08-16-2017, 09:52 PM
its a Multilevel Design Validation in a Secure Embedded Patient Monitoring System and its a method for measuring human gait (walking) posture using wearable sensors. Here The sensor used consist of a tri-axial acceleration sensor and three gyro sensors aligned on three axes. These are worn on the abdomen and the lower limb segments (both thighs, both shanks and both feet) to measure acceleration and angular velocity during walking. Three dimensional positions of each lower limb joint are calculated from segment lengths and joint angles. Segment lengths are calculated by physical measurement and joint angles can be estimated mechanically from the gravitational acceleration along the anterior axis of the segments. However, the acceleration data during walking includes three major components; translational acceleration, gravitational acceleration and external noise. Therefore, an optimization analysis was represented to separate only the gravitational acceleration from the acceleration data.a FFT analysis was applied to obtain some characteristic frequencies. A pattern of gravitational acceleration was assumed using some parts of these characteristic frequencies. Every joint position was calculated from the pattern under the condition of physiological motion range of each joint. An optimized pattern of the gravitational acceleration was selected as a solution of an inverse problem. Three healthy volunteers walking straight for 20 seconds on a flat floor were measured. For comparison reflective markers were also placed on the volunteers for camera recordings. As a result, the characteristic three-dimensional walking of each volunteer could be expressed using a stick figure model. The trajectories of the knee joint in the horizontal plane were checked by images on PC. Therefore, this method provides important quantitive information for gait (walking) diagnosis.
referance:
http://freepatentsonline7420472.html
http://faqspatents/app/20080319282
http://springerlinkindex/j66v262533v2682l.pdf
http://linkinghub.elsevierretrieve/pii/S...9008005526