Handheld Doppler
Handheld Doppler - Related Videos
09:12
Sound Waves and Doppler Shift
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2023
Source: Arianna Brown, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA Waves are disturbances that propagate through a material medium or empty space. Light waves can travel through a vacuum and some forms of matter, and are transverse in nature, which means that the oscillations are perpendicular to the direction of propagation. However, sound waves are pressure waves that travel through an elastic medium like air,...
00:56
Doppler Effect - I
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2023
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
01:05
Doppler Effect - II
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2023
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
10:46
Doppler Optical Coherence Tomography of Retinal Circulation
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Cited by 29 •
2012
Total retinal blood flow is measured by Doppler optical coherence tomography and semi-automated grading software.
10:39
Laser Doppler: A Tool for Measuring Pancreatic Islet Microvascular Vasomotion In Vivo
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Cited by 7 •
2018
Pancreatic islet microvascular vasomotion regulates islet blood distribution and maintains the physiological function of islet β cells. This protocol describes using a laser Doppler monitor to determine the functional status of pancreatic islet microvascular vasomotion in vivo and to assess the contributions of pancreatic islet microcirculation to pancreatic-related diseases.
FAQs
Its probe sends high-frequency sound waves into the body, where moving red blood cells reflect them back with a changed frequency. This change, called the Doppler shift, contains information about motion in the blood. The device processes that shift into audible signals or waveform information, allowing clinicians to assess circulation without relying solely on a palpable pulse.
The reflected frequency shift provides information related to both flow direction and velocity. Audible signals can indicate that moving blood is being detected, while waveform information offers a visual representation for vascular assessment. These outputs help clinicians evaluate peripheral arterial and venous circulation and recognize flow where physical examination alone may be difficult.
Portability allows this device to extend vascular and cardiovascular examination to the bedside and other settings without full ultrasound equipment. Its rapid, noninvasive operation supports immediate assessment rather than requiring access to a larger system. It therefore serves as a practical examination aid while providing flow-related signals or waveforms for clinical interpretation.
A clinician places the probe to assess peripheral arterial or venous circulation and listens for the resulting flow signal or examines the available waveform information. The findings can supplement the bedside examination by indicating whether blood movement is detected, its direction, and its velocity. This approach supports rapid vascular assessment without an invasive procedure.
When a peripheral pulse cannot be readily felt, the device can detect flow-related signals at the relevant vascular site. The clinician uses the audible output or waveform information to identify blood movement and support the examination. This is particularly useful when pulse palpation is inconclusive, because the assessment does not depend entirely on tactile detection.
The device can assist with fetal heart-rate monitoring, adding an application beyond peripheral arterial and venous assessment. By detecting motion-related signals, it extends cardiovascular evaluation to fetal monitoring at the bedside. This capability is useful in clinical settings where a portable assessment is needed or where a full ultrasound system is not available.