December 16, 2022

Novel wearable vest for long-term lung monitoring

Lung diseases are among the leading causes of death in the EU. Existing methods of chest disease analysis are expensive, uncomfortable, invasive, or use ionizing radiation. In response, the EU-funded WELMO consortium has developed low-cost and low-energy sensors that are integrated into a comfortable and safe vest. This allows the remote monitoring of the lungs through the collection of respiration-linked chest sounds and electrical impedance tomography signals.

CSEM's sensor vest for monitoring respiratory diseases using electrical impedance tomography and chest sound acquisition.

Respiratory diseases are one of Europe’s leading causes of death. Currently, the tools used to assess lung functions, e.g., conventional X-rays or computerized tomography scans, can not only expose the patients to ionizing radiation, but the procedures are uncomfortable, expensive, and require intermittent inpatient care. This ad-hoc monitoring ecosystem is both challenging for patients to manage and could lead to changes in their condition being missed by medical practitioners.

Medical wearables

CSEM's wearable vest for monitoring respiratory diseases using electrical impedance tomography.

WELMO vest for continuous lung monitoring

To enable the long-term and non-invasive monitoring of respiratory diseases, a European consortium developed WELMO* – a smart wearable vest that can provide 24/7 lung monitoring. CSEM was at the heart of this project, creating the system’s centerpiece, the wearable vest. The vest has 18 embedded sensors that can record in parallel both chest sounds and thoracic electrical bioimpedance (a diagnostic method to measure cardiac output non-invasively).

Patient-centric solution for monitoring respiratory diseases

The patient’s chest sounds can be picked up at six traditional locations on the lungs and upper airways where medical doctors typically place their stethoscope during an examination (four auscultation spots around the sternum’s apex, two below the clavicles). And the patient’s electrical bioimpedance is measured by 16 sensors placed around the chest’s circumference at the sternum’s apex. The bioimpedance signals are used for electrical impedance tomography (EIT). This radiation-free imaging system can analyze breathing cycles thanks to its high temporal resolution (40 Hz in the case of WELMO).

CSEM’s sensors all work in cooperation, allowing the amount of wiring connecting them to be reduced to a minimum. In this instance, only two wires were required, and if you are wondering if this lack of wire can affect or reduce the quality of the recorded signals – it doesn’t. Instead, it helps minimize patient discomfort and contributes to the overall non-invasive aspect of the vest.

Successful clinical pilot studies

WELMO has been successfully tested in two clinical pilot studies and is currently able to monitor six groups of respiratory diseases, including obstructive disease, pleural effusion, interstitial/alveolar insult, post-COVID-19 vascular disease, pneumonia, and thoracic wall insult. The publication of the findings from these studies is ongoing. Moreover, initial results have confirmed the system’s acceptance by patients and healthcare providers. Further validation studies are needed to allow the broader distribution of the WELMO system.

* WELMO = Wearable Electronics for Effective Lung Monitoring

Acknowledgments: This work was funded by the Horizon 2020 Framework Program of the European Union under grant agreement no. 825572.