Wearable Back Assist Using Elastic Members for Lumbar Offloading

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Solution Overview

Problem

Existing wearable devices for reducing lower back muscle stress, fatigue, injury, and pain are either too bulky, restrictive, or ineffective in providing passive offloading of lumbar muscles and discs during leaning and lifting, and they often increase intra-abdominal pressure or restrict spine motion.

Innovation Solution

A wearable assistance device with elastic members that provide an extensor moment to the lower back, allowing forces to bypass the muscles and discs, featuring a clutch mechanism for adjustable assistance and integration into clothing for ease of use, reducing spinal compression forces and muscle effort during lifting and leaning tasks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If assistance devices are designed with components that protrude significantly from the lower back to maximize moment arm, then mechanical advantage is improved, but device bulkiness increases and restricts basic activities

Engineering Contradiction:
Improvemechanical advantageVSAvoidbasic activities
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent repositions the moment arm generation from the lateral dimension (protruding components) to the longitudinal dimension (elastic members extending along the back). The elastic members run from the upper back to the lower back, creating moment arm effects through their length and attachment geometry rather than through lateral protrusion, thus maintaining mechanical advantage while eliminating bulkiness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses flexible elastic members (bands, straps, or fabric) instead of rigid protruding components. These flexible elements conform to the body's surface and provide the necessary mechanical advantage through their elastic properties and geometric arrangement, avoiding the bulk and restriction issues of rigid structures while maintaining force generation capability.

Inventive Principle:
Principle #30Flexible shells and thin films

2Force

If back belts and braces restrict motion of the spine to reduce forces, then spinal compression is reduced, but spine mobility is worsened

Engineering Contradiction:
Improvespinal compressionVSAvoidspine motion
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamic elastic members that automatically adjust their stiffness and force generation based on the user's movement and loading conditions. The elastic bands provide support when needed (during lifting or leaning) while allowing free motion during normal activities, eliminating the need for rigid motion restriction while maintaining spinal protection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic members are designed to self-adjust their support level based on the user's posture and activity. When the user leans forward or lifts, the elastic bands automatically generate the appropriate counterbalancing force without requiring active control or motion restriction mechanisms, providing both support and mobility simultaneously.

Inventive Principle:
Principle #25Self-service

3Force

If commercial belts increase intra-abdominal pressure to reduce forces on the spine, then spinal loading is reduced, but abdominal pressure increases

Engineering Contradiction:
Improveforces on the spineVSAvoidintra-abdominal pressure
Core Design Contradiction:
ForceVSStress or pressure

Solution Approach 1:

The patent extracts the force generation mechanism from the abdominal region and relocates it to the back. Instead of using intra-abdominal pressure (which affects internal organs), the elastic members generate counterbalancing forces externally on the back, eliminating the harmful side effect of increased abdominal pressure while still reducing spinal loading.

Inventive Principle:
Principle #2Taking out (Extraction)

4Force

If wearable devices are designed to provide passive offloading during lifting, then muscle stress is reduced, but device complexity and bulkiness increase

Engineering Contradiction:
Improvemuscle stressVSAvoiddevice structure
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The elastic members serve multiple functions simultaneously: they provide passive offloading during lifting, maintain a streamlined profile during normal activities, and can be easily adjusted or removed. This multi-functionality reduces the need for complex control systems, motors, or sensors, achieving passive assistance with minimal device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 device effectively reduces muscular effort and spinal compression by providing an assistive extensor moment, allowing for comfortable and unobtrusive use in daily activities, mitigating the risk of lower back injury and pain through reduced loading on lumbar muscles and discs.

Implementation Method 1

one or more elastic members, each of the elastic members mechanically coupling the upper-body interface to the lower-body interface and extending from the rear side of the upper-body interface to the rear side of the lower-body interface and along a back of the user so as to provide an assistive force parallel to the back of the user

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3571018B1Wearable assistance devices and methods of operation
Publication Date: 2024.10.02 VANDERBILT UNIV
  • EP3571018B1 patent drawingFigure 1~2
  • EP3571018B1 patent drawingFigure 3
  • EP3571018B1 patent drawingFigure 4A~4B

AI summary

Wearable assistance devices and methods of operating the same are provided. A wearable assistance device includes an upper-body interface with a front side and a rear side and a lower-body interface with a front side and a rear side. The assistance device also includes one or more elastic members, each of the elastic members mechanically coupling the upper-body interface to the lower-body interface and extending from the rear side of the upper-body interface to the rear side of the lower-body interface and along a back of the user so as to provide an assistive force parallel to the back of the user. Further, the assistance device also includes a clutch mechanism associated with each one of the elastic members, the clutch mechanism configured for selectively adjusting the assistive force provided by the one of the elastic members.