Task Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and Braslet-M Occlusion Cuffs, SDTO 17011 U/R (Braslet-M -- Duncan, Completed) (Completed)
Last Published:  07/30/21 01:05:34 PM (Central)
Short Title: Braslet
Responsible HRP Element: Exploration Medical Capability
Collaborating Org(s):
Funding Status: Completed - Task completed and produced a deliverable
Procurement Mechanism(s):

The Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and Braslet-M Occlusion Cuffs, SDTO 17011 (Braslet) is a collaborative effort between the National Aeronautics and Space Administration (NASA) and Russian Federal Space Agency (FSA) for which each organization acts as a portion of the co-investigator team. The goal of this investigation is to establish a valid ultrasound methodology for assessing a number of aspects of central and peripheral hemodynamics and cardiovascular function, specifically in rapid changes in intravascular circulating volume. This SDTO will use Braslet-M occlusion cuffs, which are a Russian-made operational countermeasure already pre-calibrated and available onboard for each ISS crewmember.

Braslet will use multiple modes of ultrasound imaging and measurements, in combination with short-term application of Braslet-M occlusive cuffs and cardiopulmonary maneuvers (Valsalva, Mueller) to demonstrate and to evaluate the degree of changes in the circulating volume on orbit. This will be accomplished by performing echocardiographic examinations in multiple modes (including Tissue Doppler mode), ultrasound measurements of lower extremity venous and arterial vascular responses to Braslet-M device under nominal conditions and also during cardiopulmonary Mueller and Valsalva maneuvers. Identical measurements will be repeated without Braslet-M, with Braslet-M applied, and immediately after releasing the occlusion device.

In addition to the primary goal of methodology validation for cardiovascular evaluations (including those related to circulating volume changes and manipulations), operationally relevant procedures will be developed to rule out a number of mission-impacting medical conditions. Space-adapted and non-invasive methodologies to study peripheral and central hemodynamics are a valid contribution of this investigation that can later be used to evaluate other countermeasures, as well as to diagnose or rule out arterial, venous, and cardiac pathology. The effect of prolonged weightlessness on venous capacitance or venous blood flow has not been effectively studied using ultrasound, and the protocols developed by this investigation could be used by other investigators for such purposes.

The data gathering techniques for the volume status evaluation will be validated through assessment of Braslet-M application/release effects, and the use of ultrasound will provide hitherto unobtainable data on the overall effects of Braslet-M as a countermeasure. This investigation will provide pilot data regarding the effect of occlusion cuffs on the cardiovascular system of long-duration crewmembers and reveal whether it can be used as a means of acute or chronic volume manipulation for medical purposes. This activity will also determine the on-orbit and ground resources needed to enable such research during future ISS increments until a full-scale evaluation of the Braslet-M device can be performed. This future work would specifically examine the Braslet-M effects on cardiovascular system physiology, its safety, utility, and potentially new or expanded uses. The results of the current, limited investigation will be used to optimize the pre-flight and in-flight training modules for subsequent expedition crews. The lessons learned from this investigation will be used to propose a more formal operationally relevant investigative protocol for future increments, which in turn will address the question regarding utility of Braslet-M for ISS and exploration-class missions.
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