<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Varun Singh | HXI - Human-centered eXtended Intelligence</title><link>https://hxi.ucsd.edu/people/varun-singh/</link><atom:link href="https://hxi.ucsd.edu/people/varun-singh/index.xml" rel="self" type="application/rss+xml"/><description>Varun Singh</description><generator>Wowchemy (https://wowchemy.com)</generator><language>en-us</language><copyright>HXI@UCSD © 2026</copyright><lastBuildDate>Wed, 16 Sep 2026 00:00:00 +0000</lastBuildDate><image><url>https://hxi.ucsd.edu/media/icon_hub6a2eb0317e2e2dd65a7870f7c4d84f3_27087_512x512_fill_lanczos_center_3.png</url><title>Varun Singh</title><link>https://hxi.ucsd.edu/people/varun-singh/</link></image><item><title>Contouring for Radiation Oncology: Interactive Training and Feedback</title><link>https://hxi.ucsd.edu/project/contouring/</link><pubDate>Thu, 23 Sep 2021 00:00:00 +0000</pubDate><guid>https://hxi.ucsd.edu/project/contouring/</guid><description>&lt;hr>
&lt;h3 id="overview">Overview&lt;/h3>
&lt;p>Treating patients with safe and effective radiation therapy depends critically on the precise identification of tumor and nearby normal tissues. This process, known as contouring, refers to identifying and outlining cancer and normal tissues in medical images.&lt;/p>
&lt;p>Poor radiation planning has detrimental consequences on patient well-being. Radiation plans that deviate from protocol specifications have substantially decreased survival compared to patients with compliant radiation plans. Given the impact of contouring on patient outcomes, many contouring resources exist. However, practice guidelines rarely translate into real-world clinical practices, primarily due to ineffective methods of development, delivery, and access.&lt;/p>
&lt;p>In collaboration with the department of Radiation Medicine at UCSD, we work to replace the traditional one-to-one apprenticeship model with training that is personalized, timely, and available whenever a resident is ready to practice. Three systems carry that agenda.&lt;/p>
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&lt;h3 id="icontour">iContour&lt;/h3>
&lt;p>&lt;strong>iContour&lt;/strong> is a web-based contouring platform that presents anonymized DICOM cases and gives residents immediate, structured feedback as they delineate. It grew out of needfinding with residents and attendings about when and how contouring feedback actually reaches a trainee, and out of measurements showing that everyday touch devices are accurate enough for real delineation work.&lt;/p>
&lt;p>A randomized international trial of iContour has now completed. Secondary analyses of that trial characterize the specific, site-dependent mistakes residents make before and after their clinical rotations, showing that contouring errors are predictable rather than idiosyncratic.&lt;/p>
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&lt;h3 id="vrcontour">VRContour&lt;/h3>
&lt;p>&lt;strong>VRContour&lt;/strong> asks what contouring becomes when the anatomy is no longer flat. Residents and attendings work slice by slice on 2D displays even though the structures they are outlining are volumetric. VRContour brings delineation into virtual reality, with sketching techniques designed for 3D exploration and annotation of medical images, and studies which parts of the task actually benefit from immersion.&lt;/p>
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&lt;h3 id="icontutor">iConTutor&lt;/h3>
&lt;p>&lt;strong>iConTutor&lt;/strong> is the next stage. Where iContour delivered practice and feedback, iConTutor aims to turn that into personalized tutoring: using the errors a trainee actually makes, at the disease site they are actually rotating through, to decide what feedback they should see and when.&lt;/p>
&lt;p>The completed trial and the mistake analyses are the evidence base. Because errors are predictable and site-dependent, targeted automated tutoring becomes plausible where generic feedback would not be.&lt;/p>
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&lt;h3 id="funding-and-external-collaborations">Funding and External Collaborations&lt;/h3>
&lt;p>iContour is funded by Agency for Healthcare Research and Quality (AHRQ). It is a collaboration between the &lt;a href="https://hxi.ucsd.edu" target="hxi-external" rel="noopener">HXI Lab&lt;/a> and a number of radiation oncology faculty and residents at UCSD school of medicine.&lt;/p>
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&lt;img src="https://hxi.ucsd.edu/images/ucsd_som.jpg" style="height: 150px;">
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&lt;/div></description></item><item><title>Designing and Studying eXtended Reality</title><link>https://hxi.ucsd.edu/project/extended-reality/</link><pubDate>Wed, 16 Sep 2026 00:00:00 +0000</pubDate><guid>https://hxi.ucsd.edu/project/extended-reality/</guid><description>&lt;hr>
&lt;h3 id="overview">Overview&lt;/h3>
&lt;p>The lab&amp;rsquo;s applied XR work lives in its own projects: surgical telementoring in &lt;a href="https://hxi.ucsd.edu/project/artemis/">ARTEMIS&lt;/a>, holographic stroke assessment in &lt;a href="https://hxi.ucsd.edu/project/holostroke/">HoloStroke&lt;/a>, delineation training in &lt;a href="https://hxi.ucsd.edu/project/contouring/">Contouring&lt;/a>, remote guidance in &lt;a href="https://hxi.ucsd.edu/project/eXtended-collaboration/">eXtended Collaboration&lt;/a>. This project holds the work where the headset itself is the object of study.&lt;/p>
&lt;p>One line concerns XR as a design medium. Immersive interfaces raise questions that flat displays do not: how precisely a person can draw a non-planar curve in mid-air and whether a pen, a controller, or bare hands support that best; where a step of an instruction should sit so it is readable without occluding the object it refers to; how a user interface should be laid out when the interface occupies the room. &lt;strong>PintAR&lt;/strong> lets designers sketch spatial experiences in the space where they will be used, and &lt;strong>HoloCPR&lt;/strong> places resuscitation guidance on the patient. &lt;strong>AcuVR&lt;/strong> takes the same approach to acupuncture training, where students currently learn from 2D atlases and practice on peers: it simulates customized scenarios from medical imaging and standardized anatomy models, including the sensitive areas that make practice on a person risky.&lt;/p>
&lt;p>A second line uses XR as a research instrument. A headset reproduces the same situation for every participant, under experimental control, which makes it a measurement tool. A VR paradigm presents alcohol cues in three dimensions and measures attentional bias toward them, which flat pictorial cues cannot elicit. Wheelchair users explore high-fidelity replicas of physical spaces as embodied avatars, assessing accessibility themselves before travelling. Both studies obtain observations that the real setting would make impractical or unsafe.&lt;/p>
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&lt;h3 id="collaborations">Collaborations&lt;/h3>
&lt;p>This work spans collaborations with UC San Diego Anesthesiology and the School of Medicine, the Department of Psychiatry, &lt;a href="https://research.adobe.com/" target="hxi-external" rel="noopener">Adobe Research&lt;/a>, UCLA, and Carnegie Mellon University.&lt;/p>
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&lt;img src="https://hxi.ucsd.edu/images/CSE.jpg" style="height: 80px;">
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&lt;/div></description></item><item><title>Investigating Input Modality and Task Geometry on Precision–first 3D Drawing in Virtual Reality</title><link>https://hxi.ucsd.edu/publication/2022-chen-ismar-precision-first-drawing/</link><pubDate>Fri, 14 Oct 2022 00:00:00 +0000</pubDate><guid>https://hxi.ucsd.edu/publication/2022-chen-ismar-precision-first-drawing/</guid><description/></item><item><title>VRContour - Bringing Contour Delineations of Medical Structures Into Virtual Reality</title><link>https://hxi.ucsd.edu/publication/2022-chen-ismar-vrcontour/</link><pubDate>Fri, 14 Oct 2022 00:00:00 +0000</pubDate><guid>https://hxi.ucsd.edu/publication/2022-chen-ismar-vrcontour/</guid><description/></item><item><title>Exploring Needs and Design Opportunities for Virtual Reality-based Contour Delineations of Medical Structures</title><link>https://hxi.ucsd.edu/publication/2022-chen-eics-vrcontour/</link><pubDate>Tue, 21 Jun 2022 00:00:00 +0000</pubDate><guid>https://hxi.ucsd.edu/publication/2022-chen-eics-vrcontour/</guid><description/></item></channel></rss>