Single-frequency lasers. A light at the end of the tunnel

Limb perfusion in the lower limb amputee—a comparative study using a laser Doppler flowmeter and a transcutaneous oxygen electrode

“…However, on a number of occasions some instability has been noted in the readings indicated. This instability appears to be a function of movement of the fibreoptic bundle and is related to the multimode nature of the fibres (Moore, 1985). The artefact can be overcome by stabilizing the fibre bundle, by taping it to the bed clothes for example.…”