IMU Placement Detection for Accurate Motion Tracking Assessment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motion tracking systems face issues with users incorrectly arranging inertial measurement units (IMUs) on body members, leading to inaccurate exercise assessment and potential user injury due to incorrect placement or swapping of units.
Innovation Solution
A method and system that uses a computing device to process IMU measurements to detect incorrect orientations and arrangements, adjusting the motion tracking operation automatically or providing feedback for manual correction, without requiring templates or kinematic chain equations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the motion tracking system requires users to manually arrange IMUs on body members, then the system can collect motion data, but the arrangement may be incorrect leading to inaccurate assessment and potential user injury
Solution Approach 1:
The system automatically detects incorrect IMU arrangements by analyzing motion data patterns and provides real-time feedback to users. The computing device processes measurements from multiple IMUs, identifies anomalies indicating misplacement (such as unexpected motion patterns or orientation deviations), and guides users to correct the arrangement without requiring manual calibration or therapist intervention.
Solution Approach 2:
The motion tracking system performs self-verification by automatically detecting and identifying incorrect IMU arrangements through algorithmic analysis of collected motion data. The system uses machine learning models and constraint-based validation to autonomously determine whether IMUs are properly placed, eliminating the need for external calibration procedures or expert intervention.
2Measurement precision
If calibration procedures using templates and kinematic chain equations are implemented, then IMU arrangement can be verified, but the system complexity and user burden increase
Solution Approach 1:
The patent extracts the complex calibration procedures (templates and kinematic chain equations) from the user workflow and replaces them with an automated detection algorithm. The system maintains verification capability by analyzing motion data patterns while eliminating the need for users to interact with complex calibration tools or understand sophisticated mathematical models.
Solution Approach 2:
The system replaces mechanical calibration procedures (physical templates, manual positioning tools) with a computational approach. Instead of requiring users to physically align IMUs with template markers or solve kinematic equations, the system uses algorithmic analysis of motion data to detect arrangement errors, substituting complex mechanical interaction with simpler computational verification.
3Measurement precision
If the system continuously monitors and detects incorrect IMU arrangements, then assessment accuracy is maintained, but processing requirements and system resources increase
Solution Approach 1:
The system performs partial verification by focusing computational resources on detecting specific anomaly patterns rather than continuously analyzing all motion data parameters. The detection algorithm identifies key indicators of incorrect arrangement (such as unexpected orientation changes or inconsistent motion patterns) and triggers verification only when these indicators are present, reducing overall computational energy consumption while maintaining assessment accuracy.
Data Source
Figure 1
Figure 2A~2D
Figure 3A~5
AI summary
A method for physical exercise of a person using a motion tracking system, the motion tracking system comprising a computing device and a plurality of inertial measurement units adapted to be arranged on body members of the person, the method comprising: digitally processing at least first sets of measurements provided by the units so as to determine whether and adjust the operation of the motion tracking system when: any unit of the plurality of units is arranged on a body member of the person with an orientation outside of a predetermined orientation range for a unit on that body member; and/or two or more units of the plurality of units may be arranged on interchanged body members of the person according to the predetermined unit arrangement; adjusting the operation of the motion tracking system when the computing device determines, based on at least the first sets of measurements, that: at least one unit has an orientation outside of the predetermined orientation range, and/or two or more units are arranged on interchanged body members; and digitally processing second sets of measurements provided by the units after the step of adjusting the operation of the motion tracking system so as to determine whether the person has performed the second predetermined movement according to a set of predetermined movement constraints.