Self-adjusting prosthetic socket with reciprocal actuator
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Solution Overview
Problem
Conventional prosthetic sockets are rigid and unable to accommodate short-term and long-term fluctuations in the volume and shape of the residual limb, leading to discomfort and pain for amputees due to inadequate fit, which existing solutions like multiple socks or complex sensor systems fail to address effectively.
Innovation Solution
A self-adjusting socket mechanism that uses a resilient resistive element coupled to a reciprocal actuator, which cycles to tighten the socket around the residual limb until a threshold tightness is reached, then yields to prevent further tightening, ensuring a secure and comfortable fit without the need for frequent adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional rigid sockets are used, then manufacturing is simple and cost is low, but they cannot accommodate fluctuations in residuum volume and shape leading to discomfort and pain
Solution Approach 1:
The socket incorporates a dynamic adjustment mechanism with a screw-threaded rod that allows the socket to transition from a rigid state to a flexible, adaptive state. The rod can be rotated to adjust the position of the retention mechanism, enabling the socket to accommodate changes in residuum volume and shape while maintaining a relatively simple overall structure.
2Adaptability or versatility
If multiple prosthetic socks are used to accommodate volume changes, then adaptability to volume fluctuations is improved, but the need for frequent removal and reattachment disrupts daily activities
Solution Approach 1:
The socket employs a self-adjusting mechanism where the user can independently rotate the screw-threaded rod to modify the retention pressure. This allows the amputee to accommodate volume changes without removing the prosthetic limb, simply by adjusting the rod position through the adjustment mechanism, thereby maintaining ease of operation while improving adaptability.
3Adaptability or versatility
If prosthetic socks are added to accommodate volume changes, then fit is improved, but the complexity of managing multiple socks increases
Solution Approach 1:
The invention extracts the adjustment function from the external prosthetic socks and integrates it directly into the socket structure. The screw-threaded rod mechanism allows volume changes to be accommodated by adjusting the socket's retention mechanism itself, eliminating the need to manage multiple separate socks and reducing overall system complexity.
4Reliability
If the socket is tightened securely to prevent slipping, then stability is improved, but discomfort and pain increase due to excessive pressure
Solution Approach 1:
The socket incorporates a dynamic adjustment mechanism with a screw-threaded rod that allows the user to modify the retention pressure to achieve the optimal balance between stability and comfort. The rod can be rotated to adjust the position of the retention mechanism, enabling the socket to accommodate changes in residuum volume and shape while maintaining a relatively simple structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The self-adjusting socket provides a secure and comfortable fit by automatically accommodating volume changes in the residual limb, reducing the need for frequent adjustments and minimizing discomfort, while avoiding the complexity and inconvenience of existing solutions.
Implementation Method 1
each step transmits motion to a resilient resistive element coupled to a reciprocal actuator. The resistive element can transmit the motion to the reciprocal actuator to cycle the reciprocal actuator
Implementation Method 2
configured to act through the respective mechanical linkage to incrementally tighten the retention mechanism against the residual limb on each cycle of the reciprocal actuator(s)
Implementation Method 3
The locking mechanism is carried by the housing and configured to maintain tightness of the retention mechanism against the residual limb after each cycle of the reciprocal actuator(s)
Implementation Method 4
When the tightness of the retention mechanism has reached the threshold, on each further step the respective resistive element yields to absorb the motion, so that the respective reciprocal actuator fails to cycle on each further step
Data Source
AI summary
The present disclosure describes self-adjusting sockets for lower limb prostheses in which each step transmits motion to a resilient resistive element coupled to a reciprocal actuator. The resistive element can transmit the motion to the reciprocal actuator to cycle the reciprocal actuator. Each cycle of the reciprocal actuator acts through a mechanical linkage to tighten the socket around the residuum, until a desired threshold tightness on the residuum is reached. After the threshold tightness is reached, the resistive element yields and absorbs the motion rather than transmitting the motion, so that the reciprocal actuator ceases to cycle on each step, preventing further tightening beyond the threshold.