Mid-infrared photoacoustic spectroscopy detecting continuous ultrasound for non-invasive tissue component analysis

Photoacoustic spectroscopy using mid-infrared light enables non-invasive analysis of biological tissue components. In photoacoustic spectroscopy, which detects ultrasonic waves generated by irradiation with pulsed infrared light, a method of inducing resonance by varying the pulse modulation frequency was investigated. This method was used to obtain photoacoustic spectra of human skin. Pre- and post-prandial measurements were performed over several days to investigate the feasibility of analysing blood components. The results showed that changes in measurement site, shape and daily baseline made the analysis of blood components difficult. Therefore, an investigation to reduce spectral variability is also being carried out.