| Oxygen is necessary for metabolism. It is carried from lungs to the rest of the body by hemoglobin in blood. As each hemoglobin molecule can carry a maximum of four oxygen molecules, oxygen saturation (sO2) is the measure of percentage of oxygen content in blood. For a normal person sO2 is 95% - 100%. Point-of-care testing of sO2 in blood is important in medicine. It enables doctors and caregivers for monitoring a wide variety of chronic illnesses. On the other hand, mapping of sO2 values by performing a raster scan across the region of interest in vivo is also essential in clinical and research settings, such as to evaluate the therapeutic effects of a treatment, monitoring healing of wounds, etc. Several non-invasive methods have been developed for this purpose. In this thesis, I measured the nonlinear absorption coefficient (beta) of blood samples using photoacoustic Z-scan technique. Results depict linear dependency between beta and blood oxygenation levels. |
