Engineering news
Created by engineers at the Massachusetts Institute of Technology (MIT), the ultrasound sticker is a stamp-sized device that sticks to the skin and provides continuous ultrasound imaging of internal organs for 48 hours.
In conventional ultrasound imaging, a technician first applies a liquid gel to a patient’s skin, which acts to transmit ultrasound waves. A probe, or transducer, is then pressed against the gel, sending sound waves into the body that echo off internal structures and back to the probe, where the echoed signals are translated into visual images.
Wearable ultrasound imaging tools could have “huge potential” in the future of clinical diagnosis, the researchers said, but they said current options are held back by low resolution and short imaging duration.
The ultrasound sticker reportedly produces higher-resolution images over a longer duration by pairing a stretchy adhesive layer with a rigid array of transducers. “This combination enables the device to conform to the skin while maintaining the relative location of transducers to generate clearer and more precise images,” said Chonghe Wang, lead author of a research paper on the device.
The adhesive layer is made from two thin layers of elastomer that encapsulate a middle layer of solid hydrogel, a mostly water-based material that easily transmits sound waves. Unlike traditional ultrasound gels, the MIT team’s hydrogel is elastic and stretchy.
“The elastomer prevents dehydration of hydrogel,” said Xiaoyu Chen, fellow lead author. “Only when hydrogel is highly hydrated can acoustic waves penetrate effectively and give high-resolution imaging of internal organs.”
The bottom elastomer layer is designed to stick to skin, while the top layer adheres to a rigid array of transducers that the team also designed and fabricated. The entire ultrasound sticker measures about 2cm2 by 3mm deep.
The researchers applied the stickers to volunteers and showed the devices produced live, high-resolution images of major blood vessels and deeper organs such as the heart, lungs, and stomach. The stickers maintained a strong adhesion and captured changes in underlying organs as volunteers performed various activities, including sitting, standing, jogging, and cycling.
The current design requires connecting the stickers to instruments that translate the reflected sound waves into images, but the researchers said they could have “immediate” applications in their current form. The devices could be applied to patients in hospital, for example, continuously imaging internal organs without requiring a technician to hold a probe in place.
If the stickers could be made to operate wirelessly – a goal the team is working towards – they could be made into wearable imaging products that patients could take home from a doctor’s office or even buy at a pharmacy.
“We envision a few patches adhered to different locations on the body, and the patches would communicate with your cell phone, where AI algorithms would analyse the images on demand,” said senior author, Xuanhe Zhao, professor of mechanical engineering at MIT. “We believe we’ve opened a new era of wearable imaging – with a few patches on your body, you could see your internal organs.”
This research was funded by the MIT, Darpa, the National Science Foundation, the National Institutes of Health, and the US Army Research Office through the Institute for Soldier Nanotechnologies at MIT. It was published in Science.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.