ABSTRACT
In this paper, a new surface electromyography (sEMG) signal decomposition method based on spatial location is proposed for the high-density sEMG signals in dynamic muscle contraction. Firstly, according to the waveform correlation of each muscle motor units (MU) in each channel, the firing times are extracted, and then the firing times are classified by the spatial location of MU. The MU firing trains are finally obtained. The simulation results show that the accuracy rate of a single MU firing train after classification is more than 91.67%. For real sEMG signals, the accuracy rate to find a same MU by the "two source" method is over (88.3 ± 2.1)%. This paper provides a new idea for dynamic sEMG signal decomposition.
Subject(s)
Action Potentials , Computer Simulation , Electromyography , Muscle Contraction , Muscle, SkeletalABSTRACT
Objective Endothelin-1 (ET-1) is expected to be a new therapeutic target for cerebral ischemic stroke (CIS). The content of plasma is known to increase after stroke, but the changes in the brain remain unclear. The aim of this study was to investigate the expression and distribution of ET-1 and endothelin receptors (ETR) in the brain after CIS in rats and their relationship with related brain injury. Methods We established a model of middle cerebral artery occlusion (MCAO)-reperfusion in 12 male SD rats, 6 with nylon filament inserted through the left internal carotid artery (the ischemia-reperfusion [IR] group) and the other 6 without (the sham operation group). We observed the distribution of ET-1 and ETRs in different regions of the brain by immunohistochemistry. Results Compared with the sham operation group, the IR group showed significantly higher expressions of ET-1 in the cortex (0.107 ± 0.005 vs 0.230 ± 0.019, P < 0.05), caudate putamen (0.110 ± 0.028 vs 0.198 ± 0.008, P < 0.05) and hippocampus (0.101 ± 0.005 vs 0.183 ± 0.002, P < 0.05), ETR-A in the bilateral choroid plexus (0.086 ± 0.009 vs 0.131 ± 0.001, P < 0.05), pial vessels (0.063 ± 0.003 vs 0.132 ± 0.005, P < 0.05) and middle cerebral arteries (0.079 ± 0.003 vs 0.121 ± 0.008, P < 0.05), and ETR-B in the infarcted cortex (0.032 ± 0.003 vs 0.187 ± 0.025, P < 0.05) and hippocampus (0.029 ± 0.002 vs 0.226 ± 0.019, P < 0.05) of the ischemic hemisphere. Conclusion After cerebral IR, ET-1 and ETRs are selectively expressed in different brain regions, and their distribution may be related to IR-induced brain injury.
ABSTRACT
The present study investigated the mechanisms involved in processing orientation on the frontal and ground planes. The stimuli comprised two yellow circles conceived as the endpoints of a segment and depicted on a black background. In Experiment 1, the observers performed two tasks on both planes (frontal and ground). In Task 1 they were asked to indicate the absolute location of the two endpoints, presented one at a time (successive task). In Task 2 they had to locate the relative position of the endpoints presented simultaneously (simultaneous task). Relative and absolute errors were analyzed according to a cyclopean coordinate system derived from the geometry of the visual scene. These two kinds of errors were studied within the framework of the hypothesis that each kind of task would minimize the error related to its codification. The results showed greater absolute errors in the simultaneous task than in the successive task and greater relative errors in which the successive task seemingly activated a more accurate way of codification of the orientation. In Experiment 2 we controlled the availability of visual depth cues by changing the presentation time (50 and 3000 ms) and viewing conditions (monocular and binocular) in the simultaneous task. The results showed that the precision of orientation judgments was poorer on the ground plane than on the frontal plane, except when the observers used binocular vision. These results suggest that the orientation of a segment, at least on the ground plane, can be conceptualized as a gradient of disparities.
Subject(s)
Depth Perception , Space Perception , Vision, Binocular , Vision, MonocularABSTRACT
Objective To design Radio-Frequency Identification(RFID) reader with multi-antennas of different spatial location.Methods Design scheme of RFID reader with multi-antennas of difference spatial location was presented,i.e.a separated setting with a reader and multiple detected antennas was adopted.Each antenna only identified tags in its own area.The receiving information from tags contains antenna code and data in tag's IC.Hence the reader can point the tags position through different antenna code.Results The application of RFID with multi-antennas of different spatial location to management system of combat readiness medicine can provide safe,exact and real-time information collection,processing and query for combat readiness medicine.Conclusion The system can not only provide location identification,but also reduce system cost.It will have wide application in future.