Since ECG electrodes would not be run in parallel over their entire path from electrode to the module, one approach to ensure both ECG inputs “see” the same noise is to add an antenna that runs in parallel to the other signal. This technique ensures that the external interference (RF noise, for example) remains common-mode to both inputs. If the environmental noise is common and in phase to both ECG inputs, it will be attenuated by the instrumentation amplifier thereby enhancing the performance.