This study was accredited by the Institutional Review Board and carried out with the created informed consent of all subjects. Five in a position-bodied topics and two individuals with unilateral transfemoral amputations have been recruited. The recruited AB topics ended up all healthy males free from orthopedic or neurological pathologies. The typical age was 28.six several years the regular height was 181.6 cm the common fat was 82.three kg. TF01 was a male amputee who was 33 years put up-amputation TF02 was a woman amputee who was 32 many years submit-amputation. They the two utilized passive prostheses in everyday lifestyle. In the experiments, the TF subjects wore suction prosthetic sockets, which had been hooked up to the powered prosthetic leg. A special personalized L-formed bent-knee adaptor was created for AB subjects so that they could wander with the powered prosthesis.
The experimental setup is demonstrated in Fig 3. In the experiment, the mechanical sensor measurements from the prosthesis had been recorded for intrinsic management and for evaluation functions. An inertial measurement device -dependent 3D motion seize method was employed to seize the full-body kinematics of the topics. The kinematic measurements were employed to evaluate the users walking equilibrium throughout activity transitions . All the measurements had been sampled at 100Hz and synchronized. The experimental classes have been also video-taped. Each and every subject was qualified for at the very least 10 hrs to stroll with the prototypical powered prosthesis prior to the experiment. The education was conducted by a bodily therapist and the experimenters. This coaching was needed due to the fact AB topics ended up not regular prosthesis customers and they needed to find out how to wander with a prosthesis and amputees experienced to re-adapt to the run system because they had been accustomed to making use of passive devices. In the coaching process, the intrinsic controller impedance parameters for every single management manner and each and every state had been acquired for each personal matter. All the subjects have been ready to adapt to the powered prosthesis and make a steady gait sample prior to the experiment.The experiment was performed in a laboratory setting. A total of 120 trials ended up conducted for the duration of 1 experimental session for each and every subject. In each and every demo, the matter was asked to 1st walk on one particular terrain and then transition to another. The prosthesis control method was switched by the locomotion manner simulator at a randomly picked timing during the transition time period . The very same sort of job transition with the very same mode change timing was examined 3 moments.
For amount-floor going for walks, the subject matter was questioned to wander on a straight pathway for ramp ascent/descent, the subject matter walked on a 10-foot ramp with an eight-diploma inclination angle. To protect the topics, a tumble-arrest harness was used. In addition, rest durations had been permitted between trials so that topics would not become fatigued.To discover the consequences of control mode swap timing on the prosthesis end users, each and every subjects gait efficiency during job transitions was evaluated by the subjects strolling balance and good results in performing seamless activity transitions. If the subject matter could continuously comprehensive a process changeover without stopping in the course of the transition time period, the changeover was regarded as to be productive. Each subjects walking stability was evaluated by acquiring subjective comments and calculating the full-entire body angular momentum as an objective harmony quantification index. Each topic was questioned to verbally report his/her emotion about going for walks stability right after the task transition was concluded in every single demo. The subjective comments was recorded accordingly.The entire-body angular momentum was calculated to objectively evaluate the subjects walking balance. This quantification index has been employed for the analysis of human going for walks stability. The complete-body kinematic measurements monitored by a 3D motion capture system had been employed to determine the angular momentum. A simplified human model was built in this review. This model was composed of twelve rigid human body segments, including the head, trunk, and bilateral higher arms, forearms, thighs, shanks, and feet.
Anthropometry was calculated from each matter to reconstruct the representative model. The measurements included physique excess weight, top, head circumference, and segment lengths and circumference of arms, forearms, trunk, thighs, and shanks. The mass of each and every phase was believed by using the modified Hanavan model described in. The entire-body’s angular momentum was calculated as the sum of every single specific segment’s angular momentum about the full-bodys center of mass . The placement of the entire-bodys COM was calculated as a sum of the goods of each and every individual segment’s relative masses and COM spots. Specifics about the calculation can be discovered in. The total-entire body angular momentum in the sagittal aircraft was employed to quantify a subjects walking balance. The topic was described as unstable if the observed angular momentum exceeded a defined regular assortment.