CARDIOTRACK
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Large artery stiffness and endothelial function testing - A practical solution
CardioTrack was developed specifically for the professional who demands
a quick and practical solution for the assessment of large artery stiffness and
endothelial function. This 'next generation' CardioTrack is designed for use
in clinical practice, to aid early detection, treatment, and management of
cardio-vascular disease.
Arterial Stiffness Measurement
The CardioTrack estimates large artery stiffness from the pulse waveform
obtained at the finger (digital volume pulse: DVP) with an
infra-red sensor (photoplethysmography). It is extremely easy to use, operator
independent and is very well accepted as a routine measurement by the patient.
The speed at which the pulse travels along the arterial tree is directly related
to arterial stiffness.
Measuring the time it takes for the pulse waves to travel through the
arterial system provides a simple but accurate way of measuring arterial
stiffness. The shape of the volume waveform in the finger is directly related to
the time it takes for the pulse waves to travel through the arterial tree. This very
important observation is used by the CardioTrack and makes it a powerful
non-invasive tool for the assessment of vascular changes.
The Clinical Value of Arterial Stiffness
Arterial stiffness is an independent predictor of cardiovascular risk. Arterial
stiffness is a measure of target organ damage indicating the need for lifestyle
and drug intervention The DVP waveform is independent of local changes of the
vasculature but determined by large artery stiffness (estimated by SI) and
vascular tone (estimated by RI). SI is highly correlated with PWV, as shown
below, and RI is determined by the systemic vascular tone Endothelial
Function Measurement. The DVP waveform is also very sensitive to the vascular
tone of the whole arterial tree. CardioTrack automatically analyses the finger pulse
to determine a measure of arterial stiffness and a measure of vascular tone.
The change in the DVP waveform in response to an endothelial dependant
vasodilator such as salbutamol (albuterol) can be used to assess endothelium
function. Salbutamol can be administered using an inhaler making this a very
simple test to perform in the clinic or at the bedside.
The CardioTrack uses a high fidelity photo-plethysmography transducer
with signal conditioning circuit to obtain an extremely accurate and noise free
signal of the DVP waveform. This is a simple non-operator dependent
measurement, which is well tolerated by the subject. In addition, a unique
control system maintains the light transmission at the optimum level to
accurately follow blood volume changes, independent of the subject's finger size.
The many advanced features include; a high-resolution touch sensitive colour
display giving real time blood volume pulse waveforms; signal averaging
with advanced rejection/acceptance criteria; and user customisation of many
of the analysis parameters. The CardioTrack measurements may be reviewed
at the time, during the test, or at a later date from memory, which can hold
up to 10,000 test results including the waveform. The unit can be connected
to the USB port of a PC running PCA 2-Upload software. This allows the database
including the waveforms to be uploaded to a PC for viewing, storage, report
generation, data trending and export to other applications.
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