Apparatus for monitoring and storing electrical signals indicative of a patient's heart activity is disclosed as including a memory comprising a first plurality of storage locations for receiving a series of the patient's heart signal and a second plurality of storage locations. Further, there is included...http://www.google.com.au/patents/US4367753?utm_source=gb-gplus-sharePatent US4367753 - Apparatus for monitoring and storing heartbeats of a patient
