ABSTRACT
Transducers are used to convert time-varying physiologic events (or variables) into electric signals. With the event available as an electric signal, the maximum amount of information can be obtained. In cardiology and cardiovascular physiology, the hemodynamic events most often measured are phasic pressure, flow (and velocity), volume, and length (or diameter). The transducer used to measure these variables should obey the three criteria for the faithful reproduction of an event: amplitude linearity, adequate frequency response, and phase linearity (Nichols et al., 1994a; Nichols et al., 1994b; Geddes and Baker, 1975).
