Validation of an Ex Vivo Calf Brain Force Detection System for Neurosurgical Simulation Training

Validation of an Ex Vivo Calf Brain Force Detection System for Neurosurgical Simulation Training: A Case Series Study

Neurosurgery is a high-stakes surgical specialty where errors can result in significant patient mortality and morbidity. The amount of force applied on the brain simultaneously by the multiple different instruments during complex neurosurgical procedures is a critical safety metric that, to the investigators' knowledge, has not been previously measured in a realistic operative environment.

The investigators have therefore developed a simulation platform integrating an ex vivo calf brain and a 3D-printed skull model attached to a force sensor capable of capturing real-time forces applied to the brain. A cross-sectional case series study will be conducted to evaluate the validity of the system. Medical students, neurosurgical residents, neurosurgical fellows, and staff neurosurgeons from four Quebec institutions will be recruited to perform three simulated subpial resections each using our ex vivo calf brain simulation platform. The forces applied by the microscissors, bipolar forceps, and ultrasonic aspirator onto the brain will be captured along with kinematic data. This study aims to establish the face, content, construct, and convergent validity of this ex vivo calf brain force detection system.

Study Overview

• Status: Not yet recruiting
• Conditions: Surgical Education
• Intervention / Treatment: Behavioral: Observational

Detailed Description

Background and Rationale: The subpial resection technique is a complex neurosurgical procedure that is essential for brain tumor and epilepsy surgery. However, opportunities for trainees to gain hands-on experience with this procedure without risk to patient safety are limited. The force applied on the brain during tool-tissue contact is a critical factor impacting patient safety. While virtual simulation platforms enable force monitoring, ex vivo animal brains cannot readily capture quantitative data. The investigators have therefore developed a prototype of a simulation platform that integrates a force sensor and a calf brain and can accurately detect real-time forces during simulated subpial resections. This study seeks to investigate the validity of this ex vivo calf brain force detection system.

Hypotheses:

1. The forces applied by instruments on an ex vivo calf brain during simulated subpial resection procedures will significantly differ between novice, intermediate, and expert participants.
2. The ex vivo calf brain force detection system will demonstrate face, content, construct, and convergent validity.
3. Levels of negative emotions, stress, and cognitive load will be greater in surgical trainees compared with experts.

Primary Objective: To measure and compare the forces applied by novice, intermediate, and expert participants during simulated ex vivo subpial resection procedures.

Secondary Objectives:

1. To evaluate the face, content, construct, and convergent validity of the ex vivo calf brain force measurement setup.
2. To determine how the simulation platform influences emotions, stress, and cognitive load of participants of different expertise levels.

Setting: McGill University Montreal Neurological Institute and Hospital.

Participants:

Neurosurgeons (experts): Staff neurosurgeons at McGill University, Université de Montréal, Université de Sherbrooke, or Université Laval specializing in oncology, epilepsy, pediatric, or vascular neurosurgery.

Neurosurgical fellows (trainees): Neurosurgical fellows at McGill University, Université de Montréal, Université de Sherbrooke, or Université Laval specializing in oncology, epilepsy, pediatric, or vascular neurosurgery.

Neurosurgical residents (trainees): Neurosurgical residents at McGill University, Université de Montréal, Université de Sherbrooke, or Université Laval.

Medical students (novices): Students enrolled in medical school at McGill University, Université de Montréal, Université de Sherbrooke, or Université Laval.

Design: A cross-sectional case series study.

Methodology: This study was approved by the McGill University Health Centre Research Ethics Board, Neurosciences-Psychiatry. A case series study will be conducted where medical students, neurosurgical residents, neurosurgical fellows, and staff neurosurgeons from four Quebec institutions will be recruited to perform subpial resection tasks on an ex vivo calf brain model. Calf brains will be placed in a 3D-printed skull model to mimic a realistic human operative environment. The 3D-printed skull model was prototyped from a publicly available CT scan obtained from Embodi3D, an open-access medical imaging repository, and reconstructed in 3D using the open-source software 3D Slicer version 5.10.0. A 6-degree-of-freedom force/torque sensor (Nano17 IP68, ATI Industrial Automation Inc., North Carolina, USA) and a USB data acquisition board (NI-6210, National Instruments Inc., Texas, USA) will be used to measure real-time forces applied to the brain. Participants will use microscissors, bipolar forceps, and a SONOPET ultrasonic aspirator (Stryker, Portage, Michigan, USA) to perform each simulated procedure. All three surgical instruments will be continuously tracked using infrared cameras, allowing kinematic data (velocity, acceleration, and jerk) of each instrument to be derived. The tasks will be performed using an OPMI pico surgical microscope (ZEISS, Jena, Germany) and video-recorded using a Blackfly S GigE embedded microscope camera (FLIR, Wilsonville, Oregon, USA), allowing a broader instrument view for evaluation of tracking data and postoperative performance. Before, during, and after the trial, all participants will self-report their emotions using Medical Emotions Scale (MES) and their stress using the Short Stress State Questionnaire (SSSQ) on 7-point Likert scales. All participants will also report their cognitive load after the trial using the Cognitive Load Index (CLI) on 5-point Likert scales and the NASA Task Load Index (NASA-TLX) on 7-point Likert scales. Expert participants will fill out questionnaires assessing the face and content validity of the ex vivo calf brain force detection setup on 7-point Likert scales. Blinded expert raters will watch the videos of each procedure and grade it using a modified Objective Structured Assessment of Technical Skills (OSATS) rating scale to determine the simulation platform's construct and convergent validity.

Study Procedure: Upon arrival, participants will read and sign an informed consent form. They will then fill out a pre-trial questionnaire assessing their demographic characteristics (e.g., sex, gender, age, institutional affiliation, etc.) as well as their baseline emotions and stress. Each participant will receive standardized written instructions on instrument use and function and presented with an image outlining the location of the three subpial resections on the ex vivo calf brain in front of them. Participants will adjust the operating microscope according to their preferences. The resections will be performed using microscissors to make an initial incision in the pia mater, bipolar forceps to lift the pia, and an ultrasonic aspirator to remove the assigned cortical area. After the first and second tasks, participants will fill out questionnaires assessing their emotions and stress once more. Finally, after the third task, novice and trainee participants will fill out a post-trial questionnaire assessing their emotions, stress, and cognitive load. Expert participants will fill out face and content validity questionnaires, followed by the post-trial questionnaire.

Significance: This study will provide validity evidence to support the educational utility of a novel ex vivo calf brain force detection system using both traditional and contemporary frameworks. For the first time in a realistic operative environment, it will be possible to monitor the force applied on the brain. The force and kinematic data collected from this case series study will be used to build an intelligent tutoring system capable of monitoring performance and mitigating errors during human surgical procedures.

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Bianca Giglio, MSc; Phone Number: 514-802-1608; Email: bianca.giglio@mail.mcgill.ca
• Study Contact Backup: Name: Mohammed Babgi, MD; Email: mohammed.babgi@mail.mcgill.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H3A 2B4
      • Neuro Imaging and Surgical Technologies Lab, Montreal Neurological Institute and Hospital, McGill University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Staff neurosurgeons, neurosurgical fellows, neurosurgical residents, and medical students from four Quebec institutions.

Description

Inclusion Criteria:

• Medical students, neurosurgical residents, neurosurgical fellows, and staff neurosurgeons from one of four Quebec institutions who do not fit the exclusion criteria.

Exclusion Criteria:

• For medical students, participation in a previous trial where they received training on the NeuroVR surgical simulator or the ex vivo calf brain simulation model.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Forces applied to the brain during each simulated subpial resection procedure	Throughout each simulated ex vivo subpial resection procedure, forces applied to the brain during tool-tissue contact will be measured by the force/torque sensor in grams and Newtons. This will enable for the assessment of differences in force applied by novice, intermediate, and expert participants.	1 day of study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Face validity questionnaire responses	Expert participants will fill out face validity questionnaires on 7-point Likert scales after the trial to assess the realism of the simulation platform, with 1 indicating lowest realism and 7 indicating highest realism.	1 day of study
Content validity questionnaire responses	Expert participants will fill out content validity questionnaires on 7-point Likert scales after the trial to assess the educational utility of the simulation platform, with 1 indicating lowest utility and 7 indicating highest utility.	1 day of study
Objective Structured Assessment of Technical Skills (OSATS) scores for each simulated subpial resection procedure	Blinded expert raters will review videos of each procedure and grade them using a modified OSATS rating scale on 7-point Likert scales, with 1 indicating worse performance and 7 indicating better performance. This will allow for the assessment of differences in performance between each expertise group, providing evidence of the platform's construct and convergent validity.	1 day of study
Strength of emotions elicited	Measured using the Medical Emotions Scale (MES) before the trial and after each of three simulated subpial resections. Participants self-reported emotional states via questionnaires on 7-point Likert scales, with 1 indicating lowest intensity and 7 indicating highest intensity.	1 day of study
Levels of stress	Measured using the Short Stress State Questionnaire (SSSQ) before the trial and after each of three simulated subpial resections. Participants self-reported stress states via questionnaires on 7-point Likert scales, with 1 indicating lowest intensity and 7 indicating highest intensity.	1 day of study
Levels of cognitive load	Measured using the Cognitive Load Index (CLI) after the trial. Participants self-reported cognitive load via questionnaires on 5-point Likert scales, with 1 indicating lowest intensity and 5 indicating highest intensity.	1 day of study
Levels of cognitive load	Measured using the NASA Task Load Index (NASA-TLX) after the trial. Participants self-reported cognitive load via questionnaires on 7-point Likert scales, with 1 indicating lowest intensity and 7 indicating highest intensity.	1 day of study

Collaborators and Investigators

• Sponsor: McGill University
• Investigators: Principal Investigator: Rolando F. Del Maestro, MD, PhD, Neurosurgical Simulation and Artificial Intelligence Learning Centre, McGill University; Study Director: Amir Hooshiar, PhD, Surgical Performance Enhancement and Robotics Centre, McGill University; Study Director: Houssem-Eddine Gueziri, PhD, Laboratoire sur la science des données, Université TÉLUQ; Study Director: D. Louis Collins, PhD, Neuro Imaging and Surgical Technologies Lab, McGill University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: December 12, 2025
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 13, 2026

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Surgical Education; Surgical Simulation
• Additional Relevant MeSH Terms: Health Services Administration; Quality of Health Care; Outcome Assessment, Health Care; Outcome and Process Assessment, Health Care; Watchful Waiting
• Other Study ID Numbers: 2018 4395

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data obtained from primary and secondary outcomes may be shared if other researchers have an interest in this data.
• IPD Sharing Time Frame: Data will be available for 5 years following the completion of the trial.
• IPD Sharing Access Criteria: Researchers who wish to access the data must contact the principal investigator of the trial, Dr. Rolando F. Del Maestro.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No