Digital cardiac pacemaker clocking means
First Claim
1. A digitally controlled cardiac pacemaker pulse generator powered by an electrical power source for providing cardiac stimulating pulses at a defined rate and at a defined pulse width, said pulse generator comprising:
- clock means for providing a series of clock pulses;
a resettable first counter for counting clock pulses applied thereto;
means for coupling said series of clock pulses to said first counter;
a second counter for counting pulses applied thereto;
counter interface means responsive to said first counter for providing a counting pulse to said second counter each time said first counter reaches a first count and for resetting said first counter;
rate decoding means responsive to the count of said second counter reaching a defined value for providing a signal manifesting that a cardiac stimulating pulse is to be provided;
pulse width decoding means responsive to said rate decoding means signal and the count of said first counter reaching a defined value for providing a signal manifesting the desired pulse width of said cardiac stimulating pulse; and
output means responsive to said rate decoding means signal and said pulse width decoding means signal for providing said cardiac stimulating pulse.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
13 Citations
14 Claims
-
1. A digitally controlled cardiac pacemaker pulse generator powered by an electrical power source for providing cardiac stimulating pulses at a defined rate and at a defined pulse width, said pulse generator comprising:
-
clock means for providing a series of clock pulses; a resettable first counter for counting clock pulses applied thereto; means for coupling said series of clock pulses to said first counter; a second counter for counting pulses applied thereto; counter interface means responsive to said first counter for providing a counting pulse to said second counter each time said first counter reaches a first count and for resetting said first counter; rate decoding means responsive to the count of said second counter reaching a defined value for providing a signal manifesting that a cardiac stimulating pulse is to be provided; pulse width decoding means responsive to said rate decoding means signal and the count of said first counter reaching a defined value for providing a signal manifesting the desired pulse width of said cardiac stimulating pulse; and output means responsive to said rate decoding means signal and said pulse width decoding means signal for providing said cardiac stimulating pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
Specification