NASA Boosts Heart-Monitoring Tech By Philip Chien Wired News
02:00 AM Jul, 07, 2006 http://www.wired.com/news/technology/0,71334-0.html?tw=wn_index_4 This Saturday's scheduled spacewalk from the shuttle Discovery will be the first to use a new system for remotely monitoring astronauts' vital signs in space -- after a contractor's experiment found the old system was producing bad data. Spacewalks are a strenuous activity, so before each one commences astronauts attach sensors to their bodies, identical to the ones used in doctors' offices for ECGs. Each astronaut's heart action is monitored and beamed back to Mission Control, where the on-duty flight surgeon keeps a close watch for signs of undue stress, or health issues that might call for an astronaut to take a break or cut the spacewalk short. The heart-monitoring is a staple of NASA's rigorous attention to the health of its space shuttle astronauts -- a regimen that includes "private medical conferences" where astronauts talk to the flight surgeon directly without anybody else monitoring the circuit, and an on-board medical kit with drugs, tools for minor surgery, and other critical care equipment. (Contrary to urban legend there are no suicide pills anywhere on the shuttle.) Dr. Douglas Hamilton, with NASA contractor Wyle Laboratories, designed an experimental system to improve on the ECG technology. To test it, he examined the raw data from all U.S. spacewalks. That's 91 spacewalks in American spacesuits from the shuttle and International Space Station from 1983 to 2002, according to space historian Robert Ash, adding up to 581 hours. Almost all spacewalks have two astronauts (there was a single exception -- a three person spacewalk in 1992) for a total of 3.8 million heartbeats. When Hamilton's team did some number crunching on the data, they were shocked to find indications that on several spacewalks astronauts had abnormal heart readings -- some physiologically impossible. It turned out that NASA's data-collecting system was producing false readings -- a side effect of packaging the physiological data with the space shuttle's telemetry signal, which was not designed to handle such precisely timed information. That means, at any moment, the flight surgeon might believe that an astronaut was having an arrhythmia, when he or she was just fine. "We have a certified system we know doesn't work, and a uncertified system we trust," recalled Hamilton, speaking at the Aerospace Medical Association conference in Orlando, Florida, last month. Hamilton and his team went on a crash program to finish developing the new system, and it's since been certified. This Saturday's spacewalk by Piers Sellers and Mike Fossum will be the first to make full use of the new system, which is engineered to handle the precise timing of the cardio data feed, and can automatically select the highest quality transmission source from two different satellite links -- one routed through the space shuttle, and a second relayed through the International Space Station. Future missions, though, may dispense with the ritual of monitoring astronauts' ECGs altogether. Hamilton noted that there's no evidence that stress during a spacewalk can lead to abnormal arrhythmia. Where such heartbeat irregularities have been noticed on spacewalks, scientists have been able to prove that the individuals already had arrhythmia before their missions. "We're coming close to concluding that an EVA (extra vehicular activity) does not increase the risks of cardiac arrhythmia in a healthy person, only cases are when there has been previous cardiac history," Dr. Hamilton said. "We're launching bad protoplasm" -- astronauts who aren't in 100 percent perfect health. Eliminating the remote-ECGs would result in cost savings and less work on the ground. In space, it would mean less time and effort, since astronauts would no longer have to don a biomedical harness before each spacewalk. ================================ George Antunes, Political Science Dept University of Houston; Houston, TX 77204 Voice: 713-743-3923 Fax: 713-743-3927 antunes at uh dot edu Reply with a "Thank you" if you liked this post. _____________________________ MEDIANEWS mailing list medianews@twiar.org To unsubscribe send an email to: [EMAIL PROTECTED]
