A team of MIT engineers has created a medical ultrasound system that uses a postage stamp-sized patch glued to the patient’s skin. The sensor could someday give doctors the ability to view a patient’s vital organs constantly, in real time.
“The potential is beyond imagining,” said Xuanhe Zhao, the Massachusetts Institute of Technology mechanical engineering professor who led the project. Details of the research were published on Thursday in the journal Science.
Allan Hoffman, president of Commonwealth Radiology Associates of Andover, said the MIT system “would be a paradigm shift in how ultrasound exams are administered.”
Ultrasound systems, first developed in the early 1940s, beam high-frequency sound waves into a body. The sound that bounces back is converted into video images of a patient’s organs and bones. Such scans are routinely used to monitor pregnancies, and to examine organs, bones, and blood vessels. Unlike X-rays or CT scans, ultrasound systems don’t use hazardous radiation, and unlike MRI scans, they don’t require massive magnets and a lot of electric power. They are also relatively small and portable.
Still, the machines require a skilled technician to manually aim the ultrasound probe at the correct part of the patient’s body. Also, the technician must apply a gel to the area being monitored, to ensure the sound travels properly through the body. This gel must be reapplied before each ultrasound scan. Robots are sometimes used to hold the ultrasound probe in place for extended periods, but it’s a costly and uncomfortable process.
The new MIT system would allow a doctor or technician to attach a patch directly over the area to be scanned. The patch is plugged into a device that captures the ultrasound signal, converts it to a viewable image and records it for future reference.
Just as intensive care doctors routinely use inexpensive sensors to detect a person’s heart rate or blood oxygen level, the ultrasound patch could make it just as easy for them to call up live ultrasound images of a patient’s vital organs. ”That imaging can be long term, let’s say over a full day, and continuous,” said Zhao.
In tests on human subjects, the patch worked for up to 48 hours, with no need to apply additional gel. And it continued to deliver clear, sharp images even when the test subjects engaged in vigorous activity, like running or cycling.
For now, the ultrasound patch must still be attached by wires to a receiving device. But Zhao said the next step will be a version with a built-in battery and short-range radio. A patient could connect the patch to the Bluetooth radio inside her smartphone. With such a system, the patient could be sent home, but her doctor could still order up a fresh ultrasound scan at any time.
Zhao said that the technology might eventually become cheap enough to be purchased over the counter by consumers, just as anybody can buy a heart rate monitor or oxygen sensor. That way, an expectant mother could view ultrasound images of her developing infant anytime she wants.