Investigation of methods and materials for individually mouldable micro-stereotactic frame

外科手术的各个领域都在不断进步，不断减少侵入性，并不断提高准确性要求，这使得外科医生通过辅助系统的支持越来越不可或缺。然而，这些系统通常又大又贵（如手术机器人），或者不够精确（如图像引导手术系统）。此外，这些干预措施中有相当一部分的特点是定位任务相对简单。为此，小型化的立体定向框架可能是合适的。在这个跨学科的研究项目中，应该开发一个可单独成型的仪器指南的新概念，并系统地评估其准确性和临床处理。总体目标是使外科工作人员能够在完全无菌的过程中直接在手术室中构建定位辅助装置，并具有直观且易于学习的手动步骤，以便立即为特定患者使用。这样做，将来人们应该能够在没有昂贵和复杂的辅助设备的情况下生活。因此，在这个项目中明确地探索了简化的局限性，同时牢记最高的精度要求。在项目开始时，将选择合适的材料（建模化合物，粘合剂等），并在基本实验中评估可实现的精度，术中处理以及个体建模和硬化的时间。此外，设计和精度之间的因果关系将根据实验结果进行调查。在项目的进一步过程中，这些一般性的见解将应用于新型微立体定向框架的开发过程，重点是最大的精度和最好的简单性。在最后的一系列实验中，首先使用人造颅骨模型，然后使用人类颞骨标本，系统将根据满足规定的要求进行计量评估，并进行临床评分。本基础研究与开发以微创人工耳蜗植入术作为复杂手术任务的具体实例，旨在回答以简单、低技术水平为特征的辅助系统是否适合（选定）高精度干预的问题。此外，这些发现可以得出结论，这种微立体定向框架适用于哪种类型的手术干预-以及对安全限度简化的不可接受的限制。

The ongoing progress in all fields of surgery with continuously minimized invasiveness and with ever increasing accuracy requirements makes support of the surgeon through assistance systems increasingly indispensable. However, these systems are often large and expensive (such as surgical robots) or not sufficiently accurate (such as image-guided surgery systems). In addition, a relevant proportion of these interventions are characterized by a comparatively simple positioning task. For this purpose, miniaturized stereotactic frames could be appropriate. Within this interdisciplinary research project, a new concept for an individually mouldable instrument guide should be developed and evaluated systematically regarding accuracy and clinical handling. The overall objective is to enable the surgical staff to build the positioning aid directly in the operating room in a completely sterile process with intuitive and easy to learn manual steps for an immediately use for the particular patient. Doing so one should be able to get along without expensive and complex assistance devices in the future. Therefore, the limits of simplification are explored explicitly in this project – while keeping in mind highest accuracy requirements at the same time.At the beginning of the project suitable materials (modeling compounds, adhesives, etc.) will be selected and evaluated in basic experiments regarding achievable accuracy, intraoperative handling, and time for individual modeling and hardening. In addition, the causal linkage between design and accuracy will be investigated based on experimental results. In the further course of the project, these general insights are going to be applied for the development process of a novel micro-stereotactic frame with focus on maximum accuracy and the best possible simplicity. In final series of experiments, first using artificial skull phantoms, later human temporal bone specimens, the system will be metrologically evaluated in terms of fulfilling the stated requirements as well as rated clinically. This basic research and development is carried out using minimally invasive cochlear implantation surgery as a concrete example of a sophisticated surgical task in order to answer the question whether an assistance system characterized by simplicity and low level of technology is suitable for (selected) high-precision interventions. Additionally, these findings allow to conclude for which type of surgical interventions such micro-stereotactic frames are suitable – and for which unacceptable curtailments of safety limit simplification.