Objective To develope a realtime system for ECG signals acquisition,amplification and network transmission.Methods The raw noisy ECG signals underwent gain amplification,denoising and filtering by a system developed by virtual instrument and LabVIEW,and network component programming was carried out based on TCP/IP.Then the processed ECG signals were transmitted to remote terminals with dual communication model.Results The system behaved well in easy operation,high reliability and man-machine interface,and could be used to realize remote realtime transmission and browsing of ECG signals between the hospital and medical communities.Conclusion The system may be a choice for ECG signals remote acquisition and transmission,and provides references for the development of telemedicine software.

Objective To investigate the guidance value of TOI classification in treating traumatic T-type atlantoaxial dislocation (ADD).Methods A retrospective case series study was made on 32 cases of traumatic TOI T-type ADD treated between January 2012 and December 2015.There were 19 males and 13 females,aged (38.4 ± 14.7) years.Fifteen cases of T1-type underwent external fixation or internal fixation without fusion,while 17 cases of T2-type underwent internal fixation with fusion.Symon-Lavender clinical standard,Japanese orthopedic association score (JOA),visual analogue scale (VAS),atlas-dens interval (ADI) and space available for the cord (SAC) were used to evaluate the therapeutic effect.Results Patients were followed up for 6-54 months (mean,32.4 months).At final follow-up,ADI was decreased to (2.3 ± 1.4) mm from preoperative (5.6 ± 1.6) mm,but SAC was increased to (15.4 ± 1.9) mm from preoperative (12.0 ± 2.9) mm(P ＜ 0.01).At final follow-up,cervical axial rotation range of motion was 102°-154° in T1-type cases and 57°-93° in T2-type cases.Range of motion for atlantoaxial joint was preserved in T1-type cases,but lost in T2-type cases.According to the Symon-Lavender clinical standard,there were 14 cases of mild disability,nine moderate disability,eight severe disability and one extremely severe disability before operation;there were 21 cases of mild disability,nine moderate disability and two severe disability at last follow-up.Significant difference was observed in the grades according to the Symon-Lavender clinical standard before operation and at last follow-up (P ＜0.05).At last follow-up,JOA score was increased to (14.6 ± 2.9) points from preoperative (9.9± 3.2) points,and VAS was decreased to (2.7 ± 1.3)points from preoperative (6.0 ± 1.6)points (P ＜ 0.01).Conclusions By using TOI classification,reconstruction of stability and improved neurological function can be achieved in treatment of traumatic T-type atlantoaxial dislocation.Non-fusion treatment of T1-type atlantoaxial dislocation can preserve range of motion for atlantoaxial joint.

Objective:To assess the three-dimensional dose distribution in radiotherapy plans using the structural similarity index(SSIM), compare the performance of SSIM with commonly used quality assessment indices, and develop a SSIM-based quality assessment method of multiple prescribed doses.Methods:The SSIM was introduced to providea quality score of various voxels by comparing actual and ideal three-dimensional dose data and combining the spatial location information of the voxels. Then the average value in a region of interest (ROI) was calculated as the quality score of the region. Fifty-three cases of cervical cancer were selected to analyze the correlation of the SSIM with the uniformity index (HI), conformity index (CI) of the dose distribution in various ROIs and to explore the capability of the SSIM to reflect the uniformity and conformity of dose distribution.Two types of quality defects were individually introduced into two of 53 radiotherapy plans. Then the two plans were compared with normal plans to characterize the response of the SSIM.Results:There was no correlation between HI and SSIM in positive lymph nodes(PGTVnd) due to the decrease in the HI sensitivity, while there was a significant negative correlation between them in regions where PGTVnd was removed from the planning target volume(PTV, R=-0.86, P<0.01). Meanwhile, there was a significant positive correlation between CI and SSIM in PGTVnd ( R=0.83, P<0.01). Therefore, the SSIM can be used to identify the artificial design defects in plans by determining abnormal dose gradients. Conclusions:Apart from reducing the defects of previous assessment parameters, the SSIM has the capability to assess the quality of radiotherapy plans by combining the uniformity and conformity of dose distribution and can provide accurate feedback on the spatial locations of quality defects.

Objective:To develope an automatic volumetric modulated arc therapy (VMAT) planning for rectal cancer based on a dose-prediction model for organs at risk(OARs) and an iterative optimization algorithm for objective parameter optimization.Methods:Totally 165 VMAT plans of rectal cancer patients treated in Peking University Cancer Hospital & Institute from June 2018 to January 2021 were selected to establish automatic VMAT planning. Among them, 145 cases were used for training the deep-learning model and 20 for evaluating the feasibility of the model by comparing the automatic planning with manual plans. The deep learning model was used to predict the essential dose-volume histogram (DVH) index as initial objective parameters(IOPs) and the iterative optimization algorithm can automatically modify the objective parameters according to the result of protocol-based automatic iterative optimization(PBAIO). With the predicted IOPs, the automatic planning model based on the iterative optimization algorithm was achieved using a program mable interface.Results:The IOPs of OARs of 20 cases were effectively predicted using the deep learning model, with no significantly statistical difference in the conformity index(CI) for planning target volume(PTV)and planning gross tumor volume(PGTV)between automatic and manual plans( P>0.05). The homogeneity index (HI) of PGTV in automatic and manual plans was 0.06 and 0.05, respectively( t=-6.92, P< 0.05). Compared with manual plans, the automatic plans significantly decreased the V30 for urinary bladder by 2.7% and decreased the V20 for femoral head sand auxiliary structure(avoidance)by 8.37% and 15.95%, respectively ( t=5.65, 11.24, P< 0.05). Meanwhile, the average doses to bladder, femoral heads, and avoidance decreased by 1.91, 4.01, and 3.88 Gy, respectively( t=9.29, 2.80, 10.23, P< 0.05) using the automatic plans. The time of automatic VMAT planning was (71.49±25.48)min in 20 cases. Conclusions:The proposed automatic planning based on dose prediction and an iterative optimization algorithm is feasible and has great potential for sparing OARs and improving the utilization rate of clinical resources.