Abstract: The present invention pertains to a system for monitoring the health condition of a patient, such as the condition of the patient's heart. The system comprises a patient station having means for monitoring a predetermined bodily function of the patient and a patient transmitter for transmitting information relating to the bodily function. The system is also comprised of a secondary system remote from the patient at the patient station having means for activating the patient station such that information relating to the monitored bodily function can be transmitted from the patient station to the secondary station. The secondary station is in communication with the patient station. The present invention also pertains to a method of monitoring the health condition of a patient. The method comprises the steps of providing the patient with a device for monitoring a predetermined bodily function of the patient at a patient station.

Abstract: A method and apparatus for processing electrical signals by modifying delta modulation to discrete slope delta modulation includes converting its electrical signals into compressed digital information, and representing this digital information as a sequence of slops or deltas added to the past value of the representation. For each sample period, a slope is chosen from slope tables having multiple entries and each choice is represented by a Huffman code. Signal compression occurs in two steps: first the selection of a small number of possible slopes provides compression and also the most probable slopes are represented by the shortest Huffman codes providing additional compression. Depending on the history of the slope chosen, multiple tables can be accessed with different slop entries. Two check point values are provided which code absolute output levels instead of slopes in order to facilitate recovery of the signal in the event of transmission errors.