An integrated laser blood flowmeter

• Published in: Journal of lightwave technology Vol. 21; no. 3; pp. 591 - 595
• Main Authors: Higurashi, E., Sawada, R., Ito, T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-03-2003; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomedical monitoring; Blood; Diode lasers; Diodes; Distributed feedback devices; Distributed feedback lasers; Fingers; Flowmeters; Integrated optics; Laser feedback; Lightweight; Micromachining; Optical feedback; Optical surface waves; Optical waveguides; Silicon substrates; Weight reduction
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2003.809551

We have constructed a very small and lightweight blood flowmeter using micromachining and surface mounting techniques for a wearable health monitoring system. The hybrid integrated structure of the optical system incorporates a InGaAsP-InP distributed feedback laser diode (DFB-LD) with a wavelength of 1310 nm, an edge-illuminated photodiode (PD) and a polyimide waveguide on silicon substrate (2 mm /spl times/ 3 mm). This integrated flowmeter can be positioned directly on the tissue and permits real-time monitoring of capillary microcirculation. In-vivo measurements of blood perfusion in a finger confirm the feasibility of the blood flowmeter.