IMPLANTABLE CARDIAC PACER HAVING ADJUSTABLE OPERATING PARAMETERS

• US 3,805,796 A
• Filed: 01/22/1973
• Issued: 04/23/1974
• Est. Priority Date: 05/10/1971
• Status: Expired due to Term

• Current Assignee: Telectronics Pacing Systems, Inc (Abbott Laboratories Incorporated)
• Original Assignee: Gomer L. Davies, Reese S. Terry Jr
• Inventors: Terry, Reese S. Jr., Davies, Gomer L.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/325,334
• Time in Patent Office: 456 Days
• Field of Search: 128/419C,419B,419E,419P,419R,422,423
• US Class Current: 607/30
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators

Abstract

In the implantable cardiac pacer disclosed herein, various operating parameters are determined or controlled by the information held in a digital storage register such as a binary counter. The information so held may be varied by means of pulse signals transmitted through the body of a patient within whom the pacer is implanted. Rate-sensing and count threshold control circuits are provided to prevent unintended changes in operating parameters.

Claims

1. An implantable cardiac pacer comprising:

means for detecting pulse signals having predetermined characteristics, which pulse signals can be applied externally of a patient within whom said pacer is adapted to be implanted;

a first counter interconnected with said detecting means for selectively counting detected pulse signals;

a second counter, controlled by said first counter and also responsive to said pulse signal detecting means for counting detected pulse signals occurring after the count held by said first counter reaches a preselected threshold value;

a cardiac stimulation pulse generator having at least one changeable output parameter; and

decoding means interconnected with said second counter for controlling said output parameter in predetermined correspondence with the value of the count held by said second counter.

2. In a fully implantable therapeutic device providing an electrically controlled physiological function, apparatus for adjusting the operating parameters of the device while implanted, said apparatus comprising:

means for detecting pulse signals having predetermined characteristics, which pulse signals can be applied externally of a patient within whom said device is adapted to be implanted;

a first counter interconnected with said detecting means for selectively counting detected pulse signals;

a second counter, controlled by said first counter and also responsive to said pulse signal detecting means for counting detected pulse signals occurring after the count held by said first counter reaches a preselected threshold value;

decoding means interconnecting with said second counter for controlling operating parameters of said device in accordance with the count held by said second counter; and

means for resetting said first counter if no pulse signals are received for a predetermined period.

3. In a fully implantable device for automatically providing an electrically controlled physiological function, apparatus for adjusting the operating parameters of the device while the device is implanted, said apparatus comprising:

a magnetically operable switch for detecting magnetic pulse signals, which pulse signals can be applied externally of a patient within whom said device is adapted to be implanted;

a first couNter interconnected with said switch for selectively counting operations of said switch;

means for resetting said first counter if no pulse signals are received for a preselected period;

a second counter, controlled by said first counter and selectively responsive to the operation of said switch;

means controlled by said first counter for resetting said second counter when the count held by said first counter reaches a preselected threshold level and for subsequently enabling said second counter to count switch operations; and

decoding means interconnected with said second counter for controlling the operating parameters of said device in accordance with the count held by said second counter.

4. A device as set forth in claim 3 including a one-shot multivibrator which is triggered by the operation of said switch and which generates square-wave output pulses of predetermined duration, said counters being responsive to the multivibrator output pulse to count operations of said switch.

5. A device as set forth in claim 3 wherein said first and second counters comprise complementary MOSFET integrated logic circuits.

6. An implantable cardiac pacer comprising:

a magnetically operable switch for detecting magnetic pulse signals, which pulse signals can be applied externally of a patient within whom said pacer is adapted to be implanted;

a first counter interconnected with said switch for selectively counting operations of said switch;

means for resetting said first counter if no pulse signals are received for a preselected period;

a second counter, controlled by said first counter and selectively responsive to the operation of said switch;

means controlled by said first counter for resetting said second counter when the count held by said first counter reaches a preselected threshold level and for subsequently enabling said second counter to count switch operations;

a cardiac stimulation pulse generator having at least one adjustable output parameter; and

means interconnected with said second counter for setting said output parameter to a value corresponding to the count held by said second counter.

7. In a fully implantable device for providing an electrically controlled physiological function, apparatus for adjusting the operating parameters of the device while the device is implanted, said apparatus comprising:

means for detecting pulse signals having predetermined characteristics, which pulse signals can be applied externally of a patient within whom said device is adapted to be implanted;

means responsive to a first predetermined grouping of detected pulse signals for providing a control signal;

a parameter control register having a multiplicity of states;

means for controlling the operating parameters of said device in accordance with the existing state of said control register; and

means responsive to said control signal for changing the state of said register in accordance with predetermined groupings of detected pulse signals following said first grouping of pulse signals, thereby to vary the operating parameters of said device.

8. In a fully implantable device for automatically providing electrical stimulation of tissue, apparatus for adjusting the operating parameters of the device while the device is implanted, said apparatus comprising:

means for detecting pulse signals having predetermined characteristics, which pulse signals can be applied externally of a patient within whom said device is adapted to be implanted;

means including a counter responsive to a first predetermined sequence of detected pulse signals for providing a control signal;

a parameter control counter having a multiplicity of sequential states;

means for controlling the operating parameters of said device in accordance with the existing state of said control counter; and

means enabled by said control signal for advancing the state of said control counter in response to detected Pulse signals following said first sequence of pulse signals, thereby to vary the operating parameters of said device.

9. Apparatus as set forth in claim 8 wherein said control counter is responsive to said control signal and is reset thereby to a preselected state.