Validation of the DyCare® Lynx System for Motion Analysis of the Wrist

The accepted laboratory gold standards for human motion analysis are too over-elaborated for clinical use. The DyCare® Lynx system is user-friendly and has been proven reliable for motion evaluation of different joints, but not yet for the wrist.

Therefore, this project is set to compare the wrist joint movement measurements of the DyCare® Lynx System with optoelectronic motion analysis using a marker system and infrared cameras. DyCare® Lynx is based on two inertial sensors (DyTrack) capable of objectively measuring three dimensional joint movements in real time. Each inertial sensor includes an accelerometer, gyroscope and magnetometer and captures up to 1'000 samples per second. DyCare® Lynx is certified for measurements on the human musculoskeletal apparatus (EN ISO 13485:2003 Certificate No. 15185 - M), is CE marked and will only be applied to each participant for a few minutes during the measurements. The control measurements will be conducted using a Vicon® motion capture system in the Motion Analysis Laboratory of the Department of Plastic Surgery and Hand Surgery of the University Hospital of Zurich. The Vicon® system is equipped with 11 infrared cameras. The system is made for 'Life science application' and is approved as CE medical device. A total of 10 healthy test persons will be subjected to both the DyCare® Lynx and the Vicon® measurements during standard movements as well as during activities of daily living. The wrist joint angles measured with both systems will be compared, therefore limits of agreement, maximum difference and root mean squared difference will be calculated to quantify the deviation between methods. The standard error of measurements will be calculated to determine repeatability of the systems.

Inclusion criteria

• 10 test persons with healthy right-dominant hands
• Test Persons older than 18 Years
• Test persons willing and able to give written informed consent to participate in the study

Exclusion criteria

• Inflammatory disease (e.g. rheumatoid arthritis)
• German language barrier to understand instructions
• Any disease process that would preclude accurate evaluation (e.g. neuromuscular, psychiatric or metabolic disorder)
• Legal incompetence
• Participation in any other medical device or medicinal product study within the previous months that could influence the results of the present study