This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Almond, N. E. Articles by Cooke, E. D. Search for Related Content PubMed PubMed Citation Articles by Almond, N. E. Articles by Cooke, E. D. Social Bookmarking                         What's this?

Noninvasive Measurement of the Human Peripheral Circulation: Relationship Between Laser Doppler Flowmeter and Photoplethysmograph Signals from the Finger

St. Bartholomew's Hospital, London, England

Deric P. Jones

St. Bartholomew's Hospital, London, England

Ernest D. Cooke

St. Bartholomew's Hospital, London, England

Under certain conditions laser Doppler flowmeter (LDF) signals obtained from the finger pulp may appear very similar to those obtained by use of a direct current (dc) photoplethysmograph (PPG). A combined LDF/PPG system was used in conjunction with a circumference strain gauge as an index of vol ume change to identify the conditions in which the correlation between these signals was good.

Simultaneous LDF and dc PPG measurements were made on 10 normal vol unteers by using arterial occlusion and on 7 normal subjects by using the Val salva maneuver at different elevations of the forearm and hand with respect to the midsternum. By altering the elevation of the upper limb the influence of venous filling on each of the signals during these maneuvers was observed.

Since the dc PPG signal always appeared similar to the volume change indi cated by the circumference strain gauge, it is concluded that the dc PPG signal is related to blood volume change if allowance is made for the effects of blood oxygenation. In circumstances of low venous filling, however, blood volume changes correlate well with blood flow changes, producing the correlation be tween the dc PPG and LDF traces.

The dc PPG signal may be used as a means of monitoring changes in blood flow in the finger only when venous filling is low and the return remains unre stricted. Thus, in investigations using this method, the relative position of the limb with respect to the heart should always be indicated. The LDF method appears to be a reliable indicator of blood flow changes in the microcirculation irrespective of the degree of venous filling.

Angiology, Vol. 39, No. 9, 819-829 (1988)
DOI: 10.1177/000331978803900906


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?