Can a low-cost exercise monitor provide useful heart rate monitoring for use in low-resource emergency departments?

Objective: Our objective was to study the clinical monitoring capabilities of a low-cost fitness wristband while measuring patient satisfaction with a mobility permitting device in the emergency department.

Methods: Patients enrolled were on continuous three-lead telemetry monitoring in a high acuity zone of the emergency department. Patients were given a fitness band to wear while simultaneously monitored with standard three-lead monitor. A brief survey was conducted upon study end, and data was compared between wristband and three-lead telemetry. Median heart rate (HR) values were calculated, a Bland-Altman plot was generated, and sensitivity and specificity were calculated for comparison of the formal telemetry and the inexpensive wristband.

Results: Thirty-four patients with an average age of 61.5 years were enrolled. From June to October 2019, over 100 hours of data were collected. In comparison for comfort, participants scored 9.5 of 10, preferring wristband over telemetry. Using a correlation coefficient graph, we found a significant disparity of HR readings within a telemetry range of 40 to 140 beats/min. An R-value of 0.36 was detected. Using a Bland-Altman plot, we observed a significant difference in HR between the telemetry monitor and the wristband. The sensitivity and specificity of the wristband to detect bradycardia (HR <60 beats/min) were 76% and 86%, respectively, while the sensitivity and specificity of the wristband to detect tachycardia (HR >100 beats/min) were 92% and 51%, respectively.

Conclusion: Inexpensive fitness bands cannot be a suitable tool for monitoring patient's HR because of inaccuracy in detecting bradycardia or tachycardia.