Engineers at Siemens have developed a mobile phone sized device that is capable of detecting nitric oxide (NO), an oncoming asthma attack marker, at parts per billion scale. Once the device makes it to the consumer market, asthma patients will be able to take preemptive action and raise their drug dosage levels when an attack looks impending. The new sensor can detect increases in NO one day before an acute asthma attack occurs. Over the past few years, medical researchers and health insurance companies have recognized that NO levels are an effective indication of an impending asthma attack. In the analysis of a patient’s breath, the system first converts nitrogen monoxide into nitrogen dioxide, after which the air flows across the actual sensor. Only the particles signaling the attack adhere to the sensor’s surface. This generates a voltage that is measured by a field-effect transistor. The intensity of the voltage is directly dependent on the amount of nitrogen monoxide in the patient’s breath. On the basis of this value, the patient can decide what dose of anti-inflammatory medication he or she should take. Another type of breath sensor under consideration would allow athletes to check whether they are exercising enough to burn fat. The detection principle is the same, except that the system measures the level of acetone. The latter is generated in the body when fat is burned and is also detectable in a person’s breath. Press Release Source: medGadget