The abundant muscle tissues of the forearm determine the movements of the wrist,hand and fingers together.However,linking wrist kinematics and forearm muscle activation is still a challenging.There may exist blindness...The abundant muscle tissues of the forearm determine the movements of the wrist,hand and fingers together.However,linking wrist kinematics and forearm muscle activation is still a challenging.There may exist blindness in the rehabilitation therapy of forearm muscles,due to the lack of the physiological characteristics of muscle activation and sequences.An armband with eight channels was used to collect surface electromyographic signals(sEMGs)of a specific section of the forearm under the different wrist movements,palm postures,and external loads,based on the image of magnetic resonance imaging(MRI).The collected cross-sectional muscles covered almost all surface muscles.The muscle activation could be expressed clearly by enveloping the sEMG signals of 8 muscles within a single cycle.The root mean square(RMS)and the average peak value V_(P) were used to evaluate the activation intensities of dominant muscles.The activation sequences and the absolute times of dominant muscles were obtained from the envelopes of their raw sEMGs,and not influenced by the palm postures and external loads.In addition,their RMS and V_(P) under each wrist movement increased approximate linearly with external loads.The corresponding contribution ratios were first calculated to evaluate the role played by each muscle.The well-defined data of forearm muscles could provide standard references for the rehabilitation therapy of forearm muscles.展开更多
Stroke is a major cause of death and disability among adults in China,and an efficient rehabilitation strategy has been an urgent demand for post-stroke rehabilitation.The non-invasive brain stimulation(NBS)can modula...Stroke is a major cause of death and disability among adults in China,and an efficient rehabilitation strategy has been an urgent demand for post-stroke rehabilitation.The non-invasive brain stimulation(NBS)can modulate the excitability of the cerebral cortex and provide after-effects apart from immediate effects to regain extremity motor functions,whereas robotic therapy provides high-intensity and long-duration repetitive movements to stimulate the cerebral cortex backward.The combined strategy of the two techniques is widely regarded as a promising application for stroke patients with dyskinesia.Transcranial magnetic stimulation(TMS)and transcranial electrical stimulation(TES)are important methods of NBS.Their recovery principles,stimulation parameters,and clinical applications have been summarized.The combined treatments of rTMS/tDCS and robotic therapy are analyzed and discussed to overcome the application barriers of the two techniques.The future development trend and the key technical problems are expounded for the clinical applications.展开更多
We demonstrate an all-fiber Yb:fiber frequency comb with a nonlinear-amplifying-loop-mirror-based Yb:fiber laser oscillator. The fiber-spliced hollow-core photonic bandgap fiber was used as dispersion compensator, whi...We demonstrate an all-fiber Yb:fiber frequency comb with a nonlinear-amplifying-loop-mirror-based Yb:fiber laser oscillator. The fiber-spliced hollow-core photonic bandgap fiber was used as dispersion compensator, which was also directly spliced to a piece of tapered photonic crystal fiber for an octave-spanning spectrum. The spectrum of the compressed 107 fs laser pulses was broadened, covering 600 nm to 1300 nm in a high-nonlinearity tapered fiber for f to 2f beating. The signal-to-noise ratio of offset frequency was measured to be 22 dB.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52375279,52175001)Beijing Natural Science Foundation(Grant No.3252002).
文摘The abundant muscle tissues of the forearm determine the movements of the wrist,hand and fingers together.However,linking wrist kinematics and forearm muscle activation is still a challenging.There may exist blindness in the rehabilitation therapy of forearm muscles,due to the lack of the physiological characteristics of muscle activation and sequences.An armband with eight channels was used to collect surface electromyographic signals(sEMGs)of a specific section of the forearm under the different wrist movements,palm postures,and external loads,based on the image of magnetic resonance imaging(MRI).The collected cross-sectional muscles covered almost all surface muscles.The muscle activation could be expressed clearly by enveloping the sEMG signals of 8 muscles within a single cycle.The root mean square(RMS)and the average peak value V_(P) were used to evaluate the activation intensities of dominant muscles.The activation sequences and the absolute times of dominant muscles were obtained from the envelopes of their raw sEMGs,and not influenced by the palm postures and external loads.In addition,their RMS and V_(P) under each wrist movement increased approximate linearly with external loads.The corresponding contribution ratios were first calculated to evaluate the role played by each muscle.The well-defined data of forearm muscles could provide standard references for the rehabilitation therapy of forearm muscles.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375279,52175001)National Key R&D Program of China(Grant No.2018YFB1307004).
文摘Stroke is a major cause of death and disability among adults in China,and an efficient rehabilitation strategy has been an urgent demand for post-stroke rehabilitation.The non-invasive brain stimulation(NBS)can modulate the excitability of the cerebral cortex and provide after-effects apart from immediate effects to regain extremity motor functions,whereas robotic therapy provides high-intensity and long-duration repetitive movements to stimulate the cerebral cortex backward.The combined strategy of the two techniques is widely regarded as a promising application for stroke patients with dyskinesia.Transcranial magnetic stimulation(TMS)and transcranial electrical stimulation(TES)are important methods of NBS.Their recovery principles,stimulation parameters,and clinical applications have been summarized.The combined treatments of rTMS/tDCS and robotic therapy are analyzed and discussed to overcome the application barriers of the two techniques.The future development trend and the key technical problems are expounded for the clinical applications.
基金supported by the National Key R&D Program of China(No.2016YFF0200204)the National Natural Science Foundation of China(Nos.31327901and 61475008)
文摘We demonstrate an all-fiber Yb:fiber frequency comb with a nonlinear-amplifying-loop-mirror-based Yb:fiber laser oscillator. The fiber-spliced hollow-core photonic bandgap fiber was used as dispersion compensator, which was also directly spliced to a piece of tapered photonic crystal fiber for an octave-spanning spectrum. The spectrum of the compressed 107 fs laser pulses was broadened, covering 600 nm to 1300 nm in a high-nonlinearity tapered fiber for f to 2f beating. The signal-to-noise ratio of offset frequency was measured to be 22 dB.
