At present, fatigue state monitoring of upper limb movement generally relies solely on surface electromyographic signal (sEMG) to identify and classify fatigue, resulting in unstable results and certain limitations. This paper introduces the sEMG signal recognition and motion capture technology into the fatigue state monitoring process and proposes a fatigue analysis method combining an improved EMG fatigue threshold algorithm and biomechanical analysis. In this study, the right upper limb load elbow flexion test was used to simultaneously collect the biceps brachii sEMG signal and upper limb motion capture data, and at the same time the Borg Fatigue Subjective and Self-awareness Scale were used to record the fatigue feelings of the subjects. Then, the fatigue analysis method combining the EMG fatigue threshold algorithm and the biomechanical analysis was combined with four single types: mean power frequency (MPF), spectral moments ratio (SMR), fuzzy approximate entropy (fApEn) and Lempel-Ziv complexity (LZC). The test results of the evaluation index fatigue evaluation method were compared. The test results show that the method in this paper has a recognition rate of 98.6% for the overall fatigue state and 97%, 100%, and 99% for the three states of ease, transition and fatigue, which are more advantageous than other methods. The research results of this paper prove that the method in this paper can effectively prevent secondary injury caused by overtraining during upper limb exercises, and is of great significance for fatigue monitoring.
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.
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.
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 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.
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.
A de-noising method for electrocardiogram (ECG) based on ensemble empirical mode decomposition (EEMD) and wavelet threshold de-noising theory is proposed in our school. We decomposed noised ECG signals with the proposed method using the EEMD and calculated a series of intrinsic mode functions (IMFs). Then we selected IMFs and reconstructed them to realize the de-noising for ECG. The processed ECG signals were filtered again with wavelet transform using improved threshold function. In the experiments, MIT-BIH ECG database was used for evaluating the performance of the proposed method, contrasting with de-noising method based on EEMD and wavelet transform with improved threshold function alone in parameters of signal to noise ratio (SNR) and mean square error (MSE). The results showed that the ECG waveforms de-noised with the proposed method were smooth and the amplitudes of ECG features did not attenuate. In conclusion, the method discussed in this paper can realize the ECG de-noising and meanwhile keep the characteristics of original ECG signal.
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.
To enhance the accuracy of computer-aided diagnosis of adolescent depression based on electroencephalogram signals, this study collected signals of 32 female adolescents (16 depressed and 16 healthy, age: 16.3 ± 1.3) with eyes colsed for 4 min in a resting state. First, based on the phase synchronization between the signals, the phase-locked value (PLV) method was used to calculate brain functional connectivity in the θ and α frequency bands, respectively. Then based on the graph theory method, the network parameters, such as strength of the weighted network, average characteristic path length, and average clustering coefficient, were calculated separately (P < 0.05). Next, using the relationship between multiple thresholds and network parameters, the area under the curve (AUC) of each network parameter was extracted as new features (P < 0.05). Finally, support vector machine (SVM) was used to classify the two groups with the network parameters and their AUC as features. The study results show that with strength, average characteristic path length, and average clustering coefficient as features, the classification accuracy in the θ band is increased from 69% to 71%, 66% to 77%, and 50% to 68%, respectively. In the α band, the accuracy is increased from 72% to 79%, 69% to 82%, and 65% to 75%, respectively. And from overall view, when AUC of network parameters was used as a feature in the α band, the classification accuracy is improved compared to the network parameter feature. In the θ band, only the AUC of average clustering coefficient was applied to classification, and the accuracy is improved by 17.6%. The study proved that based on graph theory, the method of feature optimization of brain function network could provide some theoretical support for the computer-aided diagnosis of adolescent depression.
Red blood cell (RBC) transfusions are frequently used in cardiac surgery. A minority of patients assume most of the blood products transfusion during and after cardiac operations. Observational analysis of transfusion in patients undergoing cardiac surgery has uniformly demonstrated that RBC transfusion is associated with a significantly increasing risk of all-cause mortality and other serious adverse outcomes. In addition, it is an established fact that such patients can tolerate relatively low hemoglubin (Hb) levels. Consequently, it becomes widely accepted that appropriate limitation of transfusions could confer a substantial benefit to patients and decrease the use of limited resource. As a result, a restrictive threshold for blood transfusion is likely to be favored under most circumstances. However, an increasing amount of data differing from the observational analysis shows that clinical outcomes in patients who received transfusions with restrictive thresholds for Hb level are not superior to those with liberal thresholds. It has created a new uncertainty regarding the use of a restrictive threshold for transfusion during the perioperative period of cardiac surgery.