A Novel Point-of-Care Smartphone Based System for Monitoring the Cardiac and Respiratory Systems

Cardio- respiratory monitoring is one of the most demanding areas in the rapidly growing, mobiledevice, based health care delivery. We developed a 12-lead smartphone-based electrocardiogram ( ECG) acquisition and monitoring system ( called " cvrPhone"), and an application to assess underlying ischemia, and estimate the respiration rate (RR) and tidal volume (TV) from analysis of electrocardiographic (ECG) signals only. During in- vivo swine studies (n = 6), 12-lead ECG signals were recorded at baseline and following coronary artery occlusion. Ischemic indices calculated from each lead showed statistically significant (p < 0.05) increase within 2 min of occlusion compared to baseline. Following myocardial infarction, spontaneous ventricular tachycardia episodes ( n = 3) were preceded by significant ( p < 0.05) increase of the ischemic index 1- 4 min prior to the onset of the tachyarrhythmias. In order to assess the respiratory status during apnea, the mechanical ventilator was paused for up to 2 min during normal breathing. We observed that the RR and TV estimation algorithms detected apnea within 7.9 +/- 1.1 sec and 5.5 +/- 2.2 sec, respectively, while the estimated RR and TV values were 0 breaths/ min and less than 100 ml, respectively. In conclusion, the cvrPhone can be used to detect myocardial ischemia and periods of respiratory apnea using a readily available mobile platform.