Various designs and features of an ambulatory transceiver and ECG lead set
are disclosed for use in remote patient monitoring. One feature involves the use
of unshielded, dual-conductor lead wires in which one conductor carries the patient's
ECG signal and the other conductor provides an RF antenna element for the transceiver.
The lead wires used in one embodiment provide improved flexibility, durability,
and antenna performance over conventional lead sets with shielded wires. Another
feature involves an antenna diversity scheme in which the transceiver switches
between two or more ECG-lead antennas, each of which is formed from one or more
ECG leads of the lead set. Another feature involves the use of a circuit within
the transceiver to monitor, and dynamically compensate for changes in, the impedance
of an ECG-lead antenna or a conductor thereof. Another feature is an improved circuit
for protecting the transceiver from damage caused by defibrillation pulses.
