内視鏡手術への適用を目指した切削・研削ハイブリッド型ドリルの骨除去メカニズムの検討

抄録

Meticulous manipulation is required for bone resection performed in the vicinity of critical organs, such as in spinal surgery. On the other hand, it is also important to perform bone resection in a shorter amount of time, as the longer the procedure, the greater the burden on both the patient and the physician. Until now, two types of tools have been used in bone resection depending on their purpose. One is a cutting tool with high removal efficiency but poor operability. The other is a grinding tool with excellent operability but low removal efficiency. However, it is undesirable to extend the procedure time to switch tools during surgery. Therefore, a tool combining both cutting and grinding mechanisms was used for orthogonal cutting experiments to investigate whether this tool could achieve both high operability and removal efficiency. In the experiment, porcine cortical bone was cut using an SUS440C tool with a diamond grinding wheel electroplated on the tip. The workpiece was tilted and fixed on a table driven by a linear motor so that the cutting depth would increase monotonically. By examining the state of the chips and the cutting force, we found that transitioning from grinding to cutting is possible by increasing the cutting depth. However, a cutting depth of 60 µm required for transitioning to cutting is quite large, and considering the conditions of the rotating tool, the operator would have to handle the tool at speeds several times faster than conventional methods. Therefore, it was found that for adaptation to endoscopic surgical tools, a mechanism that allows the transition from grinding to cutting under more practical conditions is necessary.