Probe the width of a hair to see and measure temperature deep inside the body

Hair

A tiny fibre-optic probe that can measure temperature while seeing deep inside the body has been developed in South Australia.

With an outer diameter of only 130 microns, the width of a single human hair, the probe is the smallest of its kind in the world with the ability to provide real time imaging and measure temperature.

It has been developed at the University of Adelaide and may help researchers find better treatments to prevent drug-induced overheating of the brain, and potentially refine thermal treatment for cancers.

The probe has been successfully used on tissue in the laboratory but is yet to progress to clinical trials.

Lead researcher Dr Jiawen Li from the Adelaide Medical School, ARC Centre of Excellence for Nanosale Biophotonics (CNBP) and the Institute for Photonics and Advanced Sensing IPAS) at the University of Adelaide said the probe was being prepared for testing on animal models.

Dr Li said the probe’s tiny size meant it could potentially be used deep inside the body in a minimally invasive way, allowing clinicians to see and record physiological data in real time that wasn’t previously possible.

This will allow researchers to: better understand how hyperthermia develops; test new medical treatments; or investigate the toxicology impacts of drug-taking.

“Using some drugs such as ecstasy can make certain brain regions overheat and then become damaged,” Dr Li said.

“Using the probe’s imaging function during experiments, our medical collaborators would be able to see deep inside the brain of a living organism and guide the placement of the probe to the right brain region.

“Then, they can use the probe’s built-in thermometer to monitor any changes to the local temperature of that region.”

Dr Li said the dual function of imaging and temperature measurement also had been identified as potentially optimising thermal tumour treatment to destroy cancer cells.

“What is currently happening is they don’t have good control of the temperature, especially when it’s in a blood rich area such as the liver because the blood acts as a heat sink and means the cancer cell is not fully killed by the heat,” she said.

“What we can do now is measure the temperature and know exactly where that measurement was taken.

“Because the probe is really tiny, we’ll be discussing with our collaborators how we can build this alongside their treatment device, which is also a probe. Then we’ll be able to do real time monitoring to find out what’s going on in patients and address the dose for the thermotherapy.”

It is hoped that future generations of the miniature probe will take other measurements as well – such as pH values, oxygen saturation and accumulation of fat in arteries.

Dr Li’s research has been published in the journal Optic Letters.

Professor Robert McLaughlin, Chair of Biophotonics at the University of Adelaide said South Australia was an exciting place to explore the overlap of technology and medicine.

“IPAS and CNBP has world-class expertise in photonics, and Adelaide has a large number of medical researchers that allows us to explore new ways to use light-based technologies,” he said.