ABSTRACT
The brain-computer interface (BCI) based on motor imagery electroencephalography (MI-EEG) enables direct information interaction between the human brain and external devices. In this paper, a multi-scale EEG feature extraction convolutional neural network model based on time series data enhancement is proposed for decoding MI-EEG signals. First, an EEG signals augmentation method was proposed that could increase the information content of training samples without changing the length of the time series, while retaining its original features completely. Then, multiple holistic and detailed features of the EEG data were adaptively extracted by multi-scale convolution module, and the features were fused and filtered by parallel residual module and channel attention. Finally, classification results were output by a fully connected network. The application experimental results on the BCI Competition IV 2a and 2b datasets showed that the proposed model achieved an average classification accuracy of 91.87% and 87.85% for the motor imagery task, respectively, which had high accuracy and strong robustness compared with existing baseline models. The proposed model does not require complex signals pre-processing operations and has the advantage of multi-scale feature extraction, which has high practical application value.
Subject(s)
Humans , Time Factors , Brain , Electroencephalography , Imagery, Psychotherapy , Neural Networks, ComputerABSTRACT
Objective To obtain a more suitable puncture method for venipuncture robot through experiments.Methods By using different puncture speeds and angles for biomimetic materials, the force-time curves by various puncture methods were obtained. Results During puncture process, with the increase of the puncture angle, a smaller puncture force was required. The faster puncture speed would lead to a larger puncture force. Conclusions The 40°-45° puncture angleand the 120-300 mm/min puncture speed should be used for designing the puncture method of venipuncture robot. The results provide references for selecting the puncture angle and speed of the venipuncture robot.
ABSTRACT
Objective:To explore any effect of working memory training on executive functioning and ability in the activities of daily living after a stroke.Methods:Forty-six stroke survivors were randomly divided into an experimental group and a control group, each of 23. Both groups received conventional cognitive rehabilitation (including computer-assisted cognition training and virtual reality training using upper limb rehabilitation robots), while the experimental group also received working memory training. Before, as well as after 4 and 8 weeks of the treatment, both groups′ executive functioning was evaluated using the Trail Making test, the Frontal Assessment Battery and the Wisconsin Card Sorting Test-64. Ability in the activities of daily living was quantified using the functional independence measures (FIMs).Results:There were no significant differences between the two groups in any of the measurements before the training. After 4 weeks the average scores of the experimental group on all four instruments were significantly higher than the control group′s averages. After 8 weeks the average scores had improved significantly more. The treatment group performed significantly better than the control group throughout.Conclusions:Working memory training can improve executive functioning and the daily life of stroke survivors.
ABSTRACT
Objective To explore the effect of vascular stress changes on endothelial function recovery and vascular restenosis inhibition in dynamic degradation process of the degradable stent. Methods The material parameters of the hyper-elastic vascular constitutive relationship was fitted, and the stress distribution on the intima of the blood vessel before stent implantation and during dynamic degradation was calculated by numerical simulation. In vitro culture experiments were carried out, and the stretch ratios of the silicon chambers were 0%, 5%, 10% and 15%, respectively, to simulate the mechanical environment at different degradation stages, and to explore the effects of different stretch ratios on growth state of the endothelial cells （ECs）. Results After the stent was completely degraded, the circumferential intimal stress and strain of the vessel were restored to 0.137 MPa and 5.5%, which were close to the physiological parameters (0.122 MPa, 4.8%) before stent implantation. In vitro experiments showed that the survival rate of ECs was the highest under the condition of 0.1 MPa circumferential stress and 5% strain, and adhesion growth could be achieved. Conclusions With the occurrence of stent degradation process, the circumferential stress and strain of the intima were restored to a range close to physiological parameters, which promoted the growth of ECs. The recovery of intimal function could effectively inhibit the process of vascular restenosis. The results can provide the theoretical basis and experimental platform for studying coronary intervention for the treatment of vascular restenosis.
ABSTRACT
Objective To design and develop an in vitro simulation device for circumferential stress of mural coronary artery, so as to achieve the in vitro loading of mural circumferential stress under coronary myocardial bridge oppression with different degrees. MethodsUsing the in vitro simulation device for myocardial bridge coronary artery hemodynamics, the in vitro measurement of mural circumferential stress was achieved. Based on the experimental data, the in vitro loading of mural circumferential stress under coronary myocardial bridge oppression with different degrees was achieved. Results The in vitro measurement experiment showed that the maximum, average and fluctuation of circumferential stress at proximal end of mural coronary artery would increase significantly with the increase in the degree of myocardial bridge oppression. The in vitro loading experiment of mural circumferential stress verified that the loading waveform coincided basically with the experimental waveform from in vitro measurement. Conclusions The device could realize the in vitro loading of mural circumferential stress, which provided an in vitro simulation platform which was as close as possible to the in vivo environment, so as to explore the influence from hemodynamic abnormality of proximal mural coronary artery on the occurrence of atherosclerosis and plaque rupture.
ABSTRACT
Objective To develop an innovative device for endothelial cell culture in vitro, namely, to develop a vascular endothelial cell culture device based on hemodynamic environment, so as to introduce the development and experimental study of endothelial cell culture device in vitro. Methods A device of dynamic culture system for endothelial cells in vitro on the basis of the existing research was designed with the theory and method of hemodynamics. The shear stress, positive stress and tensile stress existed at the same time in the flow environment. The development and experimental research of the device were described in detail from 5 aspects, such as the development background, structure and composition, design principle, theoretical basis and experimental research. Results The device could accurately simulate the hemodynamic environment of endothelial cells at normal level, with precise control of shear stress in 0-12 Pa range, positive stress in 0-15.96 kPa range, and tensile stress in 0-0.5 MPa range. Conclusions The device can provide a hemodynamic environment which is closer to the physiological conditions of human body, as well as a more ideal experimental environment and means for further exploring the mechanism of vascular intimal injury.
ABSTRACT
Objective To analyze the usual death causes of cardiovascular disease and the differences in gender and age .Methods By adopting the retrospective study method ,the clinical data of death cases in cardiovascular disease were collected and analyze on the situation suffering from cardiovascular disease ,direct death causes ,gender and age difference .Results (1) among 181 cases of cardiovascular disease death ,coronary heart disease(115/181 ,64% ) and hypertension(96/181 ,53% ) were the most common dis-ease ,lung infection(104/181 ,57% ) was the most common complication ;(2)There was no significant difference in the situation suf-fering from basic diseases between male and female(P>0 .05);(3)The basic diseases in cardiovascular death cases aged over 60 years old were dominated by coronary heart disease and hypertension ;the proportion of complicating pulmonary infection was grad-ually increased with age increase ;(4) in the direct death causes ,the top 3 places were sudden cardiac death (44/181 ,24 .3% ) ,multi-ple organ dysfunction syndrome(24/181 ,13 .3% ) and cardiogenic shock(24/181 ,13 .3% ) .Conclusion Strengthening the manage-ment of diagnosis and treatment on elderly patients with coronary heart disease ,hypertension ,especially those complicating diabe-tes ,strengthening the treatment intervention of lung infection in cardiovascular disease population and conducting the emphasis pro-tection on the target organ function may reduce the mortality of cardiovascular inpatients .
ABSTRACT
Objective To observe the effect of atorvastatin on intraabdominal fat and microalbuminuria (MAU) in patients with metabolic syndrome (MS). Methods Forty-four MS patients were divided into the atorvastatin group and the control group. Blood pressure and blood glucose were controlled in both groups, in addition, atorvastatin was administered to the patients in the atorvastatin group. Blood pressure, blood glucose, body weight, abdominal wall fat, intraabdominal fat and MAU were compared before and after 12 weeks’ treatment. Results Obvious decrease of the intraabdominal fat and MAU was found in the atorvastatin group compared with those before the treatment Intraabdominal fat: non-ACE1/ARB (41.76?3.61) mm vs (33.23?2.47) mm, P
ABSTRACT
Objective To evaluate the cardiovascular disease (CVD) risk of the patients with metabolic syndrome (MS) by CVD predictive models. Methods The CVD risk of MS patients (n=637) and type 2 diabetes mellitus (T2DM)(n=259) were assessed by Framingham and ischemia CVD (ICVD) predictive models. The technique of myocardial nuclide development (MCND) was used on 121 MS patients to confirm the evaluation. Results The CVD risk of MS patients was significantly higher than that of T2DM. The proportion of CVD risk ≥ 5% in MS group was significantly higher than that in T2DM group. An elevated tendency of the proportion of CVD risk ≥ 10% appeared followed the age increasing in both MS and T2DM groups. The proportion of CVD risk ≥ 5% in male patients was higher than that in females assessed by Framingham predictive model, while an opposite result was given by ICVD predictive model. The MCND findings showed that, the more the increasing of CVD risk evaluated by Framingham predictive model,the severer the myocardial ischemia was. Conclusions The CVD risk of patients with MS is significantly higher than that of T2DM assessed by the both models. Framingham model is more susceptible to predicate CHD in MS patients than ICVD model.
ABSTRACT
Objective: To research the effect and mechanism of how chitosan restrain fat-absorbtion, and provide references for developing a kind of nutritional and healthy fastfood. Methods: 1.In vitro digestion: Phosphomolybdic acid colorimetry; 2.In vivo experiment:240 rats were divided into four groups and fed with different diets: basal diet(Group A), high fat diet (Group B), chitosan supplemented diet (Group C), high fat and chitosan supplemented diet (Group D). The fat and chitosan content(%) of diet were A(10,0), B(60,0), C(8,20), D(34.3,14.8) respectively. Determine the blood lipids and fat output in dung, and observe the weight gain and swimming time. Results: 1.In vitro experiment showed chitosan acted on cholic acid at the best proportion 1∶8. 2.In vivo experiment showed chitosan can restrain fat-absorbtion, and increase fat output. Swimming in ice-water showed chitosan improved rats performance. Compared with group B, the blood lipids and weight of group C and D had no obvious change, but the fat-output much increased.