Smart Impedance Controlled Osteotomy Instrumentation

截骨术是不同外科学科的标准手术。有效地切割骨骼和保护敏感的软组织结构是至关重要的。与该领域高度相关的两种手术是开颅术（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，双皮质骨都被切割，而潜在的敏感和关键的软组织结构（如中枢神经系统、心脏、血管）必须得到保护。在开颅术中，30%的病例发生硬脑膜撕裂，这导致手术时间的显著增加，对患者的结果更差。此外，在重复胸骨切开术中胸骨后结构的损伤是高死亡率的原因，甚至随着每次再手术的进行而增加。为了在截骨术中支持外科医生，许多主动的手持器械和机器人系统被开发出来。这些半自动仪器或自动机器人根据术前或术中获得的成像数据（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，并且需要复杂地集成到医疗标准工作流程中。在手动导向仪器的情况下，仅根据过程中获得的数据自动控制一个或两个自由度，情况并非如此。其中一名申请人能够展示基于光的过程测量和控制方法的总体可行性。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，两位申请人能够展示生物阻抗谱（BIS）在手术机器人系统的自动过程控制中的潜力，用于翻修全髋关节置换术中骨水泥去除。本研究计划研究手导向、传感器集成与控制的智能胸骨开颅手术仪器的潜力。因此，必须分析BIS与传感器控制仪器的最佳集成，然后在体外验证其使用。主要的挑战是在切割过程中进行在线BIS测量，以及在外科医生的参与下对仪器进行主动容错控制。研究对象也是将智能器械的高技术精度（基于知识、传感器控制的过程控制）与外科医生的高认知能力相结合，实现对整个过程的控制。这意味着，作为复杂测量过程的补充，主动容错控制的方法，特别是关于协同人机交互的方法，必须在演示系统中实现并最终评估。

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.