Intraoral camera inspired by insect eyes

South Korea: A research team from the Korea Advanced Institute of Science and Technology (KAIST) and the Korea Institute of Optical Technology (KOPTI) has created an intraoral camera that can mimic the eyes of insects.

Led by KAIST Prof Ki-Hun Jeong, the team developed the biologically inspired intraoral camera (BIOC) with a wide angle of view and deep depth of field.

A research paper on the insect-inspired camera technology was recently published in the Journal of Optical Microsystems, a journal of the International Society of Optical Engineers.

Mimicking insect eye’s excellent visual characteristics

According to the team, the insect’s eye is a dense visual organ composed of small lenses and has excellent visual characteristics such as a wide angle of view and a wide depth of field.

Conventional dental photography technology is often limited by the use of inconvenient tools such as mirrors and cheek retractors, they explained.

To acquire basic teeth images from various angle for routine inspections – including right/left buccal and maxillary/mandibular occlusal – traditional intraoral cameras may cause discomfort to the patient, as the dentist would also need to put a mirror into the mouth to capture the reflected teeth image through a handheld camera.

Technology imitating biology

The research team designed an ultra-thin oral camera using a convex lens, a concave lens, an inverted micro lens array (iMLA), and a CMOS image sensor.

The convex and concave lenses increased the angle of view to 143 degrees, and iMLA played a role in reducing optical aberration. It was possible to obtain clear images without image blur even at close distances, imitating the visual function of insects with an infinite depth of field.

Due to the small and thin size of the camera, it is possible to observe the teeth even in an anatomically narrow area.

“The camera developed this time will not only contribute to the development of biomedical engineering technology, but will also expand its application to various fields such as monitoring, smartphones, and drones,” said the researchers.

Improving on previous insect-inspired cameras

Various species of compound insect eyes have superior visual characteristics, such as wide viewing angle and large depth of field with compact visual organs made up of tiny lenses.

As such, miniaturized insect-inspired cameras can solve the problems of conventional compact cameras. However, previously developed insect-inspired cameras suffer drawbacks including low-resolution or limited functions.

The BIOC involves a new configuration of convex-concave lens and inverted microlens arrays (iMLA) and a single CMOS image sensor on a flexible printed circuit board in a handpiece holder.

Besides increasing the field of view and reducing optical aberration by the scaling law, the new camera overcomes many chronic issues of conventional intraoral cameras, such as limited depth-of-field, thick total-track-length, and limited functional imaging.

Through the multichannel vision system, the BIOC offers multifunctional dental imaging, such as high dynamic range, 3D depth, and autofluorescence imaging.