We proposed a research of a heart sound envelope extraction system in this paper. The system was implemented on LabVIEW based on the Hilbert-Huang transform (HHT). We firstly used the sound card to collect the heart sound, and then implemented the complete system program of signal acquisition, pretreatment and envelope extraction on LabVIEW based on the theory of HHT. Finally, we used a case to prove that the system could collect heart sound, preprocess and extract the envelope easily. The system was better to retain and show the characteristics of heart sound envelope, and its program and methods were important to other researches, such as those on the vibration and voice, etc.
Fetal heart sound is nonlinear and non-stationary, which contains a lot of noise when it is colleced, so the denoising method is important. We proposed a new denoising method in our study. Firstly, we chose the preprocessing of low-pass filter with a cutoff frequency of 200 Hz and the re-sampling. Secondly, we decomposed the signal based on empirical mode decomposition method (EMD) of Hilbert-Huang transform, then denoised some selected target components with wavelet soft threshold adaptive noise cancellation algorithm. Finally we got the clean fetal heart sound by combining the target components. In the EMD, we used a mask signal to eliminate the mode mixing problem, used mirroring extension method to eliminate the end effect, and referenced the stopping rule from the research of Rilling. This method eliminated the baseline drift and noise at once. To compare with wavelet transform(WT), mathematical morphology (MM) and the Fourier transform (FT), the SNR was improved obviously, and the RMSE was the minimum, which could satisfy the need of the practical application.
ObjectiveTo investigate the effect of “noncycloplegic retinoscopy for screening myopia + subsequent wearing orthokeratology lens” process for primary and secondary school students based on physical examination center.MethodsA total of 172 primary and secondary school students undergoing vision examination in the Health Management Department (i.e. physical examination center) of the Second Affiliated Hospital of Xi’an Jiaotong University between January 2017 and December 2018 were selected as the research objects. After examination by noncycloplegic retinoscopy in the health management department, they were examined by mydriatic retinoscopy in the ophthalmology department, and then the consistency of the results of the two methods was analyzed. Then 93 students with myopia diagnosed by both methods were randomly divided into control group (n=46) and trial group (n=47), wearing frame glasses and orthokeratology lenses respectively. The diopter, eye axial length, corneal curvature and vitreous cavity depth before wearing glasses, as well as the increment of the above indicators at 3, 6 and 12 months after wearing glasses/lenses were compared between the two groups, and the incidence of complications of the two groups were compared.ResultsCompared with mydriatic retinoscopy, the positive predictive value of noncycloplegic retinoscopy was 88.6%, the sensitivity was 96.9% and the specificity was 84.2%, and the consistency kappa coefficient was 0.821 (P<0.001). Before wearing glasses/lenses, there was no significant difference in diopter, eye axial length, corneal curvature or vitreous cavity depth of both eyes between the two groups (P>0.05); at 3, 6 and 12 months after wearing glasses/lenses, the diopter increment and eye axial increment of both eyes of the trial group were less than those of the control group [left eye diopter increment: (0.48±0.07) vs. (0.73±0.08) D, (0.69±0.13) vs. (1.04±0.11) D, (0.88±0.11) vs. (1.13±0.11) D; left eye axial increment: (0.18±0.05) vs. (0.26±0.04)mm, (0.22±0.04) vs. (0.36±0.04) mm, (0.27±0.05) vs. (0.40±0.05) mm; right eye diopter increment: (0.46±0.10) vs. (0.73±0.09) D, (0.71±0.12) vs. (1.04±0.10) D, (0.90±0.10) vs. (1.17±0.11) D; right eye axial increment: (0.17±0.04) vs. (0.24±0.04) mm, (0.23±0.04) vs. (0.37±0.04) mm, (0.26±0.05) vs. (0.42±0.05) mm] (P<0.05). At 3, 6 and 12 months after wearing glasses/lenses, the changing trends of corneal curvature and vitreous cavity depth in both eyes of the trial group were different from those of the control group (PInteraction<0.05), and the corneal curvature of both eyes at each time point was lower than that before wearing lenses and that of the control group (P<0.05), while the vitreous cavity depth of both eyes was not statistically different from that before wearing lenses (P>0.05) but lower than that of the control group (P<0.05). There was no statistical difference in the incidence of common complications between the two groups (P>0.05).ConclusionIn the physical examination center, the accuracy of noncycloplegic retinoscopy for general survey of myopia in primary and secondary school students is high, and then after the diagnosis by mydriatic retinoscopy in the special department, the use of orthokeratology lens can effectively control the progress of myopia, so the process of “noncycloplegic retinoscopy for screening myopia in physical examination center + subsequent wearing orthokeratology lens in specialty” is feasible.
目的探讨胰腺血管活性肠肽瘤（VIPoma）的临床、实验室和影像学特点，以及诊断方法和治疗手段。 方法报道1例胰腺VIPoma，同时检索国内文献得到49例胰腺VIPoma患者临床资料，并对此50例病例进行分析。 结果分泌性腹泻、低血钾和代谢性酸中毒是胰腺VIPoma的主要临床表现，血浆血管活性肠肽（VIP）水平增高具有诊断价值。经手术治疗，腹泻症状可减轻或消失；对于远处转移患者，生长抑素、化疗、干扰素等治疗均有效。 结论VIPoma早期诊断困难，确诊依赖于典型临床症状、血浆VIP水平、影像学检查以及免疫组化检查。手术切除可改善预后，生长抑素等治疗可缓解症状，发生转移者也应积极治疗。
Objective To investigate the effect of the position of pancreatic duct in pancreatic section on postoperative pancreatic fistula. Methods The clinical data of patients undergoing pancreaticoduodenectomy admitted to the pancreatic surgery department of our hospital from September 2018 to August 2020 were retrospectively collected. The consistency between intraoperative pancreatic section data and preoperative CT cross-sectional images of pancreatic duct was compared, and the occurrence of postoperative pancreatic fistula was analyzed by univariate analysis and multivariate logistic regression model analysis, to determine whether the position of pancreatic duct on pancreatic section during pancreaticojejunostomy had an impact on the occurrence of postoperative pancreatic fistula. Results A total of 373 patients were included in this study. In 44 cases, the ratio of the thickness of the short distance from the center of the pancreatic duct to the edge of the pancreas at the pancreatic section was 0.41±0.09, and the imaging measurement value was 0.40±0.10. The interclass correlation coefficient detection value of the two measurement methods was 0.916 (>0.75), P<0.001, this had high consistency. Patients had a high BMI [OR=1.276, 95%CI (1.154, 1.411), P<0.000 1] and soft pancreatic texture [OR=2.771, 95%CI (1.558, 4.927), P=0.001] were independent risk factors for postoperative pancreatic fistula, while the risk of postoperative pancreatic fistula decreased with the increased proportion of pancreatic duct thickness from center to edge [OR=0.875, 95%CI (0.840, 0.911), P<0.000 1]. Conclusions Patients with high BMI and soft pancreas are independent risk factors for postoperative pancreatic fistula, and the risk of postoperative pancreatic fistula is reduced when the center of pancreatic duct is far from the edge of pancreas. The ratio of short distance from the center of pancreatic duct to the edge of pancreas to the total thickness of pancreas measured by preoperative imaging can be used to evaluate the risk of postoperative pancreatic fistula.
ObjectiveTo evaluate the postoperative complications after pancreaticoduodenectomy with modified triple-layer(MTL) duct-to-mucosa pancreaticojejunostomy and with resection of jejunal serosa, analyse the risk factors of pancreatic fistula, and compare effects with two-layer(TL) duct-to-mucosa pancreaticojejunostomy. MethodsData on 184 consecutive patients who underwent the two methods of pancreaticojejunostomy during standard PD between January 1, 2010 and January 31, 2013 were collected retrospectively. The risk factors of pancreatic fistula were investigated by using univariate and multivariate analyses. ResultsA total of 88 patients received TL and 96 underwent MTL. Rate of pancreatic fistula for the entire cohort was 8.2%(15/184). There were 11 fistulas(12.5%) in the TL group and four fistulas(4.2%) in the MTL group(P=0.039). Body mass index, pancreatic texture, pancreatic duct diameter, and methods of pancreaticojejunostomy had significant effects on the formation of pancreatic fistula on univariate analysis. Multivariate analysis showed that pancreatic duct diameter less than 3 mm and TL were the significant risk factors of pancreatic fistula. ConclusionsMTL technique effectively reduced the pancreatic fistula rate after PD in comparison with TL, especially in patients with pancreatic duct diameter less than 3 mm.