The system, including wearable patch, mobile device and application, and cloud platform were validated in an at-home home study with first-month postpartum black women in collaboration with the University of Illinois Chicago. A pair of devices was provided to twenty participants classified by maternal health clinicians as belonging to a high or low risk postpartum population based on their cardiovascular health at discharge from the clinic following their recent giving birth. The high-risk postpartum group as determined by maternal health clinicians included individuals with histories of cardiomyopathy, diabetes, thromboembolism, hypertension, or those who have ever given birth though Cesarean section. All of these are risk factors for postpartum complications, defined in the study as the occurrence of infection, thromboembolism, hypertensive crisis, cardiomyopathy, heart failure, myocardial infarction, or hospitalization.
The participants were instructed to wear the device for at least 10 minutes total per day for the first month postpartum to assess the system’s ability to inform clinicians and the participant alike on the mother’s cardiovascular health. Participant ECG was used to calculate heart rate, respiration rate, and heart rate variability, while blood oxygen saturation and a second heart rate measurement were obtained from the PPG. Temperature readings were also considered by the clinic for its interrogation of fever and infection. The tablet interface provided participants with realtime feedback on heart rate, blood oxygen, and skin temperature, and notified the user to adjust the fit of the device if poor data quality was detected by the cloud. In addition to the two sensing devices, participants were supplied by the clinic with an Android tablet loaded with mobile application and an informational video explaining the usage of the device and application. Over forty hours of submitted data were processed after the trial to assess the platform’s ability to detect differences between the high risk and low risk populations. Statistically significant different differences were observed between the two groups for heart rate (p < 0.05), heart rate variability (p < 0.01), and skin temperature (p < 0.001). No significant differences were observed between the respiration rates, blood oxygen saturations, and blood pressures of the high risk and low risk groups. No participant required emergency medical intervention during the course of the study, though one did return to the clinic as a precaution after feeling unwell and was discharged shortly thereafter.
