An electrode useful for generating electrical signals generally comprises a base and more than one dome-like protuberance on an exterior surface of the annular ring-like base. The electrodes can be utilized in connection with various probe applications. For example, the electrodes can be utilized with a probe adapted for insertion into an anatomical canal, e.g. the esophagus of an animal or a human for ECG or cardiac output measurements. An exemplary probe generally comprises a chassis with an electrical cable extending from the proximal end of the chassis and with the cable terminating at an electrical plug configured for connection to a cardiac monitor. The probe also includes an electrode assembly comprising the dome-like protuberances and configured to generate or receive electrical signals that are indicative of the cardiac functions of the patient. The probe may further include an engagement device attached to the chassis for stabilizing the probe within the esophagus. The probe may also be configured to include other sensing devices, for example, a temperature measuring device and an acoustic monitor.