TY  - JOUR
AU  - Morgado Areia, Carlos
AU  - Santos, Mauro
AU  - Vollam, Sarah
AU  - Pimentel, Marco
AU  - Young, Louise
AU  - Roman, Cristian
AU  - Ede, Jody
AU  - Piper, Philippa
AU  - King, Elizabeth
AU  - Gustafson, Owen
AU  - Harford, Mirae
AU  - Shah, Akshay
AU  - Tarassenko, Lionel
AU  - Watkinson, Peter
PY  - 2021
DA  - 2021/9/15
TI  - A Chest Patch for Continuous Vital Sign Monitoring: Clinical Validation Study During Movement and Controlled Hypoxia
JO  - J Med Internet Res
SP  - e27547
VL  - 23
IS  - 9
KW  - clinical validation
KW  - chest patch
KW  - vital signs
KW  - remote monitoring
KW  - wearable
KW  - heart rate
KW  - respiratory rate
AB  - Background: The standard of care in general wards includes periodic manual measurements, with the data entered into track-and-trigger charts, either on paper or electronically. Wearable devices may support health care staff, improve patient safety, and promote early deterioration detection in the interval between periodic measurements. However, regulatory standards for ambulatory cardiac monitors estimating heart rate (HR) and respiratory rate (RR) do not specify performance criteria during patient movement or clinical conditions in which the patient’s oxygen saturation varies. Therefore, further validation is required before clinical implementation and deployment of any wearable system that provides continuous vital sign measurements. Objective: The objective of this study is to determine the agreement between a chest-worn patch (VitalPatch) and a gold standard reference device for HR and RR measurements during movement and gradual desaturation (modeling a hypoxic episode) in a controlled environment. Methods: After the VitalPatch and gold standard devices (Philips MX450) were applied, participants performed different movements in seven consecutive stages: at rest, sit-to-stand, tapping, rubbing, drinking, turning pages, and using a tablet. Hypoxia was then induced, and the participants’ oxygen saturation gradually reduced to 80% in a controlled environment. The primary outcome measure was accuracy, defined as the mean absolute error (MAE) of the VitalPatch estimates when compared with HR and RR gold standards (3-lead electrocardiography and capnography, respectively). We defined these as clinically acceptable if the rates were within 5 beats per minute for HR and 3 respirations per minute (rpm) for RR. Results: Complete data sets were acquired for 29 participants. In the movement phase, the HR estimates were within prespecified limits for all movements. For RR, estimates were also within the acceptable range, with the exception of the sit-to-stand and turning page movements, showing an MAE of 3.05 (95% CI 2.48-3.58) rpm and 3.45 (95% CI 2.71-4.11) rpm, respectively. For the hypoxia phase, both HR and RR estimates were within limits, with an overall MAE of 0.72 (95% CI 0.66-0.78) beats per minute and 1.89 (95% CI 1.75-2.03) rpm, respectively. There were no significant differences in the accuracy of HR and RR estimations between normoxia (≥90%), mild (89.9%-85%), and severe hypoxia (<85%). Conclusions: The VitalPatch was highly accurate throughout both the movement and hypoxia phases of the study, except for RR estimation during the two types of movements. This study demonstrated that VitalPatch can be safely tested in clinical environments to support earlier detection of cardiorespiratory deterioration. Trial Registration: ISRCTN Registry ISRCTN61535692; https://www.isrctn.com/ISRCTN61535692 
SN  - 1438-8871
UR  - https://www.jmir.org/2021/9/e27547
UR  - https://doi.org/10.2196/27547
UR  - http://www.ncbi.nlm.nih.gov/pubmed/34524087
DO  - 10.2196/27547
ID  - info:doi/10.2196/27547
ER  -