How Does DVA™ Work?
DVA™ measures, refines and analyses raw data from traditional Transcranial Doppler
(TCD) ultrasound from up to 23 vessel segments to establish a hemodynamic pattern unique to
each individual tested. It combines three widely accepted physiological measures (see figure
1 below) per vessel into an integrated neurovascular profile or “score” that is precise,
clinically significant and easily interpretable
Existing TCD equipment is used to scan patients at the point of care; gathering and extracting
blood flow data from ultrasound signals for each of the 23 intracranial vessels (see Figure 2).
NHSi’s proprietary analytical software is used to calculate the three standard TCD measures.
The software automatically compiles the patient’s data and compares it to the Company’s proprietary
reference database of asymptomatic subjects (see Figure 3).
In near real time the system generates a comprehensive report describing the patient’s hemodynamic
state. This report shows TCD parameters as standard deviations from reference values in both visual
and numeric form and, where needed, also integrates additional hemodynamic or clinical information
(see Figure 4).
“NHSi’s system promises to enhance greatly the relevance and utility of TCD and other hemodynamic
data in the diagnosis and management of neurovascular disease, and in the development and assessment
of therapies for those diseases. I look forward to continuing my work with NHSi’s leadership to realize
its full scientific and commercial potential.
Rune Aaslid, Ph.D.
(Department of Neurosurgery, Uni. of Bern, Switzerland)
Inventor of TCD, author of seminal publications in neurovascular hemodynamics.
Included in the DVA™ Report, as shown in the example to the below looking at profiles for dementia,
is a graphical representation of the statistical relationship of each of the intracranial vessels to the
asymptomatic norm derived from the database along three standard TCD measurements. Together they form a
highly recognizable “profile” of normal and disease conditions.
The first Panel shows a composite DVA™ profile of all 71-80 year old members of the asymptomatic
database as compared to the mean of the entire asymptomatic database for each of the three TCD parameters
for each of the 23 measured vessels. The next Panel shows the same information for a single patient diagnosed
with dementia. The last Panel shows the same patient one year later evidencing a more pronounced dementia
profile.
This ability to compare symptomatic patients against an asymptomatic reference norm and to track disease
progression and response to therapy is an important new tool for clinicians. The profiles generated by DVA™
enable more accurate diagnoses and management of therapies, resulting in reduced costs and improved patient
outcomes.
