ABSTRACT
Characteristic smells on human breath have been widely used for clinical purposes over the last several millennia. Exhaled breath contains a multitude of volatile and nonvolatile compounds—each of which has the potential to be a disease biomarker. These breath metabolites are thought to be by-products of the constitutive biochemical processes ongoing within the human body. Breath analysis has the potential to be a powerful noninvasive technique for the diagnosis and monitoring of many different respiratory diseases such as asthma, lung cancer, or other airway inflammation disorders as well as other diseases such as diabetes and nephropathies. Breath sensors should also be sensitive enough to detect and analyze low concentration levels of biomarkers. Breath sensor systems may be categorized in two major classes: condensation devices and absorption devices. There has been vast interest in designing a real-time miniature device that could collect a sample and detect multiple breath biomarkers concurrently.
