Biomotion+ A minimiaturised bio-motion sensor
Human biomotion analysis has been widely used in a range of applications including filming, elite athletic training, entertainment, and clinical diagnosis. To quantify detailed posture, gait and movements of the subjects, most of the motion capture systems are still limited to laboratory-based settings. Current motion-tracking technologies can be mainly classified as optical, mechanical and inertial-sensor based tracking systems.
Optical motion tracking systems utilise data captured from image sensors to triangulate the 3D position of a subject between one or more calibrated cameras using special optical markers attached to a subject. The main disadvantages of these systems are associated with their high cost, complexity of the system setup and the inconvenience of these obtrusive markers, thus prohibiting its routine use in the free-living environment. Mechanical motion-capture systems directly track body joint movement using an exoskeleton or skeletal-like structure attached to the human body. Most platforms tend to be integrated as robotic platforms so as to provide mechanical support, feedback and control for limb rehabilitation applications. They are therefore limited to specialist rehabilitation clinics.
In contrast, inertial motion capture is based on inertial sensors and offers much greater ﬂexibility without spatial constraints as no external cameras, emitters or markers are required. The biomotion+ is a miniaturised inertial sensor which can be placed or worn on the body, and data can be wirelessly transmitted to a smart mobile for real-time capture and 3D reconstruction. The main beneﬁts of this wearable inertial sensor based system are that it provides a cost-effective means of real-time capture in free-living environment. Extensive studies have been conducted to demonstrate the accuracy of the platform and subject studies have been conducted to illustrate the feasibility of using the system for a range of clinical applications including sleep, posture, orthopaedic, and neuro-degenerative diseases rehabilitation.