Objective To explore the effects of cognitive reserve on brain networks based on rest state functional magnetic resonance imaging(rsfMRI).Methods Firstly,7 973 healthy middle-aged and elderly individuals were selected for rsfMRI images at UK Biobank(UKB),and 21 resting-state networks were obtained through group independent component analysis.Secondly,the parameters of network node efficiency,shortest path length and node degree centrality were extracted using graph theory analysis.Finally,four indicators of resting-state networks including activeness,network node efficiency,node shortest path length and node degree centrality were compared and analyzed,whose relationships with five cognitive reserve proxies such as education level,early fluid intelligence,sports,leisure activities and socialization level.Results The education level,early fluid intelligence and sports,and the activity correlated positively with the activeness of multi resting-state networks and the node efficiency and node degree centrality of most of cognitive control networks and default mode networks,while negatively with the shortest path length of most of cognitive control networks and default mode networks.Leisure activities,socialization level and sports had negative correlations with the activeness of the resting-state network,and had little effects on the overall topological properties of the functional network.Conclusion Resting-state networks may be affected positively by education level,early fluid intelligence and sports,while negatively by two cognitive reserve proxies including leisure activities and socialization level.[Chinese Medical Equipment Journal,2024,45(1):1-8]

Objective To propose a Kaczmarz algorithm-based fast reconstruction method of magnetic particle imaging to solve the problems of magnetic particle tomography in prolonged imaging time and computational complexity.Methods Firstly,the convergence speeds of the classical Kaczmarz algorithm and its variant algorithms were analyzed,and the number of iterations and computational time under arbitrary matrices were calculated.Secondly,the abilities of Euclidean distance and cosine distance in differentiating system data were compared,and the cosine distance-based K-means algorithm was employed to enhance the computational capability of block Kaczmarz algorithm,shorten the system matrix reconstruction time,and ultimately fast reconstruction of magnetic particle imaging was realized.The effectiveness of the proposed algorithm was verified through computer simulation.Results The proposed algorithm reduced greatly the reconstruction time and improved the spatial resolution and quality of the reconstructed images.Conclusion The proposed algorithm enables fast reconstruction of magnetic particle imaging and behaves well in reconstruction of data containing noise.[Chinese Medical Equipment Journal,2024,45(1):9-14]

Objective To design an assisted patient conveying and vibration damping system to solve the problems of operator fatigue and patient bump during casualty evacuation.Methods The assisted patient conveying and vibration damping system was composed of several conveying straps and a vibration damping mechanism.The conveying straps were made up of a waist strap,two shoulder straps,a chest strap,adhesive straps and joint components,and the joint components included adjusting buckles,big buckles,small buckles,connecting buckles and hook mechanisms;the vibration damping mechanism adopted the technical form of extension handle combined with vibration absorber,in which the extension handle was made of rigid material and the vibration absorber was equipped with a scissor guiding mechanism.Tests were carried out on the system to record the operating time of the operators and to analyze the system's vibration damping characteristics.Results The system developed extended the operating time of the stretcher conveyers while reduced the vibration during casualty transport,with a maximum vibration reduction of 71.73％.Conclusion The system developed gains advantages in low vibration and low workload,and can be used for casualty conveying in poor road conditions.[Chinese Medical Equipment Journal,2024,45(1):15-24]

Objective To design an experimental device for simulating the interface micro motion of bone trabecular prosthesis and carry out the finite element analysis.Methods The experimental device was composed of a screw-in cylinder with threads,a flexible hinge,a micro-motion rod,a trabecular prosthesis,a connecting rod and a fixation post.A model of the experimental device was constructed with SolidWorks software,and then imported into ABAQUS software to establish a finite element model.An axial displacement load was applied to the femur to analyze the effects of the position of the flexible hinge,the gap between the prosthesis and the femur and the length of the connecting rod on the micro motion.Results The interface micro motion produced by the experimental device increased with the distance of the flexible hinge from the lower end of the screwed-in cylinder;the gap between the prosthesis and the femur did not affect the interface micro motion when the gap was not lower than 20 μm;the interface micro motion rose with the length of the connecting rod.Conclusion The experimental device can accurately simulate the micro motion of different bone trabecular prosthesis interfaces,and can be used for studying the effect of the interface micro motion on osseointegration.[Chinese Medical Equipment Journal,2024,45(1):25-30]

Objective To explore the manufacturing process and performance of laser-cut 316L medical catheters based on catheter designs with different cutting methods.Methods Two design schemes of straight and oblique spiral cut were proposed under interrupted spiral cut pattern.Straight and oblique spiral cut medical catheters were obtained with desired laser parameters,cutting speed and focus position of the laser cutting machine,oxygen as the auxiliary gas and nitric acid and hydrofluoric acid as the acid cleaning solution for the post-treatment process,which were compared with Direxion torqueable microcatheter and tested for traceability,torsion control and tensile strength.Results Laser-cut 316L medical catheters were less likely to hurt blood vessels for its advantages over Direxion torqueable microcatheter in surface brightness and roundness of grooved edges,while Direxion torqueable microcatheter behaved better in intensity and width uniformity of grooves and regularity of semi circles at ends of grooves.Straight spiral cut medical catheters had the traceability,torsion control and tensile strength increased by 50％,22％and 33％respectively when compared with oblique spiral cut catheters.Conclusion Laser cutting parameters and post-treatment process are the main factors affecting the appearance and size of laser cut medical catheters,and also of importance for improving the qualified rate of product processing and assembly.The catheter cutting design scheme is also a key element influencing the physical properties of medical catheters.[Chinese Medical Equipment Journal,2024,45(1):31-36]

Objective To design a key nursing technique training platform for emergency response caregivers of nuclear,chemical and biological rescue.Methods The platform designed with B/S architecture used C# language for developing the server,HTML5 technology for building the user interface and JavaScript language for writing the logic of interaction,which was composed of three functional modules for video classroom,post-test and simulation training.Results The platform deve-loped realized training and assessment of key nursing techniques for nuclear,chemical and biological rescue without the restriction by time,space and teacher,and was of significance for enhancing the training efficacy.Conclusion The platform developed meets the needs of emergency response caregivers for key nursing techniques of nuclear,chemical and biological rescue.[Chinese Medical Equipment Journal,2024,45(1):37-41]

Objective To design an intelligent surgery management system for closed-loop management of the entire surgical process.Methods An intelligent surgery management system was developed with digital twin technology,Microsoft Visual Studio 12.0 development toolset and C# language,which realized multi-modal data acquisition with IoT devices such as radio frequency identification(RFID)bracelets,mobile terminals and positioning base stations and real-time data mirroring and gathering by change data capture(CDC)technology.There were four functional modules included in the system developed,including the modules for IoT device management,transfer process recording,intelligent management command chamber and surgical progress reminder.Results The system developed could provide real-time feedback on the operation status of all aspects of surgery,shorten the lengths of preoperative positioning and surgical reception and improve the satisfaction of both doctors and patients.Conclusion The system developed achieves closed-loop management and complete data traceability of the entire surgical process,helping to form an efficient and safe surgical operation management system.[Chinese Medical Equipment Journal,2024,45(1):42-46]

Objective To develop a time-resolved fluorescent immunoassay kit for the rapid,accurate and quantitative detection of S100B protein in serum and to evaluate its performance.Methods The test strip was prepared using time-resolved fluorescent microsphere-labeled anti-S100B polyclonal antibody and rabbit IgG antibody,labeling pads,sample pads,S100B nitrocellulose films and absorbent paper,and an S100B time-resolved fluorescence immunoassay kit was obtained by assembling the cartridge.The performance of the kit developed was evaluated by standard curve,accuracy,minimum detection limit,linear interval,specificity,reproducibility and stability.The reference intervals of 199 pieces of healthy human serum and plasma samples from a certain region were detected with the kit,and the clinical performance of the kit and Roche Elecsys S100 kit was tested by synchronous blind method to assess the consistency of the results of the two kits for 142 samples.Results The S100B time-resolved fluorescence immunoassay kit had the standard curve beingy=(1.133 02+1.752 24)/[1+(x/1.082 20)×(-0.603 52)]-1.752 24,R2=0.999 08 and the linear range being[0.05,30]ng/mL,which met the requirements of the relative deviation of the accuracy within±15％,the minimum detection limit not hgier than 0.05 ng/mL,the relative deviation of specificity within±15％and the coefficient of variation of intra-and inter-batch difference less than 15％.The stability test results indicated that the kit was valid for 12 months at 2-30 ℃ conditions.The reference intervals of serum and plasma samples measured by the kit were both lower than 0.3 ng/mL.Clinical trials showed that the results by the kit and Roche Elecsys S100 Assay Kit were in high agreement(Kappa=0.906 1＞0.80)and met the requirements.Conclusion The kit developed detects the concentration of S100B protein in serum quickly,accurately and quantitatively,and provides references for the diagnosis and treatment of neurological diseases,autoimmune diseases,cerebrovascular diseases and etc.[Chinese Medical Equipment Journal,2024,45(1):47-55]

Objective To establish a stable and reliable method for the determination of ethylene oxide residue,and to analyze ethylene oxide residue in multi components made of different materials involved in some medical devices,so as to provide references for sample selection and ethylene oxide residue detection of multi-component medical device kits.Methods A method for the determination of ethylene oxide residue of multi-component medical devices was developed using headspace-gas chromatography and DB-WAX column under the conditions of headspace extraction with equilibration at 80℃ for 20 min,and the weighing mass,linearity,limit of detection,limit of quantification,precision and recovery of the method were determined.Trials of the method were carried out on the items undergoing ethylene oxide sterilization,including disposable perineal care kit,disposable gynecological examination kit,disposable suture dressing kit,disposable debridement kit and the components contacting human body in the disposable dialysis kit,and the abilities of different materials of the components were analyzed in absorbing,retaining and releasing ethylene oxide.Results The method showed high linearity(r=0.999 8)in the range of ethylene oxide mass concentration from 0.4 to 16.0 μg/mL with a weighing mass of 1.00 g,which had the limit of detection being 0.11 μg/mL,the limit of quantification being 0.37 μg/mL and the relative standard deviations(RSDs)for the precision from 0.35％to 1.52％.The average recoveries of different spiked amounts of ethylene oxide in the three blank matrices ranged from 92.68％to 101.42％with the relative standard deviations(RSDs)from 2.46％to 7.59％,which all satisfied the detection requirements.The components made of rubber and acrylonitrile-butadiene-styrene copolymer(ABS)in multi-component medical device kits had the highest ethylene oxide residues,followed by the components made of wood,degreased cotton,polypropylene and polystyrene.Conclusion The method proposed gains advantages in easy operation and high specificity,quantification and reproducibility,which can be used for the determination of ethylene oxide residue in the multi-component medical device kit undergoing ethylene oxide sterilization.References are provided for sample selection of multi-component medical devices.[Chinese Medical Equipment Journal,2024,45(1):56-61]

Objective To compare the effects of two arc(TA)and dual arc(DA)techniques on the dose distribution to the planning target volume(PTV)and organs at risk(OAR)in volumetric modulated arc therapy(VMAT)for lower mid-thoracic esophageal cancer.Methods Ten patients with lower mid-thoracic esophageal cancer who received radiation therapy at some hospital from July 2020 to June 2022 were selected retrospectively.A TA radiation therapy plan and a DA radiation therapy plan were developed for each patient using the Ray Arc module of RayStation 4.7.5.4 planning system,and the two kinds of radiation plans were compared in terms of dosimetric parameters including D2,D5,D50,D95,D98,homogeneity index(HI),conformity index(CI),beam-on time and total monitor unit for PTV and lung V5,V10,V20,V30 and Dmean and heartV30,V40 and Dmean and spine cord Dmax for OAR.SPSS 22.0 was used for statistical analysis.Results TA and DA radiation therapy plans had no significant differences in PTV CI,HI,D2,D5,D50,D95 and beam-on time(P＞0.05),and DA plan had D98 and total monitor unit higher obviously than those of TA plan(P＜0.05).In terms of OARs protection,DA plan had heart V30,V40 and Dmean slightly lower than those of TA plan with non-significantly differences(P＞0.05),while lung V5,V30 and Dmean and spine cordDmax significantly lower(P＜0.05).Conclusion DA technique gains advantages over TA technique in PTV dose distribution and dose to OAR,and the involvement of DA technique in preparing the VMAT plan for esophageal cancer contributes to enhancing the treatment efficacy.[Chinese Medical Equipment Journal,2024,45(1):62-66]