With both a photoplethysmography (PPG; Indicor, Vixiar Medical,. Baltimore, MD) and non-invasive blood pressure (Caretaker, Caretaker Medical, Charlottesville, VA) sensors in place on the index and middle fingers, respectively, each patient will be asked to perform three mild, 10-sec Valsalva maneuvers with at least 45 seconds between. Pulse recordings will be collected from each device to compare phases of the Valsalva pulse response including pulse amplitude changes and baseline movement. The primary outcome is the correlation between pulse amplitude ratios for the pulse at the end of the Valsalva to an average baseline pulse.
This study designed is compare the pulse response to the Valsalva maneuver between a photoplethysmography sensor (PPG) and non-invasive blood pressure sensor for the purpose of validating the PPG methodology in deriving a value for the Valsalva pulse response. The aim is to show that the PPG method captures the same phase responses as the blood pressure monitor and the primary outcome is the correlation between pulse amplitude ratios for the pulse at the end of the Valsalva to an average baseline pulse.