Design and evaluation of a fibre-optic sensor for limb blood flow measurements

A fibre-optic microbending sensor for clinical use in venous occlusion plethysmography (VOP) has been developed. The sensor utilizes the microbending principle to detect the volume expansion of a limb following venous occlusion. This principle is based on the loss of energy in an optical fibre that undergoes mechanical perturbations. A comparative study of 10 healthy subjects has been made between the new fibre-optic sensor and a mercury strain-gauge sensor. Each subject's limb blood flow was recorded 10 times. The two sensor types were positioned closely together on the same limb. The result of the study shows a high correlation (r = 0.949) verifying that the fibre-optic sensor's performance makes it a suitable alternative to the mercury strain-gauge sensor.