: Krumbiegel, P.; Herbarth, O.; Despang, H.-G.; Oberst, E.; Kleinmann, L.; Fritzsch, H.

Abstract
Asthmatic and bronchitic attacks are often a reaction to air pollution. Such effects often fail to be detected during medical examinations, especially short-time sounding. To solve the problem of continuously monitoring human airway obstructions, an automatic miniature system was developed comprising the following elements: acoustic detector, frequency filter, recognition unit, registrator working on a time scale, data export module, power source. Wheezing was chosen as a characteristic pathological sound. Only typical frequencies are registered in a certain mode to optimize the likelihood of picking up true signals. The sensor is as small as a pocket-watch. It is fixed to the chest and worn there for a period of hours or days. Once the recording time is up, the sensor is returned to the physican. The data recorded are then transferred to a computer for evaluation. The sensor is currently being tested under field conditions on infants and schoolchildren.