Prosthetic Finger Coupling for Energy-Free Passive Movement
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Solution Overview
Problem
Prosthetic hands and fingers consume significant energy from limited energy storage devices due to active movements, limiting their usage time without recharging.
Innovation Solution
A prosthetic finger design with a motor-driven pivot mechanism featuring a torque-transmitting coupling element that allows both active and passive movements, utilizing an elastically preloaded coupling element to optimize energy consumption and enable passive adjustments without additional energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If active motor-driven movements are used for the prosthetic finger, then the movement capability and control precision are improved, but the energy consumption increases significantly
Solution Approach 1:
The coupling element transitions between locked and unlocked states dynamically. During passive movement, the coupling element is unlocked allowing the drive element to rotate freely without energy consumption. During active movement, the coupling element locks to transmit torque from the drive element to the carrier, enabling controlled movement only when necessary
Solution Approach 2:
The spring element automatically detects and responds to movement conditions. When external forces apply torque during passive movement, the spring element allows the coupling element to decouple without energy input. When active movement is required, the spring element engages the locking mechanism to transmit drive torque, making the system self-regulating based on movement type
2Force
If the coupling element is rigidly connected to transmit torque continuously, then the force transmission is improved, but the energy consumption during passive movements increases
Solution Approach 1:
The coupling element's connection state changes dynamically between rigidly locked and decoupled. The spring element enables the coupling element to be rigidly connected only when torque transmission is necessary for active movement, while allowing decoupling during passive movements to eliminate energy consumption
Solution Approach 2:
The locking mechanism extracts the torque transmission function from the continuous connection. The coupling element with locking elements engages only when needed, separating the torque transmission function from the rotational movement function, allowing the drive element to rotate freely during passive movements without transmitting torque
3Adaptability or versatility
If the prosthetic finger is designed with multiple pivot axes for complex movements, then the adaptability and grip options are improved, but the device complexity increases
Solution Approach 1:
The prosthetic finger is segmented into multiple independent pivot axes (first pivot axis for abduction/adduction, second pivot axis for flexion/extension). Each axis has its own drive element and coupling mechanism, allowing independent control and simplifying the overall control structure while maintaining versatility
Solution Approach 2:
The coupling mechanism with locking elements serves multiple functions: transmitting torque during active movement, enabling passive movement when unlocked, providing overload protection through decoupling, and allowing quick position adjustments. This multi-functional design reduces the need for separate components for each function
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 design extends the usable time of prosthetic hands and fingers by allowing passive movements that do not consume energy from the storage device, optimizing energy efficiency and providing overload protection and quick adjustment to different positions.
Implementation Method 1
The coupling element (18) is elastically preloaded in the longitudinal direction toward the drive element (17) by a spring element (21)
Data Source
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AI summary
The invention relates to a prosthetic finger which is associated with a motor drive (5) by means of which the prosthetic finger (101) can be pivoted relative to a chassis (100) about a first pivot axis (2), the prosthetic finger having a finger element (3) which is pivotably mounted on the chassis (100) about the first pivot axis (2) and which is coupled to a support (19), the support (19) is coupled to a drive element (17) which can be coupled to the motor drive (5) and which is torque-transmittingly coupled to the support (19), wherein the drive element (17) is torque-transmittingly coupled to the support (19) via a coupling element (18), wherein the coupling element (18) is axially displaceably mounted on the support (19) and resiliently preloaded in the direction of the drive element (17).