NASA says the UTSW brain pressure project is critical to the Mars mission

Dallas—December 13, 2021—Dr. James Leidner has a subtle smile on his face, as he envisions telling people about his extraordinary contribution to the human mission to Mars.

The research volunteer lay on the bed at UT Southwestern for 72 hours. Only at night when the researchers put his lower body in a sealed vacuum sleeping bag to pull down the body fluids, the monotony was broken, and the body fluids naturally flowed into him when lying on his back. Head.

New research published in JAMA Ophthalmology shows that by inhaling these fluids and reducing brain pressure, this specially designed sleeping bag can prevent the vision problems that astronauts endure in space. The fluid floats on the head and constantly pushes and reshapes the back of the eyeball. .

This phenomenon has plagued scientists for more than a decade and remains one of the biggest health dilemmas in manned space exploration. But the findings from UT Southwestern—which NASA recruited to find answers to astronauts’ vision problems—suggest that high-tech sacks may provide a solution.

It is worth noting that the researchers found that although lying flat for three days will produce enough pressure to slightly change the shape of the eyeball, this change did not occur when using the suction technique.

"We don't know how bad the impact will be on longer flights, such as a two-year Mars operation," said Benjamin Levine, a Southwestern cardiologist at the University of Texas, who is helping NASA solve the problem. Health risks from brain pressure and abnormal blood. Flow in space. "If the astronauts are so severely damaged that they can't see what they are doing and it will affect the mission, it will be a disaster."

NASA hopes that sleeping bags can solve a disease called space-related neuro-ocular syndrome, or SANS. The condition is characterized by gradual flattening of the eyeballs, swelling of the optic nerve, and visual disturbances.

Previous research by UT Southwestern and the Institute of Exercise and Environmental Medicine at Texas Health Presbyterian Hospital in Dallas indicated that SANS may be caused by constant pressure exerted on the brain by body fluids.

SANS is not a problem on earth. On earth, every time a person gets up, gravity will pull the liquid into the body. In space, the lack of gravity hinders this daily unloading process, allowing more than half a gallon of body fluid to collect on the head and put pressure on the eyeballs.

NASA has recorded more than half of astronauts who have served on the International Space Station for at least six months with vision problems. Some people become far-sighted, have difficulty reading, and sometimes require the assistance of the crew to conduct experiments.

"You can't stand up in space to relieve the pressure. That's the problem," said Dr. Michael Stenger, NASA's human health countermeasure element scientist.

Perhaps the best remedy so far is to use special space glasses with adjustable lenses to correct the constantly changing vision of the astronauts on the space station. But this strategy has little effect on alleviating the long-term effects on the eyeball and the concerns about potential cardiovascular complications that Dr. Levine’s team is discovering.

For example, a 2018 study showed that spending six months in a zero-gravity environment may increase the chance of developing a common arrhythmia called atrial fibrillation. This condition can cause blood clots, heart attacks, or strokes.

"Of course, we haven't recorded other effects of brain stress," Dr. Levine said. "Astronauts reported what they called'space fools'." They made more mistakes than they thought. Whether this is related to the inability to reduce stress, we don't know. "

Although some of the effects of SANS seem to be temporary-vision will return to normal soon after the astronauts return to Earth-Dr. Stenger said that the Southwestern University of Texas research has implications for the manned crews NASA hopes to launch in the 2030s. Flight to Mars is crucial. Especially sleeping bag technology can solve brain and heart problems at the same time.

"What are the long-term health consequences of (SANS)?" Dr. Stenger said. "There is a large local team that is working hard to deal with many of these risks."

The sleeping bag prototype is the culmination of several phases of research undertaken by UT Southwestern to help NASA better understand the disease, including a 2017 study that provides convincing evidence that constant pressure may indeed cause SANS.

In order to test his brain pressure theory, Dr. Levine recruited cancer survivors from all over the country, and they still have ports for chemotherapy on their heads. These ports provide a rare opportunity for researchers to directly measure the pressure in the brain.

Each of the volunteers took a zero-gravity plane into the upper atmosphere, where their body fluids floated upward. A neurosurgeon from Peter O'Donnell Jr. Brain Institute of UT Southwestern measures brain pressure by inserting a special device into the port.

"It was tough," recalled Wendy Hancock, a leukemia survivor from Philadelphia, who agreed to three dozen up and down exercises in a zero-gravity environment. "But NASA is great, so, oops, yes, I intend to seize the opportunity to help.... I do it for astronauts."

The results show that the brain pressure of people lying on the earth is actually higher than in space. However, on Earth, when a person stands and gravity pulls the fluid down, the pressure is unloaded. Space does not provide such relief for astronauts.

With this important insight, Dr. Levine's team began to cooperate with outdoor equipment retailer REI to develop a high-tech sleeping bag that astronauts can use every night to relieve brain pressure. Although similar lower body negative pressure technology has been used to maintain muscle and bone mass in space for decades, the previous prototype was not designed for prolonged use or tested as an antidote to SANS.

This bag has a sturdy frame-shaped like a space capsule-designed to fit a person from below the waist.

About a dozen people volunteered to test this technology, including Dr. Leidner, a medical resident in San Antonio, who was interested in a career in aerospace medicine.

He visited the Southwest Research Laboratory of the University of Texas twice, and he was lying in bed for three days each time. During the second visit alone, he was put in a sleeping bag for eight hours every night. The researchers compared the changes in the brain after each training session.

"Productivity is gone forever," he joked, noting the embarrassment of typing on a laptop while lying flat. "But if it helps humans land on Mars, I can tell my children that this is an experience one day."

Before NASA can introduce the technology to the space station, several questions need to be answered, including the best time that astronauts should spend in their sleeping bags each day.

But Dr. Levine said his latest findings indicate that when the space agency is ready to launch to the red planet, SANS hopes that it will not pose a health threat.

 "This may be one of the most critical medical problems discovered by the space program in the past decade," said Dr. Levine. "I thank the volunteers who helped us understand and hope to solve the problem."

Dr. Levine began studying the effects of space travel in the early 1990s, when he implanted the first catheter to monitor the heart pressure of astronauts in space. Since then, he has been collaborating with NASA on various projects and advising its flying surgeons on cardiovascular medical issues. NASA recently provided him with direct and indirect funding of $3.8 million in 13 years to study the effects of space travel on the heart.

Other key members of Dr. Levine’s team include Dr. Christopher Hearon, the lead author of the JAMA study and an assistant lecturer in the Southwestern Applied Clinical Research Department at the University of Texas; and Tony Whitworth, MD, a neurosurgery at the O'Donnell Brain Institute Doctor, he measured the patient's brain pressure in zero gravity.

Dr. Levine is a professor of internal medicine and director of the Institute of Sports and Environmental Medicine in Dallas, Texas Health Presbyterian Hospital, a cooperative institution of Southwestern University of Texas and Texas Health Resources. He holds the position of Distinguished Professor of Exercise Science at UT Southwestern.

About UT Southwestern Medical Center

UT Southwestern is one of the nation's premier academic medical centers, combining pioneering biomedical research with excellent clinical care and education. The faculty and staff of the institution have won six Nobel Prizes, including 25 members of the National Academy of Sciences, 16 members of the National Academy of Medicine, and 14 Howard Hughes Medical Institute researchers. More than 2,800 full-time faculty members are responsible for groundbreaking medical advancements and are committed to rapidly transforming science-driven research into new clinical treatment methods. UT Southwestern University doctors provide approximately 80 specialist care for more than 117,000 inpatients and more than 360,000 emergency room cases, and supervise nearly 3 million outpatient visits each year.

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