Abstract
A recent advance of the medical electronics enables us to measure various kinds of phenomena in vivo by electrical devices. Changes in physical parameters such as air flow, volume, temperature or pressure are picked up by detectors and transformed into electrical signals by transducers. Today electrical instruments can almost completely amplify and record these signals. We, however, are still confronted with misuse beyond limitations of the transducers. We should use measuring devices within their functional limits. Moreover, the obtained results should be dealt with at the level of the transducers. This is explained by comparing to a stereo system which consists of a pickup, amplifier and speaker. Reproduced sound depends entirely on the worst part of the three.
