Cornelissen M, Cornelissen P, van der Perre G, Christensen A B, Ammitzboll F, Dyrbye C
J Biomech. 1987;20(4):333-42. doi: 10.1016/0021-9290(87)90041-8.
Post mortem vibration measurements on one human tibia during gradual transection reveal the vibration modes and frequencies of a tibia during a simulated healing. The modes are identified in a tibia in an above knee amputation specimen with the leg in two positions: hanging down with the knee flexed (90 degrees) and supported in a special designed bone clamping splint (knee flexed 45 degrees). The vibration measurements are analysed using Modal Analysis and are translated to mechanical stiffness by mathematical modelling. The single bending 'free-free' mode turned out to be more sensitive to weakening of one cross-section than the 'rigid body' and single bending 'hinged-spring' modes. The error on the assessed value of the stiffness is a multiple of the error on the measured frequencies. This multiplication factor decreases for more sensitive modes. In this experiment, the results are accurate enough to reflect the asymmetric weakening imposed upon the tibia. Attempts are made towards automatization of the measurement and analysis in order to get a system for clinical use. The actual system is still too cumbersome and time consuming for standard clinical use.
在逐渐横断过程中对一根人体胫骨进行的死后振动测量揭示了模拟愈合过程中胫骨的振动模式和频率。在一个膝上截肢标本的胫骨中，当腿部处于两个位置时识别出这些模式：膝盖弯曲（90度）下垂以及支撑在一个特殊设计的骨夹固定夹板中（膝盖弯曲45度）。使用模态分析对振动测量进行分析，并通过数学建模将其转换为机械刚度。结果表明，单一弯曲的“自由-自由”模式比“刚体”和单一弯曲的“铰链-弹簧”模式对一个横截面的弱化更敏感。刚度评估值的误差是测量频率误差的倍数。对于更敏感的模式，这个乘法因子会减小。在本实验中，结果足够准确以反映施加在胫骨上的不对称弱化。为了获得一个临床使用系统，尝试对测量和分析进行自动化。实际系统对于标准临床使用来说仍然过于繁琐且耗时。
