ObjectiveTo observe the efficacy of intravitreal injection of conbercept (IVC) combined with subthreshold micropulse laser photocoagulation (SMLP) in the treatment of diabetic macular edema (DME). MethodsA randomized controlled trial. From December 2020 to January 2022, 100 patients (100 eyes) with DME diagnosed by examination in Shanxi Aier Eye Hospital were included in the study. The patients were randomly divided into IVC group (50 eyes) and IVC+SMLP group (50 eyes). All the eyes were treated with IVC once a month for 3 times, and the eyes in IVC+SMLP group were treated with SMLP within 2 weeks after IVC. All affected eyes were examined by best corrected visual acuity (BCVA), which was statistically converted to logarithm of the minimum angle of resolution (logMAR) visual acuity. The central macular thickness (CMT) was measured by optical coherence tomography. Before the treatment, the logMAR BCVA of patients in IVC group and IVC+SMLP group were 0.56±0.04 and 0.55±0.03, respectively. The CMT were (437.36±11.35) μm and (434.58±10.88) μm, respectively. There was no significant difference in logMAR BCVA and CMT between the two groups (t= 0.476, 1.027; P＞0.05). The patients were followed up for 12 months after treatment. The times of IVC and the changes of BCVA and CMT were compared between the two groups. Independent sample t-test was used to compare the logMAR BCVA, CMT and times of IVC between groups. ResultsAfter 12 months treatment, the logMAR BCVA of IVC group and IVC+SMLP group were (241.63±29.79) μm and (240.47±30.46) μm, respectively. Compared with those before treatment, 12 months after treatment, the BCVA of the two groups increased significantly (t=7.014, 5.608; P＜0.001), while CMT decreased significantly (t=8.126, 6.013; P＜0.001). There was no significant difference in BCVA and CMT between the two groups (t=0.835, 0.764; P＞0.05). The number of IVC in IVC group and IVC+SMLP group were (8.15±2.04) times and (5.91±1.80) times, respectively, and the difference was statistically significant (t=5.210, P＜0.001). ConclusionsBoth IVC+SMLP and IVC alone can effectively reduce CMT and increase BCVA in patients with DME. Combination therapy can reduce the number of IVC.
To assess the background field removal method usually used in quantitative susceptibility mapping (QSM), and to analyze the cause of serious artifacts generated in the truncated k-space division (TKD) method, this paper discusses a variety of background field removal methods and proposes an improved method to suppress the artifacts of susceptibility inversion. Firstly, we scanned phase images with the gradient echo sequence and then compared the quality and the speed of reconstructed images of sophisticated harmonic artifact reduction for phase data (SHARP), regularization enable of SHARP (RESHARP) and laplacian boundary value (LBV) methods. Secondly, we analyzed the reasons for reconstruction artifacts caused by the multiple truncations and discontinuity of the TKD method, and an improved TKD method was proposed by increasing threshold truncation range and improving data continuity. Finally, the result of susceptibility inversion from the improved and original TKD method was compared. The results show that the reconstruction of SHARP and RESHARP are very fast, but SHARP reconstruction artifacts are serious and the reconstruction precision is not high and implementation of RESHARP is complicated. The reconstruction speed of LBV method is slow, but the detail of the reconstructed image is prominent and the precision is high. In the QSM inversion methods, the reconstruction artifact of the original TKD method is serious, while the improved method obtains good artifact suppression image and good inversion result of artifact regions.
The limitation of resource of blood and risk of transfusion-transmitted infections contribute to development and generalization of restrictive transfusion strategy. However, advanced evidences of clinical trials indicated a restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs. It is time to optimize patient blood management but not free-transfusion and increase of risk of patients. The duration of red-cell storage was not associated with significant differences in the mortality and morbidity of patients. Three new pathogen-reduction technologies and pharmaceutical intervenes may provide safe of transfusion and improvement of outcomes.
Spike recorded by multi-channel microelectrode array is very weak and susceptible to interference, whose noisy characteristic affects the accuracy of spike detection. Aiming at the independent white noise, correlation noise and colored noise in the process of spike detection, combining principal component analysis (PCA), wavelet analysis and adaptive time-frequency analysis, a new denoising method (PCWE) that combines PCA-wavelet (PCAW) and ensemble empirical mode decomposition is proposed. Firstly, the principal component was extracted and removed as correlation noise using PCA. Then the wavelet-threshold method was used to remove the independent white noise. Finally, EEMD was used to decompose the noise into the intrinsic modal function of each layer and remove the colored noise. The simulation results showed that PCWE can increase the signal-to-noise ratio by about 2.67 dB and decrease the standard deviation by about 0.4 μV, which apparently improved the accuracy of spike detection. The results of measured data showed that PCWE can increase the signal-to-noise ratio by about 1.33 dB and reduce the standard deviation by about 18.33 μV, which showed its good denoising performance. The results of this study suggests that PCWE can improve the reliability of spike signal and provide an accurate and effective spike denoising new method for the encoding and decoding of neural signal.
Calculation of cardiac hemodynamic parameters is based on accurate detection of feature points in impedance cardiogram. According to these parameters, doctors can determine heart conditions, so it is very important to accurately detect the feature point of impedance differential signals. This article presents a process in which we used wavelet threshold method to de-noise signals, and then detected the feature points after six layers wavelet decomposition by using bior3.7. The experimental data were collected from healthy persons in our laboratory and twenty two clinical patients in Chongqing Daping Hospital by using KF_ICG instrument. The results indicated that this method could precisely detect feature points whether it was from healthy people or clinical patients. This helps to achieve the application of noninvasive detection cardiac hemodynamic parameters in clinical treatments by using impedance method.
ObjectiveTo evaluate the prognosis of photocoagulation and (or) cryotherapy for prethreshold type 1 and threshold disease of retinopathy of prematurity (ROP).MethodsThe data of 29 eyes of 15 infants who were diagnosed as with prethreshold type 1 or threshold disease of ROP from Jan 30th, 2003 to Jan 13th, 2005 were retrospectively analysed. Pre- and post-operative conditions of ROP were compared in the follow up. Any related local and systemic complications were recorded.ResultsIn 29 eyes which had undergone photocoagulation and (or) cryotherapy, ROP regressed completely in 19 (65.5%), remained dragged retina was found in 7 (24.1%), and retinal detachment was seen in 3 (103%). ROP regressed completely in 12 eyes (41.4%) after the initial treatment and in 7 eyes (24.1%) after the secondary treatment. During the treatment, temporary corneal haze was found in 2 eyes, vitreous hemorrhage occurred in 1 eye, and inadvertent photocoagulation at macular area happened in 1 eye. No systemic complications were found in all cases.ConclusionTimely treatment of photocoagulation and (or) cryotherapy for prethreshold type 1 and threshold disease of ROP may lead to famous prognosis.(Chin J Ocul Fundus Dis,2005,21:278-281)
Central serous chorioretinopathy (CSC) is a common macular disease, which can lead to the loss of central vision in young patients. Although the disease is self-limited to some extent, there is no shortage of patients with prolonged course and recurrent attacks, eventually leading to irreversible visual impairment. Therefore, taking reasonable treatment in a certain period is particularly important for the visual prognosis of patients. Although thermal laser photocoagulation of leakage points and photodynamic therapy (PDT) have achieved good effects, there are risks of retinal damage and retinal pigment epithelium atrophy. Subthreshold micropulse laser (SMLP) is a kind of subthreshold short pulse laser, which does not cause visible damage to the retina and is safer. In the era of lack of PDT drugs, SMLP has gradually become an important means of clinical treatment for CSC, especially for patients with no obvious leakage point or subfoveal leakage point. An in-depth understanding of the mechanism of action of SMLP and its efficacy and safety in the treatment of CSC is helpful for the promotion and application of SMLP in the clinical treatment of CSC.
This paper discusses the relationship between stimulating pulse width and the threshold of electrically evoked compound action potential (ECAP). Firstly, the rheobase and chronaxy from strength-duration curve of nerve fiber was computed using the shepherd's experiment results. Secondly, based on the relationship between ECAP and the action potential of nerve fiber, a mathematical expression to describe the relationship between stimulating pulse width and ECAP threshold was proposed. Thirdly, the parameters were obtained and the feasibility was proved to the expression with the results of experiment using guinea pigs. Research result showed that with ECAP compared to the action potential of nerve fiber, their threshold function relationship with stimulating pulse width was similar, and rheobase from the former was an order smaller in the magnitude than the latter, but the chronaxy was close to each other. These findings may provide meaningful guidance to clinical ECAP measurement and studying speech processing strategies of cochlear implant.
目的 探讨成年人颅骨表面遮盖重建（SSD）的理想阈值设定，为利用SSD进行的头部CT血管成像（CTA）去骨成像提供阈值设定的依据。 方法 选取2012年8月，在成都市第一人民医院体检的、同一单位工作的86位体检对象，进行颅骨平均CT值、腰椎骨质密度、性别及年龄的两两对照及多重线性回归拟合，建立起预估颅骨平均CT值的多重线性回归方程，计算出18～80岁人群的理论平均颅骨CT值作为SSD的理想阈值。同时收集2012年10月－2013年2月在该院进行头部CTA检查的12例患者的相关资料以验证其可行性。 结果 18～80岁人群的理论平均颅骨CT值约为640 Hu。以该值作为SSD的阈值进行去骨成像，所有患者图像质量评分均为5分，可视为去骨成功。 结论 在利用理论颅骨平均CT值作为重建阈值的基础之上，通过简单的SSD图像质量再判断及修正，即可简便地完成后处理工作，具有可行性。
Aiming at the single treatment and the design separation between treatment and assessment in electrotherapy equipment, a kind of system including low-intermediate frequency treatment and efficacy evaluation was developed. With C8051F020 single-chip microcomputer as the core and the circuit design and software programming used, the system realized the random switch of therapeutic parameters, the collection, display and data storage of pressure pain threshold in the assessment. Experiment results showed that the stimulus waveform, current intensity, frequency, duty ratio of the system output were adjustable, accurate and reliable. The obtained pressure pain threshold had a higher accuracy (<0.3 N) and better stability, guiding the parameter choice in the precise electrical stimulation. It, therefore, provides a reliable technical support for the treatment and curative effect assessment.