ATL ultrasound scanner belts in for shuttle trip to outer space

Despite the technology and capital invested in the International Space Station, the crew has to contend with some of the same problems as citizens of far-flung areas on earth. Healthcare is limited and sophisticated diagnostic imaging is not available. But just as remote villages have taken advantage of ultrasound as a do-it-all modality, so will the ISS astronauts.

On March 8, NASA is scheduled to blast a modified HDI 5000 made by Philips' ATL Ultrasound into orbit aboard the space shuttle Discovery. In the event of injury or illness, cardiologists, radiologists, and other physicians rooted to terra firma will use the world's most advanced teleradiology network to make diagnoses and guide treatment.

"If there is a medical need, ultrasound could be used in some applications that are not normally associated with it: broken bones, dental abscesses, and pneumothorax," said David Martin, lead sonographer for NASA's cardiovascular laboratory at Johnson Space Center. "With a severe injury, the stakes are too high not to use every tool at your disposal."

But the ATL scanner being lofted next month will be pressed into duty more for research than health maintenance. Astronauts will use the extraterrestrial ultrasound system to explore inner space, examining how extended space travel affects the musculoskeletal and cardiovascular systems.

"The knowledge gained may be directly applicable to patients suffering from heart failure," said Dr. James Thomas, a NASA advisor on ultrasound and director of cardiovascular imaging at the Cleveland Clinic Foundation. "At first in space, blood volume increases, but it then drops. This can mimic heart failure, which gives us an opportunity to study the effects under a more controlled situation."

Making these studies possible is a scanner in many respects no different from the flagship ATL product functioning in thousands of medical centers on the planet's surface. A key component of both space- and earth-based HDI 5000s is SonoCT, which compiles data from multiple lines of sight to increase resolution while offering tissue harmonic imaging and other advanced techniques. To get this capability into space, however, took a bit of engineering.

Every ounce of space cargo is worth more than its weight in gold, as the cost of putting a single pound into orbit is $6000. ATL cut the weight of the HDI 5000 from 440 to 200 pounds, saving taxpayers $1.44 million. Once installed in the ISS Human Research Facility, the HDI 5000 took another hit to its mass, as every cubic inch must be planned. Modifications cut the volume of the HDI 5000 by 80%. The device now requires just 14,311 cubic inches of space.

At the same time that engineers were looking for ways to trim the scanner, features had to be added to allow the HDI 5000 to withstand space-borne gremlins in the form of high temperatures, vibration, and radiation. The system had to be hardened against the high G-forces and severe vibration experienced during liftoff. In orbit, microgravity prevents air convection, which on earth allows heat to rise. Consequently, small but powerful fans were added to push heat away from the unit. Electronics and other critical components were built out of nonreactive materials or shielded against cosmic radiation. System diagnostics were tweaked to allow earth-bound engineers to repair the unit remotely.

In the past, space-based endeavors have heaped benefits on earthlings. Many were unexpected. (Who today could do without Velcro, which was invented to keep objects from floating around the cabins of spacecraft?) New medical insights may be uncovered during this flight regarding the internal workings of the body. But technological benefits might accrue as well from the challenges met by ATL engineers who had to trim the size of the HDI 5000 while making it function more reliably under harsh conditions. An immediate benefit could come from the development by Philips and ATL of switching technology and a flat screen that support the display not only of ultrasound images but of virtually any other type of biomedical data. What else might result is anybody's guess.

2/28/01, Issue # 1504, page 3.