Ahmed M Zihni, MD, MPH, Jaime A Cavallo, MD, MPHS, Ikechukwu Ohu, BS, Sohyung Cho, PhD, Michael M Awad, MD, PhD. Department of Surgery, Washington University School of Medicine; Department of Engineering, Southern Illinois University Edwardsville.
INTRODUCTION: Surgeons suffer significant ergonomic stress when performing laparoscopic procedures. Robotic surgery has been touted for the potential ergonomic advantages it may offer to surgeons, and subjective reports suggest an ergonomic benefit of the robotic platform. To date, there have been no quantitative studies of the ergonomic differences between the laparoscopic and current robotic surgical platforms. We sought to quantify these differences using surface EMG (sEMG) and the NASA task load index (NTLX). We hypothesized that task performance on a laparoscopic surgical platform will generate significantly higher levels of muscle activation as quantified by sEMG when compared to task performance on the robotic platform. We further hypothesized that significantly higher subjective workload, as quantified by NTLX, would be reported for the laparoscopic platform compared to the robotic platform.
METHODS: Thirty subjects (25 right-hand dominant, 4 left-hand dominant, 1 ambidextrous) with varying levels of surgical experience performed FLS peg transfer (PT), pattern cutting (PC), and intracorporeal suturing (IS) tasks on laparoscopic and robotic platforms. sEMG measurements were obtained from each subject’s bilateral bicep, tricep, deltoid, and trapezius muscles. Mean normalized muscle activation (%MVC) was calculated for each muscle group for each task on each surgical platform. We compared mean %MVC values with paired t-tests and considered differences with a p-value <0.05 to be statistically significant. All subjects also provided responses to the NTLX after task performance on each platform. Mean responses for each domain (mental, physical, temporal, performance, frustration, effort) were compared using paired t-tests.
RESULTS: %MVC data are shown in the table below. Significant differences of subjective workload were noted in the physical demand (59.5 laparoscopic, 24.7 robotic; p<0.001), temporal demand (45.4 laparoscopic, 31.2 robotic; p=0.020), and effort (74.3 laparoscopic, 39.6 robotic; p=0.005) domains of the NTLX.
CONCLUSIONS: Among surgeons of varying levels of experience, laparoscopic task performance generates greater muscle activation in most upper extremity muscle groups when compared to robotic task performance. In simpler tasks (PT, PC), robotic task performance appears to generate greater right trapezius activation compared to laparoscopic task performance. This is not seen in the more complex IS task, suggesting that the ergonomic challenges of laparoscopic surgery are exacerbated by increased task complexity. Subjective workload is also significantly increased by laparoscopic task performance compared to robotic task performance.