Scientists Develop Wearable Device To Monitor Changing Tumor Size Under The Skin

A team of engineering researchers from the Georgia Institute of Technology and Stanford University has developed a device that can be worn on the skin to monitor size changes in tumors on or below it.

Tumor Size Monitor. Credit: Science Advances

Wearable devices have become quite popular in recent years. Smartwatches and fitness trackers are virtually everywhere. There are also wearable devices that help monitor blood sugar levels and even epileptic seizures.

This new autonomous device brings along the capability to measure changing tumor sizes seamlessly. It features a flexible and stretchy sensor that gauges tumor size and transmits the results wirelessly to a smartphone app.

The wearable device is called FAST, which stands for “Flexible Autonomous Sensor measuring Tumors.” It is non-invasive, fast, and inexpensive and could aid in expediting cancer treatment screening. The device may also guide on how to deal with cancer more effectively.

Researchers reported the new device in the journal Science Advances.

Measuring tumor sizes

Medical professionals typically rely on imaging techniques, including X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans to learn about tumor sizes. They may also use calipers that look like metal pincers to measure tumors closer to the skin surface.

However, popular imaging methods do not deliver continuous, real-time information about tumor sizes. Calipers are also less than ideal for measuring soft tissues.

The failings of existing measuring techniques, coupled with biological disparity in tumors and small study sample sizes, make the development of more effective treatments tricky. Researchers test thousands of promising drugs for cancer every year, but only a tiny fraction becomes available to patients. The process of screening drugs is both labor-intensive and complex.

With FAST, it could become possible and faster to monitor tumor growth in real-time and remove the need for observation periods that extend over weeks. Its creators say the wearable device senses changes in tumor size on a minute-timescale.

Advanced tumor monitoring device

FAST is powered by a battery and is sensitive to 10 micrometers or a hundredth of a millimeter. Its sensor features a stretchable polymer that looks like skin and comes embedded with a gold-circuitry layer. Armed with a “small electronic backpack,” it is placed on the skin area that has a tumor to take readings.

The researchers highlighted the crucial role of the polymer membrane in the design. The sensor measures the strain of this flexible material, as it increases or decreases, and transmits the data to a smartphone app.

Stretching the membrane causes small cracks to form on the polymer’s gold layer, altering electrical conductivity and causing the sensor’s electronic resistance to surge. The cracks resolve and conductivity improves with the contraction of the material.

Promising therapies for reducing tumor growth can quickly be detected with the aid of the device’s backpack – designed by Yasser Khan and Naoji Matsuhisa, who are co-authors of this research. FAST could help researchers decide more quickly what therapies are worth studying further or to discard.

This wearable boasts of at least three major advancements, according to the researchers. The first is that it enables nonstop assessment of tumor sizes. Second, it makes it possible to measure tumor shape changes that are tricky to detect with other methods. A third benefit is that it is non-invasive and autonomous – running on battery and connecting wirelessly.

When tested in a mouse model, the device did not hinder free movement. The scientists did not have to closely manage the animals after fixing the sensor in place.

What’s more? FAST is cost-friendly. Its packs go for only about $60 and are reusable as well.

“It is a deceptively simple design,” said Alex Abramson, the study’s first author and a new assistant professor at Georgia Tech. “But these inherent advantages should be very interesting to the pharmaceutical and oncological communities. FAST could significantly expedite, automate, and lower the cost of the process of screening cancer therapies.”

The research team successfully worked a way around the concern that the sensor could put pressure on tumors and lead to inaccurate readings. It cleverly matched the flexible material’s mechanical properties to the skin, making the sensor pliant and supple like the skin.