Share Email Print

Proceedings Paper

Optical interferometric temperature sensors for intravascular blood flow measurements
Author(s): Elizabeth Carr; Eleanor C. Mackle; Malcolm C. Finlay; Charles A. Mosse; Joanna M. Coote; Ioannis Papakonstantinou; Adrien E. Desjardins
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Direct and continuous measurements of blood flow are of significant interest in many medical specialties. In cardiology, intravascular physiological measurements can be of critical importance to determine whether coronary stenting should be performed. Intravascular pressure is a physiological parameter that is frequently measured in clinical practice. An increasing body of evidence suggests that direct measurements of blood flow, as additional physiological parameters, could improve decision making. In this study, we developed a novel fibre optic intravascular flow sensor, which enabled time-of-flight measurements by upstream thermal tagging of blood. This flow sensor comprised a temperature sensitive polymer dome at the distal end of a single mode optical fibre. The dome was continuously interrogated by low coherence interferometry to measure thermally-induced length changes with nanometre-scale resolution. Flow measurements were performed by delivering heat upstream from the sensor with a separate optical fibre, and monitoring the temperature downstream at the dome with a sample rate of 50 Hz. A fabricated flow sensor was characterized and tested within a benchtop phantom, which comprised vessels with lumen diameters that ranged from 2.5 to 5 mm. Water was used as a blood mimicking fluid. For each vessel diameter, a pump provided constant volumetric flow at rates in the range of 5 to 200 ml/min. This range was chosen to represent flow rates encountered in healthy human vessels. Laser light pulses with a wavelength of 1470 nm and durations of 0.4 s were used to perform upstream thermal tagging. These pulses resulted in downstream temperature profiles that varied with the volumetric flow rate.

Paper Details

Date Published: 22 July 2019
PDF: 6 pages
Proc. SPIE 11075, Novel Biophotonics Techniques and Applications V, 1107502 (22 July 2019); doi: 10.1117/12.2527056
Show Author Affiliations
Elizabeth Carr, Univ. College London (United Kingdom)
Eleanor C. Mackle, Univ. College London (United Kingdom)
Malcolm C. Finlay, Univ. College London (United Kingdom)
Barts Heart Ctr. (United Kingdom)
Charles A. Mosse, Univ. College London (United Kingdom)
Joanna M. Coote, Univ. College London (United Kingdom)
Ioannis Papakonstantinou, Univ. College London (United Kingdom)
Adrien E. Desjardins, Univ. College London (United Kingdom)

Published in SPIE Proceedings Vol. 11075:
Novel Biophotonics Techniques and Applications V
Arjen Amelink; Seemantini K. Nadkarni, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?