{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T23:39:41Z","timestamp":1773790781102,"version":"3.50.1"},"reference-count":52,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2024,7,26]],"date-time":"2024-07-26T00:00:00Z","timestamp":1721952000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"U.S. Food and Drug Administration through the Center of Excellence in Regulatory Science and Innovation","award":["R01EY031731"],"award-info":[{"award-number":["R01EY031731"]}]},{"name":"National Eye Institute\/National Institutes of Health","award":["R01EY031731"],"award-info":[{"award-number":["R01EY031731"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Impaired retinal blood flow is associated with ocular diseases such as glaucoma, macular degeneration, and diabetic retinopathy. Among several ocular imaging techniques developed to measure retinal blood flow both invasively and non-invasively, adaptive optics (AO)-enabled scanning laser ophthalmoscopy (AO-SLO) resolves individual red blood cells and provides a high resolution with which to measure flow across retinal microvasculature. However, cross-validation of flow measures remains a challenge owing to instrument and patient-specific variability in each imaging technique. Hence, there is a critical need for a well-controlled clinical flow phantom for standardization and to establish blood-flow measures as clinical biomarkers for early diagnosis. Here, we present the design and validation of a simple, compact, portable, linear flow phantom based on a direct current motor and a conveyor-belt system that provides linear velocity tuning within the retinal microvasculature range (0.5\u20137 mm\/s). The model was evaluated using a sensitive AO-SLO line-scan technique, which showed a &lt;6% standard deviation from the true velocity. Further, a clinical SLO instrument showed a linear correlation with the phantom\u2019s true velocity (r2 &gt; 0.997). This model has great potential to calibrate, evaluate, and improve the accuracy of existing clinical imaging systems for retinal blood flow and aid in the diagnosis of ocular diseases with abnormal blood flow.<\/jats:p>","DOI":"10.3390\/diagnostics14151615","type":"journal-article","created":{"date-parts":[[2024,7,26]],"date-time":"2024-07-26T09:22:42Z","timestamp":1721985762000},"page":"1615","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Compact Linear Flow Phantom Model for Retinal Blood-Flow Evaluation"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2463-4580","authenticated-orcid":false,"given":"Achyut J.","family":"Raghavendra","sequence":"first","affiliation":[{"name":"Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA"},{"name":"Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration (FDA), Silver Spring, MD 20993, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Abdelrahman M.","family":"Elhusseiny","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8573-0042","authenticated-orcid":false,"given":"Anant","family":"Agrawal","sequence":"additional","affiliation":[{"name":"Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration (FDA), Silver Spring, MD 20993, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8019-2054","authenticated-orcid":false,"given":"Zhuolin","family":"Liu","sequence":"additional","affiliation":[{"name":"Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration (FDA), Silver Spring, MD 20993, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0532-1914","authenticated-orcid":false,"given":"Daniel X.","family":"Hammer","sequence":"additional","affiliation":[{"name":"Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration (FDA), Silver Spring, MD 20993, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3082-4604","authenticated-orcid":false,"given":"Osamah J.","family":"Saeedi","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,7,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"750","DOI":"10.1016\/j.ophtha.2013.10.022","article-title":"Retinal blood flow in glaucomatous eyes with single-hemifield damage","volume":"121","author":"Sehi","year":"2014","journal-title":"Ophthalmology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.coph.2012.09.003","article-title":"Ocular perfusion pressure and ocular blood flow in glaucoma","volume":"13","author":"Cherecheanu","year":"2013","journal-title":"Curr. 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