Abstract: A method and apparatus for providing galvanic isolation for signal communication between two electrical circuits via a capacitive coupler that is constructed from conductive and non-conductive layers of a printed circuit board. The invention can provide at low cost and with substantial galvanic isolation, the communication of data at rates of greater than 1 megabit per second. The galvanic isolation provided by the invention protects against common mode fields as well as limited differential mode fields. The invention makes use of pre-existing layers of a circuit board and does not require many other or expensive electrical components.

Abstract: A medical device, such as an electrocardiogram (ECG) monitoring apparatus, provides galvanic isolation between low voltage electronics and a plurality of externally exposed ECG (patient contact) lead wires and electrodes. The ECG lead wires and/or electrodes can potentially make unwanted contact with sources of high voltage, such as from defibrillation pulses generated by defibrillation devices. The defibrillation pulses can cause damage to the low voltage electronics within the ECG monitoring apparatus. Electrical resistance is provided outside of the ECG lead wires and electrodes and separate from the low voltage electronics to protect against misdirection of a defibrillation pulse towards the low voltage electronics, and to protect against misdirection of a defibrillation pulse away from the patient for which the benefit of the defibrillation pulse is intended.