Crew members on the International Space Station are docked some 250 miles from the nearest hospital, and that's straight down. Now that the government is talking about sending people to Mars, the distance gets real: 35 million miles and counting.

So what do you do if somebody gets sick or hurt out there? A doctor on board can take care of emergencies. But where do you turn for a specialist?

NASA's engineers and flight surgeons have come up with an idea that enables a piece of research equipment to do double duty. The International Space Station is equipped with an ultrasound machine as part of a suite of equipment used for life science research. This is the kind of machine that gives you a snapshot of your baby before the child is born. If it can make sure the kids are all right, then it should work on astronauts. The idea has spawned new medical techniques.

The plan was to have a crew member use the ultrasound probe on the spacecraft, while being coached from the ground by a trained radiologist.

There were a number of challenges to making it work, according to Scott Dulchavsky, chair of the department of surgery at Henry Ford Hospital in Detroit, and a consultant on the project. One was training non-medical personnel to use a complicated diagnostic technique. Performing scans takes a lot of training—on the order of 500 hours. Interpreting them requires a medical doctor.

Science officer Peggy Whitson uses ultrasound equipment, a tool to diagnose injuries, on board the International Space Station.

Manipulating the probe is difficult, Dulchavsky said. Organs vary in size and shift as well—especially in space—and variations on the scale of millimeters can make it difficult to locate the precise spot with the probe. Interpreting black-and-white, shadowy ultrasound images can take a radiologist years to master. Dulchavsky and NASA engineers came up with the idea of using a video stream between the Space Station and the ground base to put an expert in the loop.

Shannon Melton is a biomedical engineer who is the project leader on ultrasonics at Wyle Laboratories, a Houston-based life sciences and engineering contractor for NASA. Melton said that the strategy was to set up a streaming video link to a clinician working on the ground, who gives the crew member verbal instructions about where to place the probe to get the right image. The crew member also works with the aid of a diagram of the human body to guide placement of the probe.
According to Melton, one radiologist compared the ultrasound images from space to "a copy of a copy of a VHS tape."

Communication between the Space Station and ground has a two-second delay. Astronauts and the radiologist practice with a TiVo, which uses a hard drive to pause images, Melton said. Live communication between the Space Station and ground base is available only about 60 percent of the time.

Melton, who has been involved with the project for about five years, said that astronauts get four to six hours of training, including classroom and hands-on practice. She said that NASA has completed testing the procedure, although the technique has not yet been used in an actual medical emergency.

Dulchavsky said that the NASA initiative has expanded the possibilities of using remote diagnosis, or telemedicine, on the ground.

Emergency workers on accident scenes may use the technique. Stephen Smith, a trauma surgeon and professor of surgery at the University of Kansas in Wichita who consulted NASA on the project, said Via Christi-St. Francis Hospital in Wichita has started to train paramedics in helicopter crews that fly to accident scenes. The hospital is planning to use a communication link with medical experts in the hospital, allowing a surgeon to direct a paramedic in real time.

Smith and Dulchavsky said that the NASA project has helped to expand the potential applications of ultrasound in general. Henry Ford Hospital, for example, has used the technique to diagnose a collapsed lung instead of using the more expensive computerized tomography or X-ray.

Henry Ford Hospital is the team hospital for the Detroit Red Wings hockey team. Late last season, the team installed an ultrasound machine in its locker room to diagnose player injuries. Ultrasound is usually done at the hospital.

Piet Van Zant, a trainer for the team, has used the device to diagnose shoulder damage and other injuries. The team is considering its use next season.

"Those trials would never have been done if there had not been a stimulus from the needs of NASA on the International Space Station," Smith said.

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