Hand-held 'breathalyser' could now diagnose diabetes

Researchers at the University of Oxford have developed a new, portable breath analyser that could someday help doctors diagnose diabetes without painful pinpricks, needles or other unpleasant methods.

Many studies examining the hallmarks of diabetes in exhaled breath have shown that elevated levels of acetone are strongly linked to diabetes. 

Detecting the concentrations of any given substance in breath in a simple way, however, is a major challenge. 

Breath contains a complex mix of compounds, including water, carbon dioxide and methane, that can throw results off. 

A technique called mass spectrometry can do the job, but it is not very practical for point-of-care testing. 

Robert Peverall from University of Oxford and colleagues wanted to fill that void.

The researchers created a hand-held device with an adsorbent polymer that can trap acetone from exhaled breath, then release it into a cavity where a laser probes its concentration. 

"The device features a seven cm long high finesse optical cavity as an optical sensor that is coupled to a miniature adsorption preconcentrator containing 0.5 g of polymer material," the researchers said.

They tested the accuracy of the device on the breath of healthy participants under different conditions, such as after overnight fasting or exercising, and compared results with mass spectrometry readings. 

The measurements were a close match and covered a wide range of concentrations, including those that would suggest a patient has undiagnosed Type-1 diabetes, or has problems controlling their blood glucose, said the study published in the American Chemical Society's journal Analytical Chemistry.

Adding to the practicality of the device, the researchers said it could be re-used many times.