Wireless skin sensor could continuously track soft tissue disorders from home

Northwestern scientists have developed a novel wireless sensor device that can continuously monitor skin elasticity in patients with soft tissue disorders, including lymphedema and scleroderma, which can support early disease detection and better inform care strategies, as detailed in a study published in Science Advances.

The sensor, which is directly applied to the patient’s skin, can measure a patient’s tissue elasticity and then wirelessly transmit critical disease-progression data, enabling a health care provider to remotely access that data from the patient’s home and potentially eliminating the need for an in-person clinical examination.

“The great thing about the sensor is it’s small, the potential for home use is tremendous, and for patients who know that they are at risk and know that they need to be constantly monitoring and detecting, this could give them a really good home-based unit that could potentially communicate data directly to their physician. That’s our goal,” said Ann Marie Flores, PT, MSPT, MA, Ph.D., CLT, FAPTA, associate professor of Physical Therapy and Human Movement Sciences and of Medical Social Sciences in the Division of Implementation Science, who was a co-corresponding author of the study.

Limits of current monitoring

Current diagnostic approaches for lymphedema—chronic tissue swelling caused by damage to lymph vessels resulting from infection, cancer treatment or, in some cases, genetic mutations—include measuring the volume of the affected body part, extracellular fluid via bioimpedance spectroscopy or tissue dielectric constant, and a thorough clinical exam. There is no cure for lymphedema, and continuous monitoring is essential to mitigate disease progression and prevent infection.

Skin stiffness caused by lymphedema is measured with an indentation test (pressing on the swollen area to measure fluid buildup), a skin suction test or elastography imaging. While these techniques have been shown to be effective, they require bulky instruments and hands-on clinical examination and are less sensitive as lymphedema progresses.

How the device works

The new device, which uses technology developed by the laboratory of John Rogers, Ph.D., the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery, is flexible and can be directly applied to the patient’s skin across different parts of the body.

The device emits vibrations via an accelerometer and, from these vibrations, collects information about the skin’s stiffness, elasticity and resistance to pressure. This data can then be wirelessly transmitted from the device to the patient’s health care provider.

“The device can wirelessly transmit the data and then we can directly analyze this vibration amplitude and frequency to know the skin modulus value,” said Min-Seung Jo, Ph.D., a postdoctoral fellow in the Rogers laboratory and lead author of the study.

Deeper readings, finer distinctions

The device was also validated in patients with cancer-related lymphedema and systemic scleroderma, a rare autoimmune disorder in which excess collagen production causes patches of skin to thicken abnormally.

In both studies, the investigators found that the device’s larger contact area enabled deeper tissue monitoring, which improved the overall evaluation of disease severity and progression. The device also demonstrated a stronger correlation than commercially available clinical devices that use bioimpedance and tissue dielectric constant to detect early-stage lymphedema.

Unlike other methods, particularly bioimpedance spectroscopy, the device was also sensitive enough to distinguish among three different stages of lymphedema. The investigators also found the device’s larger contact area improved the measurement of skin stiffness during muscle movement and relaxation in patients.

Toward home-based follow-up

While clinical expertise is required to diagnose and stage lymphedema, the new device would allow patients and health care providers to monitor a patient’s disease progression while the patient is in the comfort of their own home, improving early detection, accessibility and overall care, according to the authors.

“Our next steps are to see how we can make this truly home-based, how adherent patients are [with lymphedema monitoring] and to hear what providers want to know,” said Flores, who is also director of Cancer Rehabilitation for the Cancer Survivorship Institute of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

Who’s behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

Full profile →

Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

Full profile →