The Receiver is the component of the ultrasound machine that receives the current generated in the transducer from the returning sound waves.

See also Blanking Distance, and Range Gating.

The dead or ring down zone is the distance from the front face of the transducer to the first echo that is identifiable. The signals from this region are unsuitable. The dead zone is the result of transducer ringing and reverberations from the interface between the transducer and the scanned object. Impedance matching between the transducer and the receiver is important to avoid electrical ringing.
With an increase of the frequency, the pulse length and the depth of the dead zone decrease, if all other parameters remain constant. The acoustic power also affects the depth of the dead zone.

The duty factor is the product of the pulse duration and the pulse repetition frequency (the lapse of time the transducer is actively transmitting sound).
Most transducers are acting as the receiver 99 % of the time with a duty factor of 1.

See also Dwell Time.

An omnidirectional transducer transmits or receives ultrasound waves in or from any direction with 360 degrees receiving capability.

See also Transmitter, and Receiver.

Piezo means pressure, so piezoelectric means that pressure is generated when electrical energy is applied to a quartz crystal. When electrical energy is applied to the face of the crystal, the shape of the crystal changes as a function of the polarity of the applied electrical energy. As the crystal expands and contracts it produces compressions and rarefactions, and creates sound waves. When this material is struck by sound waves it creates electrical currents.
Thus, a piezoelectric crystal can produce a pulse of mechanical energy (pressure pulse) by electrically exciting the crystal (transmitter), and they can produce a pulse of electrical energy by mechanically exciting the crystal (receiver). This ultrasound physics principle is called the piezoelectric effect (pressure electricity), which was discovered by Pierre and Jacques Curie in 1880, and is used to generate ultrasound waves. Instead of quartz crystals, piezoelectric ceramics such as barium titanate or lead zirconate titanate are also used, which are crystalline materials with similar piezoelectric properties.

See also Temporal Peak Intensity.