How to Select ESD Protection Devices for Signal Ports (e.g., ECG Leads) of a Defibrillator?

The key to selection is to minimize the impact of the protection device on signal integrity while providing sufficient protection level. It is necessary to choose TVS diodes or TVS arrays with ultra-low parasitic capacitance, typically below 1 picofarad, to avoid attenuation and distortion of microvolt-level ECG signals. The device's response time must be fast enough, usually at the nanosecond level, to quickly clamp ESD transient voltages. The device should be placed as close as possible to the port to ensure that interference is discharged to ground before entering the internal board circuits, and the protection ground loop should be as short and thick as possible.