Low frequency spontaneous fluctuations in tissue blood volume in neonates

Low frequency spontaneous fluctuations in tissue blood volume (BV) which originate from the activity of the autonomic nervous system were studied in the toes of healthy adults and in the feet of preterm and full-term neonates. Fluctuations of cardiac-induced blood volume changes (AM) were also investigated using photoplethysmography, the measurement of changes in light absorption by tissue and its constituents. Both fluctuations showed right-left correlations, which indicates mediation of central origin. The average right-left correlation coefficient for adults was significantly higher than that for neonates, probably due to incomplete maturation of the autonomic nervous system for some of the neonates.