The feasibility of a novel, wearable Doppler ultrasound to track stroke volume change in a healthy adult
Jon‐Émile S. Kenny, Igor Barjaktarević, Andrew M. Eibl, Matthew Parrotta, Bradley F. Long, Joseph K. Eibl
Abstract
Abstract: This technical note describes the feasibility of measuring and monitoring the common carotid Doppler spectrogram using a novel, wearable ultrasound patch. In addition, we compare this new ultrasound method to various stroke volume (SV) monitors during preload modifying maneuvers. SV changes were analyzed using a stand-squat-stand (SSS) maneuver performed by a volunteer. Hemodynamic changes induced by SSS were captured simultaneously using a pulse-contour analysis SV monitor as well as the novel Doppler ultrasound patch over the common carotid artery; concurrently, the subject measured either: (I) the velocity time integral (VTI) of the descending aorta in one set of SSS maneuvers or (II) bioreactance SV in a second set of SSS maneuvers. On squat, SV consistently rose by pulse contour analysis—by 24.7% and 38.5% in the two protocols, respectively. Concordantly, VTI of the descending aorta and SV by bioreactance also increased—by 39.3% and 38.3%, respectively. Furthermore, both the VTI and corrected flow time (FTc) of the common carotid artery increased with squat during the two protocols (+14.5%; +45.4% and +7.3%; +16.8%, respectively); conversely, all metrics fell from squat-to-stand. In all instances, there was good clinical correlation between the devices. Measuring and trending the common carotid artery Doppler spectrogram using a wearable, hands-free Doppler ultrasound is feasible. There was good clinical correlation with other accepted technologies during preload modifying maneuvers and the change in standard deviation of the VTI from the wearable patch was roughly one-half that of a traditional, hand-held ultrasound probe. Further testing in healthy subjects is warranted.