# Virtual prototyping for retinal prosthesis patients

> **NIH NIH R00** · UNIVERSITY OF CALIFORNIA SANTA BARBARA · 2021 · $236,458

## Abstract

Project Summary/Abstract
Retinal dystrophies such as retinitis pigmentosa and macular degeneration induce progressive loss of
photoreceptors, resulting in profound visual impairment in more than ten million people worldwide. Visual
neuroprostheses (‘bionic eyes’) aim to restore functional vision by electrically stimulating remaining cells in the
retina, analogous to cochlear implants. A wide variety of neuroprostheses are either in development (e.g.
optogenetics, cortical) or are being implanted in patients (e.g. subretinal or epiretinal electrical). A limiting factor
that affects all device types are perceptual distortions and subsequent loss of information, caused by interactions
between the implant technology and the underlying neurophysiology. Understanding the causes of these
distortions and finding ways to alleviate them is critically important to the success of current and future sight
restoration technologies. In this proposal, human visual psychophysics, computational modeling, data-driven
approaches, and virtual reality (VR) will be combined to develop and experimentally validate optimized
stimulation protocols for epiretinal prostheses. This approach is analogous to virtual prototyping for airplanes
and other complex systems: to use a high-quality model of both the implant electronics and the visual system in
order to generate a ‘virtual patient’. Retinal electrophysiological and visual behavioral data will be used to develop
and validate a computational model of the expected visual experience of patients when electrically stimulated.
One way of using this model will be to generate simulations of the expected perceptual outcome of electrical
stimulation across a wide variety of electrical stimulation patterns. These will be used as a training set for
machine learning algorithms that will invert the input-output function of the model to find the electrical stimulation
protocol that best replicates any desired perceptual experience. The model can also be used to simulate the
expected perceptual experience of real patients by using sighted subjects in a VR environment – ‘VR virtual
patients’. These virtual patients will be used to discover preprocessing methods (e.g., edge enhancement,
retargeting, decluttering) that improve behavioral performance in VR. Although current retinal prostheses have
been implanted in over 250 patients worldwide, experimentation with improved stimulation protocols remains
challenging and expensive. Implementing ‘virtual patients’ in VR offers an affordable and practical alternative for
high-throughput experiments to test new stimulation protocols. Stimulation protocols that result in good VR
performance will be experimentally validated in real prosthesis patients in collaboration with Second Sight
Medical Products Inc. and Pixium Vision, two leading device manufacturers in the field. This work has the
potential to significantly improve the effectiveness of visual neuroprostheses as a treatment option for indivi...

## Key facts

- **NIH application ID:** 10248573
- **Project number:** 5R00EY029329-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA SANTA BARBARA
- **Principal Investigator:** Michael Beyeler
- **Activity code:** R00 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $236,458
- **Award type:** 5
- **Project period:** 2020-09-30 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10248573

## Citation

> US National Institutes of Health, RePORTER application 10248573, Virtual prototyping for retinal prosthesis patients (5R00EY029329-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10248573. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*