Biomechanics on the mechanical adaptation of biological tissues and its applications to engineering

1.用植入式测力传感器测量了大鼠在体跑台力传感器对大鼠髌腱的作用力。该传感器由一个略微弯曲的不锈钢板组成，在其上粘贴了应变计。水平以0.6 km/h的速度运行时，平均峰值作用力为11.3N，峰值应力为6 MPa。当车速从0.6公里/小时提高到1.0公里/小时时，平均峰值力增加了22%，但增加幅度不大。在15度和30度的坡度上，水平跑和倾斜跑的峰值力量无显著差异。2.水平跑0.6公里/小时后，处死大鼠，对其足部进行拉伸试验。两种材料的尺寸和力学性能无显著差异。这些结果表明，峰值应力为11.3N(峰值应力为6 MPa)的循环载荷不会改变PT3的力学性能。3.将循环载荷施加于体外培养的大鼠膝腱。加载峰值应力为9 Mpa时，材料的机械强度不变，而加载峰值应力为10.5 Mpa时，材料的机械强度显著降低。这些峰值应力值分别是0.6 km/h水平跑大鼠PT的1.5倍和1.75倍。

1.The in vivo force applied to the patellar tendon (PT) of rat during treadmill running was measured using an implantable force transducer. The transducer consisted of a slightly curved stainless steel plate on which a strain gauge was bonded. The mean peak force during running at the speed of 0.6km/h on a level was 11.3N and the peak stress was 6MPa. The mean peak force increased by 22% with increase in the speed from 0.6 to 1.0km/h, but the increase was not significant. There were no significant differences in the peak force among level running and inclined running on the slopes of 15 and 30 degrees.2.After running at 0.6km/h on a level, rats were sacrificed and tensile tests were performed on their PTs. There were no significant differences in the dimensions and mechanical properties. These results indicate that the cyclic loading of the peak force of 11.3 N (the peak stress of 6 MPa) did not change the mechanical properties of PT.3.The cyclic load was applied to rat patellar tendon in vitro. The mechanical strength was unchanged by the loading of the peak stress of 9 MPa but significantly decreased by that of 10.5 MPa. These values of peak stress were 1.5 and 1.75 times of that applied to the PT of rat during running at 0.6 km/h on a level, respectively.