Smart Impedance Controlled Osteotomy Instrumentation

截骨术，切割骨头，是不同外科学科的标准程序。骨的有效切割和密切敏感的软组织结构的良好保护是至关重要的。与该领域高度相关的两种手术是颅骨切开术（打开颅骨，约66000例，德国/2008）和胸骨切开术（重新打开胸部，约13500例，德国/2008）。在这两种情况下，都会切割双皮质骨，同时必须保护潜在的敏感和活体关键软组织结构（例如中枢神经系统、心脏、血管）。在所有病例中，30%的开颅手术期间发生硬脑膜撕裂，这导致手术时间显著增加，患者的结果更差。此外，在重复胸骨切开术（resternotomy）过程中胸骨后结构的损伤是导致高死亡率的原因，甚至随着每次再次手术的进行而增加。为了在截骨术期间支持外科医生，开发了许多主动手持器械和机器人系统。这些半自动仪器或自动机器人基于术前或术中采集的成像数据（例如CT、超声）处理骨骼。这些方法的缺点是需要许多额外的程序，以及与医疗标准工作流程的复杂集成。在仅基于过程中采集的数据自动控制一个或两个自由度的手控仪器的情况下，情况并非如此。申请人之一能够展示基于光的过程测量和控制方法的一般可行性。由于基于光的测量和电流控制策略，系统对故障和干扰非常敏感。然而，在合作工作中，两个申请人能够显示的潜力，生物阻抗谱（BIS）的自动过程控制的手术机器人系统的骨水泥清除在修订全髋关节置换术。在拟议的研究项目的潜力手引导，传感器集成和控制，智能仪器resternotomy和开颅手术。出于这个原因，必须分析BIS到传感器控制仪器中的最佳集成，然后在体外验证其使用。主要挑战是切割过程中的在线BIS测量和外科医生参与下的器械主动容错控制。研究对象也是智能仪器的高技术精度（基于知识的、传感器控制的过程控制）与外科医生的高认知能力的组合，用于控制整个过程。这意味着，作为对复杂测量过程的补充，主动容错控制方法，特别是关于协同人机交互的方法，必须在演示系统中实施并最终评估。

Osteotomy, the cutting of bones, is a standard procedure in different surgical disciplines. Efficient cutting of the bone and a good protection of close sensitive soft tissue structures is crucial. Two procedures of high relevance in this area are craniotomy (opening of the skull, around 66000 cases, Germany/2008) and resternotomy (reopening of the chest, approximately 13500 cases, Germany/2008). In both cases a bicortical bone is cut, while underlying sensitive and live critical soft tissue structures (e.g. central nervous system, heart, blood vessels) have to be protected. During craniotomy in 30 % of all cases a tear of the dura mater occurs, which leads to a significant increase in operation time and a worse result for the patient. Moreover, injuries of the retrosternal structures during repeated sternotomy (resternotomy) are responsible for a high mortality which even increases with every reoperation performed.To support the surgeon during osteotomies many active hand held instruments and robotic systems were developed. These semiautomatic instruments or automatic robots process the bone on the basis of pre- or intraoperative acquired imaging data (e.g. CT, ultrasound). The disadvantages of these approaches are the many additional procedures necessary and the complex integration into the medical standard workflow. In case of a hand guided instrument, which controls one or two degrees of freedom automatically only on the basis in process acquired data, this is not the case. One of the applicants was able to show the general feasibility for a light based in process measurement and control approach. Due to the light based measurements and the current control strategy the system is very sensitive to failures and disturbances. However, in collaborative work, the two applicants were able to show the potential of bio impedance spectroscopy (BIS) for the automatic in process control of a surgical robot system for the bone cement removal in revision total hip replacement.In the proposed research project the potential of a hand guided, sensor integrated and controlled, intelligent instrument for resternotomy and craniotomy is investigated. For this reason, the optimal integration of BIS into a sensor controlled instrument has to be analyzed and after that its use is verified in-vitro. Central challenges are the online BIS measurement during the cutting process and the active fault tolerant control of the instrument under involvement of the surgeon. Object of research is also the combination of the high technical precision (knowledge based, sensor controlled process control) of the intelligent instrument with the high cognitive abilities of the surgeon for the control of the overall process. This signifies that in complement to the complex measurement process, the approaches for active fault tolerant control particularly with regard to a synergistic man-machine interaction have to be implemented into a demonstrator system and finally evaluated.