Lower limb prosthesis and control unit
First Claim
1. A lower limb prosthesis for an above-knee amputee, the prosthesis including a dynamically adjustable knee movement control unit arranged to control flexion and/or extension of a knee joint of the prosthesis automatically in response to a sensed step-to-step variability of at least one kinetic or kinematic parameter of locomotion in order to reduce the degree of variation between different values of the at least one kinetic or kinematic parameter associated with different respective steps taken by the amputee during locomotion.
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Accused Products
Abstract
A lower limb prosthesis for an above-knee amputee that includes a dynamically adjustable knee movement control unit arranged to control flexion and/or extension of a knee joint of the prosthesis automatically in response to a sensed step-to-step variability of at least one kinetic or kinematic parameter of locomotion in order to reduce the step-to-step variability.
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Citations
23 Claims
- 1. A lower limb prosthesis for an above-knee amputee, the prosthesis including a dynamically adjustable knee movement control unit arranged to control flexion and/or extension of a knee joint of the prosthesis automatically in response to a sensed step-to-step variability of at least one kinetic or kinematic parameter of locomotion in order to reduce the degree of variation between different values of the at least one kinetic or kinematic parameter associated with different respective steps taken by the amputee during locomotion.
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9. A lower limb prosthesis including
a dynamically adjustable control device for controlling movement of the prosthesis during locomotion, a transducer for generating a sensing signal related to a kinematic parameter of locomotion, and an electronic control circuit having an input coupled to the transducer and an output coupled to the control device, wherein the transducer and the control circuit are configured to determine the variability of the kinematic parameter and to generate output signals for adjusting the control device thereby to reduce the step-to-step variability of the kinematic parameter so as to obtain an optimum setting of the control device, the step-to-step variability being the degree of variation between different values of the kinematic parameter associated with different respective steps taken by the amputee during locomotion.
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17. A control system for a lower limb prosthesis comprising
an input for connection to a transducer on the prosthesis which produces an electrical transducer signal in response to flexion or extension of a joint of the prosthesis, an output for connection to a dynamically adjustable control device associated with the joint for influencing the operation of the joint during locomotion, and a processor circuit arranged to compute, from the transducer signal received at the input, a variability value indicative of the variability of a kinetic or kinematic parameter of locomotion between different steps over a period of time and, automatically in response to the variability value fulfilling a predetermined condition or conditions, to produce an output signal causing the control device to be adjusted in a manner such as to reduce said variability of the kinetic or kinematic parameter.
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19. A method of controlling a lower limb prosthesis for an above-knee amputee comprising:
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sensing a step-to-step variability of at least one kinetic or kinematic parameter of locomotion; and
controlling flexion and/or extension of a knee joint of the prosthesis automatically in response to the sensing step in a manner such that said step-to-step variability is reduced, the variability being the degree of variation between different values of said at least one kinetic or kinematic parameter associated with different respective steps taken by the amputee during locomotion. - View Dependent Claims (20)
wherein the controlling step comprises automatically adjusting a control device associated with the knee joint for variably resisting flexion and/or extension of the knee joint.
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21. A method of controlling a lower limb prosthesis for an above-knee amputee comprising:
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generating a signal indicative of a step-to-step variability of at least one kinetic or kinematic parameter of locomotion sensed over a plurality of steps taken by the amputee, the variability being the degree of variation between different values of the at least one kinetic or kinematic parameter associated with different respective steps taken by the amputee during locomotion;
adjusting a control device which controls flexion and/or extension of a knee joint of the prosthesis automatically in response to the signal indicative of a step-to-step variability obtained in the generating step; and
repeating the generating and adjusting steps in an iterative process so as to progressively reduce said step-to-step variability substantially to a minimum.
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22. A self-teaching method for a lower limb prosthesis for an above-knee amputee, the prosthesis including a dynamically adjustable knee movement control device, a transducer for producing a signal representative of a kinetic or kinematic parameter of locomotion, and a processing circuit coupled to the transducer and the control device, wherein the method comprises:
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producing a transducer output signal representative of values of said kinetic or kinematic parameter during locomotion;
processing the transducer output signal in the processing circuit to generate a signal representative of a level of the step-to-step variability of said kinetic or kinematic parameter over a plurality of steps taken by the amputee;
generating an adjusting signal and feeding it to the knee movement control device to dynamically adjust the control device thereby altering the degree to which the control device affects knee joint flexion and/or extension in subsequent steps, the adjusting signal being generated in response to said signal representative of a level of the step-to-step variability such that the adjustment causes said variability to be reduced substantially to a minimum as locomotion proceeds.
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23. A self-teaching lower limb prosthesis for an above-knee amputee comprising upper and lower leg components, a knee joint mechanism which interconnects the upper and lower leg components and which includes a knee movement control device, and an electronic control system comprising a transducer producing a transducer output signal representative of values of a kinetic or kinematic parameter of locomotion and a processing circuit coupled to the transducer, the processing circuit receiving the transducer output signal and, in response thereto, generating a signal representative of variability of said kinetic or kinematic parameter from step to step, wherein the knee movement control device includes an adjusting element for varying the degree to which it affects flexion and/or extension of the knee joint mechanism and wherein the processing circuit has an output connected to the adjusting element to set the control device for subsequent steps and provides to the output in response to the signal representative of variability an adjusting signal which dynamically adjusts the adjusting element so as to cause variability of said kinetic or kinematic parameter to be reduced substantially to a minimum.
Specification