Research Paper Volume 14, Issue 9 pp 3910—3920

Figure 2. Age breakdown of brain hemodynamic response against a maximal handgrip strength test. BOV (standard deviation or SD of oxyhemoglobin-to-total hemoglobin ratio) (A–F) reflects the magnitude of brain oxygenation fluctuation during a 30-sec rest phase, a 30-sec contraction phase (10 repetitions), and a 30-sec recovery phase. BHV (standard deviation or SD of tissue hemoglobin values) (G–L) represents the magnitude of brain hemodynamic struggle for maintaining oxygenation stability during the 3 corresponding phases. ^*α < 0.05 compared against the rest phase. Abbreviations: SD: standard deviation of the 300 optical data in 30 sec; BOV: brain oxygenation variability; BHV: brain hemodynamic variability.