|Budget Amount *help
¥3,900,000 (Direct Cost : ¥3,900,000)
Fiscal Year 1998 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1997 : ¥3,500,000 (Direct Cost : ¥3,500,000)
Stiffness of bone is changed depending on the fracture healing process. This study was conducted to develop a diagnostic device for fracture healing of bone by a modal analysis method of bone. (Materials and Method) The tibial bone of adult rabbit was subjected. The distal end was fixed on the device. A transverse wave, which was swept from 1Hz to 200Hz for 0.5sec was made to oscillate the bone. The acceleration sensor was installed in the proximal end of the tibia, and detected the translated oscillation output accelerator. The output wave form was analyzed by a FFT analyzer. The middle part of the bone was decalcificated with 5% formic acid. The authors regarded the bone as a fracture healing model of tibial bone. The fracture healing level was determined by the soaking time period. Namely, the decalcification time period was 0, 6, 18, 24, and 48hrs, respectively. Moreover, the level of decalcification was checked by an image analysis to measure the density of the Softex image. (Result) The resonance frequency of the bone without decalcification treatment was 120Hz. The resonance frequency has decreased along with the level of the decalcification of bone. Each resonance frequency, which the bone was soaked in the formic acid for 6, 18, 24, and 48hrs, was observed at 114, 103, 85, and 20Hz, respectively. On the other hand, the level of the decalcification was evaluated by the density of the Softex image. Each level was 25.6%, 28.9%, 30.4%, and 41.8% at the decalcification period of 6, 18, 24, and 48 hrs, respectively.