【作者】 罗阳；

【导师】 府伟灵；

【作者基本信息】 第三军医大学 ， 临床检验诊断学， 2008， 博士

【摘要】 目的针对传统骨外固定装置无法实时、准确判断骨愈合过程的不足,发明一套新型外固定监测传感系统。该系统能够在提供牢固固定的同时,准确监测骨愈合过程中骨断端间应力及其变化,据此构建骨愈合过程中应力变化参数模型,以此来间接判断骨痂愈合程度和骨对位情况,进而指导牵张成骨过程,补充或者替代传统影像学方法,从而减少患者的放射性暴露,促进骨折快速愈合。进一步通过一系列动物实验来验证发明的3-D骨应力监测传感系统的可靠性与有效性,为后续应用于临床提供充足的实验依据。方法1.基于现有半环滑槽式外固定架的基础,结合本课题动物实验的需要,运用Solidworks软件重新设计外固定架,以发明一种既牢固稳定,又能保证每根支撑杆受力一致的扣合式外固定装置并进行其力学性能测试。2.设计微型拉压力传感器、数据采集盒、数据分析软件,进而组装成数据采集系统并验证其测力的准确性。将其与自行研制的扣合式外固定装置有机结合而形成3-D骨外固定监测传感系统并进行整体性能测试。3.构建牵张成骨的动物模型,实时测定牵张过程中应力变化,并进行动物血清中骨转换生化标志物的动态测定,在牵张成骨的不同时期拍摄X片以观察骨愈合情况,并且分别在牵张2周、10周后截取动物骨组织进行骨生物力学性能测试和组织形态学检测。结果1.发明的扣合式外固定装置既保持半环外固定架安装简便的优点,又极大增强了抗侧向拉压和扭转力强度,同时保证了三根支撑杆受力一致。2.微型拉压力传感器在满足500N量程的前提下,整体测量精度达到了1‰,体积控制在2.5×1×1.5cm(长×宽×高)。3.试验证明传感器安放于靠近两侧固定圆环处时整个外固定装置的抗扭刚度最佳。4.传感器连续监测10天的稳定性较好,且当沿轴向中心受压时,三个传感器测试数值完全一致(CV<2%)。5.牵张成骨动物实验过程中血清Ca、P值随牵张的进行呈现出先升后降的趋势。骨碱性磷酸酶(B-ALP)与碱性磷酸酶(ALP)的变化趋势保持高度一致,且一直维持于后者在50%~60%。6.牵张成骨过程中,随着每次牵张的进行,骨应力呈现由高到低的变化趋势。并且随着牵张的进行,每天同一时间点所测应力值呈线性增加。结论1.设计发明的新型扣合式全环外固定装置克服了传统半环外固定架抗侧压和扭转强度差的缺点,同时又保留了后者安装便捷的优点,为临床上骨外固定提供了全新思路。2.设计发明的数据采集系统能够准确实现压力信号的实时、精确采集。通过将外加压力行二次换能而转换为数字信号,计算机分析软件读取该信号并实时显示、分析3个通道数据,从而实现了不同传感器通道数据得以自动处理。3.本课题创造性地将压力传感器沿三维方向安装于外固定装置的支撑杆上,实现了3个传感器将施于固定架的轴向压力均分的目标,从而成功研制出3-D骨应力监测传感系统,为进一步构建智能调控的骨外固定系统奠定了基础。4.动物实验证明:骨断端应力水平是间接反映牵张再生过程中骨痂生长情况的一个灵敏指标,监测其实时变化可以很好预测骨痂生长情况,从而补充或替代传统放射学检查方法,减少X光检查中的放射性暴露。5.牵张成骨过程中,其骨应力呈现周期性变化趋势:牵张后瞬间升高,随后呈指数函数规律缓慢降至略高于正常水平,并以此往复。6.牵张前后骨应力变化值(△F)受牵张速度、牵张时间的双重因素影响,其三者保持二元线性关系:ΔF =?99 .86+14.83×V+3.74×T更多还原

【Abstract】 ObjectiveTo overcome the shortcomings of being incapable of accurately monitoring bone-healing state in real-time by traditional external fixators, this research aims to invent a novel sensing apparatus that can effectively measure tensile force during bone healing process. Then the system parameters will be optimized and adopted to construct the animal model during the procedure of distraction osteogenesis and bone healing. The success of this research will provide a brand new experimental platform for further research on mechanism of accelerating bone healing. Moreover; this research will lay a solid foundation for further clinical application.Methods1. Based on animal experiment data, Solidworks software was used to design and improve the widely used half-ring trough external fixators. Adjust the three dimension structure of the external fixator to make each of the nods endure equal force when axially loading. And STM were used to test the mechanical characteristics.2. Design minimized strain gauge drawing force and compression force transducer, data acquisition system, and data analysis software, then verify the accuracy of its measuring data. Finally, assemble the transducer with novel full-ring shackle external fixator and test the total system characteristics.3. Establish animal model of distraction osteogenesis and bone healing procedure. Monitor the change of tensile force during distraction osteogenesis procedure, and dynamically measure the bone turnover biomarkers. Take X-ray to observe the bone callus state during different phases. Finally perform bone histology and immunohistology test.Results1. Invented full-ring shackle external fixator not only kept the advantage of easily fixing, but also enhanced the ability against stress from lateral side and torque force. More over, it guaranteed the three nods endure the same stress during axially loading. 2. Minimized force transducer has 500N range and 1‰total accuracy, the size has been minimized to 2.5×2×1.5cm(L×W×H).3. Tests have proven that the torque characteristic is the best when the transducer is fixed closest to the second or third ring.4. Continuously Monitoring on the transducers for ten days has proven that the three transducers have good stability, and can get the same testing results(CV<2%)when axially loading.5. Ca、P value in serum went up at the beginning, then dropped down as the distraction osteogenesis kept on. Moreover, the B-ALP concentration accounted for half of the ALP value, and they kept the same fluctuation trend with time.6. During distraction osteogenesis, the bone tensile force increased with each distraction and then decreased to a level just a little higher than initial one. The tensile force kept linear growing up when the distraction went on.Conclusions1. The full-ring shackle external fixator is more stable than traditional half-ring trough one especially when against lateral force and torque force. Moreover, the former guarantees the three nods endure the same stress when axially loading. It can provide a new way of thinking for clinical external fixators choosing.2. The new method that assembles force transducer with the external fixator can provide real-time, accurate and noninvasive monitoring of bone healing state. Analysis software of the connected computers can read the digital signals transformed from loaded stress and then display and analyze data from transducers at real time, which realizes automatic settlement on data from different transducers.3. The research creatively installs the transducers on the rods of the external fixator in three-dimension direction, which realizes the purpose of equalizing axial stress applied on the fixator by means of the three transducers. In this way, 3-D bone tensile force monitoring system is successfully invented and lays a solid foundation for constructing intelligence-controlled external fixation system.4. Animal experiments have proven that the bone tensile force is a sensitive index which indirectly reflects the bone callus during distraction osteogenesis. The monitoring on the real-time change of the bone tensile force can make an accurate prediction of the bone callus state, which can supplement and replace the traditional check approach of radiology, and reduce patients’exposure to X-ray.5. During distraction osteogenesis, the bone tensile force increases with each distraction and then decreases to a level just a little higher than initial one. The tensile force keeps linear growing up when the distraction goes on. Therefore, the tensile force can be a good parameter for helping monitor bone healing state.6. The change of tensile force before and after distraction(△F) is a variable depend on the frequency and time of distraction. And the fittest multiple linear regression formula is:ΔF =?99 .86+14.83×V+3.74×T更多还原