Ketamine affects the cardiovascular system, absolute cerebrovascular hemoglobin oxygenation and concentration but preserves respiratory parameters
Often regarded as artifacts, fNIRS data are rich in physiological information from which multiple physiological features can be extractedFirst, we quantified changes in cardiac signals following ketamine and saline injection. Because this is the first study in which the Kernel Flow1 TD-fNIRS headset was used to derive these signals, we used an auxiliary PPG sensor (attached to the finger) to validate the procedure. Both the PPG sensor and the Flow1 TD-fNIRS system measure pulse rate (PR), which is strongly related to HRRobust physiological measurements with the Kernel Flow1 TD-fNIRS system reveal significant differences between the ketamine and saline dosing sessions. (Next, we asked whether there were significant differences between ketamine and saline dosing sessions with respect to cerebrovascular hemodynamics and oxygenation. Therefore, we computed the absolute concentrations of oxy- and deoxy-hemoglobin concentrations commonly referred to as HbO and HbR, respectively (“Lastly, we explored other physiological measures that were captured in parallel. Using the capnography time-series recorded from the Nonin capnograph (Supplementary Fig. 