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find Keyword "synchronization" 9 results
  • Investigation on the Quality of Life and Psychological Status among Patients after Cardiac Resynchronization Therapy

    ObjectiveTo analyze the quality of life (QOL) and psychological status among patients having undergone cardiac resynchronization therapy (CRT). MethodsA total of 42 patients underwent CRT in our hospital during January 2011 to January 2014. All the patients were studied by MOS SF-36 scale and symptom checklist-90 (SCL-90) on overall QOL and psychological QOL, respectively. Another 42 healthy people in matched control group were also tested. ResultsThe QOL of patients after CRT was significantly lower than that of healthy subjects (P<0.05). The psychological status score, which was obtained by the examination of SCL-90, was significantly higher in patients after CRT than in the healthy population (P<0.05). The length of the disease course and leveling exercise tolerance are the influence factors for the QOL and psychological status in patients undergoing CRT. Gender does not make any difference between the two groups. ConclusionThe QOL of patients having undergone CRT is significantly lower than that of healthy people, and the psychological status score is higher. Medical staff need to pay attention to the mental illness (such as depression, anxiety and panic) of patients after CRT, especially in patients with long course of disease, and patients who fail to improve exercise tolerance or who are mateless. Psychological interventions can further improve the QOL of patients.

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  • Evaluation of Patient-ventilator Synchrony of Three New Types of Ventilators with Pressure Support Ventilation Mode

    Pressure-support ventilation (PSV) is a form of important ventilation mode. Patient-ventilator synchrony of pressure support ventilation can be divided into inspiration-triggered and expiration-triggered ones. Whether the ventilator can track the patient's inspiration and expiration very well or not is an important evaluating item of the performance of the ventilator. The ventilator should response to the patient's inspiration effort on time and deliver the air flow to the patient under various conditions, such as different patient's lung types and inspiration effort, etc. Similarly, the ventilator should be able to response to the patient's expiration action, and to decrease the patient lung's internal pressure rapidly. Using the Active Servo Lung (ASL5000) respiratory simulation system, we evaluated the spontaneous breathing of PSV mode on E5, Servo i and Evital XL. The following parameters, the delay time before flow to the patient starts once the trigger variable signaling the start of inspiration, the lowest inspiratory airway pressure generated prior to the initiation of PSV, etc. were measured.

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  • Multi-channel Synchronization Analysis of Mild Cognitive Impairment in Type 2 Diabetes Patients

    The cognitive impairment of type 2 diabetes patients caused by long-term metabolic disorders has been the current focus of attention. In order to find the related electroencephalogram (EEG) characteristics to the mild cognitive impairment (MCI) of diabetes patients, this study analyses the EEG synchronization with the method of multi-channel synchronization analysis--S estimator based on phase synchronization. The results showed that the S estimator values in each frequency band of diabetes patients with MCI were almost lower than that of control group. Especially, the S estimator values decreased significantly in the delta and alpha band, which indicated the EEG synchronization decrease. The MoCA scores and S value had a significant positive correlation in alpha band.

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  • Study on Brain Functional Connectivity Using Resting State Electroencephalogram Based on Synchronization Likelihood in Alzheimer's Disease

    Alzheimer's disease (AD) is the most common type of dementia and a neurodegenerative disease with progressive cognitive dysfunction as the main feature. How to identify the early changes of cognitive dysfunction and give appropriate treatments is of great significance to delay the onset of dementia. Some other researches have shown that AD is associated with abnormal changes of brain networks. To study human brain functional connectivity characteristics in AD, 16 channels electroencephalogram (EEG) were recorded under resting and eyes-closed condition in 15 AD patients and 15 subjects in the control group. The synchronization likelihood of the full-band and alpha-band (8-13 Hz) data were evaluated, which resulted in the synchronization likelihood coefficient matrices. Considering a threshold T, the matrices were converted into binary graphs. Then the graphs of two groups were measured by topological parameters including the clustering coefficient and global efficiency. The results showed that the global efficiency of the network in full-band EEG was significantly smaller in AD group for the values of T=0.06 and T=0.07, but there was no statistically significant difference in the clustering coefficients between the two groups for the values of T (0.05-0.07). However, the clustering coefficient and global efficiency were significantly lower in AD patients at alpha-band for the same threshold range than those of subjects in the control group. It suggests that there may be decreases of the brain connectivity strength in AD patients at alpha-band of the resting-state EEG. This study provides a support for quantifying functional brain state of AD from the brain network perspective.

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  • Update on nonpharmacologic treatment for heart failure

    Heart failure is a global problem that occurs in 38 million patients worldwide, and the number is dramatically increasing in elderly society. Meanwhile, heart dysfunction is also the most common disease among hospitalized patients more than 65 years, especially in high-income countries. Approximately, one million patients are hospitalized because of heart failure in the world every year. Drug therapy is currently the most popular treatment for heart failure in clinic, however, the effects are limited. Therefore, exploring novel treatment strategies gradually becomes a focus not only in basic but also in clinical research.

    Release date:2017-04-24 03:51 Export PDF Favorites Scan
  • Research on effects of low-frequency repetitive transcranial magnetic stimulation over primary motor cortex on functional connectivity of brain

    Repetitive transcranial magnetic stimulation (rTMS) can influence the stimulated brain regions and other distal brain regions connecting to them. The purpose of the study is to investigate the effects of low-frequency rTMS over primary motor cortex on brain by analyzing the brain functional connectivity and coordination between brain regions. 10 healthy subjects were recruited. 1 Hz rTMS was used to stimulate primary motor cortex for 20 min. 1 min resting state electroencephalography (EEG) was collected before and after the stimulation respectively. By performing phase synchronization analysis between the EEG electrodes, the brain functional network and its properties were calculated. Signed-rank test was used for statistical analysis. The result demonstrated that the global phase synchronization in alpha frequency band was decreased significantly after low-frequency rTMS (P<0.05). The phase synchronization was down-regulated between motor cortex and ipsilateral frontal/parietal cortex, and also between contralateral parietal cortex and bilateral frontal cortex. The mean degree and global efficiency of brain functional networks in alpha frequency band were significantly decreased (P<0.05), and the mean shortest path length were significantly increased (P<0.05), which suggested the information transmission of the brain networks and its efficiency was reduced after low-frequency rTMS. This study verified the inhibition function of the low-frequency rTMS to brain activities, and demonstrated that low-frequency rTMS stimulation could affect both stimulating brain regions and distal brain regions connected to them. The findings in this study could be of guidance to clinical application of low-frequency rTMS.

    Release date:2017-08-21 04:00 Export PDF Favorites Scan
  • Study of functional connectivity during anesthesia based on sparse partial least squares

    Anesthesia consciousness monitoring is an important issue in basic neuroscience and clinical applications, which has received extensive attention. In this study, in order to find the indicators for monitoring the state of clinical anesthesia, a total of 14 patients undergoing general anesthesia were collected for 5 minutes resting electroencephalogram data under three states of consciousness (awake, moderate and deep anesthesia). Sparse partial least squares (SPLS) and traditional synchronized likelihood (SL) are used to calculate brain functional connectivity, and the three conscious states before and after anesthesia were distinguished by the connection features. The results show that through the whole brain network analysis, SPLS and traditional SL method have the same trend of network parameters in different states of consciousness, and the results obtained by SPLS method are statistically significant (P<0.05). The connection features obtained by the SPLS method are classified by the support vector machine, and the classification accuracy is 87.93%, which is 7.69% higher than that of the connection feature classification obtained by SL method. The results of this study show that the functional connectivity based on the SPLS method has better performance in distinguishing three kinds of consciousness states, and may provides a new idea for clinical anesthesia monitoring.

    Release date:2020-08-21 07:07 Export PDF Favorites Scan
  • Study on the synchronization of biventricular beats with the control mode of left ventricular assist device

    Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52% vs. 51.77%, respectively). The systolic period was significantly shorter than the RV systolic period in the continuous-flow mode (LV vs. RV: 24.38% vs. 49.16%) and the LV systolic period at baseline. The LV systolic duration was significantly shorter than the RV systolic duration in the pulse mode (LV vs. RV: 28.38% vs. 50.41%), but longer than the LV systolic duration in the continuous-flow mode. There was no significant difference between the LV and RV systolic periods in the counter-pulse mode (LV vs. RV: 43.13% vs. 49.23%). However, the LV systolic periods was shorter than the no-pump mode and much longer than the continuous-flow mode. Compared with continuous-flow and pulse mode, the reduction in rotational speed (RS) brought out by counter-pulse mode significantly corrected the duration of LV systolic phase. The shortened duration of systolic phase in the continuous-flow mode was corrected as re-synchronization in the counter-pulse mode between LV and RV. Hence, we postulated that the beneficial effects on RV function were due to re-synchronizing of RV and LV contraction. In conclusion, decreased RS delivered during the systolic phase using the counter-pulse mode holds promise for the clinical correction of desynchrony in bi-ventricular pulse resulting from a LVAD and confers a benefit on RV function.

    Release date:2021-04-21 04:23 Export PDF Favorites Scan
  • Research on feature classification of lower limb motion imagination based on electrical stimulation to enhance rehabilitation

    Motor imaging therapy is of great significance to the rehabilitation of patients with stroke or motor dysfunction, but there are few studies on lower limb motor imagination. When electrical stimulation is applied to the posterior tibial nerve of the ankle, the steady-state somatosensory evoked potentials (SSSEP) can be induced at the electrical stimulation frequency. In order to better realize the classification of lower extremity motor imagination, improve the classification effect, and enrich the instruction set of lower extremity motor imagination, this paper designs two experimental paradigms: Motor imaging (MI) paradigm and Hybrid paradigm. The Hybrid paradigm contains electrical stimulation assistance. Ten healthy college students were recruited to complete the unilateral movement imagination task of left and right foot in two paradigms. Through time-frequency analysis and classification accuracy analysis, it is found that compared with MI paradigm, Hybrid paradigm could get obvious SSSEP and ERD features. The average classification accuracy of subjects in the Hybrid paradigm was 78.61%, which was obviously higher than the MI paradigm. It proves that electrical stimulation has a positive role in promoting the classification training of lower limb motor imagination.

    Release date:2021-06-18 04:52 Export PDF Favorites Scan
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