Kidney StonesNCT07173309
Evaluation of Eye Gaze Sharing in the Operating Room
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 18 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
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- 31 Jan 2025to 23 Aug 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Surgeons who are "adult" residents and attending urologists at Vanderbilt University Medical Center in the age range 18 to 65
- Patients who are adults with kidney stones scheduled for endoscopic surgery as clinically indicated.
Who cannot join
- Vulnerable populations, including incarceration status, pregnancy, inability to give informed consent, and serious illness likely to cause death within 5 years
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
We will perform a clinical trial to quantitatively evaluate the benefits of gaze sharing for stone localization in patients. The trainees and experts surgeons will be prospectively randomized into the control and experimental groups. Specifically, each trainee (N=10) will be tasked with stone localization as is standard of care during ten endoscopic stone surgery under the guidance of an expert surgeon. All trainees and experts will wear HoloLens 2s to track their eye gaze. surgeons will review preoperative patient images and the surgical plan to ensure all agree on the surgical plan and no abnormal anatomy is missed. Each trainee and expert surgeon will be tasked with visualizing the entire intrarenal collecting system, including the major branches and renal stones. Each surgeon will visualize the entire collecting system in a retrograde fashion from the proximal ureter successively. To avoid bias, surgeons will be blinded to the surgical monitor while the other surgeon is performing the visualization. While each surgeon is localizing stones, the HoloLens 2 will collect eye gaze data. After completion of stone localization, the remainder of the case will proceed as is standard of care. The trainees and experts in the control group's HoloLenses will not show any augmentation, but trainees in the control group will receive verbal feedback from an expert surgeon as is standard procedure. Additionally, we will validate eye gaze metrics in the control group (i.e., the primary outcome being the gaze area of interest, as well as the number of gaze fixations, fixation times, and fixation points outside the area of interest, as well as total localization time). In the experimental group, the trainees' HoloLenses will project the AR display in addition to verbal feedback from the expert surgeon. Each trainee will perform stone localization in six separate patients with either solely verbal (control group) or verbal and gaze guidance to test skill acquisition (expert group). Then, the trainees will perform stone identification in four additional patients without guidance. After localization, the remainder of the case will continue as is standard of care. After the first six patients, each trainee in both groups will perform the same visualization task on four new patients with only verbal guidance.
The intervention is only during the kidney exploration phase of the surgery. The augmented reality is turned off during the rest of the surgery, which proceeds per standard of care. The study is designed to measure the total percentage of intrarenal collecting system surface visualized during all ten surgeries to assess skill acquisition in addition to gaze data. Additionally, we will measure if there is a significant difference between the performance of each group in the last four surgeries.
Patients will undergo endoscopic stone surgery by urologic surgeons via standard of care. In the current paradigm, expert surgeons teach trainees in real-time during the surgery to develop surgical competency. An augmented reality-based gaze-sharing system deployed on Microsoft HoloLens 2 will be used to evaluate surgical competency and provide a novel method of surgical education. As the data will be passively collected, the expert surgeon will not be affected by the system and the current standard of practice will not change. Furthermore, validation of eye gaze data and guidance will be done post hoc, so there is no impact on operative time. All surgeries will be performed with a Storz Flex XC ureteroscope. Videos will be recorded via Karl Storz StreamConnect--a centralized, cloud-based, secure surgical video platform. No clinical information regarding patients will be recorded.
The goal is to analyze at least 100 datasets of trainee and expert's eye-gaze sharing data in the OR. If patients need operation on both kidneys, it will count as 2 datasets of surgeon's eye-gaze sharing data for data analysis purposes. Thus, we may end up enrolling slightly fewer than 100 patients. All endoscopic videos will be recorded and analyzed postoperatively. Further validation of eye tracking will be done post hoc, to minimize the impact on operative time.
SUMMARY: In this clinical trial, the investigators are asking surgical trainees and experts to wear the HoloLens 2 in the operating room while conducting kidney stone surgery on consenting patients (~N of 100) enrolled for this study. The investigators measure the eye gaze data of the trainee and expert using the HoloLens. In the experimental arm of the trial, the trainees get visual guidance through a hologram showing the expert's gaze in addition to the verbal guidance as their standard of care. The intervention is only on the surgeons during the kidney exploration phase of the surgery. The augmented reality is turned off during the rest of the surgery, which proceeds per standard of care.
- 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 show the surgical trainee the expert's gaze location during the kidney exploration phase of surgery.
| Study group | Role | What they receive |
|---|---|---|
| AR guided | Experimental | Trainees can see experts' gaze through the HoloLens Receives: Device: Augmented reality |
| Non-AR guided | No intervention | Trainees cannot see experts' gaze through the HoloLens. This should be the standard of care control group. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Completeness of kidney exploration
Percentage of kidney that was visualized
Measured: 1-10 minutes
Secondary outcomes (1)
Gaze path of the user while performing kidney exploration
Extracted from eye-camera recording from the HoloLens 2
Measured: 1-10 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2025
- Study start31 Jan 2025
- Primary completion23 Aug 2026
- Study completion23 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 100 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute for Biomedical Imaging and Bioengineering (NIBIB), Vanderbilt University
- Responsible party
- Principal investigator, Nicholas Kavoussi, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07173309
- Sponsor's protocol ID
- 231997B
- Other IDs
- 1R21EB035783-01
- Status last verified
- Sep 2026
- First submitted
- 29 Aug 2025
- Last updated
- 24 Sep 2026
- Results posted
- No
- 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 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Eye Gaze Sharing in the Operating Room
- ClinicalTrials.gov ID
- NCT07173309
- Acronym / sponsor ID
- 231997B
- Conditions
- Kidney Stones
- Keywords
- Kidney Stones, Augmented Reality, Gaze Guidance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Collaborators
- National Institute for Biomedical Imaging and Bioengineering (NIBIB), Vanderbilt University
- Study start
- 31 Jan 2025 (actual)
- Primary completion
- 23 Aug 2026 (actual)
- Study completion
- 23 Aug 2026 (actual)
- First posted
- 15 Sep 2025 (actual)
- Results
- Not posted in the source record
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
We will perform a clinical trial to quantitatively evaluate the benefits of gaze sharing for stone localization in patients. The trainees and experts surgeons will be prospectively randomized into the control and experimental groups. Specifically, each trainee (N=10) will be tasked with stone localization as is standard of care during ten endoscopic stone surgery under the guidance of an expert surgeon. All trainees and experts will wear HoloLens 2s to track their eye gaze. surgeons will review preoperative patient images and the surgical plan to ensure all agree on the surgical plan and no abnormal anatomy is missed. Each trainee and expert surgeon will be tasked with visualizing the entire intrarenal collecting system, including the major branches and renal stones. Each surgeon will visualize the entire collecting system in a retrograde fashion from the proximal ureter successively. To avoid bias, surgeons will be blinded to the surgical monitor while the other surgeon is performing the visualization. While each surgeon is localizing stones, the HoloLens 2 will collect eye gaze data. After completion of stone localization, the remainder of the case will proceed as is standard of care. The trainees and experts in the control group's HoloLenses will not show any augmentation, but trainees in the control group will receive verbal feedback from an expert surgeon as is standard procedure. Additionally, we will validate eye gaze metrics in the control group (i.e., the primary outcome being the gaze area of interest, as well as the number of gaze fixations, fixation times, and fixation points outside the area of interest, as well as total localization time). In the experimental group, the trainees' HoloLenses will project the AR display in addition to verbal feedback from the expert surgeon. Each trainee will perform stone localization in six separate patients with either solely verbal (control group) or verbal and gaze guidance to test skill acquisition (expert group). Then, the trainees will perform stone identification in four additional patients without guidance. After localization, the remainder of the case will continue as is standard of care. After the first six patients, each trainee in both groups will perform the same visualization task on four new patients with only verbal guidance.
The intervention is only during the kidney exploration phase of the surgery. The augmented reality is turned off during the rest of the surgery, which proceeds per standard of care. The study is designed to measure the total percentage of intrarenal collecting system surface visualized during all ten surgeries to assess skill acquisition in addition to gaze data. Additionally, we will measure if there is a significant difference between the performance of each group in the last four surgeries.
Patients will undergo endoscopic stone surgery by urologic surgeons via standard of care. In the current paradigm, expert surgeons teach trainees in real-time during the surgery to develop surgical competency. An augmented reality-based gaze-sharing system deployed on Microsoft HoloLens 2 will be used to evaluate surgical competency and provide a novel method of surgical education. As the data will be passively collected, the expert surgeon will not be affected by the system and the current standard of practice will not change. Furthermore, validation of eye gaze data and guidance will be done post hoc, so there is no impact on operative time. All surgeries will be performed with a Storz Flex XC ureteroscope. Videos will be recorded via Karl Storz StreamConnect--a centralized, cloud-based, secure surgical video platform. No clinical information regarding patients will be recorded.
The goal is to analyze at least 100 datasets of trainee and expert's eye-gaze sharing data in the OR. If patients need operation on both kidneys, it will count as 2 datasets of surgeon's eye-gaze sharing data for data analysis purposes. Thus, we may end up enrolling slightly fewer than 100 patients. All endoscopic videos will be recorded and analyzed postoperatively. Further validation of eye tracking will be done post hoc, to minimize the impact on operative time.
SUMMARY: In this clinical trial, the investigators are asking surgical trainees and experts to wear the HoloLens 2 in the operating room while conducting kidney stone surgery on consenting patients (~N of 100) enrolled for this study. The investigators measure the eye gaze data of the trainee and expert using the HoloLens. In the experimental arm of the trial, the trainees get visual guidance through a hologram showing the expert's gaze in addition to the verbal guidance as their standard of care. The intervention is only on the surgeons during the kidney exploration phase of the surgery. The augmented reality is turned off during the rest of the surgery, which proceeds per standard of care.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| AR guided | Experimental | Device: Augmented realityTrainees can see experts' gaze through the HoloLens |
| Non-AR guided | No intervention | –Trainees cannot see experts' gaze through the HoloLens. This should be the standard of care control group. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Surgeons who are "adult" residents and attending urologists at Vanderbilt University Medical Center in the age range 18 to 65
- Patients who are adults with kidney stones scheduled for endoscopic surgery as clinically indicated.
Key exclusion criteria (1 listed)
- Vulnerable populations, including incarceration status, pregnancy, inability to give informed consent, and serious illness likely to cause death within 5 years
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 show the surgical trainee the expert's gaze location during the kidney exploration phase of surgery. | Device | AR guided |
Primary outcome
Completeness of kidney exploration
Time frame: 1-10 minutes
Percentage of kidney that was visualized
1 secondary outcome
Gaze path of the user while performing kidney exploration
Time frame: 1-10 minutes
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
- 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 2 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 24 Sep 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Completeness of kidney exploration (time frame: 1-10 minutes). 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 24 Sep 2026; AzTrials last refreshed its copy on 7 Nov 2026.