# Radar Multiple Bin Selection for Breathing and Heart Rate Monitoring in Acute Stroke Patients in a Clinical Setting

## TL;DR

This study compares radar methods for monitoring breathing and heart rate in stroke patients during sleep, finding that multiple bin selection is more accurate but less continuous.

## Contribution

The study evaluates and compares multiple and single range bin selection methods for radar-based vital sign monitoring in acute stroke patients.

## Key findings

- Multiple range bin selection had lower mean absolute errors for breathing and heart rate compared to single bin selection.
- Single range bin selection provided higher temporal coverage for both breathing and heart rate monitoring.
- Multiple bin selection showed higher correlations with polysomnography reference data for both metrics.

## Abstract

Simple to use and accurate monitoring of stroke patients’ breathing and heart rate in sleep is needed to lower the risk of secondary strokes and prevent worse functional outcomes due to disturbed sleep. In this study, we computed breathing and heart rates from clinical radar sleep recordings of 49 acute ischemic stroke patients. Parallel polysomnography served as the reference for evaluation. We compared radar rates computed using previously developed multiple and single range bin selection methods. Multiple selection yielded lower mean absolute errors (breathing: 0.39 vs. 0.87 breaths per min; heart rate: 0.84 vs. 3.99 beats per min) and higher correlations with the reference (breathing: 0.95 vs. 0.85; heart rate: 0.96 vs. 0.56). However, single range bin selection produced rates for a larger proportion of recording time (breathing: 93.49% vs. 73.38%; heart rate: 81.85% vs. 19.93%). Our results indicate that multiple range bin selection provides more accurate estimates of breathing and heart rate, but it has lower temporal coverage. Easy to use radar systems could facilitate the clinical adoption of contactless breathing and heart rate monitoring in sleep, improving the care provided to stroke patients.