1.Photoplethysmography signal smoothing technology based on locally orthogonal weighted polynomial fitting
Jinlu LI ; Zhanyu LAI ; Keyang DONG ; Yufan DUAN ; Zidong DAI ; Yurong LIU ; Xiaoping JIANG
Chinese Journal of Medical Physics 2025;42(7):945-951
To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.
2.Photoplethysmography signal smoothing technology based on locally orthogonal weighted polynomial fitting
Jinlu LI ; Zhanyu LAI ; Keyang DONG ; Yufan DUAN ; Zidong DAI ; Yurong LIU ; Xiaoping JIANG
Chinese Journal of Medical Physics 2025;42(7):945-951
To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.
3.The modified single incision robot-assisted laparoscopic radical prostatectomy: initial experience and clinical efficiency
Qian LYU ; Yi WEI ; Yaoqian WANG ; Yong OU ; Qiang WANG ; Hualin FENG ; Cheng LUO ; Yu NIE ; Shangqing REN ; Fang ZHOU ; Shida FAN ; Zhengjun CHEN ; Keyang JIA ; Yang LI ; Dong WANG
Chinese Journal of Urology 2021;42(11):830-833
Objective:To evaluate the feasibility and clinical efficiency of robot-assisted laparoscopic radical prostatectomy (RARP) via extraperitoneal PORT-free single incision approach.Methods:The data of 33 patients with prostate cancer underwent the extraperitoneal PORT-free single incision RARP from November 2020 to January 2021 in Sichuan Provincial People's Hospital was retrospectively reviewed. The average age was 66.7 (58-78) years, the median PSA was 20.77 (2.89, 56.44) ng/m, and the mean Gleason score was 7.0 (6.0-9.0). The mean prostate volume was 48.4 (25.0-220.0) ml. Clinical stage: 32 cases was in cT 2a-2cN 0M 0, 1 case in cT 3aN 0M 0. 16 cases had a history of operation. All 33 operations were performed by the same operator. All operations were performed by extraperitoneal PORT-free single-incision approach. The surgical condition, postoperative complication, pathology, and follow-up results were observed. Results:In this study, 33 operations were successfully completed without conversion to open or additional single hole channel instruments. The average operation time was 61.3 (38.0-120.0) min, with the mean intraoperative bleeding volume of 72.2 (45.0-220.0) ml and the mean bladder neck urethral anastomosis time of 11.7 (8.5-15.7) min. The mean postoperative hospital stay was 7.9 (6.0-15.0) d, the mean postoperative indwelling time of urinary catheter was 6.8 (6.0-14.0) d, and the mean postoperative evacuation time was 1.0 (0.5-3.0) d. The average incision length was 5.2 (4.6-5.8) cm. There was no obvious complications. The postoperative pathological stage: 21 cases were in < pT 3a, 12 cases were in ≥ pT 3a, and 6 cases (18.8%) had positive resection margin. 29 cases (88.9%) acquired satisfactory urinary continence after operation, and the frequency of urinary pad use was ≤ 1 tablet/day. Conclusions:The extraperitoneal single-incision RARP surgical channel without PORT is safe and feasible with a satisfying cosmetic effect, which saves costs and requires less specific channel device. Simultaneously, the new approach has strong replicability, short-term tumor control and urinary control effect with rapid postoperative recovery. However, the sample size of this study is relatively small, which needs further research and demonstration
4.Research of immunogenicity of mycobacteriophage D29 toward tuberculosis therapy
Wenhui YANG ; Zhanbo WEN ; Jingsong LI ; Lingfei HU ; Long YU ; Keyang LIU ; Jie WANG ; Na LI ; Xiaokai DONG
Chinese Journal of Infectious Diseases 2012;30(2):81-84
Objective To investigate the immunogenicity of mycobacteriophage D29 (phage D 29) in guinea pig models with different delivery routes,and provide information for the application of phages in tuberculosis (TB) therapy.Methods Hartley guinea pigs were administrated with phage D29 through inhalation,intranasal drop or subcutaneous injection for 6 times within 35 days.7H9 broth aerosol inhalation and 0.85 % NaCl solution aerosol inhalation were set as solvent and negative controls,respectively.Anti-phage D29 neutralizing antibodies in sera collected weekly were measured by phage reduction neutralizing test (PRNT) and cytokine levels (interleukin-2,interleukin-4 and interferon-γ) were detected at day 35 by enzyme linked immunosorbent assay (ELISA).The data were analyzed by ANOVA and nonparametric test.ResultsNeutralizing antibodies were both negative in two control groups,while low-titer neutralizing antibodies (below 1 ∶ 100) appeared in inhalation and intranasal drop groups only at day 7 and day 14. Nevertheless, neutralizing antibodies were continuously detected in subcutaneous injection group,which increased rapidly and reached 1∶ 16 365.6 at day 35. After 35 days of experiments,serum concentrations of interleukin-2 (x2 =2.7605,P>0.05),interleukin-4 (F=2.17,P>0.05) and interferon-γ(F=0.75,P>0.05) among three treatment groups and two control groups were all not significantly different.ConclusionsThe titer of anti-phage 29 neutralizing antibodies induced by inhalation or intranasal drop administration of phage D29 are both significantly lower than subcutaneous injection.Phage D29 administration doesn’t change the levels of cytokines,which indicates that it may not break the helper T cell (Th)1/Th2 balance.
5.Comparison of multi-slice helical CT cholangiography and MR cholangiopancreatography in diagnosis of pancreaticobiliary obstructive diseases
Keyang WANG ; Xin DONG ; Wen HE
Chinese Journal of Medical Imaging Technology 2010;26(3):521-524
Objective To compare the diagnostic value of 64-slice helical CT cholangiography and MR cholangiopancreatography (MRCP) for pancreaticobiliary obstructive diseases. Methods Thirty-six patients with pathologically proved pancreaticobiliary obstruction or endoscopic retrograde cholangiopancreatography (ERCP) were examined with MRCP and routine enhanced CT scanning. CT row data of portal venous phase were reconstructed with 0.625 mm thickness and intervals. Then multiplanar reformation (MPR) of intra- and extrahepatic biliary duct, gallbladder and pancreas was generated, and curved planar reformation (CPR) was performed when necessary. The accuracy of MPR (and CPR) and MRCP in evaluating the site and nature of obstruction was compared. Results The accuracy of MPR and MRCP was 97.22% and 94.44% in evaluating the site of obstruction, respectively. In evaluating the nature of obstruction, the accuracy of MPR and MPCP was 83.33% and 80.56%, respectively, and the accuracy of MPR increased to 88.89% in combination with CPR in some patients. There was no statistical difference between the accuracy of MPR and MRCP in evaluating the site and nature of obstruction, while their diagnostic consistency was medium (Kappa=0.471). Conclusion Both MSCT cholangiography and MRCP have high diagnostic value in pancreaticobiliary obstruction, while the former gets some advantages in images review for clinicians.

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