Comparison of the models of acute hypoxia and hypoxic-ischemia in newborn piglets / 北京大学学报(医学版)

Objective:To compare the newborn piglet models of hypoxic ischemic brain damage in hypoxia and hypoxia combined with occlusion of both carotid arteries. Methods: Twenty four 7-day-old piglets were divided into two groups. Group H: mechanical ventilation with low concentration of oxygen,Group HI; mechanical ventilation with low concentration of oxygen combined with occlusion of both carotid arteries. The piglets were inhaled with 10%, 8%, and 6% low-concentration oxygen for 30 min, and grouped into mild, moderate, and severe hypoxia ones. The changes of physiological parameter, cerebral blood flow and cerebral oxygen perfusion were detected. Results: There were no significant differences in blood gas analysis of oxygen saturation, blood lactic acid and pH between the two groups(P＞0. 05) . The mean arterial pressure of severe hypoxia in HI was significantly lower than in H(P＜0.05). The cerebral blood flow in H and HI was relatively stable after different degrees of hypoxia. As compared with the cerebral blood flow perfusion in group H and HI, there were no significant differences between them ( P>0. 05). The cerebral oxygen perfusion in H and HI was significantly descent after different degrees of hypoxia (P＜ 0.05). As compared with the cerebral oxygen perfusion in groups H and HI, there were no significant differences between them. Conclusion: H and HI have the same effect on physiological parameter, cerebral volume and cerebral oxygen perfusion of newborn piglets. The mechanical ventilation with low concentration of oxygen to newborn piglets can develop the HIBD model, it is not necessary to occlude carotid arteries.

Preliminarily Application of Quantitive Detector for Human Tremor in Clinic / 中国康复理论与实践

@#ObjectiveTo test the effect of human tremor detector in clinic based on the principle of photoelectrical transformation.MethodsFifty-five subjects including normal youth and elderly persons, patients with Parkinson's disease (PD), hyperthyroidism and cerebellor ataxia were tested with human tremor detector. The displacement, frequency spectrograph, velocity and acceleration of both hands in four kinds of postures and action were involved.ResultsThe physiological tremor and pathological tremor in different kinds of patients were significantly different (P<0.05). Especially in PD, both quantitive and qualitative data had a significant difference.ConclusionHuman tremor detector can provide the evidence for early diagnosis of PD.

A study of gait recognition based on kinematics and kinetics parameters / 生物医学工程学杂志

In order to recognize people by their gait, we propose a pattern recognizing method based on kinematics and kinetics parameters. The feature extraction methods of joint angle and vertical ground reaction force (VGRF) were given. 14 healthy male subjects participated in this experiment. The experimental results showed that the correct classification rates (CCR) was 87.1% at k = 1 and 90% at k = 3 (k-nearest neighbor) based on joint angle recognition; the CCR was 85.7% at k = 1 and 80% at k = 3 based on VGRF recognition. The multivariate analysis of the experimental data proved the feasibility of gait recognition. The principal component analysis and curves of VGRF also showed that the instant of foot strike plays an important role in gait recognition.

The frequency features and application of edge detection differential operators in medical image / 生物医学工程学杂志

Edge detection is an absolutely necessary step in medical image processing, and the use of differential operators to detect edge is one of the most common and effective methods. In this paper are analyzed the frequency features of the Roberts operator, Prewitt operator, Sobel operator and Laplacian operator from the viewpoint of frequency domain, and it is proposed that the frequency features of the differential operators should be considered when differential operator is being used and/or constructed. Because edge detection operator is sensitive to the edge type, the appropriate operator should be adopted in different edge type detection. Finally, the importance and necessity of selecting edge detection operator are validated in the MRI image edge processing.

Algorithm for recognizing the markers in human motion detection / 生物医学工程学杂志

An algorithm for recognizing the markers in human motion detection is proposed in this paper. It includes three parts as follows: (1) an improved template matching method is used to acuminate the peak of the matching result. (2) The weighted average of the cross correlation between target image and template is given in order to make the resolution increase to sub-pixel level. (3) Forecasting the motion of marker and overcoming the hiding of marker are realized basing on the continuity of human motion. The result of experiments shows that the algorithm can recognize the positions of the markers at a relatively higher accuracy and speed. A gait analysis system based on this algorithm has come into use.

A study of kinematic parameters of normal youth in gait analysis / 中国康复理论与实践

@#ObjectiveTo study basic pattern of normal youth in gait analysis.Methods28 healthy young persons as experimental subjects were studied. The gait analysis system based on digital video and digital image processing was employed to obtain kinematic parameters.ResultsThe means and standard deviations of kinematic parameters of normal youth were obtained. The differences of gait patterns between males and females were compared. The correlations between gait parameters and height, weight were analyzed respectively.Conclusions It is recommended that the values of the gait parameters and the trends obtained can be used as a standard gait pattern of normal youth. Statistically significant differences exist between the males and the females for most of the gait parameters. Furthermore, the differences of the values of gait parameters between the males and the females are not led only by the difference of height except very few parameters.

康复与康复工程 / 中国康复理论与实践

@#本文就康复概念的“泛化”现象 ,提出了一些看法。对康复科学、康复系统工程及其对工程技术的需求 ,进行了分析探讨。结论 :康复工程的广义内涵是理清边界、拾遗补缺、设置接口、实现系统集成 ,利用现代工程技术的手段和方法促进残疾者的全面康复。