JMIR Publications

ABSTRACT

Background:

Postoperative deterioration is often preceded by abnormal vital parameters. Therefore, vital parameters of postoperative patients are routinely measured by nursing staff. Wrist-worn sensors could potentially provide an alternative tool for the measurement of vital parameters in low acuity settings. These devices would allow more frequent or even continuous measurements of vital parameters without relying on time consuming manual measurements, provided their accuracy in this clinical population is established.

Objective:

Asses the accuracy of heart rate (HR) and respiration rate (RR) measured via wearable photoplethysmography (PPG) wristband in a postoperative patients.

Methods:

The accuracy the wrist-worn PPG sensor was studied in 62 post-abdominal surgery patients (mean age 55 years (sd:15), median BMI 34 kg/m2 (IQR: 25-40)). The wearable obtained HR and RR measurements were compared to the reference monitor in the post-anesthesia or intensive care unit. Bland–Altman and Clarke error grid analyses were performed to determine agreement and clinical accuracy.

Results:

Data was collected for a median of 1.2 hours per patient. With a coverage of 94% for HR and 34% for RR the device was able to provide accurate measurements for the large majority of the measurements as 98% and 93% of the measurements were within 5 bpm or 3 rpm of the reference signal. Additionally, 100% of the HR and 98% of the RR measurements were clinically acceptable in Clarke error grid analysis.

Conclusions:

The wrist-worn PPG device is able to provide measurements of HR and RR that can be seen as sufficiently accurate for clinical applications. Considering the coverage, the device was able to continuously monitor HR and perform intermittent measurements of both vital parameters. Clinical Trial: https://www.clinicaltrials.gov/ct2/show/NCT03923127