No Invasive Methods For Bone quality Using Superconduction Quantum Interference Device

本文用超导量子干涉仪测量了脉冲电磁刺激（10、20、30高斯，2Hz）后兔腿的反应性电磁场。然而，我们有很多噪音组成的脉冲电磁场，反应磁场从软组织（神经，肌肉等），因此，我们无法检测到来自骨组织的反应磁场。接下来，我们尝试评估骨痂形成过程中骨组织的阻抗。我们用30只家兔胫骨延长骨痂。将30只日本白色家兔随机分为3组：ES组（早期电刺激，术后即刻开始交替电刺激），LS组（晚期电刺激，术后3周开始电刺激），C组（对照组）。等待时间为1周，延长率为0.5mm，每日2次。对延长完成后2周处死的动物进行放射学、组织学和电生理学研究。ES组和LS组骨皮质化和髓化开始早于C组，延长骨痂的骨密度值明显低于C组，ES组和LS组截骨后的阻抗值明显高于C组，随着延长骨痂的成熟，胫骨截骨的阻抗值逐渐增大。当电流路径由骨和软组织组成一个简单的并联电路时，我们认为约64%的电流通过骨组织。对延长骨痂进行交流电刺激有利于矿化骨痂的重塑，延长骨痂的阻抗反映了骨痂本身的成熟。

We tried to measure a reactive electricmagnetic field of a leg in rabbit after pulsing electromagnetic stimulation (10, 20, 30 Gaus, 2Hz) using Superconduction Quantum Interference Device. However, we had a lot of noise composed of the pulsing electromagnetic field, reactive magnetic field from soft tissues (nerve, muscle etc.), Therefore, we can not detect the reactive magnetic field from bone tissue. Next we try to evaluate the impedance of bone tissue in the process of callus formation. We used lengthend callus of tibiae in 30 rabbits. Thirty Japanese white rabbits were divided into 3 groups : Group ES (early stimulation ; Alternating stimulation from just after operation), Group LS (late stimulation ; electrical stimulation from 3 weeks after operation) Group C (control). The waiting period was 1 week and the lengthening rate was 0.5mm twice daily. Radiological, histological, and electrophysiological studies were done on animals sacrificed at 2 weeks after the completion of lengthening. Radiologically in groups ES and LS, corticalization and medullarization began earlier than in group C.The values of bone mineral density of the lengthened callus in groups ES and LS were significantly decreased as compared with those in group C.The impedance values for the resected tibia in group ES were significantly increased, as compared to those in group C.The impedance values of resected tibia increased with the maturation of the lengthened callus. When electrical current route was composed of bone and soft tissue as a simple parallel circuit, we considered that about 64% of the whole electrical current passed through bone tissue. Alternating current electrical stimulation to the lengthened callus was useful for remodeling of the mineralized callus, and the impedance of lengthened callus reflected the maturation itself.