A5057205887- Spaceflight effects on biology
- High Altitude and Hypoxia
- Traumatic Brain Injury and Neurovascular Disturbances
- Cardiovascular and Diving-Related Complications
- Heart Rate Variability and Autonomic Control
- Space Exploration and Technology
- Cerebrospinal fluid and hydrocephalus
- Hemodynamic Monitoring and Therapy
- Cardiovascular and exercise physiology
- Optical Imaging and Spectroscopy Techniques
- Neurosurgical Procedures and Complications
- Venous Thromboembolism Diagnosis and Management
- Respiratory Support and Mechanisms
- Cardiac Arrest and Resuscitation
- Intensive Care Unit Cognitive Disorders
- Cardiovascular Health and Disease Prevention
- Medical and Biological Ozone Research
- Acute Ischemic Stroke Management
- Neuroscience of respiration and sleep
- Pituitary Gland Disorders and Treatments
- Cerebral Venous Sinus Thrombosis
- Aerospace Engineering and Energy Systems
- Non-Invasive Vital Sign Monitoring
- Blood Pressure and Hypertension Studies
- Adipose Tissue and Metabolism
American Institute of Aeronautics and Astronautics
2023-2025
Massachusetts Institute of Technology
2023-2025
University of Copenhagen
2014-2024
Harvard–MIT Division of Health Sciences and Technology
2023
University of California, San Diego
2017-2022
Jacobs (United States)
2021-2022
Advanced Materials and Devices (United States)
2020
UC San Diego Health System
2018
Rigshospitalet
2005-2017
Kiel University
2014
Key Points Astronauts have recently been discovered to impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure on Earth. Gravity has profound effect fluid distribution and within the human circulation. In contrast prevailing theory, we observed microgravity reduces central venous pressure. This being said, is not reduced levels in 90 deg seated upright posture Thus, over 24 h zero gravity, brain slightly above Earth, which may explain remodelling eye...
We evaluated postural effects on intracranial pressure (ICP) and cerebral perfusion [CPP: mean arterial (MAP) - ICP] in neurosurgical patients undergoing 24-h ICP monitoring as part of their diagnostic workup. identified nine (5 women, age 44 ± 20 yr; means SD), who were "as normal possible," i.e., without indication for intervention (e.g., focal lesions, global edema, abnormalities ICP-profile, or cerebrospinal fluid dynamics). (tip-transducer probe; Raumedic) the brain parenchyma (n = 7)...
High-intensity interval exercise (HIIE) improves cerebral executive function (EF), but the improvement in EF is attenuated after repeated HIIE, perhaps because of lower lactate availability for brain. This investigation examined whether improved relates to brain uptake. Fourteen healthy, male subjects performed 2 HIIE protocols separated by 60 min rest. Blood samples were obtained from right internal jugular venous bulb and brachial artery determine arterial-venous differences across (a-v...
During long-term missions, some astronauts experience structural and functional changes of the eyes brain which resemble signs/symptoms experienced by patients with intracranial hypertension. Weightlessness prevents normal cerebral volume pressure 'unloading' associated upright postures on Earth, may be part ocular pathophysiology. By placing lower body in a negative device (LBNP) that pulls fluid away from cranial compartments, we simulated effects gravity significantly lowered within...
Abstract Aims Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used to treat type 2 diabetes and obesity. Albeit cardiovascular outcomes generally improve, treatment with GLP-1 RAs is associated increased heart rate, the mechanism of which unclear. Methods results We employed a large animal model, female landrace pig, multiple in vivo ex approaches including pharmacological challenges, electrophysiology, high-resolution mass spectrometry explore how elicits an increase...
During everyday life, gravity constantly stresses the cardiovascular system in upright humans by diminishing venous return. This decreases cardiac output and induces systemic vasoconstriction to prevent blood pressure from falling. We therefore tested hypothesis that entering weightlessness leads a prompt increase vasodilatation these effects persist for at least week of space. Cardiac mean arterial were measured 8 healthy during acute 20-s periods parabolic airplane flights on seventh...
The COVID-19 pandemic has produced critical shortages of ventilators worldwide. There is an unmet need for rapidly deployable, emergency-use with sufficient functionality to manage patients severe acute respiratory distress syndrome. Here, we show the development and validation a simple, portable low-cost ventilator that may be manufactured minimal susceptibility supply chain disruptions. This single-mode continuous, mandatory, closed-loop, pressure-controlled, time-terminated emergency...
This study explores two methods of predicting non-cyclic upper-body motions using classification algorithms. Exoskeletons currently face challenges with low fluency, hypothesized to be in part caused by the lag active control innate many leader–follower paradigms seen today’s systems, leading energetic inefficiencies and discomfort. To address this, we employ k-nearest neighbor (KNN) deep learning models predict motion characteristics, such as magnitude category, from surface...
Based on previous water immersion results, we tested the hypothesis that acute 0-G-induced increase in cardiac output (CO) is primarily caused by redistribution of blood from vasculature above legs to cardiopulmonary circulation. In seated subjects (n = 8), 20 s 0 G induced parabolic flight increased CO 1.7 ± 0.4 l/min (P < 0.001). This was diminished 0.8 0.028), when venous return prevented bilateral thigh-cuff inflation (CI) 60 mmHg. Because stroke volume during unaffected CI, lesser + CI...
Decompressive craniectomy (DC) is an emergency neurosurgical procedure used in cases of severe intracranial hypertension or impending herniation. The often lifesaving, but it exposes the brain to atmospheric pressure subsequent rehabilitation period, which changes physiology and probably leads complications such as hydrocephalus, hygromas, "syndrome trephined." objective study was effect cranioplasty on (ICP), postural ICP changes, pulse wave amplitude (PWA).
BACKGROUND: Persistent headward fluid shift and mechanical unloading cause neuro-ocular, cardiovascular, musculoskeletal deconditioning during long-term spaceflight. Lower body negative pressure (LBNP) reintroduces footward loading. METHODS: We designed, built, tested a wearable, mobile, flexible LBNP device (GravitySuit) consisting of pressurized trousers with built-in shoes to support ground reaction forces (GRF) thoracic vest distribute load the entire axial length body. In eight healthy...
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The validity of venous ultrasound (V-US) for the diagnosis deep vein thrombosis (DVT) during spaceflight is unknown and difficult to establish in diagnostic accuracy management studies this context. We performed a systematic review use V-US upper-body system identify microgravity-related changes effect interventions reverse them, assess appropriateness with terrestrial standards. An tool was developed following expert panel discussions studies, including criteria relevant crew experience,...
The hydrostatic indifference point (HIP; where venous pressure is unaffected by posture) located at the level of diaphragm and believed to indicate orthostatic redistribution blood, but it remains unknown whether HIP coincides with for blood volume (VIP). During graded (± 20°) head-up (HUT) head-down tilt (HDT) in 12 male volunteers, we determined from central VIP both using ultrasound imaging inferior caval vein (VIPui), fluid volume, regional electrical admittance (VIPadm). Furthermore,...
Choroid measurements appear to be sensitive changes in gravitational gradients, as well periods of head-down tilt (HDT) bed rest, suggesting that they are potential indicators early ocular remodeling and could serve evaluate the efficacy countermeasures for SANS. Eight hours lower body negative pressure (LBNP) daily attenuates choroid expansion associated with 3 days strict −6° HDT indicating LBNP may an effective countermeasure
In supine humans the main drainage from brain is through internal jugular vein (IJV), but vertebral veins (VV) become important during orthostatic stress because IJV partially collapsed. To identify effect of this shift in venous on cerebral circulation, study addressed both arterial and flow responses "anterior" "posterior" parts when nine healthy subjects (5 men) were seated was manipulated by hyperventilation inhalation 6% carbon dioxide (CO2). From a to position, carotid artery (ICA)...
Arterial baroreflex function is important for blood pressure control during exercise, but its contribution to cardiovascular adjustments at the onset of cycling exercise remains unclear. Fifteen healthy male subjects (24 ± 1 yr) performed 45-s trials low- and moderate-intensity cycling, with carotid baroreceptor stimulation by neck suction -60 Torr applied 0-5, 10-15, 30-35 s after exercise. Cardiovascular responses were compared those obtained rest. An attenuated reflex decrease in heart...
Changes in the gravitational vector by postural changes or weightlessness induce fluid shifts, impacting ocular hemodynamics and regional pressures. This investigation explores impact of direction on intraocular pressure (IOP), mean arterial at eye level (MAPeye), perfusion (OPP), which is critical for health. Thirteen subjects underwent 360° tilt (including both prone supine positions) 15° increments. At each angle, steady-state IOP MAPeye were measured, OPP calculated as - IOP....