Evaluation of a Wearable Physiological Status Monitor During Simulated Fire Fighting Activities

Abstract

A physiological status monitor (PSM) has been embedded in a fire-resistant shirt. The purpose of this research study was to examine the ability of the PSM-shirt to accurately detect heart rate (HR) and respiratory rate (RR) when worn under structural fire fighting personal protective equipment (PPE) during the performance of various activities relevant to fire fighting. Eleven healthy, college-aged men completed three activities (walking, searching/crawling, and ascending/descending stairs) that are routinely performed during fire fighting operations while wearing the PSM-shirt under structural fire fighting PPE. Heart rate and RR recorded by the PSM-shirt were compared to criterion values measured concurrently with an ECG and portable metabolic measurement system, respectively. For all activities combined (overall) and for each activity, small differences were found between the PSM-shirt and ECG (mean difference [95%CI]: overall: −0.4 beats/min [−0.8, −0.1]; treadmill: −0.4 beats/min [−0.7, −0.1]; search: −1.7 beats/min [−3.1, −.04]; stairs: 0.4 beats/min [0.04, 0.7]). Standard error of the estimate was 3.5 beats/min for all tasks combined and 1.9, 5.9, and 1.9 beats/min for the treadmill walk, search, and stair ascent/descent, respectively. Correlations between the PSM-shirt and criterion heart rates were high (r = 0.95 to r = 0.99). The mean difference between RR recorded by the PSM-shirt and criterion overall was 1.1 breaths/min (95%CI: −1.9 to −0.4). The standard error of the estimate for RR ranged from 4.2 breaths/min (treadmill) to 8.2 breaths/min (search), with an overall value of 6.2 breaths/min. These findings suggest that the PSM-shirt provides valid measures of HR and useful approximations of RR when worn during fire fighting duties.

Keywords:

• accuracy
• firefighter
• monitoring

ACKNOWLEDGMENTS

The research presented in this article was funded by a Department of Army grant to Globe Manufacturing Company, LLC, with a subcontract to Skidmore College, and the Department of Homeland Security Science and Technology Directorate (as part of the UCLA PHASER Program), with a subcontract to Skidmore College. We wish to express our thanks and appreciation to the Program Managers, Axel Rodriquez, and Jalal Mapar. We are also appreciative of the willingness of participants to give so generously of their time to support this work.