A new type of adhesive device may usher in a new era of ultrasound (US) technology in which US probes would be worn continuously for prolonged, hands-free monitoring of internal structures.

This would mark a pivotal change from how US is used right now. Currently, long-term monitoring requires patients to remain in an acute care facility where transducers can be applied to the skin as often as necessary.

Scientists at Massachusetts Institute of Technology (MIT) have created a new adhesive, which may eventually offer physicians continuous anatomical imaging of the human body.

Wang C, Chen X, Wang L, et al. Bioadhesive ultrasound for long-term continuous imaging of diverse organ. Science. 2022;377(6605):517–523.

 

 

The current state of ultrasound

Conventional US uses a signal generator paired with a transducer that converts energy into high-frequency sound waves to ultimately produce a picture of internal body structures and tissues.

Kocak M. Ultrasonography. Merck Manuals Professional Edition. Updated April 2021.

This low-cost, portable technology is widely used as a diagnostic tool—although other applications, such as guiding biopsy sampling, are common.

 

In some cases, long-term imaging using US provides physicians with information used to assess organ systems and other tissues over an extended period of time.

 

Novel device offers distinct advantages

The new technology couples a flat chip with a new bioadhesive material to record high-resolution US videos for up to 48 hours.

Bushwick S. This sticker looks inside the body. Scientific American. July 29, 2022.

In creating this device, researchers at MIT developed a new water-filled polymer (also called a hydrogel) that’s encapsulated within a bioadhesive elastomer. The elastomer is rubbery and helps the hydrogel maintain its shape and viscosity.

 

Unlike traditional US gel, this material prevents the formation of air bubbles that commonly appear between the skin and US probe, disrupting the imaging process. Additionally, the hydrogel-elastomer composite does not dry out like conventional gel. This allows physicians to capture images while the patient’s body is in motion.

“It’s a new window into the human body that we’ve never had before,” said Eric Topol, MD, founder and director of the Scripps Research Translational Institute, said in an article published by STAT News.

Chen E. With the help of a sticky, stretchy material, scientists design a continuous ultrasound system. STAT News. August 1, 2022.

“This is anatomy. That’s very different."

 

We’ve never had a sensor with continuous anatomical imaging.

The MIT scientists tested versions of the bioadhesive device that produced waves at different frequencies to penetrate the body at various depths. When comparing these images to those gathered using standard ultrasound technology, they found the image quality was comparable to conventional ultrasound systems.

Researchers also pointed out that this novel technology is much less expensive compared with other, more traditional imaging modalities. Also, there is no threat of radiation exposure to patients, which occurs with other imaging tests like computed tomography or positron emission tomography.

 

Limitations to overcome

First, the device must remain physically connected to a computer that collects and analyzes information gathered from the US probe. However, thanks to improved fabrication methods, electrical components continue to shrink. This could help scientists develop a miniature power source for the new device as well as a wireless data transmission system.

Another limitation involves data analysis and interpretation. Continuous US probes will generate more data than physicians are used to obtaining. Storing this massive amount of data would challenge healthcare systems.

Also, physicians would be hard-pressed to correctly interpret large amounts of data alone; however, other new technologies, such as artificial intelligence, could be used to help arrive at an appropriate, timely diagnosis.

Before bioadhesive US becomes a standard of care, it must be subjected to clinical testing and FDA approval. Eventually, this technology may join the ranks of other wearable devices used to monitor patient health.

“Our human body is radiating a lot of a highly personal, highly continuous, distributed and multimodal data about our health, our emotion, our attention, our readiness, and so on,” Nanshu Lu, PhD, a mechanical engineer at the University of Texas at Austin, told Scientific American.

So we’re full of data. The question is how to get them reliably and continuously.