Kidney StonesNCT07161024
AR Projections for Eye-gaze Evaluation in Phantoms
A study testing Augmented reality in people with Kidney Stones, run by Vanderbilt University Medical Center at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 13 years and olderHealthy volunteers can take part
- Conditions the study is for
- Kidney Stones
- What is being tested?
- Augmented reality
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Oct 2024to 5 Feb 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 13 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Urology residents at Vanderbilt University Medical Center
Who cannot join
- -
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
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.
Read more
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.
Read the detailed description
Specifically for this study, the investigators are asking each participant, all surgical trainees, to explore four phantom kidneys with stones added and count the number of stones. For each kidney phantom, the participants will have either one of three augmented reality markers to show where an expert is looking, or they will not have any visual guidance (standard of care). In all cases, the participants get verbal feedback from the expert surgeon. The goal is to compare the effect of the design of the AR marker on the trainee's performance in exploring the kidney phantom.
- Conditions
- Kidney Stones
- Being tested
- Augmented reality
- Keywords
- Kidney Stones, Augmented Reality, Gaze Guidance
- Medical subject headings
- Kidney Calculi
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Augmented realityDevice
Augmented reality markers of different designs are tested to evaluate how they affect trainee performance.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Device: Augmented reality |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 1-10 min
Secondary outcomes (3)
Gaze Metrics
total area of eye gaze seen, Extracted from eye-camera recording from the HoloLens 2
Measured: 1-10 min
Completion Time
Time for the stone identification task
Measured: 1-10 min
NASA Task Load Index
Conducted after each trial for subjective feedback; Hart and Staveland's NASA Task Load Index (TLX) method assesses work load on five 7-point scales. Increments of high, medium and low estimates for each point result in 21 gradations on the scales. total points 105. mean scores and standard deviation for each arm reported
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.
Measured: 1 min
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Sep 2025
- Study start14 Oct 2024
- Primary completion5 Feb 2025
- Study completion5 Feb 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Kidney StonesStudies of the same condition, open and under way.
- More trials run by Vanderbilt University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Device feasibility
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Vanderbilt University, National Institute for Biomedical Imaging and Bioengineering (NIBIB)
- Responsible party
- Principal investigator, Nicholas Kavoussi, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07161024
- Sponsor's protocol ID
- 231997
- Other IDs
- 1R21EB035783-01
- Status last verified
- Apr 2026
- First submitted
- 29 Aug 2025
- Last updated
- 20 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We will share the endoscope video and eye-gaze information from the study, and associated metadata, including the study protocol.
Study at a glance
From the registry record, last updated by the sponsor on 20 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- AR Projections for Eye-gaze Evaluation in Phantoms
- ClinicalTrials.gov ID
- NCT07161024
- Acronym / sponsor ID
- 231997
- Conditions
- Kidney Stones
- Keywords
- Kidney Stones, Augmented Reality, Gaze Guidance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 8 participants (actual)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Collaborators
- Vanderbilt University, National Institute for Biomedical Imaging and Bioengineering (NIBIB)
- Study start
- 14 Oct 2024 (actual)
- Primary completion
- 5 Feb 2025 (actual)
- Study completion
- 5 Feb 2025 (actual)
- First posted
- 8 Sep 2025 (actual)
- Results
- Posted 20 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Specifically for this study, the investigators are asking each participant, all surgical trainees, to explore four phantom kidneys with stones added and count the number of stones. For each kidney phantom, the participants will have either one of three augmented reality markers to show where an expert is looking, or they will not have any visual guidance (standard of care). In all cases, the participants get verbal feedback from the expert surgeon. The goal is to compare the effect of the design of the AR marker on the trainee's performance in exploring the kidney phantom.
Study design
- Primary purpose
- Device feasibility
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| AR Marker Test | Experimental | Device: Augmented realityEach 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. |
Who may qualify
- Ages
- 13 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- Urology residents at Vanderbilt University Medical Center
Key exclusion criteria (1 listed)
- -
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Augmented realityAugmented reality markers of different designs are tested to evaluate how they affect trainee performance. | Device | AR Marker Test |
Primary outcome
Stone Count
Time frame: 1-10 min
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.
3 secondary outcomes
Gaze Metrics
Time frame: 1-10 min
Completion Time
Time frame: 1-10 min
NASA Task Load Index
Time frame: 1 min
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. We will share the endoscope video and eye-gaze information from the study, and associated metadata, including the study protocol.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Augmented reality in people with Kidney Stones, run by Vanderbilt University Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 20 Apr 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Stone Count (time frame: 1-10 min). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Apr 2026.