Battery operated implanted cardiac stimulator - has signal generator with D=A converter to provide basic signal repetition rate

摘要

The cardiac stimulator is battery operated and is implanted in the patient's body. It comprises a signal generator having two externally activated levels. The first level system functions in accordance with a fixed rhythm; the second is programmed for a sequence of predetermined steps, these representing basic signal repetition rates. The rhythm programming circuit has a circuit for counting the basic repetition signals and includes a digital-analogue converter circuit responding to the output signals from the counter to produce analogue signals of the required type. The signal generator also comprises a time regulator responding to the same analogue signal.