Laser Doppler flowmeters for microcirculation measurements

Abstract

Laser Doppler flowmetry (LDF) is a technique for real-time assessment of microcirculation blood flow. LDF can be used for non-invasive perfusion monitoring (for example skin perfusion monitoring), or for invasive microcirculation evaluations (for example perfusion brain evaluations). Using a multi-wavelength laser Doppler flowmeter prototype with different spaced detection fibers, we propose to add depth discrimination capabilities to LDF skin monitoring. We also propose to build a self-mixing based laser Doppler flowmeter prototype for brain perfusion estimation. These two prototypes will solve two drawbacks prevailing in the laser Doppler flowmeters commercially available: one dealing with the absence of depth information in skin perfusion monitoring; and the other dealing with the fact that laser Doppler probes for invasive evaluations are too large for perfusion brain measurements causing damage to the tissues.