Original Article

 

Measurement of Blood Flow Velocity Waveforms in the Carotid, Brachial and Femoral Arteries during Head-Up Tilt

 

A. Azhim1, M. Katai1, M. Akutagawa1, Y. Hirao2, K. Yoshizaki3, S. Obara4, M. Nomura4, H. Tanaka5, H. Yamaguchi6, Y. Kinouchi1

 

1 Institute of Technology and Science, The University of Tokushima, Japan

2 Electronic and Mechanical sec., Tokushima Pref. I.T.C., Japan

3 Institute of Health Bioscience, The University of Tokushima, Japan

4 Dept. of Human and Social Science, The University of Tokushima, Japan

5 Faculty of Healthy and Living Science, Naruto University of Education, Japan

6 Dept. of Environmental Physiology, Tokushima Bunri University, Japan

 

Corresponding Author: Azran Azhim

Mailing Address: Institute of Technology and Science, The University of Tokushima, Japan 770-8506

Tel: +81-88-656-7475

Fax: +81-88-656-7475

Email: azran@ee.tokushima-u.ac.jp

 

 

ABSTRACT

 

The purpose of this study is to measure blood velocities in carotid, brachial and femoral arteries with synchronized measurement of electrocardiogram (ECG) during head-up tilt (HUT) using a developed telemetry measurement system. The velocity waveforms and ECG are continuously measured in six putatively healthy young subjects for 130 s during supine and 90 degrees HUT. From the measured peak systolic S1 and end-diastolic d velocities, we assess the velocity waveforms in 3 arteries by using an index of d/S1. The velocity waveforms, heart rate (HR), and blood pressure (BP) are assessed for 20 s at the stages of postural change. There is no significant change in the carotid index of d/S1, but there are significant increases in the brachial and femoral index. HUT induces increase in HR. However, BP does not change with tilt. A constant in the carotid index is due to the effect of cerebral autoregulation (CA) maintaining blood flow to the brain. In contrast, the index in the brachial and femoral is more influenced by venous pressure (VP) in postural change. In conclusion, this study demonstrates that synchronized measurement of blood velocity waveforms in carotid, brachial, and femoral in HUT using the telemetry measurement device is attainable.

 

Keywords:  blood flow velocity waveforms, synchronized measurement, head-up-tilt, venous pressure, cerebral autoregulation

 

Received 17 February; Accepted 6 June 2007

 

 

© Journal of Biomedical & Pharmaceutical Engineering 2008

ISSN 1793-4532

Volume 2, Issue 1, Page 1-6