Abstract
Purpose :
The intrinsically-photosensitive melanopsin-expressing retinal ganglion cells are of interest for many reasons. Quantifying melanopsin function with the post-illumination pupil response (PIPR) is of potential use in clinical research, but devices to test this response are expensive and are not portable. We aimed to develop a cheap and portable open-source pupilometer with the capacity to measure PIPR.
Methods :
A pupil measurement device was developed using widely available low cost componentry based on a Raspberry Pi microprocessor platform and infra-red camera. The design, software, and early findings were made freely available on an open source directory.
Results :
A portable 3D-printed goggle-shaped design was developed, that could be replicated anywhere worldwide for less than $200, including optics, electronics, and colour filters. Infrared video of the pupil was obtained and automated real time pupil size analysis was developed based on previously published techniques. Multicolour light-emitting diodes of variable intensity were used to stimulate pupil responses, offering illuminance in the blue channel up to 200 cd/m^2. The PIPR was measured and quantified in normal volunteers.
Conclusions :
The proliferation of cheap components, powerful and versatile microprocessors, and 3D printers enables the development of new clinical and research tools at low cost.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.