Ultrasound images are a safe and non-invasive way to find out how our body is working inside. They have been used in the medical field for a long time, but require large, specialized equipment that is only available in hospitals. Now, a team of engineers at MIT could make this technology not require such means, but be portable and accessible , to the point that we could buy it in a pharmacy.
The engineers have presented their adhesive design in a paper that has been published in Science . It is a device that is the size of a stamp and attached to the skin can show continuous images of the interior of the body for 48 hours. In tests, the stickers showed strong adhesion and showed variations in the volunteers’ organs while doing various activities such as sitting, running or cycling.
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 are working on making the technology wireless , an advance that would allow patients to take the 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 imagined a few patches attached to different places on the body, and the patches would communicate with the mobile phone , where AI algorithms would analyze the images on demand,” says the study’s lead author, Xuanhe Zhao, professor of mechanical engineering and engineering. MIT Civil and Environmental Sciences in a statement. “We think we have opened a new era of wearable images with a few patches on the body, you could 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 provided clear images of 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 the main 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.”
Referencias: Chu, J. 2022. MIT engineers develop stickers that can see inside the body. https://news.mit.edu/2022/ultrasound-stickers-0728
Chonghe, W. et. al. 2022. Bioadhesive ultrasound for long-term continuous imaging of diverse organs. Science. DOI: 10.1126/science.abo2542
