The Study Of The Biomechanics Of The Human Cortical Bone Treated Microwave Induced Hyperthermia

Objective: The aim of the study is to clarify the changes of the microstructure and the biomechanical properties of the human cortical bone tissue treated by hyperthermia induced by microwave, and seek the some solidified processes to prevent the occurrence of the pathological fractures of tumourous bone treated by the microwave intervening hyperthermia. The study includes three main parts. The general mechanical tests of human cortical bone: the direct observations of the fatigue injuries of bone tissue under the electronic scanning microscopy and the four point bending test of the canine femurs. Materials and methods:1.The human cortical bone was heated by the bone tumor microwave therapy instrument. The time of heating were 30 minutes and the surface temperature of the bone were controlled at 80 ℃ .After that, the mechanical testing specimen of cortical bone were machined according to the mechanical standard .The microhardness of the bone tissue were measured. The strain rate of the static test were 0. 8×10^-4 -3. 3×10^-3s^-1.The static tensile and compressive tests were performed. And the tensile and compressive strength, the fracture work and the stretching rate were measured. Then the uniaxial fatigue test were performed to measure the fatigue life, the change of the tensile / compressive strain and the change of energy dissipation were studied at different points of fatigue life fraction(Fn). Then the mechanism of fracture of the bone were analyzed under electronic microscopy. 2.The dynamical fatigue injury processes of the normal cortical bone and the hyperthermia cortical bone were observed directly under electronic scan microscopy. 3.The third part of the test is the four point bending test of the canine femurs treated by microwave induced hyperthermia The objective of third part of test is to seek the consolidation method of bone tissue treated by microwave induced hyperthermia Results: 1.The results of static test: The time and the temperature of hyperthermia induced by...