Monitors Track Vital Signs for Fitness and Safety
- Saturday, 01 January 2011
Have you ever felt nauseous reading a book in the back seat of a car? Or woken from a deep sleep feeling disoriented, unsure which way is up? Momentary mixups like these happen when the sensory systems that track the body’s orientation in space become confused. (In the case of the backseat bookworm, the conflict arises when the reader’s inner ear, part of the body’s vestibular system, senses the car’s motion while her eyes are fixed on the stationary pages of the book.) Conditions like motion sickness are common on Earth, but they also present a significant challenge to astronauts in space.
Human sensory systems use the pull of gravity to help determine orientation. In the microgravity environment onboard the International Space Station, for example, the body experiences a period of confusion before it adapts to the new circumstances. (In space, even the body’s proprioceptive system, which tells the brain where the arms and legs are oriented without the need for visual confirmation, goes haywire, meaning astronauts sometimes lose track of where their limbs are when they are not moving them.) This Space Adaptation Syndrome affects a majority of astronauts, even experienced ones, causing everything from mild disorientation to nausea to severe vomiting.
“It can be quite debilitating,” says William Toscano, a research scientist in NASA’s Ames Research Center Psychophysiology Laboratory, part of the Center’s Human Systems Integration Division. “When this happens, as you can imagine, work proficiency declines considerably.”
Since astronauts cannot afford to be distracted or incapacitated during critical missions, NASA has explored various means for preventing and countering motion sickness in space, including a range of drug treatments. Many effective motion sickness drugs, however, cause undesirable side effects, such as drowsiness. Toscano and his NASA colleague, Patricia Cowings, have developed a different approach: Utilizing biofeedback training methods, the pair can teach astronauts, military pilots, and others susceptible to motion sickness to self-regulate their own physiological responses and suppress the unpleasant symptoms. This NASA-patented method invented by Cowings is called the Autogenic Feedback Training Exercise (ATFE), and several studies have demonstrated its promise.
“We’re able to get people to significantly increase their motion sickness tolerance,” says Toscano, noting that in laboratory studies conducted over a 20-year period about 85 percent of those who have undergone the 6-hour training experienced benefits, with about 65 percent able to suppress their symptoms entirely.
In order to gather the necessary physiological data for their research and to enable the ATFE biofeedback training, Toscano and Cowings needed a practical solution for monitoring the vital signs of test subjects like astronauts and pilots.
“The biggest consideration with using physiological monitors on astronauts and aircrew is putting sensors on the body,” Toscano says. “You need to have an unobtrusive device.”
A company in Annapolis, Maryland, proved to have the technology the NASA researchers were looking for. Now the resulting partnership has both enabled NASA studies and provided powerful commercial fitness and health monitoring tools for soldiers, first responders, professional athletes, and consumers.
Zephyr Technology launched in 2003 with the goal of providing physiological status monitoring (PSM) for people in any condition or environment. Working with innovative technologies like smart fabrics and solid-state accelerometers, the company developed a unique PSM device—a narrow fabric band worn around the upper torso. Called the BioHarness, the product’s ability to capture, store, and transmit a range of vital sign data, coupled with its comfortable design, made it ideal for Toscano and Cowings’ research.