Beside containing nitrogen and carbon dioxide, gas exhaled from lungs contains many biomarkers that may point to the presence of diseases we would otherwise not know about. Being able to screen people easily and at low cost may help prevent the development of all sorts of conditions, which has led to the proliferation of breath testing technologies.
A device developed at Cambridge CMOS Sensors (CCMOSS), a spin-off of Cambridge University, uses broad spectrum infrared to detect 35 different biomarkers in exhaled air at concentrations down to one part per million.
From Cambridge University:
A number of breath analysis tests are currently in the research and development phase, most of which use mass spectrometry or lasers to analyse the breath for specific compounds. These tests can only detect a small range of compounds however, meaning that different devices are needed to detect different conditions.
The technology developed by CCMOSS is different in that it uses broadband infrared radiation to make the detection of a wide range of biomarkers possible in a single device. The company’s miniature heaters, or microhotplates, can be heated from room temperature to 700°C in a fraction of a second, a temperature high enough to emit infrared radiation and allow the sensing material to react with gas molecules.
Many gas molecules absorb infrared. The amount of radiation absorbed allows the gas to be identified and its concentration calculated – this is the basic principle behind the roadside breathalyser test. CCMOSS’ technology however, is far more sensitive. Using broadband infrared, the company’s gas sensing technology can detect wavelengths between two and 14 microns, corresponding to a wide range of biomarkers. In order to detect different wavelengths, a filter is applied on top of the detector, meaning that only infrared radiation of a particular wavelength can get through.