Papers by Keyword: Femur Bone

Abstract: The interface blunt-prosthesis from blunt-prosthesis-rod complex is the subject of stress and friction due to forces that act in the walking stage. The dermal wounds and patient's discomfort sensation that can appear can be alleviated or predicted by analyzing the stump’s pressure map taking into account tribological aspects. There are many studied related to transtibial prosthesis but studies that analyze the transfemoral prosthesis are relative rare. A analyze of pressure in blunt-prosthesis complex for transfemoral sub-ischeal prosthesis is proposed during a complete gait cycle.The experiments used three types of liners and a standard type of socket. The areas that are subject of maximum stress and friction are identified as the value of forces of moments that act n stump during a gait cycle. An integral measure and functional ones are proposed to evaluate for influence of each factor that can contribute to optimization of prosthesis and an empirical formulas that connect these measure for prediction is suggested. Theoretical approaches are presented along with experimental results and further research directions.

Abstract: Scanning electron microscope (SEM) observation showed that femur bone is a kind of bioceramic composite consisting of hydroxyapatite layers and protein matters. The hydroxyapatite layers are further composed of hydroxyapatite fiber sheets. The observation also showed that the hydroxyapatite fiber sheets possess very thin fiber shape. The thickness of the hydroxyapatite fiber sheets is within nanometer scale. The mechanism of the high fracture strength of the bone was investigated based on the microstructural characteristics of the hydroxyapatite fiber sheets and the theory of fracture mechanics. The result reveals that the thin fiber shape of the hydroxyapatite fiber sheets endows the bone with high fracture strength.