Optimization for rate responsive cardiac pacemaker

• US 5,154,170 A
• Filed: 08/14/1990
• Issued: 10/13/1992
• Est. Priority Date: 08/14/1990
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Bennett, Tommy D., Nichols, Lucy M.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US07/567,476
• Time in Patent Office: 791 Days
• Field of Search: 128/419 PG
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/37 Monitoring; Protecting
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least one selected rate control parameter. Each rate control parameter has a value which varies as a function of changes in a patient'"'"'s physiologic demand and includes a sensor system for sensing the rate control parameter value and for providing a sensor output representative thereof. The cardiac pacemaker also includes control circuitry which includes a rate response defining means for deriving desired pacing rates as a function of the sensor output and an achievement monitoring means that has a predetermined achievement criterion, for monitoring the relationship between the derived pacing rates and the achievement criterion over an optimization period. An output circuitry provides optimized pacing rates as a function of the desired pacing rates, such optimization being accomplished by adjusting the rate response function for each sensor as a function of of the monitored achievement relationship. Another optimization function is provided by adjusting a sensor weighting value which weights or regulates the relative contribution each sensor'"'"'s derived desired pacing rates will contribute toward the pacemaker-derived optimized pacing rates, such sensor weighting value being adjusted as a function of the monitored achievement relationshp, or as a function of the sensor gain optimization activity, as desired.

Claims

1. A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least one selected rate control parameter, each of said rate control parameters having a value which varies as a function of changes in a patient'"'"'s physiologic demand, comprising:

(A) sensor means for sensing each of said rate control parameter values and for providing a sensor output representative thereof;

(B) control means coupled to each of said sensor means, comprising;

(1) rate response defining means for deriving desired pacing rates for each of said sensor means as a function of said sensor output corresponding thereto, to define a predetermined rate response function for each of said sensor means, such that for a predetermined change in sensor output for each of said sensor means a corresponding change in said desired pacing rate is provided;

(2) achievement monitoring means having a predetermined achievement criterion for each of said sensor means, for monitoring the relationship between each of said derived desired pacing rates and said achievement criterion corresponding thereto over a predetermined optimization period, and for providing an achievement output indicative of each of said monitored relationship, wherein each of said achievement criterion is reflective of expected levels of exercise of said patient during said optimization period;

(3) output means for providing optimized pacing rates as a function of each of said derived desired pacing rates; and

(4) rate response control means for adjusting each of said rate response functions, for at least a portion of a subsequent optimization period, as a function of said achievement output corresponding thereto, such that each of said adjusted rate response functions provides an increased or decreased change in desired pacing rate corresponding to said predetermined change in sensor output for each of said sensor means.

2. A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least two selected rate control parameters, each of said rate control parameters having a value which varies as a function of changes in a patient'"'"'s physiologic demand, comprising:

(A) sensor means for sensing each of said rate control parameter values and for providing a sensor output representative thereof;

(B) control means coupled to each of said sensor means, comprising;

(1) rate response defining means for deriving desired pacing rates for each of said sensor means as a function of said sensor output corresponding thereto, to define a predetermined rate response function for each of said sensor means, such that for a predetermined change in sensor output for each of said sensor means a corresponding change in said desired pacing rate is provided;

(2) achievement monitoring means having a predetermined achievement criterion for each of said sensor means, for monitoring the relationship between each of said derived desired pacing rates and said achievement criterion corresponding thereto over a predetermined optimization period, and for providing an achievement output indicative of each of said monitored relationships, wherein each of said achievement criterion is reflective of expected levels of exercise of said patient during said optimization period;

(3) output means for providing optimized pacing rates derived from an adjustable sensor weighting value and each of said desired pacing rates, said sensor weighting value for weighting the relative contribution which each of said desired pacing rates contribute toward said derived optimized pacing rate; and

(4) sensor weighting control means, for adjusting said sensor weighting value, for at least a portion of a subsequent optimization period, as a function of each of said achievement outputs.

3. A rate responsive cardiac pacemaker according to claim 2, wherein:

(A) said output means further comprises;

(1) output means for providing optimized pacing rates as a function of each of said derived desired pacing rates;

(B) said control means further comprises;

(1) rate response control means for adjusting each of said rate response functions, for at least a portion of a subsequent optimization period, as a function of said achievement output corresponding thereto, such that each of said adjusted rate response functions provides an increased or decreased change in desired pacing rate corresponding to said predetermined change in sensor output for each of said sensor means; and

(C) wherein, said optimized pacing rates are provided as a function of said adjusted rate response functions and said adjusted sensor weighting value.

4. A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least two selected rate control parameters, each of said rate control parameters having a value which varies as a function of changes in a patient'"'"'s physiologic demand, comprising:

(A) sensor means for sensing each of said rate control parameter values and for providing a sensor output representative thereof;

(B) control means coupled to each of said sensor means, comprising;

(1) rate response defining means for deriving desired pacing rates for each of said sensor means as a function of said sensor output corresponding thereto, to define a predetermined rate response function for each of said sensor means, such that for a predetermined change in sensor output for each of said sensor means a corresponding change in said desired pacing rate is provided; and

(2) output means for providing optimized pacing rates derived from a predetermined sensor weighting value and each of said desired pacing rates, said sensor weighting value for weighting the relative contribution which each of said desired pacing rates contribute toward said derived optimized pacing rate.

5. A rate responsive cardiac pacemaker according to claim 4, wherein said sensor weighting value is adjustable, and said control means further comprises sensor weighting control means, for adjusting said sensor weighting value.

6. A method for providing an optimized pacing rate of stimulation pulses in a rate responsive cardiac pacemaker, as a function of at least one selected rate control parameter, each of said rate control parameters having a value which varies as a function of changes in a patient'"'"'s physiologic demand, the method comprising the steps of:

(A) sensing each of said rate control parameter values and providing a sensor output representative thereof;

(B) deriving a desired pacing rate as a function of each of said sensor outputs, thereby defining a predetermined rate response function for each of said sensor outputs which correlates said sensor output with a correspondingly desired pacing rate, such that for a predetermined change in sensor output a corresponding change in said desired pacing rate is provided;

(C) selecting an achievement criterion for each of said sensor outputs which is reflective of expected levels of exercise of said patient over a predetermined optimization period;

(D) monitoring the relationship between each of said derived desired pacing rates and said achievement criterion corresponding thereto over said optimization period, for providing an achievement output indicative of each of said monitored relationship;

(E) providing optimized pacing rates as a function of each of said derived desired pacing rates; and

(F) adjusting each of said rate response functions as a function of said achievement output corresponding thereto, such that each of said adjusted rate response functions provides an increased or decreased change in desired pacing rate corresponding to said predetermined change in sensor output.

7. A method for providing an optimized pacing rate of stimulation pulses in a rate responsive cardiac pacemaker, as a function of at least two selected rate control parameters, each of said rate control parameters having a value which varies as a function of changes in a patient'"'"'s physiologic demand, the method comprising the steps of:

(A) sensing each of said rate control parameter values and providing sensor outputs respectively representative thereof;

(B) deriving a desired pacing rate as a function of each of said sensor outputs, thereby defining a predetermined rate response function for each of said sensor outputs which correlates said sensor output with a correspondingly desired pacing rate, such that for a predetermined change in sensor output a corresponding change in said desired pacing rate is provided;

(C) selecting an achievement criterion for each of said sensor outputs which is reflective of expected levels of exercise of said patient over a predetermined optimization period;

(D) monitoring the relationship between each of said derived desired pacing rates and said achievement criterion corresponding thereto over said optimization period, for providing an achievement output indicative of each of said monitored relationships;

(E) providing optimized pacing rates as a function of each of said derived desired pacing rates by applying an adjustable sensor weighting value to each of said derived desired pacing rates to determine said optimized pacing rates, wherein said sensor weighting value functions for weighting the relative contribution which each of said derived desired pacing rates contributes toward said optimized pacing rates; and

(F) adjusting said sensor weighting value, for at least a portion of a subsequent optimization period, as a function of each of said achievement outputs.