Robot-assisted surgery is often portrayed as the ultimate expression of precision medicine: a surgeon seated at a console, controlling miniature instruments that move through tiny incisions with extraordinary accuracy. But behind the technology, the procedure remains a demanding human performance. Surgeons must interpret three-dimensional images, control delicate instruments, anticipate complications, communicate with the operating team, and make high-stakes decisions, often over several continuous hours. A new study suggests that the physical and mental strain of this work can be tracked in real time through a combination of brain, muscle, and heart signals.
The research, published online in Surgical Endoscopy, examined how stress emerged during live robot-assisted operations rather than in a laboratory simulation. A team led by Professor Yoshihiro Shimomura of Chiba University in Japan monitored seven experienced urologists as they performed robot-assisted procedures. The investigators wanted to move beyond broad assessments of surgical workload and identify the physiological changes that occur at specific moments when surgeons themselves feel their stress increasing or decreasing.
Stress is not a single process occurring in one part of the body. It can involve heightened cognitive arousal in the brain, increased muscle activation, and changes in the autonomic nervous system, which regulates functions such as heart rate and circulation. To capture these dimensions simultaneously, the surgeons wore lightweight sensors during their operations. Electroencephalography, or EEG, recorded electrical activity associated with brain function. Surface electromyography, or EMG, measured the activation of muscles in the neck and upper shoulder. Electrocardiography, or ECG, recorded the electrical activity of the heart, allowing the researchers to calculate both heart rate and heart-rate variability.
The study also addressed a major challenge in measuring stress during surgery: asking surgeons to report their feelings in the middle of a procedure could itself disrupt performance. Instead, the researchers used a technique known as video-stimulated recall. After completing an operation, each surgeon watched a recording of the view from the robotic console. While reviewing the footage, the surgeon identified moments when their stress level changed and rated the intensity on a scale from zero to nine. This approach allowed the team to connect physiological data recorded during surgery with the surgeons’ own recollections of stressful events.
Across the seven participants, the researchers analyzed 151 stress-rated moments. Four physiological patterns consistently corresponded with the surgeons’ reported stress levels. A brain-activity pattern associated with mental arousal increased as perceived stress rose. At the same time, activity in the upper shoulder muscles increased, suggesting greater muscular tension even though the surgeons were seated at the console. Heart rate also accelerated, while heart-rate variability declined. Heart-rate variability refers to the natural changes in the time interval between successive heartbeats; reduced variability is commonly associated with increased sympathetic nervous system activation, the body’s rapid-response system during demanding or threatening situations.
The importance of the findings lies in the convergence of these signals. Any one physiological measure can be difficult to interpret on its own. A faster heart rate, for example, might reflect stress, physical movement, caffeine, or other factors. Muscle activity can be influenced by posture, while EEG signals may be affected by movement or the surrounding environment. When changes in brain arousal, shoulder tension, heart rate, and heart-rate variability occur together and align with the surgeon’s own stress report, they provide a more persuasive picture of the demands of a particular operative moment.
According to Professor Shimomura, the study demonstrates that combining surgeon-reported stress annotations with multimodal physiological monitoring is feasible during real robot-assisted surgery. The approach could help researchers identify high-demand moments during postoperative review without interfering with the operation itself. Such moments might involve technically complex maneuvers, unexpected anatomical findings, difficult instrument control, communication challenges, or decisions that require the surgeon to rapidly reassess the situation. The current study did not claim that the physiological signals can independently diagnose stress in every surgeon, but it provides a foundation for developing more precise tools to study it.
The potential applications extend beyond individual surgeons. Physiological measurements could become an outcome for evaluating the entire robotic surgery work system, including the design and ergonomics of the console, communication routines between the surgeon and operating-room staff, workload distribution, procedure-specific difficulty, and the surgeon’s stage of training. If certain equipment configurations or workflow patterns repeatedly coincide with elevated stress, hospitals could redesign the environment to reduce unnecessary strain. Training programs could also use postoperative review to show developing surgeons when their physiological load peaked and how those moments related to surgical decisions or technical performance.
The researchers emphasize that larger studies will be needed before these measurements can be used for real-time clinical interventions. Future investigations involving more hospitals, additional specialties, and surgeons at different levels of experience could clarify how consistently the signals reflect stress across people and procedures. In the longer term, the same technology might support carefully designed safety systems, such as prompting a brief team review during unusually demanding cases or helping instructors provide targeted guidance to trainees. By making the surgeon’s hidden workload more visible, physiological monitoring could help transform robot-assisted surgery from a technology-centered discipline into a more human-centered one—improving surgical performance while protecting the well-being of the people responsible for using these powerful machines.
Subject of Research: People
Article Title: Multimodal physiological correlates of surgeon stress in live robot-assisted surgery
News Publication Date: 30-Jun-2026
Web References: Chiba University news; Professor Yoshihiro Shimomura
References: 10.1007/s00464-026-13054-3
Image Credits: Professor Yoshihiro Shimomura, Chiba University, Japan
Keywords
Robot-assisted surgery, surgeon stress, surgical ergonomics, physiological monitoring, EEG, EMG, ECG, heart-rate variability, robotic surgery, surgical training
Tags: autonomic nervous system changes during surgerybrain muscle heart signals in surgeryChiba University study on surgical stresshigh-stakes decision-making in robotic operationshuman factors in robotic surgeryimpact of stress on robot-assisted surgeryphysiological biomarkers of surgical stressreal-time physiological tracking during robotic proceduresrobotic surgery stress monitoringstress management in minimally invasive surgerysurgeon stress in operating roomsurgeon workload and mental strain
