Wearable ultrasound stickers being developed to help monitor chronic patients continuously

SINGAPORE – Researchers from the Massachusetts Institute of Technology, Nanyang Technological University and the National University of Singapore (NUS) are working together to develop wearable ultrasound stickers that can provide continuous imaging of a patient’s internal organs for up to 48 hours.

Traditionally, ultrasound images are captured by trained technicians who would place a handheld probe on the skin with a layer of gel. The probe sends high-frequency sound waves into the body and captures the returning echoes to form real-time images.

The researchers hope the stickers, which can stay on the skin of patients as they go about their daily lives, can help monitor chronic conditions such as heart failure and give early indications if their condition deteriorates.

These efforts are part of a multimillion-dollar and multi-year initiative supported by the National Research Foundation, called Wearable Imaging for Transforming Elderly Care, or WITEC, which is part of the Singapore-MIT Alliance for Research and Technology.

At its official launch on Dec 10 at the Campus for Research Excellence and Technological Enterprise in NUS, co-lead principal investigator of WITEC Xuanhe Zhao said ultrasound is the most widely used imaging modality in hospitals because there is no radiation, unlike X-rays or CT scans, and it is low cost.

But traditional ultrasound scans can offer a snapshot of a patient’s internal structures only at a single point in time.

“With continuous ultrasound monitoring, we can prevent disease complications, provide early diagnosis and mitigation, shorten hospital stays, and minimise the use of other expensive investigations like CT scans,” said Professor Zhao, adding that various organs such as the lungs, stomach, intestines and liver can be monitored using the technology.

The ultrasound stickers can also help to ease manpower shortages by freeing up the need for skilled ultrasound technicians, and are also more comfortable and convenient for patients without the sticky residue from ultrasound gel.

The researchers have developed a current prototype of the patch that measures 1cm by 1cm, which can provide ultrasound imaging coverage over an area of about 10cm by 10cm.

The sticker consists of a stretchy adhesive layer, where conical structures that help improve the transmission of ultrasound waves into the body can be 3D-printed.

In the first phase of the project, which will last three years from 2025 to 2028, the researchers aim to develop a cart-based system that can power the ultrasound patches, as well as receive and analyse the images from it.

In future stages, they hope to create a portable system where the ultrasound patches can be powered by a battery half the size of a cellphone. Ultrasound images can be transmitted wirelessly to an app, for example.

As part of WITEC’s research, patches of different sizes will be fabricated, including smaller ones, to be adapted for different use cases and patient needs, said Dr Zhiyuan Shen, the scientific director of WITEC.

For a start, the researchers are hoping to benefit patients with heart failure.

Tan Tock Seng Hospital (TTSH) is set to conduct a Phase 1 clinical trial in 2026 to validate the long-term effectiveness of using ultrasound imaging for continuous monitoring of chronic heart disease patients.

The year-long clinical trial will involve 50 patients who have acute decompensated heart failure with pulmonary oedema. The condition is a sudden worsening of heart failure in which the heart cannot pump effectively, causing fluid to build in the lungs and leading to severe breathing difficulties. A professional sonographer will be taking a 10-minute recording of a patient’s heart and lungs every 30 minutes.

Dr Violet Hoon, senior consultant at TTSH and lead of the clinical trial, said continuous ultrasound is non-invasive and provides imaging of the lungs to allow for early detection of fluid accumulation in acute heart failure.

An electrocardiogram, which is commonly used to monitor heart failure patients, is unable to detect fluid accumulation in the lungs due to acute heart failure.

“Continuous ultrasound imaging can help clinicians confirm diagnosis of whether a patient’s shortness of breath is due to fluid accumulation in the lung, which is one of many possible causes of shortness of breath. Through it, doctors can reach a diagnosis more quickly and improve the accuracy of detection,” said Dr Hoon.