Distance-Triggered Muscle Stimulation in Mobility Support Devices

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Solution Overview

Problem

Support devices such as wheelchairs do not effectively prevent muscle atrophy in users with limited leg use due to lack of muscle contraction.

Innovation Solution

Incorporation of electrical stimulation electrodes that activate based on distance traveled by the support device, simulating muscle contraction similar to walking, using a controller to engage electrodes with a power source and distance sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional support devices are used without electrical stimulation, then the device structure remains simple, but muscle atrophy occurs due to lack of muscle contraction

Engineering Contradiction:
Improvemuscle healthVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the support device: mobility support, distance tracking via sensors, and electrical muscle stimulation. The controller integrates these subsystems to coordinate movement detection with appropriate muscle stimulation patterns, thereby preventing muscle atrophy while maintaining device functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The controller acts as an intermediary between the distance sensor and electrical stimulation electrodes. It processes distance traveled information and translates it into appropriate stimulation patterns, mediating between the mechanical movement of the device and the physiological response required to prevent muscle atrophy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If electrical stimulation electrodes are engaged continuously, then muscle contraction is maximized, but energy consumption increases

Engineering Contradiction:
Improvemuscle healthVSAvoidpower source consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic electrical stimulation based on the distance traveled by the support device. Rather than continuous stimulation, the system engages electrodes in periodic intervals correlated with movement distance, providing sufficient muscle activation to prevent atrophy while significantly reducing overall energy consumption compared to continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The distance sensor provides feedback about the support device's movement, which the controller uses to determine when and how long to engage the electrical stimulation electrodes. This feedback mechanism ensures stimulation is provided in proportion to actual usage, optimizing the balance between muscle health benefits and energy consumption.

Inventive Principle:
Principle #23Feedback

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

Reduces muscle atrophy by mimicking walking contractions, enhancing muscle health in users.

Implementation Method 1

electrical stimulation electrodes may be engaged, thereby triggering contraction of the muscles of a user sitting within the support device

Methodology Applied
Scientific EffectElectrical stimulation: Electrical Impedance Tomography

Implementation Method 2

a distance sensor, a power source electrically coupled to one or more electrical stimulation electrodes

Methodology Applied
Scientific EffectDistance detection:

Data Source

PatentEP4168101B1Support devices including electrical stimulation systems
Publication Date: 2026.03.04 TOYOTA MOTOR NORTH AMERICA INC
  • EP4168101B1 patent drawingFigure 1
  • EP4168101B1 patent drawingFigure 2A
  • EP4168101B1 patent drawingFigure 2B

AI summary

A support device includes a base portion structurally configured to support a user, one or more engagement members coupled to the base portion and engagable with a surface, a distance sensor, a power source electrically coupled to one or more electrical stimulation electrodes, and a controller communicatively coupled to the distance sensor and the power source, the controller including a processor and a non-transitory, processor-readable storage medium including a computer readable and executable instruction set, which, when executed, causes the processor to receive a signal from the distance sensor indicative of a detected distance traveled by the support device, and send a signal to the power source to engage the one or more electrical stimulation electrodes based at least in part on the detected distance traveled by the support device.