“Technology that keeps track of how your smartphone is oriented can now give $50,000 ultrasound machines many of the 3-D imaging abilities of their $250,000 counterparts—for the cost of a $10 microchip.
In a presentation at the American College of Emergency Physicians Research Forum on October 31, doctors and engineers from Duke University and Stanford University showed how their snap-on invention can make 2-D ultrasound machines much more powerful. With a few cents’ worth of 3-D-printed materials, a microchip common to smartphones, a few wires and a laptop, a 2-D ultrasound machine can capture 3-D images of infants’ brains with similar quality to MRI or CT scans while the baby is held in a parent’s arms.
“With 2-D technology you see a visual ‘slice’ of an organ, but without any context, you may mistake it for another part, or mistake one disease process or injury for another,” said Joshua Broder, M.D., emergency physician and director of the emergency medicine residency program at the Duke University School of Medicine. “These are all problems that can be solved with the added orientation and holistic context of 3-D technology. Gaining that ability at an incredibly low cost by taking existing machines and upgrading them seemed like the best solution to us.”
The idea came to Broder while playing a game of Nintendo Wii with his son. With the game console’s ability to accurately track the exact position of the controller, Broder wondered, why not just duct-tape the controller to an ultrasound probe?
That is the basic idea behind the new device. When physicians use a 2-D ultrasound machine, they move and tilt the probe in various directions until they get the view they want. But in the process, they are essentially throwing away perfectly good data. The new device keeps track of the exact orientation of the probe while imaging a patient, so that those images can be stitched together in three dimensions.
“If each image were a playing card, then it would be like putting them all together in order into a deck so you can flip through it,” said Broder. “Each image is a slice that makes up the whole.”
The prototype includes a 3-D-printed harness that snaps on to the ultrasound probe to securely attach the position-tracking microchip. That harness then snaps into one of several platforms that restricts its movement to a single axis of rotation.
For example, one platform only allows the probe to swing in an arc like a door on a hinge. Another only allows it to twist in a circle along its vertical axis. These platforms are meant to allow the orientation of the probe to change while keeping the device centered over one location on a patient.
The microchip is connected to a computer via a USB cord, while the ultrasound device itself is connected through any type of visual cord, be it USB, HDMI or DVI. As long as the ultrasound machine has a video output—which nearly all of them do—the new device can upgrade it to three dimensions.
“We’ve tried it on all types of ultrasound machines made by GE, Siemens, Philips, SonoSite—you name it—and it’s worked every time without any previous testing,” said Broder. “After a quick arc or twist of the probe, the software churns out a 3-D image in a matter of seconds.”
The invention is currently being tested in clinical trials at both Duke and Stanford, and the study presented at the research forum is a perfect example of its utility.
Some newborns need brain imaging to diagnose congenital problems, but infants are notoriously difficult to scan. MRI machines require stillness over an extended period of time to achieve high resolution, which means either sedating the baby or settling for a lower resolution. CT scans provide excellent 3-D images, but expose the infant to radiation.
Both require the baby be put into a large machine and cost a lot of money. Neither are good options.
In the study, physicians were able to take a normal ultrasound probe upgraded with the 3-D conversion kit, center it above the infant’s head, twist the probe 180 degrees, and get 3-D images of similar quality to either CT or MRI. The whole process took a few seconds and was completed while the babies were still in their mothers’ arms.
“Ultrasound is such a beautiful technology because it’s inexpensive, it’s portable, and it’s completely safe in every patient,” said Broder. “And it’s brought to the bedside and it doesn’t interfere with patient care.”
According to Broder, the 3-D upgrade kit is “months away from being ready for primetime.” It has come a long way since he envisioned it in 2014, and he attributes its success to the resources available at both Duke and Stanford.
After spending his spare time on it as a labor of love for a year, Broder sought help from Bob Barnes, an instructor in Duke’s Masters of Engineering Management program who leads a course on creating biomedical devices. Barnes introduced Broder to the Duke engineers who would come to form the team behind the success of the new device: Matt Morgan, an undergraduate at the time who is now in graduate school at Duke, and Carl Herickhoff and Jeremy Dahl, who were both biomedical engineering instructors and professors at Duke.
Herickhoff and Dahl have since taken positions at the Stanford University School of Medicine, where they continue to develop the device. Their effort is supported by Stanford’s branch of the Wallace H. Coulter Foundation, which supports collaborative translational research projects at several universities, including Duke.
The team also had initial help with the patenting and company formation through the Duke Office of Licensing and Ventures. More recent support has come from grants from the Emergency Medicine Foundation and General Electric, which are funding clinical trials for the device’s use to locate and identify bleeding and hemorrhages in patients with traumatic shock.
The team believes their current clinical trials and support will allow them to bring their idea to market in only a couple of years. They envision a wide range of benefits, such as bringing 3-D imaging to limited-resource areas both at home around the world and lowering the cost of care. They are also working to bridge some of the gaps between their work-around 3-D technology and current 3-D ultrasound devices, such as the ability to capture a beating heart in motion.
With the resources available to them, Broder has high expectations for the coming years.
“I have been working at Duke since 2005 but my focus had always been on taking care of patients, conducting clinical research with existing imaging technologies and educating residents,” said Broder. “I look back and can’t believe that I was as blind as I was to the opportunities of having a world-class university with an engineering school focused on innovation and collaboration right down the street. It really broadened my horizons to what was possible.””