To apply electrical stimulation to the specific phase position of electroencephalogram （EEG） waveform, a nervous electrical stimulation system was developed using general data acquisition card and LabVIEW virtual in...To apply electrical stimulation to the specific phase position of electroencephalogram （EEG） waveform, a nervous electrical stimulation system was developed using general data acquisition card and LabVIEW virtual instrument environment. The hippocampal field potential signal in the brain of rat was sampled using the acquisition card＇ s A/D channel, and the amplitude and cycle characteristics were analyzed and the wave peak or trough of the coming field potential （ 0 ） rhythm was predicted using LabVIEW program. Meanwhile, the needed stimulus signal was output at the specified phase position via the digital port or D/A channel of the acquisition card, so as to implement the nerve stimulation. The experimental result showed that the prediction accuracies of 0 -rhythm wave peak and trough were up to 92% and 86%, respectively. The electrical stimulation system can be applied to predicting a variety of nervous rhythm wave phases and other signal characteristics because of its universality and flexibility. Thus, a new loop control stimulation method is provided for the nerve electrophysiology study and the electrical stimulation treatment of brain diseases.展开更多
Mechanosensors are the most important organelles for osteocytes to perceive the changes of surrounding mechanical environment.To evaluate the biomechanical effectiveness of collagen hillock,cell process and primary...Mechanosensors are the most important organelles for osteocytes to perceive the changes of surrounding mechanical environment.To evaluate the biomechanical effectiveness of collagen hillock,cell process and primary·cilium in lacunar-canalicular system(LCS),we developed pressure-electricity-structure interaction models by using the COMSOL Multiphysics software to characterize the deformation of collagen hillocks-and primary cilium-based mechanosensors in osteocyte under fluid flow and electric field stimulation.And mechanical signals(pore pressure,fluid velocity,stress,deformation)were analyzed in LCS.The effects of changes in the elastic modulus of collagen hillocks,the number and location of cell processes,the length and location of primary cilia on the mechanosensitivity and the overall poroelastic responses of osteocytes were studied.These models predict that the presence of primary cilium and collagen hillocks resulted in significant stress amplifications(one and two orders of magnitude larger than osteocyte body)on the osteocyte.The growth of cell process along the long axis could stimulate osteocyte to a higher level than along the short axis.The Mises stress of the basal body of primary cilia near the top of osteocyte is 8 Pa greater than that near the bottom.However,the presence of collagen hillocks and primary cilium does not affect the mechanical signal of the whole osteocyte body.The established model can be used for studying the mechanism of bone mechanotransduction at the multiscale level.展开更多
The purpose of this study is to investigate different factors of the artifact in surface electromyography(EMG) signal caused by functional electrical stimulation(FES). The factors investigated include the size of stim...The purpose of this study is to investigate different factors of the artifact in surface electromyography(EMG) signal caused by functional electrical stimulation(FES). The factors investigated include the size of stimulation electrode pads, the amplitude, frequency, and pulse width of the stimulation waveform and the detecting electrode points. We calculate the root mean square(RMS) of EMG signal to analyze the effect of these factors on the M-wave properties. The results indicate that the M-wave mainly depends on the stimulation amplitude and the distribution of detecting electrodes,but not on the other factors. This study can assist the reduction of artifact and the selection of detecting electrode points.展开更多
文摘To apply electrical stimulation to the specific phase position of electroencephalogram （EEG） waveform, a nervous electrical stimulation system was developed using general data acquisition card and LabVIEW virtual instrument environment. The hippocampal field potential signal in the brain of rat was sampled using the acquisition card＇ s A/D channel, and the amplitude and cycle characteristics were analyzed and the wave peak or trough of the coming field potential （ 0 ） rhythm was predicted using LabVIEW program. Meanwhile, the needed stimulus signal was output at the specified phase position via the digital port or D/A channel of the acquisition card, so as to implement the nerve stimulation. The experimental result showed that the prediction accuracies of 0 -rhythm wave peak and trough were up to 92% and 86%, respectively. The electrical stimulation system can be applied to predicting a variety of nervous rhythm wave phases and other signal characteristics because of its universality and flexibility. Thus, a new loop control stimulation method is provided for the nerve electrophysiology study and the electrical stimulation treatment of brain diseases.
基金supported by the National Natural Science Foundation of China(Grant Nos.11972242,11632013,11702183)China Postdoctoral Science Foundation(Grant No.2020M680913).
文摘Mechanosensors are the most important organelles for osteocytes to perceive the changes of surrounding mechanical environment.To evaluate the biomechanical effectiveness of collagen hillock,cell process and primary·cilium in lacunar-canalicular system(LCS),we developed pressure-electricity-structure interaction models by using the COMSOL Multiphysics software to characterize the deformation of collagen hillocks-and primary cilium-based mechanosensors in osteocyte under fluid flow and electric field stimulation.And mechanical signals(pore pressure,fluid velocity,stress,deformation)were analyzed in LCS.The effects of changes in the elastic modulus of collagen hillocks,the number and location of cell processes,the length and location of primary cilia on the mechanosensitivity and the overall poroelastic responses of osteocytes were studied.These models predict that the presence of primary cilium and collagen hillocks resulted in significant stress amplifications(one and two orders of magnitude larger than osteocyte body)on the osteocyte.The growth of cell process along the long axis could stimulate osteocyte to a higher level than along the short axis.The Mises stress of the basal body of primary cilia near the top of osteocyte is 8 Pa greater than that near the bottom.However,the presence of collagen hillocks and primary cilium does not affect the mechanical signal of the whole osteocyte body.The established model can be used for studying the mechanism of bone mechanotransduction at the multiscale level.
基金State Key Laboratory of Robotics and Systemgrant number:SKLRS-2012-ZD-04+1 种基金Natural Science Foundation of Shanghaigrant number:14ZR1421300
文摘The purpose of this study is to investigate different factors of the artifact in surface electromyography(EMG) signal caused by functional electrical stimulation(FES). The factors investigated include the size of stimulation electrode pads, the amplitude, frequency, and pulse width of the stimulation waveform and the detecting electrode points. We calculate the root mean square(RMS) of EMG signal to analyze the effect of these factors on the M-wave properties. The results indicate that the M-wave mainly depends on the stimulation amplitude and the distribution of detecting electrodes,but not on the other factors. This study can assist the reduction of artifact and the selection of detecting electrode points.
