Ultrasound is defined by the American National Standards Institute as "sound at frequencies greater than 20 kHz". In air at atmospheric pressure, ultrasonic waves have wavelengths of …

2025年1月26日 · Ultrasonics, vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz. The term sonic is applied to …

Explain the principles of sound wave propagation, including frequency, wavelength, amplitude, and velocity. Describe the piezoelectric effect and how it is used in ultrasound transducers. …

2020年7月16日 · This chapter serves as a basic overview of ultrasound physics and image acquisition. This includes standard machine functionality and transducer manipulation. …

Ultrasound probes, called transducers, produce sound waves that have frequencies above the threshold of human hearing (above 20KHz), but most transducers in current use operate at …

2025年1月3日 · Ultrasonic waves are sound waves that are above the range of sound audible to humans. The ultrasonic waves are produced by the electrical stimulation of a piezoelectric …

The characteristics of ultrasound, such as frequency and intensity, are wave properties common to all types of waves. Ultrasound also has a wavelength that limits the fineness of detail it can …

The information in an ultrasonic image is influenced by the physical processes underlying propagation, reflection and attenuation of ultrasound waves in tissue

2017年6月4日 · Sound waves are emitted from the ultrasound transducer with a known amplitude, direction, and frequency. However, interactions with tissues in the body result in alterations of …

Ultrasound imaging near the surface of the body is capable of resolutions less than a millimeter. The resolution decreases with the depth of penetration since lower frequencies must be used …