Siemens has developed a sensor that can warn users of constricted airways a day before an asthma attacks occur. The sensor works by measuring the level of nitrogen monoxide (NO) on a patient’s breath to find out if their bronchial tubes have been inflamed. Usually inflammation happens long before an attack, and being able to predict it is half the battle won. Patients can then take the appropriate medical treatment.
Currently devices like these exist, but they are much too large and bulky to be carried around everywhere. The new sensor from Siemens is much smaller and is about the size of a mobile phone. In addition to detecting the levels of NO in patients, the device can be modified to detect other types of gasses so it can be used for other purposes such as detecting fires and possibly the detection of lung cancer in the future.
Siemens’ sensor, which is slightly smaller than a mobile phone, works by converting NO to nitrogen dioxide (NO2).When air flows across the sensor, it selectively catches the NO2, which gives rise to a small electrical voltage that indicates chemical levels on the breath in parts per billion (ppb).
“This high sensitivity provides an early warning and allows patients to adjust their medication accordingly” said Dr Maximilian Fleischer, who helped develop the device.
‘We use the universal CMOS chip platform, called GasFET by scientists,’ said Fleischer. ‘Different receptor layers can be attached to the platform to adapt it for different applications, such as the detection of fires.’
Siemens used the same concept in 2004, to develop gas sensors for use in industrial systems. The group is now developing sensors that could allow athletes to check whether they are exercising enough to burn fat, by measuring levels of acetone
But Fleischer believes the technology has far wider implications. ‘There are some interesting options out there,’ he said. ‘For instance, sensors such as this could in future be used for the early detection of lung cancer.’