Hand Versus Foot Controls for Robotic Surgery Simulation

Study Rationale and Scientific Background Surgical techniques have evolved from conventional open surgery to minimally invasive laparoscopic approaches, which reduce surgical trauma, postoperative pain, and length of hospital stay. Despite these advancements, complex operations remain time-consuming and physically demanding, placing significant ergonomic strain on surgeons. Robotic-assisted surgery addresses these limitations by enhancing precision, improving visualization, and optimizing ergonomics.[4] As robotic platforms become integrated into modern surgical practice, trainees face exposure to these systems early in their careers. Effective use of robotic technology requires motor and cognitive skills that differ fundamentally from open or laparoscopic approaches.[7] Among these skills, mastery of clutch control plays a pivotal role in ensuring efficient instrument positioning, maintaining a stable working posture, and minimizing unnecessary movements.[6,8,10] Inappropriate or inefficient clutch use can disrupt surgical workflow, increase cognitive workload, prolong task completion time, and contribute to early operator fatigue.[3,6] These challenges are particularly evident during the initial learning phase of robotic surgery. Inefficiencies during this early period have downstream clinical implications, as increased operative time, excessive instrument movement, and higher cognitive workload are associated with technical errors, surgeon fatigue, and potentially compromised patient safety.[1,5] Optimizing fundamental console skills like clutch control may improve simulator performance and contribute to safer, more efficient operative performance in clinical practice.[7,10] Foundational habits established early may persist throughout a surgeon's career, making early training critical.

Modern platforms like the Da Vinci Xi system offer multiple clutch control modalities, most commonly the hand clutch and the foot clutch. Previous simulation research has primarily focused on validating simulator platforms, assessing general psychomotor skill acquisition, or comparing novice and expert performance. Few investigations have specifically examined how different clutch control modalities influence performance metrics during early skill acquisition, as existing literature largely evaluates overall proficiency rather than isolating clutch control as a specific technical component. Consequently, the relative advantages of hand clutch versus foot clutch in facilitating efficient instrument repositioning and minimizing cognitive workload remain poorly defined. Additionally, prior studies often include heterogeneous participant groups with varying laparoscopic or robotic exposure, making it difficult to isolate the true effect of clutch modality on individuals without prior robotic experience. Clarifying this effect in true novice users is essential for developing structured training curricula.

Definitions for Intervention Group

The trial isolates and compares the two distinct control interfaces provided by the Da Vinci Xi console for instrument clutching:

• Hand Clutch group This control utilizes a dedicated finger clutch button located on the master controllers. Proper execution requires the user to place their thumb and middle finger into the Velcro loops of the controllers, leaving the index finger free to manipulate the button. To execute a clutch, the user must pull back the button and hold it, move their hand to the desired ergonomic location, and then release the button to re-engage instrument control. This modality allows for the repositioning of individual hands independently to optimize workspace placement.
• Foot Clutch group: This control utilizes the footswitch panel located at the base of the console. The master clutch pedal allows for the simultaneous repositioning of both hands without moving the surgical instruments. Depressing the pedal disengages the master controllers from the instrument arms, allowing the user to reposition their hands to a neutral, ergonomic posture before releasing the pedal to resume active manipulation.

Phase I: Enrollment, Baseline, and Practice Session All prospective participants undergo an initial screening phase. Eligible surgical trainees from participating specialties (general surgery, obstetrics and gynecology, urology, cardiothoracic surgery, and pediatric surgery) are brought into the simulation suite outside of regular academic or clinical working hours (specifically between 16:00 and 18:00 on weekdays or 08:00 and 16:00 on weekends) to prevent clinical conflicts.

Upon entering the study, participants complete a baseline questionnaire requiring approximately 5 to 10 minutes to capture demographic data, including sex, age, year of residency or fellowship training, and verification of zero prior robotic surgical experience.

Following the baseline documentation, a standardized pre-simulation orientation is provided by the research staff for 10 to 15 minutes. This orientation features a scripted introduction to the Da Vinci Xi console architecture, a detailed mechanical explanation of both the hand clutch and foot clutch mechanisms, and a live or recorded demonstration of the designated clutch simulation task.

Participants then initiate an equal-exposure practice session lasting approximately 20 minutes. During this session, every participant is required to perform exactly two practice attempts using the hand clutch configuration and exactly two practice attempts using the foot clutch configuration. This ensures all individuals possess identical baseline mechanical familiarity with both interfaces prior to the trial washout period. A designated question and clarification period concludes the session, allowing participants to ask specific questions about the console or software mechanics to ensure complete understanding.

Phase II: Washout Period and Experimental Testing To minimize the immediate learning effects and psychomotor memory carryover from the practice session, a strict one-week interval is enforced for all participants.

Upon returning exactly one week later for their formal testing session, individual group allocation is determined using a concealed randomization process: participants draw a sealed envelope that assigns them to either Group A (Hand Clutch) or Group B (Foot Clutch).

The experimental testing phase is conducted individually at the Da Vinci Xi surgical console. The software environment initializes a standardized, automated clutch simulation module. Participants must perform the task utilizing exclusively their assigned clutch modality; inter-group cross-contamination or utilization of the alternative clutch interface is strictly prohibited. The test is executed exactly once per participant over a duration of approximately 10 minutes.

To ensure safety and uniform testing conditions, a research staff member remains present throughout the simulation to monitor for physical symptoms, system errors, or protocol deviations, and to provide technical assistance if required. The simulator tracking software records all motion, error, and time variables directly from the console architecture.

Immediately following the simulation test, participants complete a post-simulation satisfaction questionnaire. This 5-minute psychometric assessment uses a 5-point Likert scale (ranging from 1: Strongly Disagree to 5: Strongly Agree) to evaluate subjective domains, specifically user-reported ease of use, physical comfort during manipulation, intuitive learning difficulty, precise instrument control, and overall satisfaction with the assigned modality.

Risk Alleviation and Safety Protocol The simulation testing involves minimal risk; however, localized physical and psychological discomforts may occur. Anticipated risks include localized muscle fatigue or strain within the hands, arms, or feet due to repetitive simulator control manipulation. Eye strain or visual fatigue may arise from continuous focus within the console's 3D viewer, and mild dizziness or tension headaches can occur during continuous simulator operation. Additionally, participants may experience psychological discomfort or performance-related stress stemming from perceived evaluation anxiety.

To mitigate these risks, the investigator or a trained research assistant remains positioned adjacent to the console throughout the session to actively monitor the participant for objective indicators of distress, vertigo, or physical exhaustion. The protocol restricts the duration of active testing, and participants maintain the absolute right to pause, suspend, or permanently terminate the simulation at any point if they experience physical discomfort or performance anxiety.

If a participant flags symptoms, standard basic supportive care is deployed immediately, including providing a dedicated resting area, drinking water, and clinical monitoring of their condition. In instances where minor symptoms do not quickly resolve, the individual's participation is discontinued.

To protect against coercion or academic pressure, recruitment is conducted solely via general electronic announcements or public notices rather than direct supervisor invitations. Participants are explicitly informed during consent that their objective performance metrics are entirely confidential, will not be shared with instructors or authorities, and hold no bearing on their academic evaluations, clinical training assessments, or professional status within the university.

Inclusion criteria

• Active surgical trainees (residents or fellows) currently enrolled in a recognized surgical specialty program, including general surgery, obstetrics and gynecology, urology, cardiothoracic surgery or pediatric surgery, at Prince of Songkla University
• Complete absence of prior hands-on experience performing clinical robotic surgery or undergoing formalized robotic simulator training

Exclusion criteria

• Pre-existing physical, orthopedic, or neurological conditions that impair standard motor function of the upper or lower limbs, including active movement disorders or motor control deficits capable of confounding objective simulation performance metrics.