Fibre optic intravascular measurements of blood flow: A review

Abstract

Fibre optic sensors are well suited to measuring fluid flow in many contexts, and recently there has been burgeoning interest in their application to direct, invasive measurement of blood flow within human vasculature. Depending on the sensing method used and assumptions made, these intravascular measurements of blood flow can provide information about local blood velocity, volumetric flow, and flowderived parameters. Fibre optic sensors can be readily integrated into medical devices, which are positioned into arteries and veins to obtain measurements that are inaccessible or cumbersome using non-invasive imaging modalities. Measurements of flow within coronary arteries is a particularly promising application of fibre optic sensing; recent studies have demonstrated the clinical utility of certain flow-based parameters, such as the coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). In this review, research and development of fibre optic flow sensors relevant to intravascular flow measurements are reviewed, with a particular focus on biomedical clinical translation.

Fiber-optic probes for real-time pH monitoring

“…44 The minute dimensions of the fiber pH sensors make them appropriate to be directly placed in arteries, veins, or tissues for real-time and continuous monitoring. 45 The developed pH sensor can be integrated with the present in-dwelling medical devices, such as catheters, which would lower the barriers to adoption through subtle modifications to the existing clinician behavior. The real-time monitoring of pH is beneficial in many situations.…”

Single-fiber probes for combined sensing and imaging in biological tissue: recent developments and prospects

“…They also have potential uses in cardiovascular imaging to visualize blood vessels, assess blood flow, and detect plaque buildup. Potential combined modalities are pH or nitric oxide sensing [ 84 ] combined with OCT imaging for plaque detection; or pressure sensing [ 85 ] with imaging for plaque detection and blood flow analysis.…”