Device and methods for a wearable medical device are disclosed. The device and methods use an on-board mobile system to alert emergency services when the user is in cardiovascular distress. The device takes advantage of newly miniaturized electrocardiograph, pulse oximetry sensors, mutual reinforcement and anomaly detection algorithms. Electrocardiograph waveforms are recorded digitally for physician review with emphasis on critical events. In the occurrence of a immediate critical-need cardiac event, the system will contact emergency services (EMS) for assistance. The system is a biometric monitoring system that implements key concepts of cardiovascular monitoring through pulse oximetry and electrocardiography (ECG). The system implements key concepts of ECGs and active/capacitive electrodes to produce a wireless network of (individually isolated) ECG nodes that can produce a system ranging from 3 to 16 leads.
