Patient monitoring systems and methods

A system for monitoring patient physiological data, comprising:

• a pad having a plurality of electrical contacts formed thereon in a predetermined pattern, the electrical contacts being configured to sense electrical signals produced by a patient's body;
• a controller in communication with the electrical contacts and configured to select at least two electrical contacts, each sensing a processable electrical signal, and to process a differential signal derived from the processable signals;
• and
• an output device in communication with the controller for displaying the patient's physiological data based on information processed by the controller;
• wherein the controller is further configured to actively change the selection of the at least two electrical contacts over time by periodically determining which of the plurality of electrical contacts are in contact with the patient and changing the selection of the at least two electrical contacts based on an assessment of the quality of the sensed electrical signals.