A transducer converts one form of energy to another. For most ICU monitors that will be mentioned, this consists of converting the pressure in a vessel into an electrical signal, which is displayed on a monitor. This electrical signal changes directly with the intravascular pressure.
The electrical signal is thus displayed in a waveform that instantly reflects the changes in pressure in the vessel.
As with all measurement systems, it is important that the derived signal is an accurate reflection of the signal measured. Interference from other equipment, damping of the system, low signal to noise ratio, and erroneous calibration or zeroing will all lead to inaccuracies.
Figure 2. Invasive monitors and the role of the transducer.