Wearable Coil Kinematics Monitoring
Solution Overview
Problem
Current technologies for monitoring joint flexion are limited by their requirement for lab environments, obtrusiveness, safety concerns, and inability to capture both angular and rotational motions in real-world settings with precision and comfort.
Innovation Solution
A wearable system utilizing transverse and longitudinal electrically-conductive coils that generate and receive magnetic flux to monitor joint flexion and rotation, integrated into daily garments, operating wirelessly and insensitive to line-of-sight, with resonant coils optimizing power transfer and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If camera-based techniques (optical/infrared cameras with retro-reflective markers or markerless depth-sensitive cameras) are used to monitor joint flexion, then measurement precision is improved, but the system is restricted to lab environments and requires line-of-sight
Solution Approach 1:
The patent replaces optical/mechanical measurement systems (cameras, markers, depth sensors) with an electromagnetic field-based system using inductive coils. The coils generate and detect changes in magnetic flux caused by body movement, enabling measurement without line-of-sight requirements and allowing operation in natural environments while maintaining measurement capability
Solution Approach 2:
The patent introduces magnetic flux as an intermediary between the measurement system and body movement. The inductive coils generate magnetic flux that penetrates tissue to detect motion, serving as a mediator that enables measurement through the body without requiring direct optical contact or line-of-sight
2Adaptability or versatility
If Inertial Measurement Units (IMUs) combining accelerometers, gyroscopes and magnetometers are used, then the system can operate in real-world environments, but integration drift occurs and the devices are obtrusive and not injury-safe
Solution Approach 1:
The patent replaces inertial sensors (accelerometers, gyroscopes, magnetometers) that require complex integration algorithms with a direct electromagnetic induction system. The inductive coils directly detect motion through magnetic flux changes without integration, eliminating drift accumulation and improving measurement reliability over time
Solution Approach 2:
The inductive coil system is passive and does not require active processing or correction algorithms. The magnetic flux changes directly indicate motion, allowing the system to self-monitor without external intervention for drift correction or calibration, improving long-term reliability
3Adaptability or versatility
If bending sensors relying on strain produced upon constituent material are used, then the system operates in non-contrived settings and does not require line-of-sight, but the sensors are placed atop the joint restricting natural movement
Solution Approach 1:
The patent uses magnetic flux as an intermediary that penetrates through tissue to detect motion. The coils are placed away from the joint (on adjacent body segments) rather than directly on the joint, allowing natural movement without restriction while still detecting motion through the magnetic field that passes through the joint area
Solution Approach 2:
The patent replaces mechanical bending sensors that physically constrain joints with electromagnetic inductive coils that detect motion remotely through magnetic flux. This substitution eliminates the need for direct contact with the joint, allowing unrestricted natural movement while maintaining measurement capability
4Measurement precision
If time-of-flight sensors using body-worn ultrasonic or ultra-wideband transceivers are used, then the system can measure distance and movement, but line-of-sight is required at all times and the devices are obtrusive
Solution Approach 1:
The patent replaces ultrasonic and ultra-wideband time-of-flight sensors with inductive coils that operate on electromagnetic induction. This substitution eliminates the line-of-sight requirement because magnetic flux penetrates tissue directly, allowing measurement through body segments rather than requiring direct transmission paths between sensors
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
Enables seamless, precise monitoring of joint flexion and rotation in natural environments, improving comfort and safety while being robust and capable of capturing a wide range of human movements, outperforming existing technologies in terms of accuracy and usability.
Implementation Method 1
A wearable system utilizing transverse and longitudinal electrically-conductive coils that generate and receive magnetic flux to monitor joint flexion and rotation
Implementation Method 2
operating wirelessly and insensitive to line-of-sight, with resonant coils optimizing power transfer and robustness
Data Source
AI summary
A system and method are provided for monitoring body kinematics. A wearable coil configuration of the system comprises at least first and second electrically-conductive coils adapted to be secured to a subject in a predetermined spatial relationship and orientation relative to one another. The first coil acts as a first transmitter and generates a first magnetic flux when a first electrical current is passed through it. The second coil acts as a receiver. The first magnetic flux induces a first electrical current or voltage in the second coil. A measurement instrument of the system is configured to measure the first electrical current or voltage and to output a first measurement signal. A processor, which may be part of, or external to, the system is configured to execute a motion monitoring algorithm that processes at least the measurement signal to determine at least a first motion made by the subject.