Brain perfusion monitoring with frequency-domain and continuous-wave near-infrared spectroscopy: a cross-correlation study in newborn piglets

The newborn piglet brain model was used to correlate continuous-wave (CW) a nd frequency-domain (FD) near-infrared spectroscopy Six ventilated and inst rumented newborn piglets were subjected to a series of manipulations in blo od oxygenation with the effects on brain perfusion known to be associated w ith brain hypoxia-ischaemia. An excellent agreement between the CW and FD w as demonstrated. This agreement improved when the scattering properties (de termined by the FD device) were employed to calculate the differential path length factor, an important step in CW data processing.