INTRODUCTION: Real-time cardiovascular imaging during hypergravity exposure has been historically limited by technological and physical challenges. Previous efforts at sonographic hypergravity imaging have used fixed ultrasound probes; the use of hand-held ultrasound, particularly performed by minimally trained laypersons, has been less explored. Here we will discuss handheld sonography to self-visualize carotid vascular and cardiac changes during hypergravity. METHODS: Three subjects with variable ultrasound experience ranging from no familiarity to extensive clinical experience used handheld ultrasound at rest and under stepwise +Gz hypergravity exposures (maximum +3.5 Gz) to visualize carotid vascular changes. Subxiphoid cardiac ultrasound was obtained by the most experienced subject. Subjects had variable prior hypergravity experience; all were trained in anti-G straining techniques. Sonographically inexperienced subjects underwent a brief (< 5 min) familiarization with the ultrasound probe, user interface, and desirable viewing window immediately prior to centrifugation; real-time coaching was provided. Ultrasound images were correlated to self-reported symptoms and hemodynamic data. RESULTS: Handheld ultrasound performed as desired; all subjects were successful at obtaining ultrasound images with adequate capture of windows of interest. Subxiphoid imaging efforts were limited by probe overheating and associated with variable quality of imaging due to probe displacement from straining techniques; the subject noted transient, mild discomfort and ecchymosis after imaging in the subxiphoid region. DISCUSSION: Even individuals with minimal or no ultrasound experience successfully obtained usable images under centrifuge conditions. While there were some limitations, this technical demonstration provides initial validation of handheld sonography as an available tool for real-time cardiovascular imaging in a hypergravity environment. Blue RS, Ong KM. Handheld sonographic cardiovascular imaging under hypergravity conditions. Aerosp Med Hum Perform. 2024; 95(3):158–164.
Jugular imaging window. The jugular imaging window was identified by the following landmarks: the jugular valve was first identified (point 1), followed by the base of the skull (point 4), then two equidistant points between points 1 and 4 (points 2 and 3). Point 2 was marked for ease of identification during centrifuge profiles.
Jugular imaging by minimally experienced sonographer (Subject 2). A) Jugular vein as imaged by a minimally experienced sonographer while relaxed at +3.5 Gz. B) Jugular venous distention as imaged by a minimally experienced sonographer performing an anti-G straining maneuver at +3.5 Gz. The carotid artery is marked by a star; the jugular vein is indicated by a white arrow.
Jugular imaging by a novice sonographer (Subject 3). A) Jugular vein as imaged by a novice sonographer while relaxed at +3.5 Gz. B) Jugular venous distension as imaged by a novice sonographer performing an anti-G straining maneuver at +3.5 Gz. The carotid artery is marked by a white star; the jugular vein is indicated by a white arrow.
Subxiphoid cardiac imaging by an experienced sonographer (Subject 1). A) Subxiphoid imaging at rest before profile initiation. B) The same image is presented with a white outline of right ventricle volume. C) Subxiphoid imaging while relaxed at +3.5 Gz. D) The same image is presented with a white outline of right ventricle volume. Note the relative collapse of the right ventricle and the partial loss of the ideal cardiac imaging window due to challenging probe management under hypergravity conditions.
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