MIT researchers have designed a wearable ultrasound patch that can image organs just like traditional ultrasound but without the need for cold gel or an operator. While they used it to measure bladder fullness, the device could also be used to image other internal organs, providing a new approach to disease monitoring.
Ultrasound is widely used in clinical practice. This imaging technique is painless, non-invasive, does not use ionizing radiation, and provides real-time images. However, current ultrasound examinations require the patient to lie on a table, apply (usually cold) conductive gel, and have an operator operate the transducer.
MIT researchers have designed a wearable ultrasound device in the form of a patch that eliminates gel and operators and can accurately image the bladder to determine how full it is. And the design is adaptable.
Canan Dagdeviren, the corresponding author of the study, said: "This technology is very versatile and can be used not only in the bladder but in any deep tissue of the body. It is a novel platform that can identify and characterize many diseases that we carry in our bodies."
The researchers focused on bladder ultrasound in part because they were inspired by Dagdeviren's younger brother, who was diagnosed with kidney cancer several years ago. Since having one of his kidneys removed, he has had difficulty completely emptying his bladder.
"With millions of people suffering from bladder dysfunction and related diseases, it's no surprise that bladder volume monitoring is an effective way to assess kidney health," Dagdeviren said.
The array is arranged in an X shape to provide a larger field of view. In this case, the device is capable of imaging the entire bladder, which measures approximately 4.7x3.1 inches (12x8 cm) when full. The patch is naturally sticky and adheres gently to the skin, making it easy to apply and remove. Underwear or tights can hold it in place more securely.
The researchers tested the cUSB-Patch's ability to measure bladder capacity on 20 patients ranging in age from 18 to 64 years old and with a range of body mass indexes. The researchers first took images of patients with their bladders full, then with their bladders partially empty, and finally with their bladders completely empty. The cUSB-Patch's imaging performance is comparable to that of traditional ultrasound probes and is suitable for all patients regardless of body mass index.
Because the device has a wide field of view, no pressure is required, as is the case with traditional ultrasonic sensors, and no gel is required. To view images taken with the cUSB-Patch, the researchers connected the ultrasound array to a traditional ultrasound machine. They are developing a portable device, about the size of a smartphone, that can be used to view images.
The researchers hope to develop an ultrasound device that can be used to image other organs, such as the pancreas, liver or ovaries. The location and depth of each organ requires changing the frequency of the ultrasound signal, which requires new piezoelectric materials.
"For any organ that we need to visualize, we go back to step one, choosing the right materials, designing the right device, and then fabricating everything before testing the device and doing clinical trials," Dagdeviren said.
The research was published in the journal Nature Electronics.