Laser nose sniffs out diseases and intoxication

Odour identification is based on the detection of gaseous compounds.

BIGTALK is a interview series, where big questions are asked from the scientists of University of Helsinki. On this episode Ville Halonen talks with postdoctoral researcher Markus Metsälä from the Department of Chemistry.

Researchers at the Kumpula Campus are using laser spectroscopy to develop methods for measuring minute concentrations of gases in the exhaled air of humans. Their goal is to create an extremely accurate “laser nose”.

“We hope our laser nose will facilitate the diagnosis of diseases in the future,” explains Markus Metsälä from the Laboratory of Physical Chemistry, University of Helsinki.

“Illnesses and bacterial infections alter the concentrations of volatile compounds in exhaled air. All the volatile compounds found in our blood are also present in small concentrations in the air we exhale.”

It has taken several years of meticulous basic research to devise reliable measurement methods – and many more are still ahead.

“The human body is such a complex system that measurements must also be intricate. Molecules behave differently during exhalation: the concentrations measured around the mouth may be far different from those in the lungs.”

Only a few breath tests have so far been introduced into clinical use. In Finland, exhaled air-based diagnoses focus especially on helicobacter strains causing gastric ulcers and cancers. Furthermore, measurements of nitrogen monoxide from exhaled air are used to follow up asthma treatment.

Research in Kumpula currently focuses on ammonia and hydrogen cyanide.

“The ammonia concentration in exhaled air is related to liver and kidney malfunction, while hydrogen cyanide is an indicator of intoxication from fire-induced smoke inhalation.”

While less familiar than carbon monoxide, hydrogen cyanide is a common cause of smoke inhalation-related deaths in residential fires: burning furniture materials release copious amounts of it. The problem on the scene of fire is that no method yet exists for quickly determining whether a victim is suffering from carbon monoxide or hydrogen cyanide intoxication. Each requires a specific treatment.

“A blood test is too slow for diagnosing the intoxication agent, but a laser nose could be ideal for this purpose. A device measuring the concentration of hydrogen cyanide in exhaled air would enable paramedics to rapidly determine the cause of intoxication and thus save lives.”

Laboratory of Physical Chemistry »»

All Big Talk videos »»

Research Database TUHAT: Markus Metsälä »»

Comment on Facebook »»

Text: Tapio Ollikainen
Photo and video: Tapio Ollikainen and Tiina aarniala
Translation: Language Services/Language Centre (University of Helsinki)
University of Helsinki, digital communications

News of the month »»
News archive »»
University of Helsinki