Portable Camera Module Could Monitor Health From Home

Fundus photography, a standard imaging tool used by ophthalmologists, has existed for almost two centuries. However, its use in remote and low-resource regions, where traveling to a clinic is not always practical, has been limited.

A compact eye fundus camera system has been developed that allows a user to photograph retinal images of the interior of the eye by using high-speed image-processing NIR light. At 2.3 mm², the system is small enough to fit on a smartphone. It can be mounted on a smartphone without compromising the power necessary for capturing highly detailed images of the interior lining of the eye.

Portable NIR fundus camera (left) and image taken with it (right). Courtesy of Jun Ohta.

Created by researchers at Nara Institute of Science and Technology (NAIST), the camera can achieve 1,000 images per second. This ensures that the camera can quickly align itself with constant changes in the path of the light that travels through the retina to the back of the eye.

To ensure that the light from the camera is strong enough to illuminate the interior of the eye, researchers used a modified CMOS sensor. The miniaturized sensor incorporates three NIR filters, which acquire three signals that can be given a red, green, or blue value, to generate a color photograph of the eye.

The fundus of the eye is the only place where blood vessels can be observed from outside the body, and its observation is useful not only for eye diseases but also for prevention of lifestyle diseases.

The compact module can be mounted on a smartphone for use in the home. Courtesy of Jun Ohta.

Professor Jun Ohta, who researches photonic devices for biomedical uses, imagines a future where patients can be diagnosed with nothing more than the phone in their pocket.

“People may be able to take a picture of their eye by themselves and know the status of their health from the fundus image," Ohta said. "This could open the door for a personal health care system using fundus images. In addition, they could send it to a doctor over the internet. For people in countries like Japan perhaps, visiting an ophthalmologist is not difficult. However, in many countries, it is a real privilege. I want to see our technology improve people’s health globally.”

The research — "Next-generation Fundus Camera with Full Color Image Acquisition in 0-lx Visible Light by 1.12-micron Square Pixel, 4K, 30-fps BSI CMOS Image Sensor with Advanced NIR Multi-spectral Imaging System" — was presented at the 2018 Symposia on VLSI Technology and Circuits, June 18-22, 2018, in Honolulu.