The phenomenon has vexed scientists for more than a decade and remains among the greatest health dilemmas of human area exploration. However the findings from UT Southwestern– which NASA employed to seek answers to astronauts vision issues– suggest the high-tech sacks might provide a solution.
Body fluids in zero gravity use constant pressure behind the eyes, causing progressive flattening of the eyeball, swelling of the optic nerve, and vision impairment. Credit: UT Southwestern Medical Center
Notably, researchers found that while simply three days of lying flat caused sufficient pressure to slightly modify the eyeballs shape, no such modification occurred when the suction technology was used.
” We dont understand how bad the impacts might be on a longer flight, like a two-year Mars operation,” stated Benjamin Levine, M.D., a UT Southwestern cardiologist who is assisting NASA deal with the health threats of brain pressure and unusual blood circulation in area. “It would be a disaster if astronauts had such serious disabilities that they could not see what theyre doing and it compromised the objective.”
Reshaping eyeballs
NASA hopes the sleeping bag can address a condition called spaceflight-associated neuro-ocular syndrome, or SANS. The condition is defined by progressive flattening of the eyeball, swelling of the optic nerve, and vision disability.
Previous studies by UT Southwestern and the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas revealed SANS is likely brought on by the consistent pressure that body fluids apply to the brain.
SANS is not a problem in the world, where gravity pulls fluids down into the body each time a person rises. In area, the lack of gravity prevents this day-to-day unloading procedure, permitting more than half a gallon of body fluids to gather in the head and use pressure to the eyeball.
Dr. Benjamin Levine of UT Southwestern has researched the effects of space travel considering that the early 1990s, when he implanted the very first catheter to monitor the heart pressure of an astronaut in area. Credit: UT Southwestern Medical
NASA has recorded vision problems in more than half of the astronauts who served for a minimum of 6 months on the International Space Station. Some became farsighted, had trouble checking out, and sometimes required crewmates to assist in experiments.
” You cant stand up in area to unload the pressure. Thats the problem,” stated Michael Stenger, Ph.D., a scientist with NASAs Human Health Countermeasures Element.
Other dangers
Perhaps the very best treatment up until now has been using unique area glasses with adjustable lenses that remedy astronauts changing vision aboard the space station. This method does little to ease issues about the long-lasting results on the eyeball, nor the prospective cardiovascular complications that Dr. Levines group is discovering.
A 2018 research study, for example, revealed that spending 6 months in absolutely no gravity may increase the odds of establishing a common heart arrhythmia called atrial fibrillation. This condition can result in embolism, cardiovascular disease or stroke.
” And its certainly possible there are other effects of brain pressure we havent recorded yet,” Dr. Levine stated. Whether that has anything to do with the inability to decrease the pressure, we do not understand.”
Although some results of SANS appear momentary– vision returns to regular shortly after astronauts return to Earth– Dr. Stenger said UT Southwesterns research study is essential to the manned Mars flight that NASA wishes to release in the 2030s. The sleeping bag innovation, in particular, might attend to both the brain and heart problems.
” What are the long-term health consequences (of SANS)?” Dr. Stenger stated. “Theres a large team on the ground working to neutralize a lot of these dangers.”
Determining brain pressure
The sleeping bag model is the culmination of a number of stages of research carried out by UT Southwestern to assist NASA better understand the condition, consisting of a 2017 research study that offered compelling evidence that consistent pressure might indeed contribute to SANS.
To test his theory on brain pressure, Dr. Levine recruited cancer survivors from throughout the country who still had ports on their heads where they had received chemotherapy. These ports provided scientists rare access to determine pressure straight in the brain.
The volunteers each went on a zero-gravity airplane flight into the upper environment where their body fluids drifted up. A neurosurgeon from UT Southwesterns Peter ODonnell Jr. Brain Institute measured the brain pressure by placing special devices into the port.
” It was hard,” remembered Wendy Hancock, a leukemia survivor from Philadelphia who accepted go on more than 3 dozen up-and-down maneuvers into absolutely no gravity. “But NASA is incredible, so, heck yeah, I was going to leap at the opportunity to assist. … I did it for the astronauts.”
The resulting research study showed that brain pressure in an individual who rests in the world is actually higher than in space. On Earth the pressure is unloaded when the individual stands and gravity pulls the fluids down. Space supplies no such relief for astronauts.
A new treatment
With this crucial insight, Dr. Levines group began working with the outdoors equipment merchant REI to develop a modern sleeping bag that might be used by astronauts each night to discharge pressure in the brain. Comparable lower body negative pressure innovation has been used for decades to maintain muscle and bone mass in area, previous prototypes were not designed for numerous hours of usage or evaluated as a remedy for SANS.
The bag has a strong frame– appropriately formed like a space pill– and is created to fit over an individual from the waist down.
About a lots people volunteered to check the technology, consisting of Dr. Leidner, an internal medicine hospitalist in San Antonio who is interested in pursuing a career in aerospace medicine.
He made 2 gos to– three days each– to a UT Southwestern research study room where he lay in bed. Only throughout the 2nd visit was he put in the sleeping bag for 8 hours each night. Researchers compared modifications in the brain after each stint.
” Being efficient has actually headed out the window,” he joked, explaining the awkwardness of typing on his laptop computer while lying flat. “But its an experience I could inform my kid one day if it assists people arrive on Mars.”
Numerous concerns need to be responded to prior to NASA brings the technology on the space station, including the optimal amount of time astronauts need to invest in the sleeping bag every day.
However Dr. Levine said his newest findings show SANS hopefully wont be a health threat by the time the area agency is prepared to release to the Red Planet.
” This is maybe one of the most mission-critical medical concerns that has actually been discovered in the last years for the space program,” Dr. Levine said. “Im appreciative for the volunteers who are assisting us comprehend, and ideally, repair the problem.”
Long-lasting research
Dr. Levine has actually researched the effects of area travel since the early 1990s, when he implanted the very first catheter to keep an eye on the heart pressure of an astronaut in space. Considering that then, he has actually worked with NASA on numerous projects and recommends its flight cosmetic surgeons on cardiovascular medical issues. NASA recently granted him $3.8 million in indirect and direct financing over 13 years to study the impacts of space travel on the heart.
Reference: “Effect of Nightly Lower Body Negative Pressure on Choroid Engorgement in a Model of Spaceflight-Associated Neuro-ocular SyndromeA Randomized Crossover Trial” by Christopher M. Hearon Jr, PhD; Katrin A. Dias, PhD; Gautam Babu, MD; John E. T. Marshall, MD; James Leidner, MD; Kirsten Peters, BS; Erika Silva, MS; James P. MacNamara, MD; Joseph Campain, BS and Benjamin D. Levine, MD, 9 December 2021, JAMA Ophthalmology.DOI: 10.1001/ jamaophthalmol.2021.5200.
Other essential members of Dr. Levines group consisted of Christopher Hearon, Ph.D., first author on the JAMA study and Assistant Instructor in the Department of Applied Clinical Research at UT Southwestern; and Tony Whitworth, M.D., a neurosurgeon from the ODonnell Brain Institute who measured clients brain pressure in zero gravity.
Dr. Levine is Professor of Internal Medicine and Director of the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas, a collaboration in between UT Southwestern and Texas Health Resources. He holds the Distinguished Professorship in Exercise Sciences at UT Southwestern.
About UT Southwestern Medical.
UT Southwestern, one of the nations premier scholastic medical centers, incorporates pioneering biomedical research study with exceptional clinical care and education. UT Southwestern physicians provide care in about 80 specializeds to more than 117,000 hospitalized clients, more than 360,000 emergency situation space cases, and oversee nearly 3 million outpatient visits a year.
James Leidner spent three nights in a state-of-the-art sleeping bag that dumps pressure in the brain by suctioning fluids into the lower body.” And its definitely possible there are other effects of brain pressure we havent documented yet,” Dr. Levine said. Brain Institute measured the brain pressure by placing unique devices into the port.
The resulting research study revealed that brain pressure in a person who lies down on Earth is actually higher than in space. Dr. Levine has researched the results of space travel given that the early 1990s, when he implanted the first catheter to keep an eye on the heart pressure of an astronaut in area.
James Leidner invested 3 nights in a high-tech sleeping bag that discharges pressure in the brain by suctioning fluids into the lower body. NASA hopes the sack can be utilized by astronauts in area to alleviate the vision problems they typically endure throughout longer missions. Credit: UT Southwestern Medical
UTSW brain pressure project crucial to Mars mission, NASA says.
A subtle smile emerged on Dr. James Leidners face as he imagined informing people of the unusual contribution he made to humanitys objective to Mars.
For 72 straight hours, the research study volunteer lay in a bed at UT Southwestern, the monotony broken only at night when researchers placed his lower body in a sealed, vacuum-equipped sleeping bag to take down body fluids that naturally flowed into his head while supine.
New research published in JAMA Ophthalmology reveals that by suctioning these fluids and discharging brain pressure, the specially created sleeping bag may prevent vision problems astronauts endure in space, where fluids drift into the head and constantly push and improve the back of the eyeball.
