April 21, 2009 By Blake Harris
Photo: William D. Richard (left) takes an ultrasound probe of colleague David Zar's carotid artery with a low-power imaging device he designed. (David Kilper/WUSTL Photo)
In the Star Trek TV series, the vision of the future included a palm-sized medical scanner, which according to the shows background notes was said to be available from the 2150s. This was able to perform simple diagnostic functions such as reading vital signs and internal scans.
We are perhaps going to be ahead of schedule in developing this kind of capability. Computer engineers at Washington University in St. Louis have coupled USB-based ultrasound probe technology with a smartphone, enabling a compact, mobile computational platform and a medical imaging device that fits in the palm of a hand.
"Twenty-first century medicine is defined by medical imaging," said David Zar, research associate in computer science and engineering one of the two researchers working on the project. "Yet 70 percent of the world's population has no access to medical imaging. It's hard to take an MRI or CT scanner to a rural community without power."
William D. Richard, Ph.D., WUSTL associate professor of computer science and engineering, and Zar succeeded in making commercial USB ultrasound probes compatible with Microsoft Windows mobile-based smartphones, thanks to a $100,000 grant Microsoft awarded the two in 2008. Zar wrote the phone software and firmware for the probes; Richard came up with the low-power probe electronics design. He began working on ultrasound system designs 25 years ago, and in that span he has shrunk the electronics from cabinet-sized to a tiny circuit board one inch by three inches. A typical, portable ultrasound device may cost as much as $30,000. Some of these USB-based probes sell for less than $2,000 with the goal of a price tag as low as $500.
Photo: The image of Zar's carotid artery appears on this small, portable smartphone connected to the probe by a USB driver. (David Kilper/WUSTL Photo)
According to an article by Tony Fitzpatrick, published on the university's web site, the researchers had to optimize every aspect of probe design and operation, from power consumption and data transfer rate to image formation algorithms. As a result, it is now possible to build smartphone-compatible USB ultrasound probes for imaging the kidney, liver, bladder and eyes, endocavity probes for prostate and uterine screenings and biopsies, and vascular probes for imaging veins and arteries for starting IVs and central lines, according to Fitzpatrick. Both medicine and global computer use will never be the same.
"You can carry around a probe and cell phone and image on the fly now," Richard said in a news statement. "Imagine having these smartphones in ambulances and emergency rooms. On a larger scale, this kind of cell phone is a complete computer that runs Windows. It could become the essential computer of the Developing World, where trained medical personnel are scarce, but most of the population, as much as 90 percent, have access to a cell phone tower."
Zar said the vision of the new system is to train people in remote areas of the developing world on the basics of gathering data with the phones and sending it to a centralized unit many miles, or half a world away where specialists can analyze the image and make a diagnosis.
Richard and Zar have discussed a potential collaboration with researchers at the Massachusetts Institute of Technology about integrating their probe-smartphone concept into a suite of field trials for medical applications in developing countries.
"We're at the point of wanting to leverage what we've done with this technology and find as many applications as possible," Richard said.