Crum, who is a principal physicist at APL-UW, said kidney stones could be a serious problem on a long-duration mission. "It is possible that if a human were in a space exploration environment and could not easily return to Earth, such as a mission to an asteroid or Mars, kidney stones could be a dangerous situation," Crum said. "We want to prepare for this risk by having a readily available treatment, such as pushing the stone via ultrasound."
Before a stone can be pushed, it needs to be located. Standard ultrasound machines have a black and white imaging mode called B-mode that creates a picture of the anatomy. They also have a Doppler mode that specifically displays blood flow and the motion of the blood within tissue in color. In Doppler mode a kidney stone can appear brightly colored and twinkling. The reason for this is unknown, but Crum and Bailey are working to understand what causes the Twinkling Artifact image.
"At the same time, we have gone beyond Twinkling Artifact and utilized what we know with some other knowledge about kidney stones to create specific modes for kidney stones," Bailey said. "We present the stone in a way that looks like it is twinkling in an image in which the anatomy is black and white, with one brightly colored stone or multiple colored stones."
Once the stones are located, the ultrasound machine operator can select a stone to target, and then, with a simple push of a button, send a focused ultrasound wave, about half a millimeter in width, to move the stone toward the kidney's exit. The stone moves about one centimeter per second. In addition to being an option to surgery, the technology can be used to "clean up" after surgery.
"There are always residual fragments left behind after surgery
|Contact: Brad Thomas|
National Space Biomedical Research Institute