A wearable ultrasound monitor can image the bladder and determine how full it is. The MIT-developed device could help patients with bladder or kidney disorders more easily track whether these organs are functioning properly.Photo courtesy of the researchers / MIT

A new ultrasound wearable device can measure how full your bladder is

The wearable device, designed to monitor bladder and kidney health, could be adapted for earlier diagnosis of cancers deep within the body.

MIT researchers have created a patch-like wearable ultrasound monitor that can image organs within the body without the use of an ultrasound operator or the application of gel.

The researchers demonstrated that their patch can accurately image the bladder and determine how full it is in a new study. According to the researchers, this could make it easier for patients with bladder or kidney disorders to determine whether these organs are functioning properly.

This method could also be used to monitor other organs within the body by relocating the ultrasound array and adjusting the frequency of the signal. Such devices may be able to detect cancers that form deep within the body, such as ovarian cancer, earlier.

“This technology is versatile and can be used not only on the bladder but any deep tissue of the body. It’s a novel platform that can do identification and characterization of many of the diseases that we carry in our body,”

says Canan Dagdeviren, an associate professor in MIT’s Media Lab and the senior author of the study.

Lin Zhang, an MIT research scientist; Colin Marcus, an MIT graduate student in electrical engineering and computer science; and Dabin Lin, a professor at Xi’an Technological University, are the lead authors of a paper describing the work, which appears today in Nature Electronics.

Ultrasound wearable device – Wearable monitoring

Dagdeviren’s lab, which specializes in the development of flexible, wearable electronic devices, recently created an ultrasound monitor that can be incorporated into a bra and used to screen for breast cancer. The team used a similar approach in the new study to develop a wearable patch that can adhere to the skin and take ultrasound images of organs located within the body.

The researchers decided to focus on the bladder for their first demonstration, partly inspired by Dagdeviren’s younger brother, who was diagnosed with kidney cancer a few years ago. He had difficulty completely emptying his bladder after having one of his kidneys surgically removed. Dagdeviren wondered if an ultrasound monitor that shows how full the bladder is could help patients like her brother or others with bladder or kidney problems.

“Millions of people are suffering from bladder dysfunction and related diseases, and not surprisingly, bladder volume monitoring is an effective way to assess your kidney health and wellness,”

she says

Currently, the only way to measure bladder volume is to visit a medical facility and use a traditional, bulky ultrasound probe. Dagdeviren and her colleagues wanted to create a wearable option for patients to use at home.

To accomplish this, the researchers created a flexible patch of silicone rubber embedded with five ultrasound arrays made from a new piezoelectric material developed specifically for this device. The arrays are arranged in the shape of a cross, allowing the patch to image the entire bladder, which measures approximately 12 by 8 centimeters when full.

The patch’s polymer is naturally sticky and adheres gently to the skin, making it simple to attach and detach. When applied to the skin, underwear or leggings can help keep it in place.

Bladder volume

The researchers demonstrated that the new patch could capture images comparable to those taken with a traditional ultrasound probe in a study conducted with collaborators from the Center for Ultrasound Research and Translation and the Department of Radiology at Massachusetts General Hospital and that these images could be used to track changes in bladder volume.

The researchers recruited 20 patients with varying BMIs for the study. The subjects were photographed with a full bladder, then a partially empty bladder, and finally a completely empty bladder. The new patch produced images of comparable quality to traditional ultrasound, and the ultrasound arrays worked on all subjects regardless of body mass index.

Because the field of view is large enough to encompass the entire bladder, no ultrasound gel or pressure is required when using this patch, as with a regular ultrasound probe.

The researchers connected their ultrasound arrays to the same type of ultrasound machine used in medical imaging centers to view the images. The MIT team is now developing a portable device the size of a smartphone that could be used to view the images.

“In this work, we have further developed a path toward clinical translation of conformable ultrasonic biosensors that yield valuable information about vital physiologic parameters. Our group hopes to build on this and develop a suite of devices that will ultimately bridge the information gap between clinicians and patients,”

says Anthony E. Samir, director of the MGH Center for Ultrasound Research and Translation and Associate Chair of Imaging Sciences at MGH Radiology, who is also an author of the study

The MIT team also hopes to create ultrasound devices that can image other organs in the body, such as the pancreas, liver, or ovaries. The frequency of the ultrasound signal must be adjusted based on the location and depth of each organ, which necessitates the development of new piezoelectric materials. For some of these deep-seated organs, the device may be more effective as an implant rather than a patch.

“For whatever organ that we need to visualize, we go back to the first step, select the right materials, come up with the right device design and then fabricate everything accordingly,”

before testing the device and performing clinical trials, Dagdeviren says

“This work could develop into a central area of focus in ultrasound research, motivate a new approach to future medical device designs, and lay the groundwork for many more fruitful collaborations between materials scientists, electrical engineers, and biomedical researchers,”

says Anantha Chandrakasan, dean of MIT’s School of Engineering, the Vannevar Bush Professor of Electrical Engineering and Computer Science, and an author of the paper.

The research was funded by a National Science Foundation CAREER award, a 3M Non-Tenured Faculty Award, the Sagol Weizmann-MIT Bridge Program, Texas Instruments Inc., the MIT Media Lab Consortium, a National Science Foundation Graduate Research Fellowship, and an ARRS Scholar Award.

Source: MIT