| 摘要 |
A programmable pacemaker apparatus having a microprocessor and means for receiving program information from an external source, means for generating and delivering stimulus signals and means for sensing the occurrence of natural heartbeats in a patient, and having a battery source powering the apparatus, said microprocessor being combined with program instructions stored in memory for controlling the operation of said pacemaker, comprising controller circuit means external to said microprocessor and interconnected therewith for controlling the operating state of said microprocessor, said controller means having occurrence means for determining the occurrence of given events. The controller means further comprises means for stopping operation of the microprocessor on command from the microprocessor and for starting operation of the microprocessor upon determination of one of said events, whereby the microprocessor normally is on less than about 25% of the time. The pacemaker provides for at least two modes of pacing rate control, whereby the patient's heartbeat can be overdriven, or abrupt changes in rate are not followed beyond a selected rate change limit. Means are provided for microprocessor control of testing of pacemaker conditions, and for limiting current to the pacemaker output circuit when the battery voltage drops below a predetermined value. |
