Adaptive Arm Support with Varying Offset Force
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Solution Overview
Problem
Existing arm support systems, such as static armrests, are ineffective for tasks requiring moderate to large ranges of motion as they do not accommodate the full movement of the arm, leading to fatigue in users, especially during prolonged activities like surgery, dentistry, or product assembly.
Innovation Solution
An adaptive arm support system comprising a harness with a pivotable arm bracket and compensation elements that apply a varying offset force to counteract gravitational forces, allowing the arm to move freely while reducing muscle strain by transferring weight to the torso or other body regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If static armrests are used, then arm support is provided at fixed positions, but the system cannot accommodate large ranges of motion and causes user fatigue
Solution Approach 1:
The arm support system transitions from static to dynamic through multiple pivot joints that enable the armrest to follow the natural movement of the user's arm through various ranges of motion. The pivotable connection between the armrest, support arm, and torso support allows continuous adaptation to arm position changes while maintaining support effectiveness.
2Adaptability or versatility
If the arm support system follows full arm movement, then range of motion is accommodated, but gravitational force on the arm causes muscle strain and fatigue
Solution Approach 1:
The compensation element (spring) provides an upward counterbalancing force that offsets the downward gravitational force acting on the user's arm. This anti-weight mechanism reduces the net force the user's muscles must exert to maintain arm position, thereby reducing fatigue while allowing full range of motion through the pivot joints.
3Object-affected harmful factors
If compensation elements provide constant offset force, then gravitational force is counteracted, but the force profile does not match the varying gravitational moment through range of motion
Solution Approach 1:
The system employs asymmetric geometry in the armrest and support arm configurations, where the distances from pivot points to contact points vary through the range of motion. This asymmetric arrangement creates a mechanical moment arm that changes with position, allowing the spring force to generate a varying counterbalancing moment that matches the gravitational moment profile across different arm positions.
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 adaptive arm support system enables users to perform tasks with extended arm motion for extended periods with reduced fatigue, as it dynamically adjusts to the arm's position and movement, distributing the weight and reducing strain on the back and shoulders.
Implementation Method 1
one or more compensation elements coupled to the arm support to apply an offset force to at least partially offset a gravitational force acting on the arm
Implementation Method 2
The one or more compensation elements may include one or more elements, e.g., a resilient element, mounted on the arm bracket
Data Source
Figure 1~2
Figure 3A
Figure 3B~3C
AI summary
Systems and methods are provided for supporting an arm of a user using a harness configured to be worn on a body of a user; and an arm support coupled to the harness configured to support an arm of the user, the arm support configured to accommodate movement of the arm while following the movement without substantially interfering with the movement of the user's arm. One or more compensation elements (74) may be coupled to the arm support to apply an offset force to at least partially offset a gravitational force acting on the arm as the user moves and the arm support follows the movement of the user's arm, the one or more compensation elements (74) providing a force profile that varies the offset force based on an orientation of the arm support.