Monitoring of Pulse Pressure and Arterial Pressure Waveform Changes during the Valsalva Maneuver by a Portable Ultrasound System.

This work presents non-invasive evaluation of the arterial blood pressure (ABP) waveform during the Valsalva maneuver. Ultrasound scanning is conducted to acquire blood flow and arterial distension signals. Motion-tolerant ultrasound measurement schemes are employed by using two wide rectangular transducers. Pulse pressure (PP) estimated at the common carotid artery is compared to that of a finger waveform measured by a volume clamping device. The changes of PP are correlated between the two measurements. A more depressed dicrotic notch during the Valsalva strain is observed, and beat-to-beat variations of PP and a pulse rate caused by respiration and baroreflex is observed during the control. This validation suggests novel opportunities to investigate the pathophysiology of cardiovascular diseases through the noninvasive ABP waveform monitoring during the stress test.