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.
