Comparison of manual and hydraulically automated actuation for cochlear implant electrode insertion

Introduction Recent studies suggest that slow and steady electrode array (EA) insertion reduces insertion forces and thus intracochlear trauma in cochlear implantation surgery. In order to overcome the natural limitations of manual capabilities we developed a hydraulically actuated insertion tool (Cochlea Hydrodrive, CHD). In this study, we aimed to evaluate the performance of the CHD in terms of steadiness of motion and compared it to manual actuation.

Material and Methods  The motion was evaluated by tracking optical markers fixed to a surgical forceps and to the hydraulic actuator of the CHD respectively. The average velocity as well as the velocity variation was used to characterize the motion in each trial. The manual actuation was performed by six test participants which were instructed to feed an EA through a cylindrical hole as slowly and evenly as possible (6 trials per person). The automated actuation was performed with a target speed of 0.1 mm/s using the CHD system (n = 6).

Results Over all trials with manual actuation, a mean average velocity of 0.59 ± 0.29 mm/s with a mean velocity variation of 0.31 ± 0.15 mm/s was measured. Using the CHD, the target speed was accomplished with an average velocity of 0.1 ± 0.01 mm/s and a velocity variation of 0.02 ± 0.003 mm/s.

Discussion and Conclusion The results show that automatic actuation using the CHD outperforms manual actuation, as motion is possible at a much slower velocity with a substantially improved steadiness. These findings emphasize the limitations of manual actuation and the potential advantages of automated EA insertion with the CHD for future clinical use.

German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) under Germany’s Excellence Strategy – EXC 2177/1 – Project ID 390895286.

Publication History

Article published online:
12 May 2023