Based on the structure and motion bionic principle of the normal adult fingers, biological characteristics of human hands were analyzed, and a wearable exoskeleton hand function training device for the rehabilitation of stroke patients or patients with hand trauma was designed. This device includes the exoskeleton mechanical structure and the electromyography (EMG) control system. With adjustable mechanism, the device was capable to fit different finger lengths, and by capturing the EMG of the users' contralateral limb, the motion state of the exoskeleton hand was controlled. Then driven by the device, the user's fingers conducting adduction/abduction rehabilitation training was carried out. Finally, the mechanical properties and training effect of the exoskeleton hand were verified through mechanism simulation and the experiments on the experimental prototype of the wearable exoskeleton hand function training device.
Bionics ; instrumentation ; Electromyography ; Exoskeleton Device ; Fingers ; Hand ; Humans ; Motion ; Stroke Rehabilitation

Objective: To evaluate the expression of cytokeratin (CK)7, CK8/18, CK19 and p40 in esophageal squamous cell carcinoma (ESCC) and its significances. Methods: One hundred and ninety cases of surgically resected ESCCs and 154 normal esophageal tissues as control were collected at the First Affiliated Hospital of Zhengzhou University in 2012.Of the 190 ESCC cases including 116 male and 74 female, aged 28-82 (60.3±8.6) years, 88 cases <60 years old and 102 cases ≥60 years old. Tissue sections were immunostained for CK7, CK8/18, CK19 and p40, and the expression was evaluated and correlated with the clinicopathologic findings and outcome. Results: CK19 and p40 were expressed in 190 cases of ESCCs; with 147 cases (77.4%) and 151 cases (79.5%) showing high p40 and CK19 expression, respectively; while 43 cases (22.6%) and 39 cases (20.5%) showed low p40 and CK19 expression, respectively. The low expression groups showed more lymph node metastases and higher pTNM stages compared to the high expression groups. The high CK19 expression group showed better prognosis than the low expression group (P<0.01); p40 expression was not correlated with prognosis(P>0.05). In contrast, CK7 and CK8/18 expression was only seen in 29 cases (15.3%) and 59 cases (31.1%) of ESCCs, respectively, and their expression correlated significantly with the degree of tumor differentiation and lymph node metastasis (P<0.05). The prognosis in the CK7 negative group was better than that in the CK7 positive group. Similar results were found in CK8/18 expression. Multivariate analysis revealed that pTNM stages, low CK19 expression and CK8/18 expression were independent prognostic factors. Conclusions Low p40 expression and the expression of CK7 and CK8/18 cannot exclude poorly-differentiated ESCCs.CK7 and CK8/18 expression and low CK19 and p40 expression in the ESCCs are associated with lymph node metastasis and poor prognosis. Decreased expression of CK19 and positive expression of CK8/18 in ESCCs are independent prognostic markers.

The rotation center of traditional hip disarticulation prosthesis is often placed in the front and lower part of the socket, which is asymmetric with the rotation center of the healthy hip joint, resulting in poor symmetry between the prosthesis movement and the healthy lower limb movement. Besides, most of the prosthesis are passive joints, which need to rely on the amputee's compensatory hip lifting movement to realize the prosthesis movement, and the same walking movement needs to consume 2-3 times of energy compared with normal people. This paper presents a dynamic hip disarticulation prosthesis (HDPs) based on remote center of mechanism (RCM). Using the double parallelogram design method, taking the minimum size of the mechanism as the objective, the genetic algorithm was used to optimize the size, and the rotation center of the prosthesis was symmetrical with the rotation center of the healthy lower limb. By analyzing the relationship between the torque and angle of hip joint in the process of human walking, the control system mirrored the motion parameters of the lower on the healthy side, and used the parallel drive system to provide assistance for the prosthesis. Based on the established virtual prototype simulation platform of solid works and Adams, the motion simulation of hip disarticulation prosthesis was carried out and the change curve was obtained. Through quantitative comparison with healthy lower limb and traditional prosthesis, the scientificity of the design scheme was analyzed. The results show that the design can achieve the desired effect, and the design scheme is feasible.
Arthroplasty, Replacement, Hip ; Artificial Limbs ; Biomechanical Phenomena ; Hip Joint ; Hip Prosthesis ; Humans ; Prosthesis Design ; Range of Motion, Articular ; Walking

Objective To analyze the gait characteristics of hip disarticulation amputees, and analyze the reasons for their differences from normal gait, so as to assist clinical diagnosis and evaluation. Methods Through the portable human motion capture device and plantar pressure analysis system, the kinematics and plantar pressure information of 5 hip amputees were collected and compared with 15 healthy volunteers in control group. Gait differences between the amputees and normal subjects and between the affected leg side and the healthy leg side of the amputees were compared. Results The proportion of double-support period for hip amuptees was higher than that of normal gait. Step length, step time, loading response period, mid support period, pre-swing period, proportion of the swing period for the affected leg side and healthy leg side of hip amputees showed significant differences with those of control group. The relative symmetry index of the gait for hip amputees was 0.60±0.05. Compared with the affected leg side, the support period of the healthy leg side was extended, the step length was shortened, the ground reaction force was greater than that of the affected leg side, and the center of pressure trajectory shifted to the affected leg side. Conclusions The gait of hip amputees is significantly different from that of normal people. Hip amputees have weak walking ability, poor gait symmetry, and they lack of continuity in the body’s center of gravity. The results provide experimental basis and theoretical analysis for the design of mechanical structure and control system of novel hip prosthesis.

Objective To study mechanical properties of the interface between hip residual limb and hip socket during the stance phase by using the finite element analysis (FEA) method, so as to provide the theoretical basis for structure optimization and design of hip socket, as well as the research basis for comfort evaluation of hip socket. Methods According to CT scan images of the patient’s residual limb, the model of bone, soft tissues and socket was reconstructed by reverse modeling. The distribution of normal stress and shear stress on the interface between hip residual limb and hip socket was analyzed and a pressure acquisition module system was designed to verify the stress distribution condition. Results The interfacial stress between hip residual limb and hip socket was mainly distributed in the waist and the bottom of the residual limb, and the interfacial stress was more evenly distributed in the rest of the residual limb. The results of finite element calculation were in good agreement with the system measurement results of pressure acquisition module. Conclusions In order to improve force transfer and safety and comfort of the hip socket, it is necessary to fully consider stress condition of the waist and bottom of the residual limb, as well as the coordination degree between residual limb and hip socket.

Objective:To assess the diagnostic efficacy of upper gastrointestinal endoscopic image assisted diagnosis system (ENDOANGEL-LD) based on artificial intelligence (AI) for detecting gastric lesions and neoplastic lesions under white light endoscopy.Methods:The diagnostic efficacy of ENDOANGEL-LD was tested using image testing dataset and video testing dataset, respectively. The image testing dataset included 300 images of gastric neoplastic lesions, 505 images of non-neoplastic lesions and 990 images of normal stomach of 191 patients in Renmin Hospital of Wuhan University from June 2019 to September 2019. Video testing dataset was from 83 videos (38 gastric neoplastic lesions and 45 non-neoplastic lesions) of 78 patients in Renmin Hospital of Wuhan University from November 2020 to April 2021. The accuracy, the sensitivity and the specificity of ENDOANGEL-LD for image testing dataset were calculated. The accuracy, the sensitivity and the specificity of ENDOANGEL-LD in video testing dataset for gastric neoplastic lesions were compared with those of four senior endoscopists.Results:In the image testing dataset, the accuracy, the sensitivity, the specificity of ENDOANGEL-LD for gastric lesions were 93.9% (1 685/1 795), 98.0% (789/805) and 90.5% (896/990) respectively; while the accuracy, the sensitivity and the specificity of ENDOANGEL-LD for gastric neoplastic lesions were 88.7% (714/805), 91.0% (273/300) and 87.3% (441/505) respectively. In the video testing dataset, the sensitivity [100.0% (38/38) VS 85.5% (130/152), χ2=6.220, P=0.013] of ENDOANGEL-LD was higher than that of four senior endoscopists. The accuracy [81.9% (68/83) VS 72.0% (239/332), χ2=3.408, P=0.065] and the specificity [ 66.7% (30/45) VS 60.6% (109/180), χ2=0.569, P=0.451] of ENDOANGEL-LD were comparable with those of four senior endoscopists. Conclusion:The ENDOANGEL-LD can accurately detect gastric lesions and further diagnose neoplastic lesions to help endoscopists in clinical work.

Objective:To construct a real-time artificial intelligence (AI)-assisted endoscepic diagnosis system based on YOLO v3 algorithm, and to evaluate its ability of detecting focal gastric lesions in gastroscopy.Methods:A total of 5 488 white light gastroscopic images (2 733 images with gastric focal lesions and 2 755 images without gastric focal lesions) from June to November 2019 and videos of 92 cases (288 168 clear stomach frames) from May to June 2020 at the Digestive Endoscopy Center of Renmin Hospital of Wuhan University were retrospectively collected for AI System test. A total of 3 997 prospective consecutive patients undergoing gastroscopy at the Digestive Endoscopy Center of Renmin Hospital of Wuhan University from July 6, 2020 to November 27, 2020 and May 6, 2021 to August 2, 2021 were enrolled to assess the clinical applicability of AI System. When AI System recognized an abnormal lesion, it marked the lesion with a blue box as a warning. The ability to identify focal gastric lesions and the frequency and causes of false positives and false negatives of AI System were statistically analyzed.Results:In the image test set, the accuracy, the sensitivity, the specificity, the positive predictive value and the negative predictive value of AI System were 92.3% (5 064/5 488), 95.0% (2 597/2 733), 89.5% (2 467/ 2 755), 90.0% (2 597/2 885) and 94.8% (2 467/2 603), respectively. In the video test set, the accuracy, the sensitivity, the specificity, the positive predictive value and the negative predictive value of AI System were 95.4% (274 792/288 168), 95.2% (109 727/115 287), 95.5% (165 065/172 881), 93.4% (109 727/117 543) and 96.7% (165 065/170 625), respectively. In clinical application, the detection rate of local gastric lesions by AI System was 93.0% (6 830/7 344). A total of 514 focal gastric lesions were missed by AI System. The main reasons were punctate erosions (48.8%, 251/514), diminutive xanthomas (22.8%, 117/514) and diminutive polyps (21.4%, 110/514). The mean number of false positives per gastroscopy was 2 (1, 4), most of which were due to normal mucosa folds (50.2%, 5 635/11 225), bubbles and mucus (35.0%, 3 928/11 225), and liquid deposited in the fundus (9.1%, 1 021/11 225).Conclusion:The application of AI System can increase the detection rate of focal gastric lesions.

The body weight support rehabilitation training system has now become an important treatment method for the rehabilitation of lower limb motor dysfunction. In this paper, a pelvic brace body weight support rehabilitation system is proposed, which follows the center of mass height (CoMH) of the human body. It aims to address the problems that the existing pelvic brace body weight support rehabilitation system with constant impedance provides a fixed motion trajectory for the pelvic mechanism during the rehabilitation training and that the patients have low participation in rehabilitation training. The system collectes human lower limb motion information through inertial measurement unit and predicts CoMH through artificial neural network to realize the tracking control of pelvic brace height. The proposed CoMH model was tested through rehabilitation training of hemiplegic patients. The results showed that the range of motion of the hip and knee joints on the affected side of the patient was improved by 25.0% and 31.4%, respectively, and the ratio of swing phase to support phase on the affected side was closer to that of the gait phase on the healthy side, as opposed to the traditional body weight support rehabilitation training model with fixed motion trajectory of pelvic brace. The motion trajectory of the pelvic brace in CoMH mode depends on the current state of the trainer so as to realize the walking training guided by active movement on the healthy side of hemiplegia patients. The strategy of dynamically adjustment of body weight support is more helpful to improve the efficiency of walking rehabilitation training.
Biomechanical Phenomena ; Gait ; Hemiplegia ; Humans ; Pelvis ; Range of Motion, Articular ; Stroke Rehabilitation ; Walking

The motor nervous system transmits motion control information through nervous oscillations, which causes the synchronous oscillatory activity of the corresponding muscle to reflect the motion response information and give the cerebral cortex feedback, so that it can sense the state of the limbs. This synchronous oscillatory activity can reflect connectivity information of electroencephalography-electromyography (EEG-EMG) functional coupling. The strength of the coupling is determined by various factors including the strength of muscle contraction, attention, motion intention etc. It is very significant to study motor functional evaluation and control methods to analyze the changes of EEG-EMG synchronous coupling caused by different factors. This article mainly introduces and compares coherence and Granger causality of linear methods, the mutual information and transfer entropy of nonlinear methods in EEG-EMG synchronous coupling, and summarizes the application of each method, so that researchers in related fields can understand the current research progress on analysis methods of EEG-EMG synchronous systematically.
Electroencephalography ; Electromyography ; Humans ; Motor Cortex ; physiology ; Muscle, Skeletal ; physiology ; Research

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.
Aged ; Betacoronavirus ; isolation & purification ; Cannula ; Coronavirus Infections ; therapy ; Humans ; Oxygen ; administration & dosage ; Pandemics ; Pneumonia, Viral ; therapy