SBIR Phase I: A hand-held retinal imager that incorporates a flat lens and total internal reflection illumination

The broader/commercial impact of this SBIR Phase I project is to facilitate retinal screening at primary (non-ophthalmologist) points of care. Diabetic retinopathy is the leading cause of blindness in Americans aged 20-74. Delivering efficient and cost-effective retinal screening to the millions of at-risk patients is both imperative and a pressing engineering challenge. This project will test a unique lens design and imaging method as the first steps toward building an intuitive, affordable hand-held retinal imager specifically targeted to primary care physicians and non-ophthalmologist healthcare providers. Enabling widespread diabetic retinopathy screening at primary points of care will bring preventive screening to previously under served patient populations, including poor urban and rural areas. Allowing primary care physicians to offer these services will reduce the workload for over-burdened eye specialists. Freeing up specialists’ time and resources to be utilized more efficiently will also reduce costs to the healthcare system. This project seeks to develop a novel lens geometry that will enable more efficient illumination of the retina during imaging. The company's innovative and improved methodology will decrease imaging failure along with device size and cost, resulting in increased reliability, retinal screening efficiency, and accessibility. This project builds on empirical insights into the pitfalls and failure modes of retinal screening. Lenses with the novel geometry will be prototyped, and the optical performance of the lens and illumination system will be tested using physical and biological eye models. Briefly, computational modeling will be used to predict the properties (e.g., uniformity of retinal illumination) of candidate lens geometries challenged with a 5 mm aperture. Next, a physical prototype for the optical and electronic components will be assembled, followed by proof-of-concept tests with physical and biological models of the eye to compare the performance of prototype lenses to predicted values. These critical results will guide the company’s efforts to refine its design, transition from prototype to production model for cost-effective manufacturing, and to plan pilot trials as it moves this hand-held retinal imager toward the clinic. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.