초록 ▼

A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programm

A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signaling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals. The program signal acceptance circuit performs several different checks on the detected programming signal including a parity check, an access code check and determining if the proper number of signals were transmitted within a given time. The timing circuit of the pulse generator includes a crystal clock oscillator and counter means for counting the clock pulses therefrom to determine the rate of the pacemaker. The pulse width of each pacemaker pulse is determined by using a voltage controlled oscillator in place of the crystal oscillator to obtain energy compensation due to the battery voltage decreasing with time.

대표청구항 ▼

A body-implantable medical device adapted to periodically treat the body comprising: battery means for supplying energy to said device, said battery means having a characteristic such that the energy provided thereby decreases with time; controllable timing means for establishing a parameter of the

A body-implantable medical device adapted to periodically treat the body comprising: battery means for supplying energy to said device, said battery means having a characteristic such that the energy provided thereby decreases with time; controllable timing means for establishing a parameter of the periodic treatment of the body in response to a control signal; and battery monitoring means for periodically detecting the energy of the battery means just prior in time to the periodic treatment of the body and for providing the control signal for controlling the treatment parameter as a function thereof, the controlled parameter providing an externally recognizable indication of the energy of the battery means.