Photoacoustic study of iron-deficiency anaemia.

A photoacoustic spectrum of a smear of whole blood clearly shows all of the details of the haem absorption in an optical spectrum and good optical absorption data without a data extraction procedure. There are three peaks; gamma (420 nm), beta (550 nm), and alpha (585 nm) in the band 350-700 nm. For iron-deficiency anaemia the peak/peak ratios, ratios of the value of peak gamma to that of the peak beta and peak alpha, and the integral/integral ratios, ratios of the value of the integral under the peak gamma to that under the peak beta, peak alpha, peak beta and peak alpha are closely related to the variation of haemoglobin concentration. Linear relationships among the ratios and the Hb concentration are found. These ratios could be a good index of haem synthesis disturbance.