Evaluation method of assistance effect of extravehicular activity glove exoskeleton under weightlessness / 中国康复理论与实践

ObjectiveTo establish a multi index fusion hand grip fatigue prediction model to evaluate the power-assisted effect of the glove exoskeleton prototype for extravehicular clothing. MethodsBP neural network algorithm was used to establish a hand fatigue prediction model. The related factors of hand fatigue were determined with isometric grasping fatigue experiment, and the input variables of BP neural network were determined as cylinder diameter, grasping force, grasping duration and root mean square of electromyography. The fatigue data corresponding to variables of each group were obtained through experiments and subjective fatigue measurement scales, and a fatigue evaluation model based on multi-source fusion of BP neural network algorithm was established. The relationship model between fatigue and assistance effect was established, and the assistance effect of the exoskeleton prototype was evaluated through the degree of fatigue relief. ResultsThe correlation coefficient was 0.974 between the predicted results of the model and the target value. Moreover, it effectively predicted the assistance effect of different prototypes. ConclusionThe BP neural network model established by combining the grasping strength, grasping object parameters and human electromyography can predict hand fatigue, which can be used to evaluate the assistance effect of glove exoskeleton and other hand aids.

CT and MRI finding and clinical feature of extrapleural solitary fibrous tumor / 中国医师进修杂志

Objective To investigate the CT and MRI finding of extrapleural solitary fibrous tumor (ESFT) to improve the preoperative diagnostic ability of such tumors. Methods The clinical data and CT/MRI finding of 11 ESFT patients confirmed by pathology from January 2007 to June 2018 in Jiaxing Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medicine University were retrospectively analyzed. CT scan was performed in 9 cases and MRI scan in 4 cases. Results Of the 11 patients with ESFT, 6 cases occurred in the abdominal cavity, 3 cases in the cavitas pelvis and 2 cases in the ocular region. All the tumors were solitary, and the maximum diameter of the lesion was (8.3 ± 4.2) cm. The boundary of the tumor was clear in 7 cases, and the boundary was not clear in 4 cases. The tumor form was circular or fusiform in 6 cases and lobulated in 5 cases (some tumors had notch sign). CT scanning presented isodensity or inhomogeneous low density, including 4 cases of cystic degeneration accompanied by inner grid separation, and 3 cases of patchy calcification. The enhanced scanning mass showed 6 cases of geographic enhancement and 7 cases of earthworm drilling soil. MRI T1WI showed slightly lower signal intensity; T2WI fat-suppression sequences showed slightly higher mixed signal intensity in 2 cases and an iso-to high mixed signal intensity in 2 cases; and DWI showed uneven high signal intensity in 3 cases. The solid part of the enhanced scanning showed'fast enhancement and slow washout'. Conclusions ESFT is usually manifested as isolated mass, and its CT and MRI finding has certain characteristics, especially in the diagnosis and differential diagnosis of the disease, such as geographic enhancement and earthworm drilling soil signs.

Effects of different conversion time to open surgery on prognosis after laparoscopic radical resection for colorectal cancer / 中华消化外科杂志

Objective To investigate the effects of early and delayed conversion to open surgery on the prognosis after laparoscopic radical resection for colorectal cancer.Methods The retrospective cohort study was conducted.The clinicopathological data of 119 patients who were converted to open surgery in laparoscopic radical resection for colorectal cancer in the ZiBo First People's Hospital from January 2008 to December 2014 were collected.There were 66 males and 53 females,aged from 20 to 84 years,with an average age of 55 years.Of the 119 patients,82 who were converted to open surgery within 60 minutes after the start of laparoscopic surgery and 37 who were converted to open surgery after 60 minutes since the start of laparoscopic surgery were allocated into early conversion group and delayed conversion group.Observation indicators:(1) surgical situations and postoperative recovery;(2) perioperative complications;(3) follow-up.Follow-up using telephone interview,mail and outpatient examination was performed to detect patients' survival once 3 months within 2 years and once a year after 2 years postoperatively up to September 2017.Measurement data with normal distribution were represented as Mean±SD,and comparison between groups was analyzed using the independent sample t test.Count data were represented as absolute number or percentage,and comparison between groups was analyzed using the chi-square test or Fisher exact propability.Comparison of ordinal data was analyzed using the rank sum test.The survival rate was calculated using the Kaplan-Meier method and Log-rank test was used for survival analysis.Results (1) Surgical situations and postoperative recovery:patients in the two group underwent laparoscopic radical resection of colorectal cancer successfully.The operation time,time to first defecation,duration of postoperative hospital stay were (202±44) minutes,(2.6 ± 1.1) days,(9 ± 5) days in the early conversion group and (230±45) minutes,(3.7±2.1) days,(12±6) days in the delayed conversion group,showing statistically significant differences between the two groups (t=-3.106,-3.450,-2.865,P＜0.05).The time to first flatus was (1.8± 0.6) days and (2.0 ± 0.8) days in the early conversion group and delayed conversion group,respectively,with no statistically significant difference between the two groups (t =-1.245,P＞ 0.05).(2) Perioperative complications:8.5％ (7/82) of patients in the early conversion group had perioperative complications,including 2 of early postoperative inflammatory bowel obstruction,2 of postoperative incisional infection,1 of chylous fistula,1 of urinary retention,3 of anastomotic fistula;the same patient can merge multiple complications.Patients with perioperative complications were cured after symptomatic and supportive treatment.Meanwhile,35.1％ (13/37) of patients in the delayed conversion group had perioperative complications,including 8 of early postoperative inflammatory bowel obstruction,3 of postoperative incisional infection,6 of urinary retention,3 of anastomotic fistula;the same patient can merge multiple complications.Patients with perioperative complications were cured after symptomatic and supportive treatment.There was a statistically significant difference in the incidence of perioperative complications between the two groups (x2=12.902,P＜0.05),a statistically significant difference in the early postoperative inflammatory bowel obstruction and urinary retention between the two groups (P＜0.05),and no statistically significant difference in the postoperative incisional infection,chylous fistula,anastomotic fistula between the two groups (P＞0.05).(3) Follow-up:112 out of 119 patients were followed up for 5.2-101.9 months,with a median time of 32.1 months.The 5-year survival rate was 70.5％ and 63.6％ in the 79 patients of early conversion group and 33 of delayed conversion group,showing no statistically significant difference between the two groups (x2 =0.038,P＞0.05).Conclusions Delayed conversion after 60 minutes since the start of laparoscopic surgery will lead to the slower recovery of intestinal function and prolonged hospitalization time,and increase the rates of early postoperative inflammatory intestinal obstruction and postoperative urinary retention.Therefore,a comprehensive analysis of the feasibility of laparoscopic surgery in the initial exploration is recommended and a fast decision on early conversion is necessary.

Polyacrylamide hydrogel, an ultrasonic coupling agent: optimization process and acoustic performance characterization / 中国组织工程研究

BACKGROUND: Ultrasonic coupling agent is indispensable in ultrasonic imaging. The service life and change frequency of the ultrasonic probe is determined by the internal coupling agent of the chosen hydrogel material. Due to defects in the existing gel-formula, after a period of time in use it can cause the surface depression of probes and thus influence the ultrasonic imaging quality. OBJECTIVE: To optimize the gel formula of the coupling agent. METHODS: The amplified synthesis process of polyacrylamide hydrogel was optimized by changing the ratio of monomer concentration to N, N-methylenebisacrylamide crosslinker in the synthesis conditions, and the factors influencing its acoustic properties were explored to meet the technical requirements in the clinical use process. RESULTS AND CONCLUSION: When the monomer concentration was set to 70 g/L and the mass ratio of monomer to crosslinker was 7:1, the polyacrylamide hydrogel was in the best state. The obtained polyacrylamide hydrogel had a stable swelling rate, had a strong ability to keep water and make the volume reduce under the influence of the operating temperature of ultrasound, and its relative amplitude changed less with the change of ultrasonic frequency. The sound attenuation coefficient of polyacrylamide hydrogel would be higher when the frequency of ultrasonic sound source was higher. The changes of monomer concentration would have significant impacts on the acoustic properties of polyacrylamide hydrogel. Therefore, by controlling the monomer concentration ratio, we can prepare the coupling agent that exhibits relatively stable acoustic properties at an optimum concentration and achieves an optimal imaging effect.

A biocompatibility study on Allomax mesh implanted in different planes of abdominal wall in a rat model / 中华普通外科杂志

Objective To evaluate biocompatibility of Allomax mesh implanted in different planes of abdominal wall in a rats model.Methods SD rats were randomly assigned to the profacial group (Onlay group),the retro-rectus group (Sublay group) versus the intraperitoneal group(IPOM group) according to different abdominal wall planes the mesh implanted,Adhesion and shrinkage of the mesh were observed,and quantitative measurements were conducted in fibroblast ingrowth,scaffold degradation,extracellular matrix deposition and numbers of vascular ingrowth after 1,3 and 6 months mesh was implanted.Results Macroscopic observation showed both Onlay and Sublay groups was superior to IPOM group in abdominal wall integration,which included shrinkage,relocation and adhesion of the mesh at all the time points,and most or whole of the mesh had incorporated with host abdominal wall at 6 months.Most of the mesh had not incorporated with host abdominal wall and shrinkage and relocation of the mesh were found in IPOM group at 6 months.Microscopic investigation showed lipocytes appeared in the mesh in Sublay group at 3 months,and numbers of ingrowth of fibroblast and neovascularization in Sublay group were significantly less than in Onlay and IPOM group at 6 months.Scaffold degradation and extracellular matrix deposition were remarkably less in Sublay group in comparison with Onlay group and IPOM group after 1,3 and 6 months.Conclusions Biocompatibility of AlloMax mesh implanted in profacial plane of abdominal wall was superior to implanted in retro-rectus plane and intraperitoneal plane as showed in a rat model.