At the 2015 American Urological Association annual meeting in New Orleans, Dr. Jonathan Harper will present the findings of an FDA-registered "first in humans" trial to non-surgically propel and expel kidney stones from the body.

Harper and colleagues in the Department of Urology and Applied Physics Laboratory at the University of Washington have invented a new way to facilitate kidney stone passage or dislodge large obstructing stones, using ultrasound.

 Ultrasound technologies have been successfully used for many years on the International Space Station (ISS), primarily to perform imaging of the astronauts' eyes, bones, and internal organs.

The successful outcome of this clinical trial mitigates the risk of renal stone formation, as identified on NASA's Human Research Roadmap. With one probe placed on the patient's skin, a physician can target the stone on the system's ultrasound image. The system focuses ultrasound waves on the stone, which makes the stone "hop" to a new location. Importantly, ultrasound technology does not expose patients to x-rays or other forms of ionizing radiation. Fifteen volunteers with various body sizes presenting with stones of as large as 14 mm and from all regions of the kidney were included in the clinical trial. Kidney stones were moved in all but one subject. 

Harper said, "The impact of this technology on the US healthcare system is substantial because more Americans experience nephrolithiasis, or kidney stone disease, than develop diabetes or heart disease. Kidney stones cause severe pain, obstruction of the urinary tract, and loss of worker productivity. The use of ultrasound technology to move kidney stones is a major advance with broad clinical utility for people on Earth."

This clinical trial has been advanced with funding from the National Space Biomedical Research Institute (NSBRI). "During space flight, microgravity, dehydration, and altered bone metabolism collectively increase the likelihood of an astronaut developing a kidney stone," said Jeffrey P. Sutton, M.D., Ph.D., NSBRI's President, CEO and Institute Director.

Kidney stones have been observed in U.S. astronauts before and after spaceflight and one Russian cosmonaut reported abdominal pain on orbit which was suspected to be due to a kidney stone; however, the pain resolved within a few days. Non-invasive approaches to move and ultimately expel kidney stones from the body provide medical capabilities needed by NASA and other international space agencies.

If stones can be moved and then passed while they are relatively small, downstream complications such as infection and sepsis that could end space missions may be avoided.