The aim of this study is to establish a new dynamic model for balance keeping control in upright standing; and to deduce the underlying possible control mechanism of central neuronal system with a special concern on the roles of pelvis and its muscles. The dynamic model including five joints, i. e. two ankles, two hips and one lumbosacral making up a multi-link system being driven by two pairs of muscles, the psoas major (PM) and glutaeus medius (GM). In coronal section, experimental data shows the ankle and lumbosacral sway in almost the same amplitude, whereas their phase difference is approximately equal to π. The results indicate that the trunk is keeping perpendicularly to horizon during the standing process. By defining the model's physical parameters, assuming that the corrective torque needed for balance keeping process is regulated by PID (stands for proportional, integral and derivative) control, the body sway can be simulated. The simulation result is quite consistent with the experimental data suggests that the pelvis is one of the most important structure in balance keeping, moreover, the dynamics of the present proposed balance keeping model is a quite useful model for analyzing the posture sway.

With transmission electron microscopy,the endoplasmic reticulum of the parathyroid chief cells in normal and cadmium-treated golden hamsters was observed. After 1 month treatment of cadmium, there were dilated and whorl-shaped rough endoplasmic reticulum in the chief cells. After 3 and 6 months treatment of cadmium, there were concentric membranous body and paired endoplasmic reticulum in the chief cells. The mechanism responsible for the morphological change of the endoplasmic reticulum after cadmium treatment and the possible toxicologic effect were discussed.

Objective To probe into possibilities and sensitivity of CCD video camera system in the assessment of balance function.Methods The system is composed of a CCD video camera,a video image capture board and analysis software.Three indexes:Trunks,ayAngle (TSS Trunk Sway Speed(TSS) and fall index (FI).the normal group:FI≥I; mild group:0.7≤FI＜I; moderate group:0.4≤FI＜0.7; severe group:FI ＜0.4.Disorder of balance function group:42 patients with cerebrovascular accident,mean age of (67.4±8.0) years.Control group:42 healthy subjects,mean age of (65.3±6.5) years.All cases were measured by Berg balance scale and determinated three times by CCD video camera system with eye opening (eo) and eye closing(ec),and averaged.Results There were very significant differences in TSAeo,TSAec,TSSeo,TSSec,FIeo,FIec between disorder of balance function group and control group (P＜0.01).as well as Berg balance scale (P＜0.05).In disorder of balance function group,the differences among three groups were significant in TSAeo,TSAec,TSSeo,TSSec (P＜0.05).There were significant differences in TSAeo,TSAec,TSSeo,TSSec between severe group and mild group (P＜0.01) as well as in Berg balance scale (P＜0.05).Conclusions CCD video camera system has a higher sensitivity in assessment of body,balance than Berg balance sca land great value in clinical application.

The purpose of this study was to identify the relationships between trunk sway (TS) and the motion of center of pressure (COP) during quiet upright stance. Eight young healthy subjects (averaged 24±6.7 years) including 3 females were recruited for this study. By comparing TS with COP, we found that TS is moving in phase with COP both in lateral and sagittal plane. On the basis of observations that the COP-TS error signal is very similar to the changes of friction between the feet and floor. We also found that the friction is the impetus of trunk sway obeying the Newton's law. Then, a dynamic model between TS and COP can be identified. The results showed that TS and the motion of COP are in accordance with a specific differential equation. Supporting TS is v and COPS is u, then u can be expressed as : u=-Hm/k v+hv, where H, k, h are constants, m is the body mass. The simulation results fitted the experimental findings very well. The results suggested that TS instead of COP is a promising index for human standing ability assessment.

In order to get more pulse diagram valuable information, we summarized the traditional acceleration in the pulse chart based on the calculation of a new high-precision calculation of the acceleration pulse graph algorithms, being suitable for a large amount of data to adapt to requirements of high-resolution digital pulse diagram analysis, optimizing the acceleration pulse mapping process, reducing the impact of noise on data analysis, and improving the ability to distinguish details of the image. In addition, we used the spectrum analysis diagram for high-precision acceleration pulse. By doing so, we overcomed the traditional acceleration noise in the pulse data as the large loss, we found flat pulse, slippery pulse, taut pulse acceleration spectrum of feature points in the new Chinese medical traditional pulses. We then were able to recognize the pulse diagram calculated at the acceleration level to identify the frequency domain.
Algorithms ; Equipment Design ; Humans ; Medicine, Chinese Traditional ; instrumentation ; methods ; Pulse

Keeping upright stance is important to other complex motions like locomotion and running for human beings. The mechanism of balance-keeping control in upright standing is still unknown. This study was conducted to analyze the body sway by using a simple PID (proportional, integral, derivative) control model and to investigate the influence of vision on its gains. Ten healthy subjects took part in the study. The upright body was modeled as one-link inversed pendulum model. While determining the model parameters according to subject's physical statue, the gain of PID parameters, (K_P, K_D, K_I are gains of proportion, derivative, and integral respectively.) could be estimated. Four kinds of visual patterns, (three for central visual field stimulation, one is eyes closed) were designed for visual stimulation. The results showed that the gain of K_D was decreased significantly in eyes closed (131.5±37.6 Nms/rad in eyes open and 90.4±26.0 Nms/rad in eyes closed, p<0.001), and, K_P, K_I were not changed. The results suggested that the PID control model was a promising means for individual balance ability analysis and that the visual effect on balance-keeping control in upright standing was analogized to a damper in the mechanical system.