Application
The pocket size Doppler blood flow detector is a simple device enabling a wide range of easy and reliable
diagnosis of blood flow in the vessels.
The Doppler probe is positioned over the examined vessel. The pencil type probe should be between 45 and
60 degree to the skin surface.
The Doppler signal detected in normal arteries generally contains easily differentiated flow phases; first,
louder with higher frequency (higher pitch) and next, with lower intensity and frequency (lower pitch). First
sound is like a strong whistle of wind, remaining two are like more silent noise. In a little narrower arteries
second phase disappear. In extremely narrow arteries (more than 50 %) there is heard only first phase suited to
systole. One-phase signal has usually high frequency and sounds like hiss. Under narrowing, sound has complex
character. It’s contained from high frequency suited to acceleration of flow with put, loud, booming tone which is
connected with disturbing flow from narrowing.
The Doppler signal from the stenosed vessels has higher frequency in the first, systolic phase. The successive
phases are considerably faded down or they disappear completely.
The Doppler diagnosis helps to investigate blood flow, localize the stenosis and occlusions. The unit is
applicable, helpful and it can successfully replace the stethoscope for measurements of blood pressure in patient
with difficult to hear Korotkoff sounds. This application is especially important in detecting of peak systolic
pressure (measured with cuffs and sphygmomanometer). The most common application is ABI (ankle brachial
index) calculation.
Operation
Sonomed Doppler is easy and handy to use. The unit design was though to simplify its use reducing to
minimum controls - volume up/down and on/off switches.
The front of the probe or patients skin should be covered with Ultrasound Gel in the way assuring good
acoustic coupling. It’s better to use more than less Ultrasound Gel. The automatic noise control reduces initial
noise and strong signals from probe movements. Despite of this during putting Ultrasound Gel at the probe it isn’t
advisable work with maximal volume. It is recommended to avoid use of an excessive force pressing probe on
patient’s body during examination by probe’s head as it could cause a pain. Sometimes Ultrasound Gel can also
breed skin’s allergy.
For shipment and transportation probe could be disconnected from main unit. Push-pull probe connectors are
marked
and
situated on side of the main unit. A pair of connectors is symmetrical, generally do not care
to the connecting order (with flat transducer, due the geometry, and only in difficulties it is worth to check both
positions). The self-latching mechanism of connectors protects of pulling out by the cable.
To disconnect always
pull the metal part of the connector!
The basic version operates at ultrasonic frequency 5MHz that is the most common to cover wide range of
applications. 8MHz model is also offered. The pencil type transducers are offered as standard, other shapes like
flat one with “pre-set” Doppler angle are available.
To turn on the device – press button
ON
, to turn off - press
OFF.
To increase the volume - press
to
decrease
.
The continuous green LED light indicates that the unit is turned on. The pulsating green light shows that the
batteries should be recharged. When the unit is not used for a few minutes or batteries are low, it will be turned
off automatically.
