A team of South Australian and German researchers and clinicians have developed the world's smallest imaging device to look inside blood vessels.

The world's smallest imaging device to look inside blood vessels has been developed to help scientists better understand the causes of heart disease and attacks.

Researchers from the University of Adelaide (UOA) and Germany's University of Stuttgart used 3D micro-printing to develop the flexible endoscope.

The camera-like imaging device has a protective plastic casing and is less than half a millimetre wide, or about the thickness of a human hair.

Cardiovascular disease kills one Australian every 19 minutes, but the UOA says in a statement the new technology can lead to improved treatment and prevention.

UOA researcher Jiawen Li said the build-up of plaques, made up of fats, cholesterol and other substances, in vessel walls were a major factor in heart disease.

"It's amazing what we can do when we put engineers and medical clinicians together," Dr Li said on Tuesday.

"Preclinical and clinical diagnostics increasingly rely on visualising the structure of the blood vessels to better understand the disease.

"Miniaturised endoscopes, which act like tiny cameras, allow doctors to see how these plaques form and explore new ways to treat them."

University of Stuttgart's optical design and simulation leader Simon Thiele said making high-quality endoscopes of such size was difficult in the past.

"Using 3D micro-printing, we are able to print complicated lenses that are too small to see with the naked eye," Dr Thiele said.

"Until now, we couldn't make high-quality endoscopes this small."

The study has been published in the journal Light: Science & Applications.