Many diseases are accompanied by characteristic odors, and their recognition can provide diagnostic clues, guide the laboratory evaluation, and affect the choice of immediate therapy. The study of the chemical composition in human breath using gas chromatography/mass spectrometry (GC/MS) has shown a correlation between the volatile compounds and the occurrence of certain illnesses. The presence of those specific compounds can provide an indication to physiological malfunction and support the diagnosis of diseases. This condition requires an analytical tool with very high sensitivity for measurement.

A number of volatile compounds, called biomarkers, are found in breath samples, normally at low parts per billion (ppb) levels. Usually, the concentration of the chemical markers in the human breath is very low and the background relative humidity is high, almost 100%. The technology developed in this work uses an array of chemical sensors combined with humidity, temperature, and pressure for real-time breath measurement to correlate the chemical information in the breath with the state and functioning of different human organs.

The low-power, compact tool, called a nanosensor array chip, is used for such an analysis, in-situ and in real time. This tool will provide a non-invasive method for fast and accurate diagnosis at the medical point of care or at home. The sensor chip will have multiple sensors on it for a comprehensive measurement of chemical composition, temperature, humidity, and pressure. The sensor data collected from this chip can be wired or wirelessly transmitted to a computer terminal at the doctor’s desk or hospital monitoring center. The sensor chip can be connected directly or via USB to a cellphone for data transmission over a long distance, and receive an instruction from a doctor’s office for immediate therapy.

The high sensitivity of the sensors is obtained from the nanostructure materials that possess the high surface area and well-organized molecular structures. This system uses a network of nano-chemical sensors combined with a monitoring system composed of humidity, temperature, and pressure sensors assembled on a silicon chip for real-time chemical and physical property measurement of human breath for non-invasive and low-cost medical diagnosis.

This invention will be useful for astronaut health monitoring, point-of-care for medical diagnosis, and early warning of any diseases correlated to the excess of chemicals in the biospecies.

This work was done by Jing Li of Ames Research Center. NASA invites companies to inquire about partnering opportunities and licensing this patented technology. Contact the Ames Technology Partnerships Office at 1-855-627-2249 or This email address is being protected from spambots. You need JavaScript enabled to view it.. Refer to ARC-16902-1.

NASA Tech Briefs Magazine

This article first appeared in the August, 2015 issue of NASA Tech Briefs Magazine.

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