RESUMEN
ObjectiveAiming at the need of control strategy switching of intelligent above-knee prosthetic, taking the plantar pressure of human walking as the research object, and based on fuzzy logic algorithm, a gait phase division method based on plantar pressure of prosthetic is proposed. MethodsThree flexible force sensors installed on the soles of the false feet were used to collect the plantar pressure information of the test object under three different walking modes (walking on the flat road, walking downhill and walking down the stairs). After data fusion processing, it was sent to the fuzzy logic controller, and the recognition results were output according to the IF-THEN rule, the scale and sensitivity factor. ResultsThrough the testing of five healthy people as substitute, the results showed that the accuracy of gait phase recognition for walking on the flat road, walking down the stairs and walking downhill were (95.3±2.4)%, (81.5±6.3)% and (90.7±3.5)%, respectively. ConclusionThe accuracy of recognition basically meets the requirements in this project. This method can be applied in the gait phase recognition of intelligent above-knee prosthetic.
RESUMEN
Objective To investigate the relationship between lesion size of solitary bone cyst ( SBC) and pathological fracture of calcaneus, so as to provide references for the treatment of SBC. Methods The three dimensional (3D) finite element model of foot and ankle was established based on CT images. Four models with gradient spherical bone defects were constructed in the focal area to simulate different SBC lesion sizes, and the biomechanical characteristics of calcaneus in different gait phases were analyzed. Results With the increasement of SBC size, the kinematics of calcaneus did not change significantly, but the peak stress of calcaneus increased gradually. When the SBC size exceeded 75% of the calcaneal width, the stress in calcaneal sulcus and cortical bone below SBC increased by 1. 48 times and 7. 74 times, respectively. Conclusions The risk of pathological fracture increases when the SBC diameter exceeds 75% of the calcaneal width, and early surgical intervention should be recommended. The calcaneal sulcus and the cortex bone below SBC are stress concentration regions and can be used as important areas to evaluate pathological fractures.