Projects

In the case of impaired cerebrospinal fluid absorption, or hydrocephalus, the pressure in the cerebral cortex increases, which also narrows the blood vessels that supply the brain, and thus the dynamics of blood flow pulsations in these blood vessels change. The dynamics of blood pulsations change in a similar way in the case of narrowing of the blood vessels, which is caused, for example, by calcification of the arteries of the leg. Both situations would require a simple, repeatable, and inexpensive diagnostic method for early detection and monitoring of changes. Therefore, the aim of the postdoctoral project and a study carried out at the City University of London was to investigate the effect of constriction on the pulsating optical signal recorded from an artery and to develop an optical method to detect the constriction. An arterial system was developed consisting of a pump and tubing that created different levels of fluid flow obstruction. Suitable optical sensors were built to record the optical signal from the tubes and later from the arteries. In the built arterial system, an optical signal related to the change in blood volume and flow was recorded before and after the induced constriction in the tube. Characteristic changes were detected in the signals, which are directly related to narrowing of the arteries mimicking tubes. As follows, the study was carried out in a small group of subjects, in which the constriction in the arm arteries was artificially induced at different levels. The changes detected from the optical pulsating signal recorded from the artery of the arm were consistent with the changes in the optical signal found in the constructed model. These results provide some confidence that this method and optical technology can be used to detect narrowing of the arteries. However, further studies are needed, for example in patients with calcified leg arteries, and thus to monitor and, if necessary, to improve this methodology.