Central serous chorioretinopathy (CSC) is a common macular disease, mainly manifested as a plasma detachment of the macula. Photodynamic therapy (PDT) is an effective treatment for CSC, but with the shortage of the photosensitizer Verteporfin, the effective treatment of CSC has become a common concern for ophthalmologists. In this paper, based on the latest research results on the relationship between the changes in the thickness of the outer nuclear layer and the natural course of the disease and PDT therapy, we propose that patients with CSC should receive effective treatment as early as possible to prevent irreversible damage to visual function due to the thinning of the outer nuclear layer. In addition to PDT, it is recommended that laser photocoagulation or subthreshold micropulse laser treatment of the leaking spot should be considered first, depending on the presence of the leaking spot and its location in relation to the macula center. Anti-vascular endothelial growth factor therapy can be considered if there is a combination of choroidal neovascularization and/or polypoidal choroidal vasculopathy. Other treatments that have not been demonstrated to be effective in evidence-based medicine are not recommended.
Aiming at the defects that the traditional pulse transit time (PTT) detection methods are sensitive to changes in photoplethysmography (PPG) signal and require heavy computation, we proposed a new algorithm to detect PTT based on waveform time domain feature and dynamic difference threshold. We calculated the PTT by using dynamic difference threshold method to detect the R-waves of electrocardiogram (ECG), shortening the main peak detection range in PPG signal according to the characteristics of the waveform time domain, and using R wave to detect the main peak of PPG signal. We used the American MIMIC database and laboratory test data to validate the algorithm. The experimental results showed that the proposed method could accurately extract the feature points and detect PTT, and the PTT detection accuracies of the measurements and the database samples were 99.1% and 97.5%, respectively. So the proposed method could be better than the traditional methods.
Muscle fatigue has widespread application in the field of rehabilitation medicine. The paper studies the muscle fatigue using surface electromyogram (sEMG) in the background of rehabilitation training system. The sEMG and ventilatory threshold of vastus lateralis, rectus femoris and erector spinae are collected synchronously and the electromyogram fatigue threshold (EMGFT) of different sEMG was analyzed by increasing load cycling experiments of 10 healthy subjects. This paper also analyzes the effect of isotonic and isometric contraction on EMGFT. Results showed that the appeared time of EMGFT was earlier than that of ventilatory threshold in the incremental load cycling. While the differences were subtle and EMGFT was verified to be effective. EMGFT has been proven effective for different muscle contraction by comparing the EMGFT of vastus lateralis and erector spinae. EMGFT could be used to keep muscle injuries from overtraining in the process of rehabilitation. Therefore, EMGFT has a great significance for femoral shaft fractures’s fatigue monitoring in rehabilitation training.
ObjectiveTo systematically review the non-inferiority trials in the cardiovascular domain that utilize medical devices as interventions, and investigate its characteristics and threshold settings. MethodsThe PubMed, Embase, and CENTRAL databases were electronically searched to collect non-inferiority trials in the cardiovascular field involving medical devices from inception to July 26, 2023. Two reviewers independently screened literature and extracted data. The reported information included basic characteristics, features of non-inferiority trials, and threshold-setting features of the included studies. Data analysis was performed using Excel 2020 and R 4.2.1 software. ResultsA total of 214 studies were included, with 167 studies (78.0%) focusing on interventions related to coronary artery stents. The trials predominantly utilized a two-arm design (92.9%), with a prevalent use of non-inferiority absolute thresholds (96.7%) as the criteria for non-inferiority determination. In 150 studies (70.1%), non-inferiority thresholds were established based on estimated control group effect values, while 33 studies (15.4%) did not report the source of these values. The non-inferiority trial endpoint outcomes exhibited diversity, and there were substantial differences in threshold settings. The three most studied qualitative indicators were target lesion failure rates (2.1%-8.6%), target vessel failure rates (2.5%-19.6%), and major adverse cardiovascular events rates (2.1%-10.0%). Late lumen loss (0.1-0.4 mm) emerged as the most frequently studied quantitative indicator. After converting absolute non-inferiority thresholds for all indicators into relative thresholds, the range was 1.20-3.67. ConclusionSignificant variations in non-inferiority threshold settings are observed for identical endpoint outcomes across included studies, highlighting a lack of reporting on the rationale behind threshold settings.
Abstract This experiment was to study the feasibility from direct observation of muscle contraction of the lower extremity fromelectrical stimulation threshold of nerve fascicle in identifying the Iα intrafusal afferent fibers during selective posterior rhizotomy (SPR) and to investigate the clinical relationship between the muscle spasm and the electrical stimulation of nerve fascicles. The electrical stimulation threshold of all nerve fascicles in 36 cases during SPR were analysed statistically. The results showed that there was a significant difference between the electrical stimulation threshold of the severed nerve fascicles and intact nerve fascicles no matter the nerve root or each posterior nerve rootlet was examined. It was simple and reliable for surgeons to identify correctly the Iα intrafusal afferent fibers intraoperatively from direct observation of the electrical stimulation threshold of nerve fascicle.
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.
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)
ObjectiveTo investigate the time relationship of the change, and diagnostic accuracy and sensitivity between retinal light threshold fluctuations (LTF) and retinal nerve fiber layer (RNFL) and ganglion cell complex(GCC) thickness on high-risk primary open-angle glaucoma (POAG). MethodsTotally 319 patients (319 eyes) with high-risk in POAG from the First Affiliated Hospital of Kunming Medical Universityand during December 2009 and December 2017, 50 healthy individuals (50 eyes) as control were collected in this longitudinal cohort study. Visual field and OCT were reviewed every 6 months on the high-risk group and every 12 months on the control group. High-risk groups inclusion criteria: vertical C/D≥0.6; early visual field defect (according to glaucoma visual field damage GSS2 quantitative grading standards, mean deviation and pattern standard deviation of central field exceeds the border as an early visual field defect); continuous repeatable results. The first field and OCT results in the absence of visual field defects and C/D≥0.6, which were conformed reliability indicators and removed learning effects as a baseline. When patients achieve POAG diagnosis criteria first time which was recorded as a turning point. And they were divided into early group meanwhile were ended of follow-up. After the last follow-up, the inspection data was segmented counted in yearly interval. The changes of LTF, thickness of RNFL and GCC during the follow-up period in the early POAG group and the control group were observed. The loss rate and change rate in each period were compared for the assessment of their trends with time. Followed by calculation of the area under receiver operating curves (AUC) to compare the predicted value of POAG and the sensitivity at 95% specificity in each period. ResultsAfter last follow-up, totally 67 patients 67 eyes (early POAG group, 37 males and 30 females) were entered the turning point. The mean follow-up of the early POAG group and the control group were 6.6 and 6.4 years. The average RNFL thickness was 79.05±8.09 μm, GCC thickness was 71.58±8.41 μm, LTF was ?6.05±7.02 dB in early POAG group. The average RNFL thickness was 93.49±6.24 μm, GCC thickness was 79.72±6.32 μm, LTF was ?0.31±0.58 dB in the control group. The differences of LTF and the thickness of RNFL and GCC were statistically significant (t=?5.97, ?10.42, ?5.60; P＜0.001). The AUC of RNFL, GCC thickness and LTF increased with time in the early POAG group. The sensitivity was gradually increased at 95% specificity: 5th year before to at turning point, RNFL thickness AUC was 0.15, 0.65, 0.71, 0.77, 0.85, 0.92, and sensitivity was 20%, 56%, 61%, 65%, 70%, 76%, respectively; GCC thickness AUC was 0.12, 0.53, 0.69, 0.74, 0.82, 0.90, and sensitivity was 14%, 53%, 69%, 74%, 82%, 90%, respectively; the AUC of LTF was 0.10, 0.21, 0.33, 0.75, 0.86, 0.91, and sensitivity was 7%, 17%, 44%, 65%, 78%, 87%, respectively. ConclusionsThe earliest time of structural functional damage of POAG is at the 4th year before confirmed, simultaneous RNFL diagnosis accuracy and sensitivity are better than GCC and LTF. The earliest time of visual functional damage of POAG is at the 2th year before confirmed, simultaneous LTF diagnosis accuracy and sensitivity are better than RNFL and GCC.
The brain-computer interface (BCI) systems used in practical applications require as few electroencephalogram (EEG) acquisition channels as possible. However, when it is reduced to one channel, it is difficult to remove the electrooculogram (EOG) artifacts. Therefore, this paper proposed an EOG artifact removal algorithm based on wavelet transform and ensemble empirical mode decomposition. Firstly, the single channel EEG signal is subjected to wavelet transform, and the wavelet components which involve EOG artifact are decomposed by ensemble empirical mode decomposition. Then the predefined autocorrelation coefficient threshold is used to automatically select and remove the intrinsic modal functions which mainly composed of EOG components. And finally the ‘clean’ EEG signal is reconstructed. The comparative experiments on the simulation data and the real data show that the algorithm proposed in this paper solves the problem of automatic removal of EOG artifacts in single-channel EEG signals. It can effectively remove the EOG artifacts when causes less EEG distortion and has less algorithm complexity at the same time. It helps to promote the BCI technology out of the laboratory and toward commercial application.
It is difficult to distinguish the inferior alveolar nerve (IAN) from other tissues inside the IAN canal due to their similar CT values in the X image which are smaller than that of the bones. The direct reconstruction, therefore, is difficult to achieve the effects. The traditional clinical treatments mainly rely on doctors' manually drawing the X images so that some subjective results could not be avoided. This paper proposes the partition reconstruction of IAN canal based on shape features. According to the anatomical features of the IAN canal, we divided the image into three parts and treated the three parts differently. For the first, the directly part of the mandibular, we used Shape-driven Level-set Algorithm Restrained by Local Information (BSLARLI) segment IAN canal. For the second part, the mandibular body, we used Space B-spline curve fitting IAN canal's center, then along the center curve established the cross section. And for the third part, the mental foramen, we used an adaptive threshold Canny algorithm to extract IAN canal's edge to find center curve, and then along it established the cross section similarly. Finally we used the Visualization Toolkit (VTK) to reconstruct the CT data as mentioned above. The VTK reconstruction result by setting a different opacity and color values of tissues CT data can perspectively display the INA canal clearly. The reconstruction result by using this method is smoother than that using the segmentation results and the anatomical structure of mental foramen position is similar to the real tissues, so it provides an effective method for locating the spatial position of the IAN canal for implant surgeries.
