At the moment, for the device to work, it needs to be connected to instruments that convert ultrasound waves into images. Still, the researchers suggest that even so, the stickers could be used on patients in hospital in a similar way to EKG stickers that monitor the heart. Clear and continuous images of the organ would be obtained without the need for a technician to be present.
Meanwhile, scientists they are working on making the technology wireless, an advance that would allow patients to take the glued adhesive from the health center to their home or even buy it at the pharmacy. They are also developing algorithms that can better interpret and diagnose the images of the stickers and that are based on AI.
“We imagine a few patches attached to different places on the body, and the patches would communicate with the mobile phonewhere AI algorithms would analyze images on demand,” says study lead author Xuanhe Zhao, professor of mechanical engineering and civil and environmental engineering at MIT in a statement. “We believe we have ushered in a new era of wearable images ( ‘wearable’) with a few patches on the body, could you see your internal organs“.
How do the adhesives work?
The adhesive layer of the device is made up of two thin layers of elastomer that encapsulate an intermediate layer of solid hydrogel, a water-based material that easily transmits sound waves. This hydrogel differs from the traditional ones because it is elastic and extensible.
“The elastomer prevents the hydrogel from dehydrating,” says Xiaoyu Chen, who has also participated in the study. “Only when the hydrogel is highly hydrated can acoustic waves effectively penetrate and deliver high-resolution images of internal organs.”
The lower layer of elastomer is designed to stick to the skin, while the upper layer adheres to a rigid array of transducers (they serve as a device that converts one type of energy into another) that the team also designed and manufactured. The entire ultrasound sticker is about two square centimeters wide and three millimeters thick, about the size of a postage stamp.
The researchers subjected the ultrasound sticker to a series of tests with healthy volunteers, who wore the stickers on various parts of the body, such as the neck, chest, abdomen and arms. The stickers remained attached to the skin and offered clear images of the underlying structures for 48 hours. During this time, the volunteers did different activities: running, lifting weights, cycling…
From the images of the stickers, the team was able to observe the change in diameter of major blood vessels when sitting or standing. The stickers also captured details of deeper organs, such as the change in shape that occurs in the heart during exercise. The researchers were also able to observe how the stomach distended and then shrunk as the volunteers drank and then expelled the liquid from their bodies. Even while some volunteers were lifting weights, the team was able to detect bright patterns in the muscles, indicating temporary micro-damage.
“Thanks to imaging, we could catch the moment of a workout before overload and stop it before the muscles give out,” says Chen. “We don’t yet know when that time may be, but now we can provide imaging data that experts can interpret.”
References: Chu, J. 2022. MIT engineers develop stickers that can see inside the body.
Chonghe, W. et. to the. 2022. Bioadhesive ultrasound for long-term continuous imaging of diverse organs. Science. DOI: 10.1126/science.abo2542