Three Dimensional Motion Analysis of Hand Tremors During Endoscopic Ear Surgery

[Background] Endoscopic surgery is developing in various clinical specialties. During ear endoscopic surgery, a surgeon has to hold an endoscope with one hand and operate the surgical instruments with another hand. Therefore, the stability of the surgeon’s hand affects the field of surgical view and quality of the surgery considerably. There are few techniques which are used during surgery to stabilize the endoscope. However, no study has evaluated the efficacy of such techniques in detail. This study examined the three dimensional movement of an endoscope to compare and evaluate the effect of various stabilization techniques to reduce the hand tremor while using the endoscope. [Methods] A non-randomized controlled trial involving 15 medical students was conducted in Tottori University, Japan. Subjects held an endoscope with their non-dominant hand and manipulated it using three different stabilization techniques i.e. with resting the elbow on the table, resting the endoscope on the ear canal, both with the elbow on the table and endoscope on the ear canal. For the control, subjects were made to use the endoscope without any stabilization technique. The endoscopic movement was measured with and without using the stabilization techniques. [Results] The results obtained in this study indicated that manipulating the endoscope with resting the elbow on the table restrains both vertical (Y-axis) and optical axis (Z-axis) direction of tremor, and manipulating the endoscope by resting it on the ear canal restrains both vertical (Y-axis) and horizontal axis (X-axis) direction while the combined use of both the techniques reduces the endoscope movement in all the three X, Y and Z axes. [Conclusion] In conclusion, concomitant use of both techniques appears to be clinically beneficial in endoscopic ear surgery.