Totally 20 manufacturers for implantable medical devices had their unannounced inspection introduced,whose problems and key control pointes were analyzed in terms of plant and facilities,equipment,document management,design and development,procurement,production management and quality control.Some suggestions were put forward including promoting the awareness of the first responsible person of the enterprise,strengthening the competence level of the enterprise personnel and enhancing the ability of the enterprise to operate the quality management system,which were of great significance for enterprises to improve the quality of implantable medical devices.[Chinese Medical Equipment Journal,2025,46(7):81-86]

Three typical failures of large-aperture 16-slice spiral Siemens SOMATOM Sensation Open CT were introduced in terms of phenomenon,cause and treatment method.References were provided for medical engineers to treat similar failures.

The malfunctions of Philips IQon Spectral CT System were introduced in terms of image ring artifact,failure in gantry staring and low speed in image reconstruction,with the causes being analyzed and the elimination measures put forward.References were provided for treating similar failures.

Objective To propose an abdominal organ segmentation method based on a cross-fusion skip-connection mechanism to enhance the overall segmentation effect of abdominal organs.Methods Firstly,the Swin-Unet network was used as the baseline segmentation model,into which an enhanced dual cross attention(EDCA)module was integrated to refine features by fusing multi-scale encoder features;secondly,a decoder-guided cross-fusion attention(DCFA)module was added to reconstruct encoder information under the guidance of decoder features so as to mitigate the semantic gap between the features of the encoder and decoder;finally,a cross-fusion skip-connection mechanism was designed based on EDCA and DCFA modules to achieve effective feature transmission from encoder to decoder features.The cross-fusion skip connection mechanism-based abdominal organ segmentation model had its effectiveness validated by the experiments carried out on Synapse multi-organ CT dataset and comparison with some mainstream abdominal organ segmentation models including TransUNet,UNetR,UCTransNet,MT-UNet and Swin-Unet.Results The Swin-Unet model based on the cross-fusion skip connection mechanism achieved a Dice similarity coefficient(DSC)of 80.30%and a Hausdorff distance(HD)of 18.26 mm,outperforming the other mainstream abdominal organ segmentation models.Moreover,the model proposed had the number of parameters(27.18M)and floating-point operations per second(6.16×10?/s)both superior to those of the other mainstream abdominal organ segmentation models while close to those of Swin-Unet.Conclusion The proposed method effectively enhances the segmentation of abdominal organs,providing an effective design approach for optimizing segmentation models based on U-shaped structures.

Objective To propose a multiple regression-variational auto-encoders(MR-VAE)model to realize precise and non-invasive prediction of intra-abdominal pressure(IAP)in critically ill patients.Methods At first,a dataset was constructed by retrospectively analysing baseline characteristics and clinical indicators of 100 critically ill patients admitted to the Intensive Care Unit of Daping Hospital of Army Medical University between 30 August 2019 and 30 March 2021.Then,a MR-VAE prediction model was developed by integrating a feedforward neural network for supervised regression onto a variational autoencoder(VAE)framework and incorporating multiple regression strategies to mitigate feature interference.Finally,the MR-VAE model had its performance evaluated by its comparison with five classical models including support vector machines(SVM),convolutional neural networks(CNN),Scikit-learn integrated model(SIM),multi-layer perceptron(MLP)and K-nearest neighbors(KNN),and its prediction accuracy verified by testing the data of 10 randomly selected patients.Results The MR-VAE model behaved the best when compared with the five classical models,with a mean squared error(MSE)of 0.207,a root mean square error(RMSE)of 0.454,a mean absolute error(MAE)of 0.361,a median absolute deviation(MAD)of 0.243,an explained variance score(EVS)of 0.814 and a R2of 0.823,which also outperformed the five models in fitting performance,convergence and final loss.In random sample testing,the MR-VAE model exhibited high consistency between predicted and actual values.Conclusion The MR-VAE model proposed can accurately predict IAP,which has great potential in reducing the repeated measurements of IAP in critically ill patients and providing new ideas for the early diagnosis and treatment of IAH.

Objective To explore the performance of gallium nitride(GaN)-based digital circuit chips applied in nuclear radiation environments and investigate the feasibility of their use in control chips for robots transporting injured personnel.Methods First,a GaN-based NAND gate digital circuit chip was fabricated.Second,both the GaN-based digital chip and the SN74AHCT1G00 silicon-based digital chip were irradiated with 60Co gamma-ray.The irradiation doses for the GaN-based digital chip were 1 Mrad(Si)and 2 Mrad(Si),while the irradiation dose for the SN74AHCT1G00 silicon-based digital chip was 1 Mrad(Si).Finally,the post-irradiation electrical performance of the two chips was measured using a Keithley 4200A-SCS semiconductor characterization system.Results Under 60Co gamma-ray irradiation doses of 1 Mrad(Si)and 2 Mrad(Si),the response delay of the GaN-based digital circuit chip was only on the order of 0.1 μs.In contrast,the response rate of the SN74AHCT1G00 silicon-based digital circuit chip significantly degraded under 60Co gamma-ray irradiation dose of 1 Mrad(Si),rendering it unable to perform the NAND gate logic function.Conclusion GaN-based digital circuit chips exhibit high radiation resistance in 60Co gamma-ray irradiation environments,with no significant performance degradation.Compared with silicon-based digital circuit chips,they demonstrate considerable advantages and can preliminarily meet the requirements for control chips of robots transporting injured personnel in nuclear radiation environments.

Objective To carry out emergency medical system modification design for EC135 P3H helicopter without compromising the original airframe structure so as to enhance aeromedical rescue capabilities.Methods Firstly,the original cabin seats were removed and medical floor was installed in the cabin;secondly,the medical chair,medical stretcher trolley and its fixing components,storage boxes and oxygen cylinders were mounted onto the floor;finally,a medical equipment fixing frame was formed based on the original helicopter sill structure so as to accommodate medical devices such as defibrillators,ventilators and injection pumps.The modification design scheme had its effectiveness verified with overall aircraft load balance analysis,mechanical analysis,dynamic impact tests of seats and actual modification and flight tests.Results EC135 P3H helicopter proved to meet all the airworthiness certification requirements after emergency medical system modification.Conclusion The proposed modification scheme enables EC135 P3H helicopter to rapidly transition between standard and medical configurations,enhancing its emergency medical rescue capabilities and providing references for medical modifications of helicopters with similar configurations.

Objective To build a hospital data service portal system based on central authentication service(CAS)to solve the problems of dispersed user identity data and low management efficiency caused by independent operation of multiple systems.Methods The CAS-based hospital data service portal system was designed with B/S architecture and developed with Spring MVC framework,which implemented unified authentication with CAS technology and achieved standardized access protocols for integrated access,centralized management and service consolidation across various application systems.There were five functional modules involved in the system for homepage,workflow management,system administration,log management and message management.Results The system significantly enhanced user accessibility and data extraction efficiency,effectively reduced the complexity of system integration and operational maintenance burdens and ensured user privacy and data security.Conclusion The portal system provides users with an easy-to-use,secure and reliable data service portal,laying the foundation for building an efficient,intelligent and safe hospital data service system.

Objective To explore the ArcCHECK system-based methods for dose verification of ultra-long target for cervical cancer VMAT so as to assure the precision of cervical cancer radiotherapy.Methods A total of 33 patients with ultra-long target(target length≥26 cm)admitted to some hospital for cervical cancer VMAT from 2021 to 2023 were selected retrospectively,and radiotherapy plans were designed for the patients with VMAT technology and verified dosimetrically with different methods.Firstly,the dose distribution data were collected respectively at 5 and 8 cm away from the center of the ArcCHECK system along the bed exit direction,and enrolled into Group Test 1 and Test 2 respectively.Then the ArcCHECK system was flipped 180°,and the dose distribution data were acquired at 8 cm away from the center along the bed exit direction and included into Group Test 3.Dose merging between Group Test 2 and Test 3 with the Merge function was carried out to obtain the dose distribution data which were divided into Group Test 4.The monitor units of Group Test 1,2 and 4 were summarized,and difference analyses were performed on the length of the target area,detection point and irradiation time.Group Test 1,2 and 4 were compared in terms of γ pass rate,normalized dose deviation,confidence limit(CL)of pass rate and acceptance rate(γ pass rate≥95%and γ pass rate≥90%).Spearman's correlation coefficient was used to correlate the parameters such as maximum transverse diameter,length,volume and monitor unit of the target area and expected execution time of the plan.SPSS 19.0 software was used for statistical analysis.Results Group Test 1,2 and 4 had the monitor unit being(758.76±107.63)MU,and had statistically significant differences in length of the target area,detection point and irradiation time(P<0.01).In Group Test 4 γ pass rate under 2%/2 mm criterion did not reach 90%,and in Group Test 1 and 2 γ pass rates under 3%/3 mm and 3%/2 mm criteria both amounted to 95%.Group Test 1,2 and 4 had statistically significant differences in γ pass rate and normalized dose deviation(all P<0.05).In Group Test 1 there were more than 90%of the verification results where γ pass rate≥95%and more than 95%where γ pass rate≥90%under 3%/3 mm criterion.The monitor unit was positively correlated with the maximum transverse diameter,length and volume of the target area,respectively(0.337≤r≤0.568,P<0.05),and the expected execution time of the plan was positively correlated with the volume and monitor unit of the target area,respectively(0.457≤r≤0.517,P<0.01).Conclusion The dose verification method with the target at 5 cm away from the center along the bed exit direction can be applied clinically with high feasibility to the dose verification during the radiotherapy of the cervical cancer VMAT patients with ultra-long target,with the safety of the verification devices ensured effectively.

Objective To investigate the dosimetric effect of a biological optimization approach combining physical optimization with generalized equivalent uniform dose(gEUD)on hippocampus avoidance whole-brain radiotherapy(HA-WBRT).Methods A retrospective review was conducted of 20 patients with multiple brain metastases who underwent whole-brain radiotherapy at a certain hospital between May 2021 and December 2022.Two radiotherapy plans including plan_DV and plan_gEUD were designed for each patient by using Eclipse V15.6 planning system.Plan_DB used conven-tional dose-volume(DV)physical optimization,and plan_gEUD went through re-optimization with an Upper gEUD function applied to hippocampal region and hippocampal protection zone.Evaluation was carried out in accordance with RTOG 0933 guidance for the absolute values D2%,D98%and D50%received by 2%,98%,and 50%of the target volume in the planning target volume,conformity index(CI),homogeneity index(HI),gradient index(GI)and the dosimetric indexes of hippocampal region,hippocampal protection zone and other organs at risk(OARs).SPSS 26.0 software was used for statistical analysis.Results The two kinds of plans both had the target volume coverage meet the requirements of RTOG 0933 guidance.Plan_gEUD had the D98%,D2%and V105 of the planning target volume lower than those of plan_DV,with the differences being statistically significant(all P<0.05).The two kinds of plans had no significant differences in monitor unit,D50%and Dmax of PTV,HI,CI and GI(all P>0.05).Plan_gEUD had the Dmax and Dmean of hippocampal region and them of hippocampal pro-tection zone lower than those of plan_DV,and the optic nerve Dmax of plan_gEUD was higher than that of plan_DV,with the differences being statistically significant(all P<0.05).There were no statistically significant differences between the two kinds of plans in the Dmax of inner ear,optic chiasm,lens,and eyeball(all P>0.05).Conclusion Physical optimization in the HA-WBRT plan combined with gEUD optimization results in a greater dose reduction to the hippocampus while maintaining target coverage.