Advances in gas sensors moving breath analysis into the clinic
Posted on 25/06/2018
The idea that you can diagnose disease by the aroma on a patient’s breath has been around since the time of Hippocrates (c 460-370 BC). The smell of exhaled acetone as an indicator of uncontrolled diabetes is well-known and is well documented in the literature, but the identification of other biomarkers did not start in earnest until the early 1970s.
By rapidly cooling breath to very cold temperatures, Linus Pauling was able to extract samples of exhaled volatile organic compounds, which he analysed using gas chromatography. In doing so, he demonstrated that human breath contains a complex mixture of over 250 different compounds. More recently, the use of mass spectrometry has allowed these biomarkers to be identified and work has begun to correlate them with specific diseases. The potential for breath-based, non-invasive diagnostic tests is now being realised. Cooling breath samples down to sub -70°C and subsequent analysis using large, laboratory instruments is not easily achievable at the bedside. Clearly, handheld instruments with minimal sample preparation are needed.
Innovate UK has funded a number of breath-diagnostic projects over the past few years. The “Sensors Europe” conference stream at the IDTechEx show in Berlin, hosted a session on Medical Biosensors, where two of the UK projects were presented. Both technologies used proprietary printed nanosensors but aimed to look at different diseases using slightly different approaches.
Victor Higgs, Managing Director of Applied Nanodetectors Ltd, presented a platform technology, which can be used to monitor a range of biomarkers (up to eight simultaneously). The company has various options, but their initial application is for asthma; monitoring patient health and predicting asthma attacks, using just four biomarkers. It is estimated that the 20 million asthma patients in the EU each cost their respective healthcare systems around 7000 euros per year in medicines and treatments. Applied Nanodetectors predicts that up to 75% of hospital admissions can be prevented using their technology.
A similar approach was presented by Tony Killard, Chief Technology Officer of BreathDX. Instead of one disease, using a range of biomarkers, BreathDX looks at just one biomarker, which is important in a number of diseases. If there’s a defect in nitrogen metabolism, for example through liver disease, kidney disease etc, there is an accumulation of ammonia in the body. This can result in Hepatic Encephalopathy, which can be fatal. Current tests for ammonia require specialists to take blood, which is then shipped on ice to a central laboratory. This is obviously slow and expensive.
BreathDX hope to have systems installed for testing at patients’ homes later this year. Applied Nanodetectors’ systems will be available to GP surgeries in 2019 and versions for home-use within three years. Both technologies promise significant benefits to patients and healthcare budgets and will open up substantial markets in their respective areas.
With other companies also interested, we expect to see significant growth in the use of breath in diagnostics in the coming years, with the UK leading the way. Applied Nanodetectors won the Best New Product award at the IdTechEx conference.
There are three other KTN articles following the IdTechEx conference which can be accessed here. Simon Yarwood looks at Energy Harvesting, and Monika Dunkel shares thoughts on the emerging trends exhibited at the conference in a two part piece: read part one here and part two here.
Find out more about Mark Littlewood, Head of Emerging Technologies here.