'Enose' Device Sniffs Out Asthma

(HealthDay News) -- A device dubbed the electronic nose -- or Enose -- may be able to spot differences in the breath of people with asthma and those without, potentially aiding in diagnosis, Dutch experts say.

However, this "scent detective" is still in the early stages of development and can't yet effectively distinguish between mild and severe asthma, they added.

"Our Enose was able to recognize patients with mild and severe asthma from healthy subjects with promising discrimination rates. However, the discrimination between mild and severe asthma was less powerful," said study author, Dr. Silvano Dragonieri, of Leiden University Medical Center.

If validated by other studies, "Enose technology might be a noninvasive, quick, cheap and easy to perform [diagnostic] method," he added.

Dragonieri presented the findings Monday at the American Thoracic Society international conference in San Francisco.

Currently, asthma is diagnosed based on symptoms and on measures of lung function. The signs of asthma include coughing, shortness of breath, wheezing and a feeling of tightness in the chest, according to asthma and allergy specialist Dr. Clifford Bassett, a clinical instructor at the New York University School of Medicine.

The problem is that other conditions can also mimic those signs and symptoms. Those conditions include bronchitis, sinusitis and even too much exposure to secondhand smoke, so it's not always simple to diagnose the disease.

"Asthma is a common, treatable disease. But asthma can be a life-threatening condition. Any time clinicians can do a better job identifying patients at high risk of asthma, by any means, that's a very important thing," Bassett said of the new device's potential.

The Enose sniffs out asthma through chemical vapor sensors that detect chemicals called volatile organic compounds (VOCs) in exhaled breath.

"A person's breath contains a mixture of thousands of VOCs that may be used as markers of lung disease," said Dragonieri. Devices like Enose have been already used in the food, wine and perfume industries, and they can also detect explosives or toxic chemicals, making the technology useful in the fight against terrorism.

Along with this study of the Enose in asthma, the technology is also being studied to assess its usefulness in detecting lung cancer.

Every person has a unique "smell print," which the device can sniff out, the researchers explained. To assess the effectiveness of the Enose in accurately diagnosing asthma, Dragonieri's team compared the smell prints of 20 people with asthma -- 10 with mild airway disease and 10 with severe -- to the smell prints of 20 healthy volunteers.

The device was 95 percent effective in picking out who had asthma and who didn't, but only 65 percent effective at discerning mild from severe asthma.

"There may be several reasons [why the device wasn't as sensitive at detecting differences in asthma levels], but we can only speculate," explained Dragonieri. "It might be the VOC's composition, regardless of its severity, so the changes of VOCs spectrum are noteworthy between healthy subjects and asthmatics and less evident between severe and mild asthmatics."
"Enose technology is still in an embryonic stage," he added. "It has the potential to become a useful diagnostic tool, but still many other steps have to be done before this method can be validated," he said.

More information
To learn more about how asthma is currently diagnosed, visit the National Heart, Lung and Blood Institute.