Implantable cardiac stimulator with state machine for automatically controlling gain

摘要

A state machine for automatic gain control of sensing functions in an implantale cardiac stimulator. The state controls sensing levels based on present sensed conditions and on the prior state of the heart. Different rates of adjustment are selected under varying conditions so that the gain level for sense amplifiers can be adjusted without significant overshoot. The state machine comprises a set of four conditions or states together with interconnections or logical paths from one state to another. The rate of adjustment of sense amplifier gain is based on the path traversed in the state machine so that different effective time constants for the control function may be used for different conditions.