A connector (sensor assembly) [100] includes a housing [2], a female snap connection (connector member) [22] carried by the housing [2] and configured to mechanically and electrically connect to a male snap connector member [21] of an electrode [4], a three-axis accelerometer [3] carried by the housing [2] and configured to sense proper acceleration of the connector [100], and a microprocessor (microcontroller) [10] in electrical communication with the female snap connection [22] and with the accelerometer [3]. The microprocessor [10] is configured to receive cardiac activity data from the electrode [4], to receive proper acceleration data from the accelerometer [3], and to correlate [960, 1045, 1135] the cardiac activity data to the proper acceleration data to define processed data.