Pupilmate: A do-it-yourself frugal pupilometer.

Abstract

The pupillary direct and consensual reflex is an important non-invasive quick assessment of the neurological state of the eye. Currently, there is no cheap and affordable recording tool for screening and documentation of a relative afferent pupillary defect. We describe how to construct a frugal, do-it-yourself handheld scotopic binocular pupillometer device called Pupilmate. Two simple Wi-Fi-enabled board cameras fitted on both sides of the back of a rectangular cardboard box separated by a central paper divider, one side of the rectangular box was left open. An infrared red (IR) light source in the form of light-emitting diodes (LEDs) was fitted around each of the cameras. Two white light LEDs were fitted on either side of the box controlled by a two-way switch. A simultaneous video stream of both pupils could then be tuned in on any chosen device using the internet. Each pupil is manually illuminated for a desired time allowing recording of direct as well as consensual reflexes, which are objectively observed. Pupil reaction was easily recorded and repeatable using Pupilmate. It served as a good medium for initial screening in an outpatient department (OPD) setting, outreach programs, clinics, etc.