Angioscan Electronics AngioScan-01, User Manual, Page: 31 / 119

AngioScan Medical Tests 27
© 2014 AngioScan-Electronics LLC
4 AngioScan Medical Tests
4.1 PPG Contour Analysis
4.1.1 Patient preparation requirements
1. The testing can be conducted at any time. However, when the purpose of the study is to evaluate the
effects of a therapy (for instance, therapies for treating hypertension, heart disease, or diabetes), the
testing should be done in the morning in order to eliminate the influence of circadian rhythms on test
results.
2. Smoking, vasoactive drugs, caffeine, alcohol, and other stimulants, intense physical activity should be
avoided one day before the testing with Angioscan.
3. Immediately before the testing, the subject should rest for no less than 10 minutes in a warm,
darkened and quiet room.
4. The testing should be done either in the supine or seated position. The patient’s hands should be
placed at the heart level. The test results recorded in the supine or a seated position have marked
differences. This is due to the changes in transmural pressure in the aorta and the arteries of the arm.
When the contour analysis is performed from time to time in order to monitor the changes in the
measured parameters, the testing should be done on the same hand. In this case, the right hand is
preferred due to the anatomy of the arterial vessels.
An example of the data collected during contour analysis in different positions of the patient.
The diagrams below demonstrate the importance of adherence to the patient preparation requirements
above. The diagrams show the signals recorded from the same subject in the seated and the supine
positions. In this example, all of the observed differences are due exclusively to the effect of orthostasis
(i.e., the patient's position) on the patient’s hemodynamics.