The images created from ultrasound are a safe and non-invasive option to know how our body works inside. They have been used for a long time in medicine, for example, to find out the health status of a baby inside her mother or to find the reason why an organ such as the heart is inflamed. To capture these images, specialist technicians manipulate ultrasound wands and probes to direct sound waves into the body. These waves are reflected to produce high-resolution images.
Right now, however, ultrasound imaging requires bulky, specialized equipment available only in hospitals and doctors’ offices. But a new design by MIT engineers could make the technology as portable and accessible as buying Band-Aids at the drug store.
In an article recently published in the journal Science, engineers present the design of a new ultrasound tag: a postage-stamp-sized device that adheres to the skin and can provide continuous ultrasound images of internal organs for 48 hours. hours. During trials, the stickers maintained strong adhesion and captured changes in the underlying organs as the volunteers performed various activities, including sitting, standing, jogging, and cycling.
Although the current design still requires attaching the stickers to instruments that translate reflected sound waves into images, their creators point out that even in their current form, the stickers could have immediate applications: for example, the devices could be applied to patients in the hospital. , similar to heart-monitoring EKG stickers, and could image internal organs continuously without the need for a technician, maintaining analysis for much longer.
If the devices can be made to work wirelessly, a goal the team is currently working on, ultrasound stickers could become portable imaging products that patients could take home from a doctor’s office or even buy. in a pharmacy.
“We visualized some patches attached to different places on the body, and the patches would communicate with your cell phone, where AI algorithms would analyze the images on demand,” he explains in a statement.Xuanhe Zhao, professor of mechanical and civil engineering and environmental engineering at MIT and lead author of the paper. “We think we have opened a new era of wearable imaging: with a few patches on your body, you could see your internal organs.”
How do they work
The MIT team’s new ultrasound sticker produces higher-resolution images over a longer period of time by combining an elastic adhesive layer with a rigid array of transducers. “This combination allows the device to adapt to the skin while maintaining the relative location of the transducers to generate clearer and more precise images,” he explains. Chonghe Wangan MIT graduate student and one of the paper’s authors.
The device’s adhesive layer is made of two thin layers of elastomer encapsulating a middle layer of solid hydrogel, a primarily water-based material that readily transmits sound waves. Unlike traditional ultrasound gels, the MIT team’s hydrogel is elastic and also prevents dehydration of the hydrogel. “Only when the hydrogel is highly hydrated can acoustic waves effectively penetrate and deliver high-resolution images of internal organs.”
The lower elastomeric layer is designed to adhere to the skin, while the upper layer is glued to a rigid array of transducers that the team also designed and manufactured. The entire ultrasound label is approximately 2 square centimeters wide and 3 millimeters thick, roughly the area of a postage stamp.
The researchers put the ultrasound tag through a series of tests with healthy volunteers, who wore the stickers on various parts of their bodies, including their necks, chests, abdomens and arms. The stickers remained attached to the skin and produced clear images of underlying structures for up to 48 hours. During this time, the volunteers performed a variety of activities in the lab, from sitting and standing, to jogging, biking, and lifting weights.
From the images of the stickers, the team was able to observe the change in diameter of the main blood vessels when they were sitting or standing. The stickers also captured details of deeper organs, such as the way the heart changes shape as it strains during exercise. The researchers were also able to watch the stomach distend and then shrink as the volunteers drank and then expelled the juice from their system. And while some volunteers were lifting weights, the team was able to detect bright patterns in the underlying muscles, indicating temporary microdamage.
“With imaging, we could capture the moment in a workout before overuse and stop before muscles become sore,” says Chen. “We don’t yet know when that time might be, but now we can provide imaging data that experts can interpret.”