Foot Gait Event Measurement for Single-Sensor Lower Limb Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gait analysis methods require sensors to be attached to multiple positions on the legs, and the length of the lower leg must be measured in advance to estimate knee and thigh positions, limiting their effectiveness.
Innovation Solution
A measurement device that detects gait events from time-series sensor data using a single sensor on the foot, employing a geometric model with constraint conditions to perform lower limb measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors are attached to multiple positions on the legs to perform gait analysis, then measurement precision is improved, but device complexity and ease of operation deteriorate
Solution Approach 1:
The invention extracts the essential measurement function to a single sensor attached only to the foot, eliminating the need for multiple sensors on the legs. The system achieves gait analysis by detecting foot motion characteristics and deriving lower limb movement information through calculation, thereby simplifying the measurement setup while maintaining analysis accuracy
Solution Approach 2:
The invention introduces a geometric model as an intermediary that connects foot sensor data to lower limb motion analysis. The model uses constraint conditions representing human body mechanics to calculate knee and hip joint positions from foot acceleration data, enabling indirect measurement of lower limb movements without direct sensing
2Measurement precision
If the length of the lower leg is measured in advance to estimate knee and thigh positions, then measurement precision is improved, but ease of operation and productivity deteriorate
Solution Approach 1:
The system performs self-calibration by automatically determining lower limb length parameters during the measurement process itself. The geometric model uses the detected foot motion data and constraint conditions to infer limb dimensions without requiring external measurement tools or manual input, making the system self-sufficient and eliminating pre-measurement requirements
Solution Approach 2:
The invention performs preliminary determination of geometric parameters (such as lower limb length) during the initial measurement phase using the constraint conditions and detected foot motion. This preliminary action embeds the necessary calibration information into the model before full gait analysis begins, enabling subsequent accurate position estimation without separate pre-measurement steps
3Device complexity
If a single sensor is used on the foot to perform lower limb measurements, then device complexity and ease of operation are improved, but measurement precision deteriorates
Solution Approach 1:
The invention transforms the measurement approach by changing from direct measurement of lower limb parameters to indirect derivation through foot motion parameters. The geometric model converts foot acceleration data into knee and hip joint position information by applying kinematic relationships and constraint conditions, achieving accurate lower limb measurement through parameter transformation rather than direct sensing
Solution Approach 2:
The system measures foot motion in three-dimensional space using a single sensor and then uses geometric modeling to infer lower limb joint positions in a different dimensional framework. The constraint conditions establish relationships between foot position and joint positions, enabling the system to calculate unmeasured dimensions from measured ones through mathematical transformation
Data Source
AI summary
A measurement device that includes a detection unit that detects a gait event from time-series data of sensor data related to motion of a foot, and a measurement unit that performs a measurement of lower limbs by using the sensor data for a prescribed period with a timing of the gait event as a start point, based on a geometric model on which a constraint condition related to motion of the lower limbs is imposed.