In order to improve the motion fluency and coordination of lower extremity exoskeleton robots and wearers, a pace recognition method of exoskeleton wearer is proposed base on inertial sensors. Firstly, the triaxial acceleration and triaxial angular velocity signals at the thigh and calf were collected by inertial sensors. Then the signal segment of 0.5 seconds before the current time was extracted by the time window method. And the Fourier transform coefficients in the frequency domain signal were used as eigenvalues. Then the support vector machine (SVM) and hidden Markov model (HMM) were combined as a classification model, which was trained and tested for pace recognition. Finally, the pace change rule and the human-machine interaction force were combined in this model and the current pace was predicted by the model. The experimental results showed that the pace intention of the lower extremity exoskeleton wearer could be effectively identified by the method proposed in this article. And the recognition rate of the seven pace patterns could reach 92.14%. It provides a new way for the smooth control of the exoskeleton.
Objective To evaluate the short-term effectiveness of talonavicular arthrodesis for Müller-Weiss disease. Methods Between May 2013 and February 2015, 13 patients with Müller-Weiss disease were treated with talonavicular arthrodesis. There were 11 females and 2 males with an average age of 59 years (range, 42-67 years). The disease duration was 8-20 years (mean, 13 years). According to Maceira stage, there were 7 cases of stage Ⅲ, 6 cases of stage Ⅳ. The foot longitudinal arch height measured on weight-bearing X-ray films was (43.1±1.8) mm; the Meary angle and talocalcaneal angle measured on lateral X-ray films were (–2.8±2.3)° and (5.8±2.4)°, respectively; the calcaneal valgus angle measured on Saltzman position X-ray films was (–2.0±0.7)°. The American Orthopaedic Foot and Ankle Society (AOFAS) score was 43.5±12.4, and visual analogue scale (VAS) score was 7.3±1.5. Results All the patients were followed up 14-39 months (mean, 20 months). The symptoms of foot pain and intermittent claudication disappeared in all patients. All cases achieved bony union, the fusion time was 12-16 weeks (mean, 13 weeks). There was no complications such as wound infection, skin necrosis, or internal fixator broken. At last follow-up, the foot longitudinal arch height, Meary angle, talocalcaneal angle, and calcaneal valgus angle were (52.5±2.2) mm, (1.3±2.2)°, (16.5±3.7)°, and (0.4±0.7)°, respectively; the AOFAS score and VAS score were 83.8±9.1 and 1.0±0.4, respectively; all were significantly improved when compared with preoperative ones (P<0.05). Conclusion If the subtalar and calcaneocuboid joints are relatively healthy, talonavicular arthrodesis may be a reliable and effective surgical option for Müller-Weiss disease that is resistant to conservative treatment.
Objective To compare the functional and radiological outcomes of supramalleolar osteotomy (SMOT) between with and without fibular osteotomy for varus ankle osteoarthritis. Methods Between April 2009 and April 2014, 41 patients (41 feet) with mid-staged varus ankle osteoarthritis were treated with SMOT. Fibular osteotomy was not performed in 19 cases (group A), and fibular osteotomy was performed in 22 cases (group B). There was no significant difference in gender, age, side, body mass index, osteoarthritis stage, pathogeny, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind score, ankle osteoarthritis scale (AOS) pain and function scores, range of motion (ROM) of the ankle joint, tibial articular surface angle (TAS), talar tilt angle (TT), tibiocrural angle (TC), and tibial lateral surface angle (TLS) between 2 groups (P>0.05). The bone union was observed after operation, and functional and radiological outcomes were compared between 2 groups at last follow-up. Results All incisions healed by stage I, and no surgery related complications occurred. The mean follow-up time was 36.6 months (range, 16-55 months). Pain and limited activity were observed in 1 case of groups A and B respectively, and ankle arthrodesis was performed. All cases achieved bony union; the bone union time was (3.6±0.4) months in group A and (3.9±0.7) months in group B, showing no significant difference (t=1.61,P=0.12). At last follow-up, no significant difference was found in TAS, TLS, TT, and TC between groups (P>0.05). However, group B was significantly better than group A in improvement of TT and TC (P<0.05). The AOFAS ankle-hind score, AOS pain and function scores, ROM of the ankle joint showed no significant difference between groups (P>0.05). According to the modified Takakura stage, the improvement rates of groups A and B were 55.6% and 57.1%, respectively; no significant difference was found between 2 groups (χ2=0.01,P=0.92). Conclusion SMOT with fibular osteotomy is helpful in correction of TT and TC in patients with relative longer fibula.
Objective To investigate the functional outcomes of buttress plate fixation and simple screws fixation for the treatment of supination-adduction type-II medial malleolar fractures so as to provide reference for selection of internal fixation. Methods Between March 2009 and December 2012, 53 patients with supination-adduction type-II medial malleolar fractures were treated with open reduction and internal fixation. Of them, buttress plate fixation was used in 30 cases (buttress plate fixation group), and screws fixation was used in 23 cases (screw fixation group). There was no significant difference in age, gender, injury cause, injury side, disease duration, and combined injuries between 2 groups (P>0.05). Complications and full weight-bearing time were recorded; the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS) were used to evaluate the functional outcomes. Post-operative anteroposterior and lateral X-ray films were taken to evaluate fracture reduction and union condition. And the treatment failures were recorded. Results There was no significant difference in incision related complication rate and infection rate between 2 groups (P>0.05). The patients were followed up 46-91 months (mean, 64.5 months) in buttress plate fixation group and 44-86 months (mean, 59.5 months) in screw fixation group. The full weight-bearing time of the buttress plate fixation group was significantly shorter than that of screw fixation group (t=2.05,P=0.04). During follow-up time, malunion and nonunion occurred in 2 cases and 1 case of screw fixation group; anatomic reduction and bony union were observed in the other patients of 2 groups. The union time showed no significant difference between 2 groups (t=1.06,P=0.30). No significant difference was found in AOFAS score and good and excellent rate, VAS score, operation failure rate, and traumatic osteoarthritis rate between groups (P>0.05). Conclusion For patients with supination-adduction type-II medial malleolar fracture, the angle between fracture line and tibial axial line is too small to be fixed firmly with simple screws fixation, with a relatively higher failure rate. And buttress plate fixation can reach rigid fixation, and has better functional outcomes.
ObjectiveTo use failure mode and effect analysis (FMEA) to check and improve the risk of severe acute respiratory syndrome coronavirus 2 nucleic acid detection, and explore the application effect of FMEA in the emergency inspection items.MethodsFMEA was used to sort out the whole process of severe acute respiratory syndrome coronavirus 2 nucleic acid detection from January 30 to February 21, 2020. By establishing the theme, setting up a team, analyzing the failure mode and potential influencing factors. Then calculate the risk priority number (RPN), formulate preventive measures and implement continuous improvement according to the analysis results.ResultsA total of 2 138 cases were included. After improvement, the number of potential failure modes has been reduced by 2 (17 vs.19); the value of total RPN decreased (3 527.49 vs. 1 858.28). There was significant difference in average RPN before and after improvement [(185.66±74.34) vs. (97.80±37.97); t=6.128, P<0.001].ConclusionsIn the early stage of emergency inspection items, using FMEA can systematically check the risk factors in the process, develop improvement measures. It also can effectively reduce the risk of severe acute respiratory syndrome coronavirus 2 nucleic acid detection in hospital.