Breath test developed for type 1 diabetes diagnosis

A breath sensor which has potential for use in diagnosing type 1 diabetes has undergone successful clinical testing in Europe.

Developed by researchers at ETH Zurich, a science and technology university in Switzerland, the device can selectively detect acetone on a person’s breath, even at very small concentrations. And because patients with type 1 diabetes exhale air which has a level of acetone which is slightly higher than that on the breath of healthy individuals, the researchers predict that finger-pricks for diabetes testing could soon become a thing of the past. [Anal Chem 2010;82:3581-3587]

The ultimate goal of the breath sensor would be to replace the more invasive method of extracting blood, said Professor Sotiris Pratsinis, who specializes in particle technology at the Institute of Process Engineering, ETH Zurich. “I believe this [sensor] can be quite viable in the form of an [inhaler/exhaler] device.”

The typical concentration of acetone in a healthy person is about 900 particles per billion (ppb). The level is about two-fold higher in patients with type 1 diabetes and even higher in those with diabetic ketoacidosis, a potentially serious condition that can occur when a diabetic patient has not taken enough insulin.

Built by Pratsinis and his team, the breath sensor can detect acetone levels as low as 20 ppb, a concentration which is about 90 times lower than that typically occurring in the breath of someone with diabetes. It has also been shown to function well in extremely moist air (>90 percent humidity), which is a characteristic of human breath.

This highly sensitive acetone sensor is comprised of a thin film of semi-conducting, mixed ceramic nanoparticles between a set of gold electrodes, enabling it to act as an electrical resistor. If a patient with diabetes were to breathe on the sensor, the puff of acetone-filled air would cause the resistance to drop suddenly. In contrast, if a healthy subject was to breathe onto the device, there would be little change in the resistance.

This technology and adaptations of it may have several clinical applications in the future, said Pratsinis. “New materials can help develop diagnostics for routine monitoring [of other] chronic illnesses,” he said.

In terms of its use in the management of diabetes, a breath sensor would provide a simple means for quick and easy diagnoses, negating the need for taking blood samples to measure blood sugar level. Patients may even be able to use the technology in their own homes. Importantly, the sensors could also find their way into emergency departments to determine if a patient is suffering from diabetic ketoacidosis.

Source: mims.com