Lower limb prosthesis and control unit
First Claim
1. A self-teaching lower limb prosthesis for an above-knee amputee, the prosthesis comprising:
- an upper limb portion and a lower limb portion connected to each other by a knee joint that allows flexion and extension of the limb portions relative to each other; and
a dynamically adjustable knee movement control unit arranged to control flexion and/or extension movements of the knee joint of the prosthesis so as to adjust the rate at which the knee joint swings, wherein the control unit comprises;
an electronic storage device storing a target relationship between walking speed and a parameter that is a ratio of (i) a flexed state duration of an amputee'"'"'s gait during use of the prosthesis to (ii) one of an extended state duration and a total cycle period of the amputee'"'"'s gait during use of the prosthesis, the relationship defining a plurality of values of the parameter associated with different respective walking speeds,a monitoring system comprising a sensor arranged to sense flexion and extension movements of the knee joint and a processor that receives signals from the sensor and processes the signals to generate monitoring signals representative of walking speed values and values of the parameter occurring during use of the prosthesis at different walking speeds, andan adjustment system arranged to adjust the control unit automatically in response to said monitoring signals indicating deviation of the parameter from the target relationship, such that;
when the parameter is below the target relationship at a given walking speed the adjustment system adjusts the control unit to reduce the rate at which the knee joint swings; and
when the parameter is above the target relationship at a given walking speed the adjustment system adjusts the control unit to increase the rate at which the knee joint swings.
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Accused Products
Abstract
A self-teaching lower limb prosthesis, for an above-knee amputee, including a dynamically adjustable joint movement control unit arranged to control operation of the joint automatically. A control unit electrically stores a target relationship between a kinetic or kinematic parameter of locomotion and walking speed. The relationship defines a number of values of the parameter associated with different walking speeds. The control unit generates monitoring signals representative of walking speed values and values of the parameter occurring at different walking speeds. An adjustment system adjusts the control unit automatically when the monitoring signals indicate deviation from the target relationship so as to bring the parameters close to that defined by the target relationship.
40 Citations
12 Claims
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1. A self-teaching lower limb prosthesis for an above-knee amputee, the prosthesis comprising:
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an upper limb portion and a lower limb portion connected to each other by a knee joint that allows flexion and extension of the limb portions relative to each other; and a dynamically adjustable knee movement control unit arranged to control flexion and/or extension movements of the knee joint of the prosthesis so as to adjust the rate at which the knee joint swings, wherein the control unit comprises; an electronic storage device storing a target relationship between walking speed and a parameter that is a ratio of (i) a flexed state duration of an amputee'"'"'s gait during use of the prosthesis to (ii) one of an extended state duration and a total cycle period of the amputee'"'"'s gait during use of the prosthesis, the relationship defining a plurality of values of the parameter associated with different respective walking speeds, a monitoring system comprising a sensor arranged to sense flexion and extension movements of the knee joint and a processor that receives signals from the sensor and processes the signals to generate monitoring signals representative of walking speed values and values of the parameter occurring during use of the prosthesis at different walking speeds, and an adjustment system arranged to adjust the control unit automatically in response to said monitoring signals indicating deviation of the parameter from the target relationship, such that; when the parameter is below the target relationship at a given walking speed the adjustment system adjusts the control unit to reduce the rate at which the knee joint swings; and when the parameter is above the target relationship at a given walking speed the adjustment system adjusts the control unit to increase the rate at which the knee joint swings. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A self-teaching lower limb prosthesis for an above-knee amputee, wherein the prosthesis includes a knee joint and a dynamically adjustable knee movement control unit arranged to control flexion and/or extension movement of the knee joint of the prosthesis according to speed of walking so as to adjust the rate at which the knee joint swings, the control unit including an electronic storage device storing a target relationship between walking speed and a parameter of locomotion that is a ratio of (i) a flexed state duration of an amputee'"'"'s gait during use of the prosthesis to (ii) one of an extended state duration and a total cycle period of the amputee'"'"'s gait during use of the prosthesis, the relationship defining a plurality of values of the parameter of locomotion associated with different respective walking speed ranges, settings of the control unit for the different walking speed ranges being obtained by comparing sensed values of said parameter of locomotion with target values of the parameter respectively associated with the walking speed ranges such that when the sensed value of the parameter is below the target value at a given walking speed the adjustment system adjusts the control unit to reduce the rate at which the knee joint swings, and when the sensed value of the parameter is above the target value at a given walking speed the adjustment system adjusts the control unit to increase the rate at which the knee joint swings, and wherein the control unit is operable to dynamically adjust boundaries between neighbouring walking speed ranges in response to a distribution of measured walking speed samples within the ranges thereby to adapt the ranges to the walking characteristics of the amputee.
Specification