In an online source reconstruction apparatus and method, a sensor (12) acquires an electromagnetic physiological signal, a signal processing circuit (14) communicates with the sensor, and a processor communicates with the signal processing circuit. The processor is configured to support multiple threads of execution with one thread being a measurement module (16) and a second thread being a source reconstruction module (18). The signal processing by the signal processing circuit (14) is controlled by a feedback loop (30) from the measurement module (16).
