Mental Stress Assessment and Clinical Application of Wearable Devices as Evaluable Outcomes in Robotic Prostatectomy

Because of the rapid uptake of robot-assisted radical prostatectomy (RARP), educational programs or established methods based on the skill level and mental stress of surgeons have yet to be established. This study aimed to measure physiologic stress as heart rate (HR) changes and heart rate variations (HRVs) in surgeons wearing a device during RARP.

We collected device data for 30 consecutive cases from surgeon A, relatively inexperienced in RARP, and surgeon B, experienced in over 200 cases. As a wearable device, we used Fitbit Charge 2 (Fitbit Inc., San Francisco, CA, USA). Surgical outcomes included estimated blood loss volume and robotic console time; HR changes and HRVs in each surgeon were measured. The standard deviation of NN intervals (SDNN) for HRV was calculated and cumulative sum (CUSUM) control charts used to quantitatively evaluate surgeons' learning curves.

For surgeon A, as case numbers increased, console time was significantly reduced; maximum and average HRs were also significantly decreased. However, a trend was not observed for surgeon B. The SDNN, as a biomarker of mental stress in surgeon B, was significantly better compared with surgeon A. For surgeon A, according to an analysis using CUSUM methods, and average and maximum HRs, learning curves with regard to console time and estimated blood loss volume were similar.

By using a wearable device, mental stress, as represented by the HRV, could be easily estimated and visualized as a surgical outcome. This affected surgeons' learning curves, including for console time and estimated blood loss volumes.