Doppler probe

Doppler probe

Etymology: Christian J. Doppler
a handheld diagnostic device that emits ultrasonic waves into the body. Reflection of the waves by a moving structure causes a change in their frequency. The Doppler probe has been used as a diagnostic tool since 1960 to study changes in blood flow in arteries and veins.
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Doppler flow detector

Doppler,

Christian J., Austrian mathematician and physicist in U.S., 1803-1853.
Doppler bidirectional test
Doppler echocardiography - use of Doppler ultrasonography techniques to augment two-dimensional echocardiography by allowing velocities to be registered within the echocardiographic image. Synonym(s): duplex echocardiography
Doppler effect - a change in frequency is observed when the sound and observer are in relative motion away from or toward each other. Synonym(s): Doppler phenomenon; Doppler principle
Doppler flow test
Doppler measurement
Doppler phenomenon - Synonym(s): Doppler effect
Doppler principle - Synonym(s): Doppler effect
Doppler probe
Doppler pulse evaluation
Doppler scope
Doppler shift - the magnitude of the frequency change in hertz when sound and observer are in relative motion away from or toward each other.
Doppler ultrasonography - application of the Doppler effect in ultrasound to detect movement of scatterers (usually red blood cells) by the analysis of the change in frequency of the returning echoes.
Doppler ultrasound flowmeter
Doppler ultrasound segmental blood pressure testing

Doppler probe

portable, ultrasound-emitting and receiving device, used in assessment of: (1) arterial systolic blood pressure; (2) quality of blood flow in arteries and veins (slow flow is less audible than normal flow); (3) direction of blood flow in veins; (4) health of the arterial wall (a triphasic sound indicates good arterial wall elasticity, a biphasic sound indicates moderate arterial wall elasticity and a monophasic sound indicates poor arterial wall elasticity/hardening of arteries); also facilitates calculation of ankle-brachial and toe-brachial pressure indices (Box 1; Table 1; see Table 2)
Box 1: The interpretation of Doppler arterial sounds
  • Triphasic (three clear sounds at each pulse beat): a triphasic sound indicates a very healthy artery, with no impedance to blood flow, and good elastic arterial walls. Note: The third sound may not be heard without headphones

  • Biphasic (two clear sounds at each pulse beat): a biphasic pulse sound indicates reasonable arterial health

  • Monophasic (one sound at each pulse beat): a monophasic pulse sound indicates poor arterial health, inelastic arteries and poor peripheral perfusion

Table 1: Arterial features determined by Doppler ultrasonography
Arterial pulse rateBy noting the number of beats in a 10-second period and multiplying by 6 to give the number of beats per minute
Systolic blood pressureBy noting the pressure value at which the first pulse sound is heard when a sphygmomanometer cuff (just proximal to the pulse point and inflated to a level that obliterates arterial sounds) is deflated.
Note: The Doppler cannot be used to record the diastolic blood pressure, as it continues to pick up the sound of the pulse, even when the cuff is fully deflated/removed
Elasticity of the arterial wallInterpreted from the phasic quality (tri-, bi-, monophasic) of the audible pulse (Box 2)
Direction of blood flowInterpreted from the direction arrow on the display panel
Box 2: The interpretation of Doppler arterial sounds
  • Triphasic (three clear sounds at each pulse beat): a triphasic sound indicates a very healthy artery, with no impedance to blood flow, and good elastic arterial walls. Note: The third sound may not be heard without headphones

  • Biphasic (two clear sounds at each pulse beat): a biphasic pulse sound indicates reasonable arterial health

  • Monophasic (one sound at each pulse beat): a monophasic pulse sound indicates poor arterial health, inelastic arteries and poor peripheral perfusion

Table 2: Interpreting ankle brachial (A/B) indices
Systolic pressure ratio (A/B)Interpretation
0.9-1.1Normal
0.5-0.9Arterial compromise/impaired arterial supply to lower leg/foot; patient may report claudication
<0.5Severe arterial supply/frank ischaemia of lower leg and foot; patient may report rest pain
0.1-0.2Impending/frank ischaemic gangrene
> 1.1Incompressible leg artery due to MÖnckeberg's sclerosis; compromised arterial supply to lower leg and foot
References in periodicals archive ?
Movement of skin beneath the Doppler probe results in a biphasic Doppler shift as skin is stretched beneath at the beginning of each movement and recoils at the end of the movement.
The ABI is also a reliable method for screening leg pain, ischemia of the legs, screening for atherosclerosis and the evaluation of vascular compromise in patients with trauma of the lower legs (Grenon, et al, 2009) The only tools required for the testing are a blood pressure cuff and a continuous wave 5 to 10 mHz Doppler probe as well as a skilled technician.
In the first stage, the superficial temporal artery was identified anterior to the tragus, and its course was traced superiorly with a Doppler probe.
Right now in our institution, when we give systemic t-PA within 3 hours [after a stroke], we always put a transcranial Doppler probe on the scalp to help the patient pass the clot faster.
The Company has been engaged in the development of its cardiac output monitor and accompanying disposable Extravascular Doppler probe for the past three years.
CardioQ[TM] involves inserting a small Doppler probe into a patient's esophagus through their mouth or nose to actively and accurately measure blood flow and fluid levels in real time so the physician can optimize fluid levels if any problem is detected.
They reported that the Doppler probe located the axillary artery and detected the turbulence in the blood flow after the insertion of an intra-arterial needle: an excellent block was obtained by injecting local anaesthetic under ultrasound examination (4).
Ultrasound Scanning Machine with Color Doppler Probe and Biopsy guide system with abdom nal and TRUS prooes 134.
2 MHz continuous wave Doppler probe was placed in the suprasternal notch or above the clavicle, and directed at the aortic valve.
However, close to 20 years after the significant value of GDT protocols was established using Doppler probes which are inserted into the patient's esophagus, GDT is used in just a fraction of major surgical procedures.
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