Development of subliminal persuasion system to improve the upper limb posture in laparoscopic training: a preliminary study

Abstract

give advice on improving trainees' posture. However, a poor posture can result in increased static muscle loading, faster fatigue, and impaired psychomotor task performance. In this paper, the authors propose a method, named subliminal persuasion, which gives the trainee real-time advice for correcting the upper limbs posture during laparoscopic training like the expert but leads to a lower increment in the workload.Methods: A 9-axis Inertial Measurement Unit (IMU) was used to compute the upper limbs posture, and a Detection Reaction Time (DRT) device was developed and used to measure the workload. A monitor displayed not only images from laparoscope, but also a visual stimulus, a transparent red cross superimposed to the laparoscopic images, when the trainee had incorrect upper limbs posture. One group was exposed, when their posture was not correct during training, to a short (about 33 ms) subliminal visual stimulus. The control group instead was exposed to longer (about 660 ms) supraliminal visual stimuli.Results: We found that subliminal visual stimulation is a valid method to improve trainees' upper limbs posture during laparoscopic training. Moreover, the additional workload required for subconscious processing of subliminal visual stimuli is less than the one required for supraliminal visual stimuli, which is processed instead at the conscious level. Conclusions:We propose subliminal persuasion as a method to give subconscious real-time stimuli to improve upper limbs posture during laparoscopic training. Its effectiveness and efficiency were confirmed against supraliminal stimuli transmitted at the conscious level: subliminal persuasion improved upper limbs posture of trainees, with a smaller increase on the overall workload.

Impact of Obesity on Surgeon Ergonomics in Robotic and Straight-Stick Laparoscopic Surgery

“…WMS risk and surgeon longevity are vital for service provision, especially with the increasing feminisation of the medical work force, and consideration is needed when designing surgical instruments so that the characteristics of the surgeons who will be using them in the future are taken into account. The information gained from IMU/EMG analysis could be used to develop training tools in order to encourage surgeons to adopt better working practices, such as subliminal visual stimulation, which has been successfully used to improve the upper limb posture in SS training [9].…”

“…Specifically designed theatre suites have been shown to improve the ergonomics of MIS and consequentially impact on surgeons' neck posture [5], however such facilities are not available to every surgeon performing MIS. Other techniques have been explored with the aim of reducing WMS, include video assessment with feedback [6], teaching coping techniques and awareness [7], a physical ergonomic body support [8] and subliminal visual stimulation [9], with varying success.…”