Instrumentation and Measurement Physics(DIMP)
Physique des instruments et mesures (DPIM)
Juan Jose ALVARADO-GIL
University of Guelph
Study of Blood Sedimentation by Photothermal and Optical Techniques
Blood sedimentation rate is a usual indicator in clinical diagnosis, being especially helpful as an auxiliary method in the determination of diseases. The use of new techniques in the study of these phenomena would permit to establish more adequate methodologies as well as new applications of this clinical indicator.
The dynamics of fish blood sedimentation is studied at real time using photoacoustic, photopyroelectric and optical techniques. In the case of photothermal techniques two configurations are shown, direct illumination of the sample and illumination of the substrate in which the blood is standing. It is shown that the time evolution of the signal follows a second order kinetics, dominated by the change of the optical properties in the first case and by the thermal ones in the second.
In the case of the optical techniques the study is based on the analysis of light transmission through the blood. The transmitted light is simultaneously monitored by a vertical arrangement of optical fibres connected to photodiodes. This technique permits us to study the dynamics of sedimentation at real time and at different heights. It is shown that the results for the parameters of sedimentation depend strongly on the height at which the optical fibres are positioned. This allows us to find the optimal height at which this kind of studies could provide consistent and precise results. Results for fish belonging to three experimental groups treated with different substances are presented. The differences observed in the sedimentation rates are discussed.