Non-Invasive Methodology for Detection of Vital Signs by PPG Signals Collected from the Finger via Smartphone Camera for Individuals Aged 18 to 70: Randomized Controlled Trial (Preprint)

Abstract

Monitoring vital signs is an essential part of evaluating health, and smartphones with built-in photoplethysmography (PPG) sensors are becoming viable alternatives to conventional, gold-standard medical equipment in vitals monitoring. It is critical, however, to compare newer technologies with more conventional medical tools. The focus of this research is to compare vital signs recorded using the smartphone app CarePlix Vitals to those collected from traditional, gold-standard medical equipment. Healthcare provider CareNow Pvt Ltd. funded this research.

This research aims to evaluate the accuracy of vital signs obtained by the smartphone app CarePlix Vitals in comparison to known methods.

The Careplix Vitals app utilized PPG signals obtained from partially automated finger scanning on various smartphone models to measure the following vital signs readings: pulse, respiration rate, oxygen saturation, heart rate variability, and blood pressure. We compared these readings to those of the following traditional medical devices: the Polar H9, the Polar H10, the Omron HEM 7120 BP monitor, the Masimo MightySat Rx, and the Omron HEM 7120 BP monitor. We performed statistical analyses to validate the accuracy of CarePlix Vitals vital signs readings in comparison those made by traditional medical devices. The Confidence Interval for hypothesis testing was set at 95%. Participants were recruited offline from SSKM Hospital and participated in an unblinded, face-to-face, open trial. Ethical approval was obtained from all participants, and data quality control measures were implemented to ensure data accuracy.

The following percentages were obtained by CarePlix Vitals in terms of accuracy: 98.56% for heart rate (HR), 98.18% for respiratory rate (RR), 98.14% for oxygen saturation (SpO2), 91.20% for systolic blood pressure (BP), and 89.89% for diastolic BP. There was an accuracy of 97.85% (AE<=12 msec) for RMSSD values of HRV, and a precision of 92.62% (AE<=25 msec) for SDNN measurements. Our findings suggest that the CarePlix Vitals app could be used as an alternative for traditional methods such as a pulse oximeter, digital blood pressure, or polar belt in an adult population.

Results demonstrate that the vitals readings by the Careplix Vitals app are substantially equivalent to those of predicate devices. As smartphone-based technologies continue to advance, this study contributes valuable insights to the field of vital signs monitoring. Despite the promising results, we acknowledge certain limitations of this method, including PPG signal corruption due to movement artifacts. Addressing these limitations in future iterations will further enhance the practicality and precision of CarePlix Vitals. Further studies with larger and more varied populations will be crucial toward corroborating the efficacy and generalizability of the CarePlix Vitals app.

CTRI/2023/07/055351