BACKGROUND: The design of the microstructure of human bone is in fact to construct a model, which could characterize the connecting-porosity cell frame structure. As the porosity structure is represented as irregular curve, and this irregularity has close relationship with the bone function, does the fractal theory effectively find the irregularity containing in the irregular structure?OBJ ECTIVE: To analyze the microstructure of human bone by applying the fractal property, and construct the 3D model that has structural similarity to the natural bone. With the help of Rapid Prototyping technology, a new bionic technique instead of traditional modeling method is presented to model artificial human bone.DESIGN: Computer aided bionic design.SETTING: Biomaterials and Engineering Center of Wuhan University ofTechnoiogy.MATERIALS: The experiment was carried out in the Biomaterials and Engineering Center of Wuhan University of Technology from January to June 2005. The material is the original gray chart of hip joint of one healthy middle-aged male.METHODS: The contour of the human bone microstructure was obtained by exaltation and extraction of the grey chart.B-spline technique was used for vectorization. ①The fractal theory was adopted to compute the fractal dimension of typical aperture structure and the result was represented by dimensions (D=2s, s is the slope of fitting line) to find the inherent relation among apertures. ② Monte Carlo method was used to generate the two-dimensional model of microstructure of bone with the appropriate porosity. The 3D model was manufactured by rapid prototyping technology.MAIN OUTCOME MEASURES: ①Fractal dimension of porous structure of human bone; ② Results of 2D and 3D model of the microstructure of human bone.RESULTS: ①The fractal dimensions of some representative apertures were between 1.14and 1.28. The fractal dimensions of these micro-apertures are rather close, which testified the self-similarity in the edge contour of the microstructure of human bone. ②3D model was generated by cumulating the plane model layer by layer with the rapid prototyping technology. If the high porosity of plane model was ensured, the porosity and connectivity of 3D model could meet the high requirement. Through the computer simulating, the porosity of the model was greater than 40%, which meets the design requirement.CONCLUSION: Fractal theory is applied in the construction of 2D model of human bone based on the requirements in bionic design of the microstructure model of human bone. The fractal characteristics of the grey chart of human bone and the edge contourof its typical micropore are analyzed. The software suitable for 2D tissue engineered bionic microstructure of human bone is developed with VC++, meanwhile, 3D cell scaffold model is constructed by cumulating the planer model, which meets the human bone functions.

Objective To compare the effect of two different fluid infusion models in the non-operative management of spleen rupture .Methods The clinical data of 46 cases of spleen rupture with non-operative management from 1995 to 2001 were analyzed retrospectively. Results In the non-operative management of spleen rupture, patients received continuous but rather slow fluid infusion had higher successful treatment rate(95.24%) and less intra- abdominal bleeding than those in patients received rapid fluid infusion (91.02%) . Conclusions In the non- opeative management of spleen rupture, continuous but rather slow fluid infusion model is superior to traditional rapid fluid infusion.

Hospital logistics management provides critical support for clinical work, and the management of materials is key to logistics management. Based on an analysis of current logistics management of the hospital, desirable results on logistics materials management have been harvested. The measures taken include optimizing management workflow and reinforcing cost control, in combination with such efforts as regulations improvement, higher informatization level and staff teamwork building.

Enhanced recovery after surgery (ERAS) has been widely used in perioperative optimization. As an important component of ERAS, rehabilitation medicine mainly focuses on perioperative physical fitness management, respiratory training, exercise training to reduce the incidence of postoperative pulmonary infection, improve gastrointestinal and cardiopulmonary function. This paper explains rehabilitation medicine for respiratory, musculoskeletal, cardiovascular and digestive systems during the perioperative period.
Humans ; Perioperative Care ; Postoperative Complications ; prevention & control ; Postoperative Period ; Rehabilitation ; methods ; standards