A team in Australia and Germany has developed the world’s smallest imaging device, with only one human hair. Its ability to move down the blood vessels of mice provides an unprecedented ability to perform 3D scans on humans at microresolution resolution. To create the miniature endoscope, the team used a thin fiber less than half a millimeter (0.02 inches) in diameter, including its protective case.
The researchers used 3D microprinting technology to print a miniature lateral lens less than 0.13 mm (0.005 inches) in diameter into it. The fiber is then connected to an optical coherent tomography (OCT) scanner as a flexible probe.
OCT is a 3D deep-sensitive scanning technology commonly used in retinal mapping in the field of optometrist and ophthalmology. It uses near-infrared light-penetrating tissue to measure wave interference between the reference beam and the probe beam to create a real-time 3D image that can be viewed through the human surface at a microresolution resolution.
With this breakthrough, the team built an OCT scanning device small enough to push away the body’s blood vessels. This ultra-thin probe rotates and slowly pulls back to create a 3D map of the surrounding environment, about half a millimeter deep on the surface. It provides unprecedented ability to scan the body’s vascular system, looking for plaques made up of fat, cholesterol and other substances that tend to accumulate on the walls of blood vessels and cause heart disease.
The team successfully tested the device in human and mouse blood vessels, proving that it provided high-quality OCT images and the flexibility to reach where the body needed it. Its precisely printed lens gives the scanner five times as much depth as previously attempted, and researchers believe the tiny probe could open up new scanning options in hard-to-reach places, such as the ear’s cochlear implant and possibly even parts of the nervous system.