Accuracy of Vital Signs Measurements by a Smartwatch and a Portable Health Device: Validation Study.

BACKGROUND: New consumer health devices are being developed to easily monitor multiple physiological parameters on a regular basis. Many of these vital sign measurement devices have yet to be formally studied in a clinical setting but have already spread widely throughout the consumer market. OBJECTIVE: The aim of this study was to investigate the accuracy and precision of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and oxygen saturation (SpO2) measurements of 2 novel all-in-one monitoring devices, the BodiMetrics Performance Monitor and the Everlast smartwatch. METHODS: We enrolled 127 patients (>18 years) from the Thomas Jefferson University Hospital Preadmission Testing Center. SBP and HR were measured by both investigational devices. In addition, the Everlast watch was utilized to measure DBP, and the BodiMetrics Performance Monitor was utilized to measure SpO2. After 5 min of quiet sitting, four hospital-grade standard and three investigational vital sign measurements were taken, with 60 seconds in between each measurement. The reference vital sign measurements were calculated by determining the average of the two standard measurements that bounded each investigational measurement. Using this method, we determined three comparison pairs for each investigational device in each subject. After excluding data from 42 individuals because of excessive variation in sequential standard measurements per prespecified dropping rules, data from 85 subjects were used for final analysis. RESULTS: Of 85 participants, 36 (42%) were women, and the mean age was 53 (SD 21) years. The accuracy guidelines were only met for the HR measurements in both devices. SBP measurements deviated 16.9 (SD 13.5) mm Hg and 5.3 (SD 4.7) mm Hg from the reference values for the Everlast and BodiMetrics devices, respectively. The mean absolute difference in DBP measurements for the Everlast smartwatch was 8.3 (SD 6.1) mm Hg. The mean absolute difference between BodiMetrics and reference SpO2 measurements was 3.02%. CONCLUSIONS: Both devices we investigated met accuracy guidelines for HR measurements, but they failed to meet the predefined accuracy guidelines for other vital sign measurements. Continued sale of consumer physiological monitors without prior validation and approval procedures is a public health concern.

The accuracy of blood pressure measurement by a smartwatch and a portable health device.

Objectives: Handheld medical devices and smartwatches that measure BP without a cuff have recently become available. Since these measurements are relatively more user-friendly than conventional cuff-based measurements they may aid in more frequent BP monitoring. We investigated the accuracy and precision of two popular cuff-less devices: the Everlast smartwatch and the BodiMetrics Performance Monitor.Methods: We enrolled 127 patients from the Thomas Jefferson University Hospital Preadmission Testing Center. Research staff were trained to measure BP according to manufacturer guidelines for the investigational devices. The Everlast smartwatch provides measurements of systolic (SBP) and diastolic (DBP) BP, whereas the Bodimetrics only provides SBP. Reference BP measurements were obtained using a hospital-grade automated sphygmomanometer. After 5 minutes of quiet sitting, four standard and three investigational BP measurements were taken with sixty seconds in between each measurement. The reference BP value was calculated by determining the average of the 2 standard BP measurements that bounded the investigational measurements. We thus determined 3 comparison pairs for each investigational device in each subject. We calculated the mean (SD) of the absolute difference between the respective investigational devices and the reference for SBP and DBP.Results: Data from 42 individuals was excluded because of variation in standard BP measurements per prespecified rules. Of 85 participants used for analysis, 36 (42%) were women, the mean (SD) age was 53 (21) years, 32 (38%) self-reported hypertension, and 97% of these (n = 31) reported taking antihypertensive medications. The average differences between the Everlast watch and reference were 16.9 (13.5) mm Hg for SBP and 8.3 (6.1) mm Hg for DBP. The average difference between the Bodimetrics performance monitor and the reference was 5.3 (4.7) mm Hg for SBP.Conclusions: The Everlast smartwatch and the BodiMetrics Performance Monitor we tested are not accurate enough to be used as BP measurement devices.

Cuff-Less Methods for Blood Pressure Telemonitoring.

Blood pressure telemonitoring (BPT) is a telemedicine strategy that uses a patient's self-measured blood pressure (BP) and transmits this information to healthcare providers, typically over the internet. BPT has been shown to improve BP control compared to usual care without remote monitoring. Traditionally, a cuff-based monitor with data communication capabilities has been used for BPT; however, cuff-based measurements are inconvenient and cause discomfort, which has prevented the widespread use of cuff-based monitors for BPT. The development of new technologies which allow for remote BP monitoring without the use of a cuff may aid in more extensive adoption of BPT. This would enhance patient autonomy while providing physicians with a more complete picture of their patient's BP profile, potentially leading to improved BP control and better long-term clinical outcomes. This mini-review article aims to: (1) describe the fundamentals of current techniques in cuff-less BP measurement; (2) present examples of commercially available cuff-less technologies for BPT; (3) outline challenges with current methodologies; and (4) describe potential future directions in cuff-less BPT development.