RAD 352 Ultrasound Physics

Sound is a mechanical wave, a longitudinal wave, a type of pressure wave, and a form of energy. It requires a medium to travel and is not ionizing radiation.

The three primary acoustic variables are pressure, density, and distance (particle motion).

A parameter is a measurable quantity that can be directly or inversely related to other parameters.

The parameters of sound waves include Period, Frequency, Amplitude, Power, Intensity, Propagation Speed, and Wavelength.

Period is defined as the time it takes for one cycle to occur, measured in microseconds (μs).

Frequency is defined as the number of cycles per second, measured in hertz (Hz), kilohertz (kHz), or megahertz (MHz).

Frequency and period are inversely related; as frequency increases, period decreases, and vice versa.

Propagation speed is the speed at which a sound wave travels through a medium, measured in meters per second (m/s) or millimeters per microsecond (mm/μs).

Propagation speed is influenced by the stiffness (elasticity) and density (inertia) of the medium.

Stiffness is directly related to propagation speed; the stiffer the medium, the faster the propagation speed.