AR Projections for Eye-gaze Evaluation in Phantoms

NCT07161024 | Completed Results

• 2 other identifiers: 2319971R21EB035783-01
• Study Type: interventional
• Target: 8
• Locations: 1 country
• Sites: 1

Brief Summary

This project aims to develop an augmented reality (AR) tool to enhance skill acquisition for endoscopic kidney stone surgery. Of the 100,000 patients who undergo an endoscopic kidney stone treatment annually in the United States, 25% will require a repeat stone surgery within 20 months of their index surgery. The repeat stone surgery rate is almost completely driven by postoperative residual stone fragments, which lead to ureteral obstruction, causing pain, urinary tract infection, and kidney injury. One significant factor that contributes to residual stone fragments is limited visualization of the entire collecting system - a skill directly associated with surgeon experience. This leads to novice surgeons having a much higher recurrence rate than experienced ones. As the incidence of kidney stone disease continues to increase (prevalence of 10%, incidence of 1116 per 100,000), improved endoscopic surgical training is required to improve outcomes of stone surgeries and minimize complications by improving stone-free rate. Currently, skill assessment during endoscopic stone surgery is limited. There are no objective metrics for endoscopic surgery to assess skill. The only feedback trainees get is in the form of verbal communication from expert surgeons, usually after the conclusion of surgery. Thus, most feedback is synoptic and limited in facilitating skill acquisition. Operative time and patient safety concerns restrict the amount of active, real-time feedback given during a case for skill acquisition. Endoscopic kidney stone surgery is uniquely challenging given the small depth and field of view of current endoscopes, which complicate the complete visualization of the entire collecting system. Navigation of the collecting system relies on mentally mapping preoperative imaging to the endoscopic surgical field. Success in mapping relies on hand-eye coordination, memory, and spatial reasoning, which are gained through practice. Thus, there is a need for tools that facilitate endoscopic surgical skill acquisition. The overarching hypothesis for this research is that surgical skill acquisition and outcomes for endoscopic kidney stone surgery can be improved by analyzing eye gaze data and using expert gaze to guide surgical trainees intraoperatively. Eye gaze guidance has been shown to lead to better skill acquisition in virtual reality surgical tasks compared with motion guidance alone. The proposed system would provide real-time education for trainees during endoscopic stone surgery, such as through head-mounted displays (i.e., the Microsoft HoloLens 2). The investigators have previously demonstrated eye gaze sharing in phantoms. By implementing this system in the operating room (OR), the investigators would be able to instill durable skill acquisition in trainees. The investigators will also implement the NASA-task load index for the trainees to gauge the usability of the system.

Conditions

Kidney Stones

Keywords

Kidney Stones; Augmented Reality; Gaze Guidance

Outcome Measures

Primary Outcomes (1)

• Stone Count

  percentages of stones seen; The NASA Task Load Index (NASA-TLX) assesses participants' subjective workload after completing all tasks under each control method. It includes six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration. Each dimension is rated from 0 to 100, with higher scores indicating greater perceived workload. The overall task load index is calculated as the average of the six dimension scores, resulting in a total score ranging from 0 to 100, where higher scores represent greater overall task load.

  1-10 min

Secondary Outcomes (3)

• Gaze Metrics

  1-10 min

• Completion Time

  1-10 min

• NASA Task Load Index

  1 min

Study Arms (1)

AR Marker Test

EXPERIMENTAL

Each user performs a kidney stone identification task in phantoms with each of three augmented reality markers, and without any marker. The phantoms and markers ordering are randomized to reduce learning effect.

Device: Augmented reality

Interventions

Augmented reality DEVICE

Augmented reality markers of different designs are tested to evaluate how they affect trainee performance.

AR Marker Test

Eligibility Criteria

• Age: 13 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Urology residents at Vanderbilt University Medical Center

Sponsors & Collaborators

• Vanderbilt University Medical Center: lead
• Vanderbilt University: collaborator
• National Institute for Biomedical Imaging and Bioengineering (NIBIB): collaborator

Study Sites (1)

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

Location

MeSH Terms

Conditions

Kidney Calculi

Condition Hierarchy (Ancestors)

Nephrolithiasis; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Urinary Calculi; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Limitations and Caveats

small sample size

Results Point of Contact

• Title: Nicholas kavoussi
• Organization: Vanderbilt University Medical Center

nicholas.l.kavoussi@vumc.org

4434651485

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DEVICE FEASIBILITY
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor Department of Urology

Study Record Dates

• First Submitted: August 29, 2025
• First Posted: September 8, 2025
• Study Start: October 14, 2024
• Primary Completion: February 5, 2025
• Study Completion: February 5, 2025
• Last Updated: April 20, 2026
• Results First Posted: April 20, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ANALYTIC CODE
• Time Frame: The manuscript describing the study method and findings has been accepted for publication and will appear in September. We plan to upload the data to the NIDDK repository by December 2025. We foresee both being available indefinitely.
• Access Criteria: Anyone can access the research manuscript with aggregate results. Access to individual data will be controlled through the NIDDK repository and available only for research purposes.

Locations

US (1)