At Georgia Institute of Technology, scientists have built a device for continuous sampling and analysis of air quality asthma patients find themselves in. Using the various sensors integrated by Keehi Technologies, the device will help to investigate what environmental conditions trigger an asthma attack.
Although no one fully understands why certain people get asthma, doctors know that once a person has it, his/her lungs can overreact to environmental stimuli causing chest tightness or breathlessness, known as an asthma attack.
The new sensor system measures airborne exposure to formaldehyde, carbon dioxide, ozone, nitrogen dioxide, temperature, relative humidity and total volatile organic compounds (VOCs). VOCs are emitted as gases from products such as paints, cleaning supplies, pesticide formulations, building materials and furnishings, office equipment and craft materials.
In addition to detecting the seven environmental stimuli mentioned above, a special mesh filter collects particles. A pump pulls air through the filter so that the quantity of particles can be measured at the end of the sampling period. The composition of the collected particulate can also be analyzed in the laboratory.
The battery-powered system fits into the pocket of a vest and contains commercially available sensors that were integrated into a single system by Mark Jones, chief executive officer of Keehi Technologies.
“The device weighs less than one pound including batteries and it takes a measurement of air every two minutes, stores the data in on-board memory and then sleeps to conserve battery power,” said Jones.
Bayer and GTRI Research Scientist Robert Hendry calibrated and tested the sensors in a large room-sized chamber that simulates real-world environmental conditions inside buildings. Coupled with sensitive mass spectrometers, the chamber allows the changing indoor air chemistry to be studied in detail.
The sensor system is designed to be comfortably worn in the pockets of a vest throughout the day and kept at the bedside while sleeping at night. Another vest pocket contains an electronic peak flow meter to periodically measure pulmonary function. When experiencing an asthma attack, the vest wearer notes what time it occurred and Bayer can examine the levels of the chemical compounds at that time.