A Novel Wearable Device for Continuous Temperature Monitoring & Fever Detection

Abstract

Objective: Continuous temperature monitoring in high-risk patients can enable healthcare providers to remotely track patients' temperatures, promptly detect fevers and timely intervene to improve clinical outcomes. We evaluated if a novel wearable, continuous temperature monitor (Verily Patch) can reliably estimate body temperature and early detect fevers in an outpatient setting in patients at a high risk of febrile neutropenia (FN) who recently underwent chemotherapy and autologous stem cell transplantation (ASCT). Methods: 86 patients at a high risk for FN were prospectively enrolled at Mayo Clinic, MN. Patients wore the device in their axilla region for 7 days post ASCT and recorded self-measured oral temperatures every 3 hours. Patients were also followed using clinical standard-of-care procedures with daily oral temperature assessment. The clinic- and patient-assessed oral temperatures were used to develop and evaluate Verily Patch's body temperature and early fever detection algorithms using a K-fold cross-validation approach. Results: The Verily Patch reliably measured body temperatures with an error of 0.35 ± 0.88°F in comparison to clinic- and patient-assessed oral temperatures. The sensitivity and specificity of the patch in detecting clinic-assessed fever episodes was 90.2% and 87.8%. The patch detected 14.3 times the number of clinic-assessed fever episodes with a median lead time of 4.3 hours. Conclusion: Patient self-monitoring of temperature and fever incidents suffers from low accuracy and is impractical for extended periods of time. Continuous temperature monitoring by a wearable device (such as Verily Patch) has the potential to overcome these challenges resulting in better patient clinical outcomes and more cost-effective care.

Keywords: Continuous temperature monitoring; early fever detection; febrile neutropenia; machine learning; wearable devices.

Figures

FIGURE 1.

Schematic illustration showing (a) patient enrollment and characteristics, (b) study timeline showing device application, removal and clinic- and patient-assessed oral temperature measurements, (c) Verily Patch device, and (d) a sample signal from device’s skin and ambient sensors.

FIGURE 2.

Agreement between clinic- and patient-assessed oral temperatures and patch measured body temperatures.

FIGURE 3.

Static fever detection: (a) Distribution of patch measured body temperatures in febrile and afebrile groups, and (b) ROC curve of patch’s performance in static fever detection and best operating point (threshold: 99.83°F) shown as a blue cross. The area under the ROC curve (AUC) values are shown in the legend.

FIGURE 4.

A representative case of the patch’s early fever episode detection versus clinic-recorded fevers. The plot also shows clinic- and patient-assessed oral temperatures.