Validity of the single-limb electrocardiographic technology in the warfighter monitor™

Devices equipped with electrocardiographic (ECG) technology possess design limitations reducing their feasibility across a range of users and environments.

This study evaluated the validity of a novel, single-limb biomedical device using single‑lead ECG technology located on the upper arm for monitoring cardiac activity in a large, diverse sample.

A cross-sectional study was conducted among 931 adults from May to September 2024 at an outpatient medical center in the United States. ECG recordings were captured on the Warfighter Monitor™ (WFM; Tiger Tech Solutions, Miami, FL). Each participant wore two ECGs simultaneously, a standard Lead-I ECG on the chest (ECG-Chest) and a WFM on the upper arm (ECG-Bicep), for 5 to 7 min. Agreement between ECG-Chest and ECG-Bicep measurements for HR and HRV were evaluated using Pearson correlations, Bland-Altman, and ANOVA.

The study population was diverse in age (17-99 years), sex (53.4% male), and ethnicity (53.7% Hispanic or Latino), and comorbidities: cardiovascular (61.2%), respiratory (31.5%), cancer (20.3%), endocrine (43.4%), and neurological (32.5%) disorders. Near-perfect correlations (0.995-0.997, p < 0.0001) and negligible mean differences (-0.02 to 0.05 bpm or ms, p < 0.00001) were found between ECG-Chest and ECG-Bicep for HR and HRV metrics.

The near-perfect agreement in HR and HRV between ECG recordings measured at the chest and bicep, confirms the strong validity of the WFM for precise, ECG-based monitoring across a broad set of demographics. These results demonstrate the high accuracy, versatility, and feasibility of the WFM to accurately monitor HR and HRV.