ABSTRACT
The present paper is to study the center line of the plantar pressure of normal young people, and to find the relation between center line of the plantar pressure and gait stability and balance. The paper gives the testing principle and calculating methods for geometric center of plantar pressure distribution and the center of pressure due to the techniques of footprint frame. The calculating formulas in both x direction and y direction are also deduced in the paper. In the experiments carried out in our laboratory, the gait parameters of 131 young subjects walking as usual speed were acquired, and 14 young subjects of the total were specially analyzed. We then provided reference data for the walking gait database of young people, including time parameters, space parameters and plantar pressure parameters. We also obtained the line of geometry center and pressure center under the foot. We found that the differences existed in normal people's geometric center line and the pressure center line. The center of pressure trajectory revealed foot movement stability. The length and lateral changes of the center line of the plantar pressure could be applied to analysis of the plantar pressure of all kinds of people. The results in this paper are useful in clinical foot disease diagnosis and evaluation of surgical effect.
Subject(s)
Humans , Foot , Physiology , Gait , Pressure , Reference Values , WalkingABSTRACT
BACKGROUND: Traditional cancellous bone porosity detection methods such as direct method,gas expansion method,mercury injection method,density and osmotic suction measurement have many disadvantages,such as low efficiency,labor-intensive and complexity.OBJECTIVE: To process cancellous bone chips using MATLAB image processing method to calculate cancellous bone porosity.METHODS: Using MATLAB image processing method,the stained cancellous bone images were subjected to uneven lighting removal,image enhancement,binarization,removing interference objectives to obtain binary two-dimensional matrix.RESULTS AND CONCLUSION: Slice image was composed of bone and pore space.The slice image was segmented to calculate its porosity.This solves the problem of the inequality of light intensity and other interferences in image information that affect the statistics.The image processing and analysis methods of bone slices were performed using MATLAB,which can be used for cancellous bone porosity measurements and be used to explore the distribution and variation of porosity.Selecting different regions to calculate the different porosity of each area can be used to analyze the distribution of the pore.This method provides a method for the study of trabecular bone structure.
ABSTRACT
Knee joint is the largest and most complex joint of human body. Knee prosthesis, as the core component of lower limb, has a great expectation on simulated properties. Based on bionics, this study was designed to analyze kinematic characteristics of simulated knee joint, such as the sliding and rolling ratio of the knee as well as the instantaneous center curve, in order to further investigate an ideal simulated knee joint which was highly similar to normal knee joint. Movement regularity of human knee joint was simplified to introduce biomechanical model of knee joint so as to analyze and deduce formula of sliding ratio, rolling ratio, and instantaneous center curve. The calculation results were compared with parameters of human knee joint, suggesting a high coincidence between simulated and human knee joint. This provides an evidence for analyzing stability of motion and further studying structure and function of simulated knee joint, and this also provides basis for further research artificial simulated leg.
ABSTRACT
The prosthesis is forced by pneumatic artificial muscle, which can swing like human legs by inputting signals such as square waves and trigonal waves.Its swing performance is tested under such triggerings in order to find out a best motivating curve rendering the prosthesis performance almost the same as what human legs do. Compared with the normal human pace graph, the curve matches very well in the ascending edge but quite a discrepancy in the end of descending edge. According analyzing the reasons of the discrepancies, we could know how to ameliorate the design of the next generation of the bionic legs.
ABSTRACT
A model of fluid dynamics related to the myocardial bridginged and mural coronary artery was designed and manufactured according to the physical principle and characteristic of the mural coronary artery. The model can imitate systematically well the effect of myocardial bridging on hemodynamic change of the mural coronary artery under different controlled experimental parameter. The methodology is proved to be feasible and has good prosperity of experimental study.