42. The device according to claim 41, further comprising;

a first output to output a first output signal indicative of the state of the main artificial proprioceptors;

a second output to output a second output signal indicative of the phase of locomotion portion; and

a third output to output a third output signal indicative of the portion of locomotion.

43. The device according to claim 41, further comprising:

means for pre-processing the data signals before obtaining the derivative signals.

44. The device according to claim 43, wherein the means for pre-processing the data signals comprise:

means for filtering the data signals;

means for normalizing the data signals; and

means for binary formatting the data signals to adapt them to input specifications of the first state machines.

45. The device according to claim 44, further comprising:

means for converting the data signals using first conversion coefficients obtained a zero-calibration procedure.

means for converting the data signals using second conversion coefficients obtained a weight-calibration procedure.

46. The device according to claim 41, wherein the main artificial proprioceptors are plantar pressure sensors, the device comprising

means for sensing the plantar pressure at a plurality of locations, the data signals being indicative of the plantar pressure at these locations.

47. The device according to claim 46, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including an angular position s nsor provided between two movable parts of the prosthesis, the angular position sensor generating a data signal indicativ of the angular position between the two movabl parts, the data signal from the angular position sensor being used in at least one of the events in the second state machine.

48. The device according to claim 46, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including two angular velocity sensors, one being provided on a shank of a non-amputee leg and the other being on a residual limb, the angular velocity sensors generating data signals indicative of the angular velocity measured at each angular velocity sensor, the data signals from the angular velocity sensors b ing used in at least one of the events in the second state machine.

49. The device according to claim 46, wherein the plantar pressure is sensed for at least four locations, two of the locations being at a right foot and two of the locations being at a left foot.

50. The device according to claim 47, wherein one of the locations at the right foot and one at the left foot are at a calcaneus region, another one of the locations at the right foot and one at the left foot are at a metatarsophalangeal region.

51. The device according to claim 50, wherein the right and left plantar pressure sensors are provided in corresponding insoles.

52. The device according to claim 50, wherein one of the feet is an artificial foot, the other being a natural foot.

53. The device according to claim 50, wherein both feet are artificial feet.

54. The device according to claim 50, wherein the means for obtaining the third derivative signal for at least one of the data signals comprise:

means for obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneous region of the right foot; and

means for obtaining the third derivative for the data signal indicative of the plantar pressure at the calcaneous region of the left foot.

55. The device according to claim 54, wherein further comprising:

means for calculating complementary signals from at least some of the data signals, the states of the main artificial proprioceptors being selected with data, complementary and derivative signals.

56. The device according to claim 55, wherein the means for calculating complementary signals comprise:

means for calculating a first complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the left foot;

means for calculating a second complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the right foot;

means for calculating a third complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot;

means for calculating a fourth complementary signal using the data signals indicative of the plantar pressure at the metatarsophalangeal region of the right foot and that of the left foot; and

means for calculating a fifth complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot, and the metatarsophalangeal region of the right foot and that of the left foot.

57. The device according to claim 41, wherein the means for generating the phase of locomotion portion using the states of the main artificial proprioceptors comprise:

means for appending binary labels representing the state of each main artificial proprioceptor to create a binary label representing the phase of locomotion portion.

58. The device according to claim 41, further comprising:

means for receiving at least some of the data signals from a wireless transmission.

59. A control system for controlling an actuated prosthesis in real time, the system comprising;

a plurality of main artificial proprioceptors;

means for obtaining a first and a second derivative signal for at least some of the data signals;

means for obtaining a third derivative signal for at least one of the data signals;

a set of first state machines, the first state machines being used to select one state among a plurality of possible states for each main artificial proprioceptor with the corresponding data and derivativ signals;

means for generating the phase of locomotion portion using the states of the main artificial proprioceptors;

a second state machine, the second state machine being used to select the portion of locomotion among a plurality of possible portions of locomotion using events associated to the data signals;

means for calculating a locomotion speed value;

means for storing a lookup table comprising coefficient values with reference to at least phases of locomotion, portions of locomotion and locomotion speed values;

means for determining actual coefficient values from the lookup table using at least the phase of locomotion portion, the portion of locomotion and the locomotion speed value;

means for calculating at least one dynamic parameter value of the actuated prosthesis using the coefficient values from the lookup table and at least some of the data signals; and

means for converting the dynamic parameter value into an output signal to control the actuated prosthesis.

60. The method according to claim 59, wherein the means for storing the lookup table comprise coefficient values with reference to phases of locomotion, portions of locomotion, locomotion speed values and data signals in a binary format, the means for determining coefficient values from the lookup table using the phase of locomotion portion, the portion of locomotion, the locomotion speed value and the binary formatted data signals.

61. The system according to claim 59, wherein the actuat d prosthesis is an actuated leg prosthesis for above-knee amputees, the means for calculating at least one dynamic parameter value comprising:

means for calculating at least one torque value and angular position valu.

62. The system according to claim 59, wherein the actuated prosthesis includes an actuator using electric power, the output signal being indicative of the electrical power to be supplied to the actuator.

63. The system according to claim 59, further comprising:

means for adjusting the output signal in response to at least one feedback signal received from the prosthesis.

64. The system according to claim 63, wherein there are at least a first and a second feedback signal, the first feedback signal being indicative of a relative angular position measured between two movable parts of a knee joint, and the second feedback signal being indicative of a torque value measured between the two movable parts.

65. The system according to claim 59, wherein the lookup table comprises experimental data obtained using a non-amputee.

66. The system according to claim 59, further comprising:

means for pre-processing the data signals before obtaining the derivative signals.

67. The system according to claim 66, wherein the means for preprocessing comprise:

means for filtering th data signals;

means for normalizing the data signals; and

means for binary formatting the data signals to adapt them to input specifications of the first state machines.

68. The system according to claim 67, wherein the step of normalizing the data signals comprises:

means for converting the data signals using first conversion coefficients obtained during a zero-calibration procedure.

means for converting the data signals using second conversion coefficients obtained during a weight-calibration procedure.

69. The system according to claim 59, wherein the main artificial proprioceptors include plantar pressure sensors, the system comprising:

means for sensing the plantar pressure at a plurality of locations, the data signals being indicative of the plantar pressure at these locations.

70. The system according to claim 69, wherein the plantar pressure is sens d for at least four locations, two of the locations being at a right foot and two of the locations being at a left foot.

71. The system according to claim 69, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including an angular position sensor provided between two movable parts of the prosthesis, the angular position sensor generating a data signal indicative of the angular position b tween the two movable parts, the data signal from the angular position sensor being used in at least one of the events in the second state machine.

72. The system according to claim 69, further comprising auxiliary artificial proprioceptors, the auxiliary artificial proprioceptors including two angular velocity sensors, one being provided on a shank of a non-amputee leg and the other being on a residual limb, the angular velocity sensors generating data signals indicative of the angular velocity measured at each angular velocity sensor, the data signals from the angular velocity sensors being used in at least one of the events in the second state machine.

73. The system according to claim 70, wherein one of the locations at the right foot and one at the left foot are at a calcaneus region, another one of the locations at the right foot and one at the left foot are at a metatarsophalangeal region.

74. The system according to claim 71, wherein the right and left plantar pressure sensors are provided in corresponding insoles.

75. The system according to claim 71, wherein one of the feet is an artificial foot, the other being a natural foot.

76. The system according to claim 71, wherein both feet are artificial feet.

77. The system according to claim 71, wherein the means for obtaining the third derivative signal for at least one of the data signals comprises:

means for obtaining the third derivative for the data signal indicative of th plantar pressure at the metatarsophalangeal region of the right foot; and

means for obtaining the third derivative for the data signal indicativ of th plantar pressure at the metatarsophalangeal region of the left foot.

78. The system according to claim 77, wherein further comprising:

means for calculating complementary signals from at least some of the data signals, the states of the main artificial proprioceptors being selected with data, complementary and derivative signals.

79. The system according to claim 78, wherein the means for calculating the complementary signals from at least some of the data signals include:

means for calculating a first complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the left foot;

means for calculating a second complementary signal using the data signals indicative of the plantar pressure at the calcaneus region and at the metatarsophalangeal region of the right foot;

means for calculating a third complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot;

means for calculating a fourth complementary signal using the data signals indicative of the plantar pressure at the metatarsophalangeal region of the right foot and that of the left foot; and

means for calculating a fifth complementary signal using the data signals indicative of the plantar pressure at the calcaneus region of the right foot and that of the left foot, and the metatarsophalangeal region of the right foot and that of the left foot.

80. The system according to claim 59, wherein the means for generating the phase of locomotion portion using the states of the artificial proprioceptors comprise:

means for appending binary labels representing the state of each artificial proprioceptor to create a binary label representing the phase of locomotion portion.

81. The system according to claim 59, further comprising:

means for receiving at least some of the data signals from a wireless transmission.