Engineers at MIT have developed a technique which enables ultrasound images of organs within the human body to be captured using a simple patch that is stuck on the skin.
The device could potentially eliminate the need for time-consuming hospital visits, and allowing for the real-time monitoring of organs, or of stents, plates and other surgical implants.
Ultrasound imaging, or sonography – a technique first developed as a means of detecting enemy submarines during World War I – has been used medically since the 1940s. Most people will be familiar with the process, as it is widely used in the prenatal care of pregnant women – the first picture ever taken of you, was almost certainly an ultrasound image.
Sonography offers many advantages over other forms of medical imaging such as X-rays, MMRI or CAT scans. It involves less bulky, high-tech equipment and operatives require less training. It’s portable – ultrasound examinations can be carried out at a patient’s bedside – and is a far less costly procedure to carry out.
The process works by applying a gel to the skin, which allows ultrasound waves – which are soundwaves at ultra-high frequencies far above the threshold of human hearing – to penetrate the body. A wand-like device then captures the echoes as those sound waves reflect back off internal structures such as bones and organs, and uses that information to create a visual image of what’s going on inside the body.
Scientists have tried previously to replace that ‘wand’ with a stick-on, flexible patch, but that proved problematic. Because the patch was flexible, the tiny probes within it moved around relative to each other as the body moved – making for blurry, low-resolution images.
The patch developed at MIT is different, as it uses a rigid array of sensors that maintain their relative positions (thus ensuring crisp, clean images) but that are attached to a three-ply adhesive patch. This patch consists of two thin layers of elastomer, between which sits a middle layer of elastic, stretchy hydrogel – a water-based material that facilitates the transmission of the soundwaves. The entire assembly measures around 2cm square and is 3mm thick, making it roughly the same size as a postage stamp.
At the moment, the patch still needs to be connected to a machine that interprets the sound information and converts it into an image, but the team now hope to develop a version that works wirelessly – opening the door to a wide array of potential applications, from the monitoring of digestive disorders to avoiding injuries caused by over-exercise.
“We envision a few patches adhered to different locations on the body, and the patches would communicate with your cellphone, where AI algorithms would analyse the images on demand,” said research lead Prof Xuanhe Zhao.
“We believe we’ve opened a new era of wearable imaging: with a few patches on your body, you could see your internal organs.”
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Russell Deeks is a freelance writer with nearly 30 years’ journalism experience, working across the fields of music, technology and science – which, he says, cross over more often than you might think. Despite the drawback of holding a degree in English & American Literature, he has been a regular contributor to BBC Science Focus since 2006.