Background: The change in the corrected flow time of the common carotid artery (ccFT{}_{\mathrm{\Delta }}) has been used as a surrogate of changing stroke volume (SV{}_{\mathrm{\Delta }}) in the critically-ill. Thus, this relatively easy-to-obtain Doppler measure may help clinicians better define the intended effect of intravenous fluids. Yet the temporal evolution of SV{}_{\mathrm{\Delta }} and ccFT{}_{\mathrm{\Delta }} has not been reported in volunteers undergoing a passive leg raise (PLR). Methods: We recruited clinically-euvolemic, non-fasted, adult, volunteers in a local physiology lab to perform 2 PLR maneuvers, each separated by a 5 minute ‘wash-out’. During each PLR, SV was measured by a non-invasive pulse contour analysis device. SV was temporally-synchronized with a wireless, wearable Doppler ultrasound worn over the common carotid artery that continuously measured ccFT. Results: 36 PLR maneuvers were obtained across 19 ambulatory volunteers. 8856 carotid Doppler cardiac cycles were analyzed. The ccFT increased nearly ubiquitously during the PLR and within 40–60 seconds of PLR onset; the rise in SV from the pulse contour device was more gradual. SV{}_{\mathrm{\Delta }} by +5% and +10% were both detected by a +7% ccFT{}_{\mathrm{\Delta }} with sensitivities, specificities and areas under the receiver operator curve of 59%, 95% and 0.77 (p 0.001) and 66%, 76% and 0.73 (p 0.001), respectively. Conclusions: The ccFT{}_{\mathrm{\Delta }} during the PLR in ambulatory volunteers was rapid and sustained. Within the limits of precision for detecting a clinically-significant rise in SV by a non-invasive pulse contour analysis device, simultaneously-acquired ccFT from a wireless, wearable ultrasound system was accurate at detecting ‘preload responsiveness’.