Speed-adaptive and patient-adaptive prosthetic knee
First Claim
1. A method of adaptively controlling the stance phase damping of a prosthetic knee worn by a patient, comprising the steps of:
- providing a memory in said prosthetic knee, said memory having stored therein correlations between sensory data and stance phase damping established in clinical investigations of amputees of varying body size;
measuring instantaneous sensory information using sensors local to said prosthetic knee as said patient stands, walks or runs; and
using the instantaneous sensory information in conjunction with said correlations to automatically adjust stance phase damping suitable for said patient without requiring patient specific information to be pre-programmed in said prosthetic knee.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to an automated speed-adaptive and patient-adaptive control scheme and system for a knee prosthesis. The control scheme and system utilizes sensory information measured local to the prosthesis to automatically adjust stance and swing phase knee resistances to a particular wearer under a wide variety of locomotory activities. Advantageously, no patient-specific information needs to be pre-programmed into the prosthetic knee by a prosthetist or the patient. The system is able to adapt to various types of disturbances once the patient leaves the prosthetist'"'"'s facility because it is patient-adaptive and speed-adaptive.
-
Citations
31 Claims
-
1. A method of adaptively controlling the stance phase damping of a prosthetic knee worn by a patient, comprising the steps of:
-
providing a memory in said prosthetic knee, said memory having stored therein correlations between sensory data and stance phase damping established in clinical investigations of amputees of varying body size;
measuring instantaneous sensory information using sensors local to said prosthetic knee as said patient stands, walks or runs; and
using the instantaneous sensory information in conjunction with said correlations to automatically adjust stance phase damping suitable for said patient without requiring patient specific information to be pre-programmed in said prosthetic knee. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of adaptively controlling the swing phase damping torque of a prosthetic knee worn by a patient as the patient travels at various locomotory speeds, ground contact time of a prosthetic foot connected to said prosthetic knee by a prosthetic leg being indicative of the locomotory speed of said patient, said method comprising the steps of:
-
continuously measuring the contact time over periods of one gait cycle as said patient ambulates at various locomotory speeds;
storing the contact time within a memory of said prosthetic knee in time slots corresponding to the locomotory speed of said patient;
iteratively modulating the swing phase damping for knee flexion to achieve a target peak flexion angle range until the damping converges within each time slot;
iteratively modulating the swing phase damping for knee extension to control the impact force of the extending prosthetic leg against an artificial knee cap of said prosthetic knee until the extension damping converges within each time slot; and
using the converged damping values to automatically control swing phase damping at all locomotory speeds. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. An adaptive prosthetic knee for controlling the knee damping torque during stance phase of an amputee, comprising:
-
a controllable knee actuator for providing a variable damping torque in response to command signals;
sensors for measuring the force and moment applied to said prosthetic knee as said amputee moves over a supporting surface;
a controller having a memory and adapted to communicate command signals to said knee actuator and receive input signals from said sensors, said memory having stored therein relationships between sensory data and stance phase damping established in prior clinical investigations of patients of varying body size;
whereby, said controller utilizes sensory data from said sensors in conjunction with said relationships to adaptively and automatically control the damping torque provided by said knee actuator during stance phase independent of any prior knowledge of the size of the amputee. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
the prosthetic knee as recited in claim 24;
a stump socket in mechanical communication with said prosthetic knee and adapted to receive the residual limb of an amputee;
a prosthetic shank portion in mechanical communication with said prosthetic knee; and
a prosthetic foot in mechanical communication with said prosthetic shank portion.
-
-
26. The prosthetic knee of claim 13, wherein said memory has further stored therein converged swing phase damping values for automatically controlling swing phase damping torque at various locomotory speeds substantially without pre-programmed amputee specific information.
-
27. The prosthetic knee of claim 26, wherein said sensors comprise force sensors for determining ground contact time of a prosthetic foot connected to said prosthetic knee for estimating said locomotory speeds.
-
28. The prosthetic knee of claim 13, wherein said memory has further stored therein converged swing phase flexion damping values to achieve a target peak flexion angle range for automatically controlling swing phase flexion damping torque at various locomotory speeds substantially without pre-programmed amputee specific information and said sensors comprise means for determining ground contact time of a prosthetic foot connected to said prosthetic knee for estimating said locomotory speeds, said contact time is stored within said memory in time slots corresponding to said locomotory speeds of said amputee.
-
29. The prosthetic knee of claim 13, wherein said prosthetic knee further comprises a knee cap for providing an extension stop.
-
30. The prosthetic knee of claim 29, wherein said memory has further stored therein converged swing phase extension damping values to control the impact force against said knee cap at full swing phase extension for automatically controlling swing phase extension damping torque at various locomotory speeds substantially without pre-programmed amputee specific information and said sensors comprise means for determining ground contact time of a prosthetic foot connected to said prosthetic knee for estimating said locomotory speeds, said contact time is stored within said memory in time slots corresponding to said locomotory speeds of said amputee.
-
31. The prosthetic knee of claim 30, wherein said memory has further stored therein a clinically determined relationship between said impact force and optimal swing phase extension damping.
Specification