Angioscan Electronics AngioScan-01, User Manual, Page: 51 / 119

AngioScan Medical Tests 47
© 2014 AngioScan-Electronics LLC
3. After adding a new patient profile to the database, open the window "Measurements" and choose the
"Occlusion Test" tab.
4. Place the optical sensors at the tips of the patient's index fingers ensuring that the connecting sensor
cable is on the same side as the finger nail.
5. The sensor channel 1 (Ch1 on the device) should be placed on the right index finger. The sensor
channel 2 is placed on the left index finger. Once the sensors are placed on fingers, the moving pulse
waves are seen on the screen. Make sure that the "Level" is in the range of 4 to 60, and the
parameter "PI" is over 1%. Otherwise, the test results are not reliable.
6. Click "Record" to initiate the occlusion test. Pre-occlusion pulse waves are recorded for one minute.
As the data recording continues, a 5-minute occlusion is performed by inflating a standard blood
pressure cuff to a suprasystolic pressure (i.e. systolic blood pressure plus 50 mm Hg). After 5
minutes, the cuff pressure is released and the device continues to collect pulse wave data for 3
minutes, after which the device automatically stops recording.
7. To save the results, click "Save".
4.2.3 Occlusion test results
At the end of an occlusion test performed with Angioscan device, the following test results are shown:
1. The change in the amplitude of pulse wave amplitude before and after occlusion is calculated. The
change in the amplitude characterizes the change in blood volume in small resistive arteries and
arterioles.
2. Phase shift. This parameter characterizes the vasomotor response of the major arteries distal to the
site of occlusion. The physiological significance of this parameter is to assess the effect of the occlusion
on the pulse wave velocity, which is due to the reduced tone of smooth muscles in the arterial wall after
an occlusion as an effect of post-occlusive nitric oxide production.
Thus, the results of the occlusion test occlusion can judge the state of endothelial function in small
resistance arteries (occlusion index) and large muscle (phase shift).
4.2.3.1 Occlusion indexes by sensor channel
Occlusion test is performed with an optical sensor on channel 1 registering the effects of occlusion and
an optical sensor on channel 2 serving as a reference (control) channel.
The two-channel system takes into account the various effects on the pulse waves that can occur during
the occlusion test, such as changes in blood pressure.
As an example, the occlusion test results shown below demonstrate an occlusion index of 1.7 on
Channel 1 and an occlusion index of 0.5 on Channel 2. These indices characterize the change in
amplitude and represent the average ratio of the amplitudes before and after occlusion. In this example,
the amplitude of channel 1 increased 1.7 times and decrease by 50% on channel 2.