A sound wave is a mechanical wave
Mechanical waves require a medium in order to transport their energy from one location to another. They cannot propagate in vacuum. Mechanical waves can be longitudinal or transverse.

A sound wave is a longitudinal wave
In a longitudinal wave the oscillating disturbance is parallel to the direction of travel. Sound waves are always longitudinal waves: The air molecules vibrate in the same direction as the sound wave travels and form a series of compressions (high pressure) and rarefactions (low pressure), where the molecules are squeezed together and pulled apart respectively.

Human speech and ultrasound are examples of sound wave transmission
When people speak, air is the medium that carries the sound waves of speech from one person to another

When medical ultrasound is used to visualise a blood vessel, the soft tissues of the patient is the medium

When the molecules of the medium vibrate, they transmit the sound wave. The vibrations that transmit sound are not the result of an entire volume moving back and forth at once. Instead, the vibrations occur among the individual molecules of the substance, and the vibrations are transferred from one molecule to the next and thereby move through the medium in waves

The result is that regions of the medium become alternately more dense (compressions or condensations) and less dense (rarefactions). The individual particles only move directly toward or directly away from the vibration source to create compression or rarefaction. This means that sound waves are longitudinal waves

Basic understanding of ultrasound physics is crucial for achieving proficiency in clinical ultrasound

This module explains the basic concepts of waves, sound waves, ultrasound, the ultrasound system, system and user controlled ultrasound imaging, ultrasound imaging artefacts, and patient safety

The module presents the fundamental concepts of ultrasound theory in an easy, comprehensible and intuitive way using minimum mathematical terminology

For the specially interested participant, the basic mathematics are explained in text boxes and figures to the right. However, that is not mandatory reading

The course provides an essential understanding of ultrasound physics so you can succeed with the practical application of clinical ultrasound while avoiding the pitfalls

The learning objective is to gain knowledge of the basic principles of:

? wave physics and acoustic physics
? ultrasound and medical ultrasound
? the ultrasound system
? the system controlled ultrasound imaging
? the user controlled ultrasound imaging
? the ultrasound imaging artefacts
? patient safety

Clinical ultrasound has evolved into a pervasive and universal tool facilitating increased success, quality, safety, and cost-effectiveness of all kinds of clinical diagnostic and interventional procedures.

Ultrasound ought to be applied wherever the diagnostic and interventional clinical procedures can be improved for the benefit of the patients.

Securing proficiency of the application of clinical ultrasound requires educational resources, training, and certification developed by and anchored in recognised institutions and societies.