Wearable device monitors for signs of heart failure in real time

Developed by researchers from Florida Atlantic University’s College of Engineering and Computer Science in collaboration with FAU’s Christine E. Lynn College of Nursing, the technology, the technology is based on sensors embedded in a lightweight belt worn around the waist to monitor thoracic impedance, electrocardiogram (ECG), heart rate and detection of motion activity.

Thoracic impedance is a critical bio-signal to monitor heart failure progression, and ECG is a vital bio-signal to diagnose and predict cardiovascular diseases. ECG measures electrical signals through the heart using a Holter monitor, which is not suitable for point-of-care use.

For the study, published in Scientific Reports, researchers tested the wearable device in different conditions including sitting, standing, lying down and walking. For each condition, results were obtained for each of the sensors sequentially. The physiological parameters selected are significant in determining heart failure symptoms. 

Findings showed that all of sensors kept track of the changes for all the different conditions. The position sensor correctly highlighted the change in position in different conditions and could be used to identify different states of the wearer of the device. In addition, the heart rate sensor continually kept track of the heart rate. Importantly, the device correctly highlighted minute changes in thoracic impedance.

Like most ECG monitors, the ECG sensor in the wearable device was very sensitive to motion, particularly while walking. However, even while walking the ECG sensor retained its QRS complex (the electrical impulse as it spreads through the ventricles of the heart) along with R-peaks (intervals of the QRS complex), which are indicators for left ventricular hypertrophy, indicative of an increase in the size of myocardial fibres in the main cardiac pumping chamber. 

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“All of the sensors we integrated into our belt module can easily be worn for a long period of time without affecting the patient’s daily activities,” said Waseem Asghar, PhD, senior author and an associate professor in FAU’s Department of Electrical Engineering and Computer Science. “Importantly, continuous and real-time monitoring of heart failure symptoms could alert patients and their health care providers of the patient’s declining health. In turn, health care providers could intervene with medications to avoid patient hospitalisation.”

The researchers expect that their technology will have higher predictive values for heart failure with increased specificity and high sensitivity.

“Approximately 1 in 4 patients with heart failure are readmitted within 30 days of discharge from the hospital and about half are readmitted within six months,” said Mary Ann Leavitt, PhD, co-author and an assistant professor in FAU’s Christine E. Lynn College of Nursing. “Healthcare wearable devices such as the prototype we have developed have the potential to decrease hospital readmissions in a cost-effective way that also is safe and convenient for the wearer.”

Based on the study results, the researchers are currently testing the module over a set of diverse subjects to develop an algorithm to predict heart failure over the test set.