Implantable cardiac stimulation device and method for varying pacing parameters to mimic circadian cycles
First Claim
1. In an implantable stimulation device, a method of automatically adjusting a desired pacing parameter to mimic natural diurnal fluctuations, the device having a sensor capable of sensing a physiological parameter having circadian variations, the method comprising:
- determining a daytime and a nighttime value for the desired pacing parameter;
sensing the physiological parameter for a predetermined period of time;
deriving, from the sensed physiological parameter, an average daytime and an average nighttime value for the physiological parameter;
determining a circadian-based function based on the daytime and the nighttime value of the desired pacing parameter, and based on the average daytime and nighttime value of the physiological parameter;
determining a current value for the physiological parameter;
determining a current circadian-based value for the desired pacing parameter based on the circadian-based function and the current value of the physiological parameter, whereby the desired pacing parameter changes diurnally as the physiological parameter changes; and
adjusting the desired pacing parameter according to the circadian-based value.
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Accused Products
Abstract
Provided herein are methods and apparatus for automatically adjusting pacing parameters in implantable programmable stimulation devices, such as rate-responsive pacemakers and cardioverter defibrillators. The methods and apparatus provide a circadian varying pacing parameter (e.g., pacing rate, AV Delay, etc.) that very closely mimics the natural diurnal fluctuations of a patient'"'"'s heart. Using physiological parameters that vary diurnally (e.g., minute ventilation and/or activity variance, etc.), a circadian-base value is derived. In the preferred embodiments, the physiological measurements are used to derive a histogram from which certain characteristic values are determined. These physiological characteristic values, along with the predetermined characteristic rates, automatically and periodically determine a transfer function from which the patient'"'"'s appropriate circadian base rate is derived. Further contemplated herein are the use of more than one physiological parameter to derive a final circadian base rate, and stimulation devices employing these methods.
351 Citations
47 Claims
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1. In an implantable stimulation device, a method of automatically adjusting a desired pacing parameter to mimic natural diurnal fluctuations, the device having a sensor capable of sensing a physiological parameter having circadian variations, the method comprising:
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determining a daytime and a nighttime value for the desired pacing parameter; sensing the physiological parameter for a predetermined period of time; deriving, from the sensed physiological parameter, an average daytime and an average nighttime value for the physiological parameter; determining a circadian-based function based on the daytime and the nighttime value of the desired pacing parameter, and based on the average daytime and nighttime value of the physiological parameter; determining a current value for the physiological parameter; determining a current circadian-based value for the desired pacing parameter based on the circadian-based function and the current value of the physiological parameter, whereby the desired pacing parameter changes diurnally as the physiological parameter changes; and adjusting the desired pacing parameter according to the circadian-based value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In an implantable programmable rate-responsive stimulation device, a method of automatically determining a circadian base pacing rate wherein the circadian base pacing rate mimics natural diurnal fluctuations in heart rate, the device having a sensor capable of sensing a physiological parameter having circadian variations, the method comprising:
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determining a daytime and a nighttime value for the pacing rate; sensing the physiological parameter for a predetermined period of time; determining an average daytime and an average nighttime value for the sensed physiological parameter; determining a base rate slope based on the daytime and nighttime values of the pacing rate and the average daytime and nighttime values for the physiological parameter; determining a current value for the physiological parameter; determining a current circadian-based value for the pacing rate based on the base rate slope and the current value of the physiological parameter; and adjusting the pacing rate according to the current circadian-based value. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A cardiac stimulation device for automatically adjusting at least one pacing parameter to mimic natural diurnal fluctuations, comprising:
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a pulse generator for generating stimulation pulses to the heart; a sensor capable of sensing a physiological parameter having circadian variations for a predetermined period of time; means for determining a desired daytime and nighttime target value for a desired pacing parameter; a processor, coupled to the pulse generator, the sensor, and the determining means, for automatically adjusting the desired pacing parameter about the desired target values to mimic natural circadian fluctuations, the processor including; means for deriving at least an average daytime and an average nighttime value in the physiological parameter; means for determining a current value for the physiological parameter; and means for determining a current circadian-based value for the desired pacing parameter based on the desired daytime and nighttime target values of the desired pacing parameter, and the average daytime and nighttime values of the physiological parameter, and the current value of the physiological parameter; whereby the current circadian-based value of the desired pacing parameter changes diurnally as the value of the physiological parameter changes. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A cardiac stimulation device for automatically adjusting at least one pacing parameter to mimic natural diurnal fluctuations, comprising:
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a pulse generator that generates stimulation pulses to the heart; a sensor that senses a physiological parameter having diurnal variations and generates sensor signals thereof; a memory that stores at least two predetermined values of the pacing parameter, the values corresponding to a diurnal rhythm; and a processor, coupled to the pulse generator, the sensor and the memory, that controls the at least one pacing parameter, the processor further determines diurnally varying values for the at least one pacing parameter based upon a function of the diurnal variations of the physiological parameter and corresponding values of the pacing parameter, and the processor triggers the pulse generator to generate stimulation pulses in accordance with the diurnally varying values of the pacing parameter. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44)
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45. In an implantable stimulation device, a method of automatically adjusting a desired pacing parameter to mimic natural diurnal fluctuations, the device having a sensor capable of sensing a physiological parameter having circadian variations, the method comprising:
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sensing a physiological parameter having diurnal variations; determining at least two diurnally varying values of the pacing parameter which correspond to a diurnal range of operation; determining diurnally varying values for the at least one pacing parameter based upon a function of the diurnal variations of the physiological parameter and the corresponding diurnally varying values of the pacing parameter; and triggering the device to generate stimulation pulses in accordance with the circadian varying values of the pacing parameter. - View Dependent Claims (46, 47)
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Specification