METHOD AND APPARATUS FOR MONITORING AND STIMULATING THE ACTIVITY OF THE HEART

• US 3,638,656 A
• Filed: 08/14/1969
• Issued: 02/01/1972
• Est. Priority Date: 08/26/1968
• Status: Expired due to Term

• Current Assignee: Alfred Liechti, Juan Ulrich Zumstein, Theo Grandjean
• Original Assignee: Alfred Liechti, Juan Ulrich Zumstein, Theo Grandjean
• Inventors: Grandjean, Theo, Zumstein, Juan Ulrich, Liechti, Alfred
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/850,116
• Time in Patent Office: 901 Days
• Field of Search: 128/419P,422,2.6F
• US Class Current: 607/27
• CPC Class Codes: A61N 1/36564 controlled by blood pressure

Abstract

The intensity of the stimulation pulses from the output stage is increased step-by-step to an adjustable maximum value by a regulating stage. The latter is fed pulses derived from the activity of the heart. When these pulses are absent or late, the value of a shunt combination of resistances is increased in steps until an adjustable maximum value is reached, as determined by a potentiometer connected in parallel with these resistances and also connected to the control electrode of a component in the output stage.

Claims

1. A method of monitoring and stimulating the activity of the heart, comprising the steps of generating pulses at a standard pulse rate, conducting stimulation pulses to the heart, converting the movements of the heart into electrical signals, and automatically increasing the intensity of the stimulation pulses to an adjustable maximum value when these electrical signals do not appear during one period of a standard pulse rate.

2. The method as defined in claim 1, wherein the electrical signals converted from the movements of the heart are derived from the intracardiac pressure.

3. The method as defined in claim 1, including the step of indicating the number of stimulation pulses.

4. A device for monitoring and stimulating the activity of the heart comprising an input amplifier for amplifying electrical signals derived from the activity of the heart, a pulse generator in circuit with said input amplifier fOr producing pulses at a standard rate, an output stage in circuit with said pulse generator for generating stimulation pulses, and a regulating stage connected to said output stage including means for automatically increasing the intensity of the stimulation pulses that follow a stimulation pulse that is too weak to produce said signals.

5. The device as defined in claim 4, wherein said output stage includes means for delivering widened stimulation pulses to said regulating stage, said means of said regulating stage comprising a first input connected to said output stage receiving therefrom and having means responding to a trailing edge of said widened stimulation pulses, a second input in circuit with said input amplifier for receiving pulses from said input amplifier, a gate cutoff whenever said second input receives pulses, a third input connected to said pulse generator for receiving from said pulse generator pulses at the standard rate, said gate being connected in circuit with said third input.

6. The device as defined in claim 5, further including means for differentiating the widened pulses connected with said first input, said differentiating means being in circuit with said regulating stage.

7. The device as defined in claim 5, wherein said means of said regulating stage further comprises a plurality of resistances, a plurality of switching transistor means in circuit with said gate for connecting and disconnecting, in response to signals passed by said gate, said plurality of resistances in various combinations between two points of said regulating stage, so as to increase in steps the intensity of the stimulation pulses, and a potentiometer for regulating the intensity of the stimulation pulses connected between said two points.

8. The device as claimed in claim 7, including a cutoff circuit for suspending the step-by-step action of said regulating stage when the adjustable maximum value of the stimulation pulses is reached.

9. The device as defined in claim 4, further including a counter for indicating the number of stimulation pulses generated.