Active implantable medical device with dynamic optimization of stimulation pulse energy
First Claim
1. An active implantable medical device for stimulation, resynchronization, and/or defibrillation, comprising:
- a stimulation circuit adapted to deliver stimulation pulses to an electrode in contact with a heart of a patient;
a capture test circuit adapted to detect a presence or an absence of a contraction of the heart subsequent to a stimulation pulse; and
an energy adjustment circuit adapted to adjust an energy of the stimulation pulses delivered by the stimulation circuit by independently controlling a stimulation voltage and a pulse width of the stimulation pulse for each stimulation pulse delivered;
wherein the energy adjustment circuit is configured to implement an iterative algorithm, wherein the iterative algorithm at each current iteration comprises testing to determine whether a contraction of the heart occurs at a plurality of energy values, wherein the testing comprises;
setting a value of high energy, wherein the value of high energy includes a first pulse width and a first stimulation voltage;
setting a value of low energy, wherein the value of low energy includes a second pulse width and a second stimulation voltage, wherein the second pulse width is less than the first pulse width, and wherein the second stimulation voltage is less than the first stimulation voltage;
delivering a stimulation pulse with the value of low energy; and
performing a capture test to detect the presence or the absence of a contraction of the heart; and
in the presence of a contraction;
ending the current iteration; and
transitioning to a new iteration, wherein the value of the delivered energy that produced the presence of a contraction is set as a new value of high energy; and
in the absence of a contraction;
applying consecutive counter-stimulation pulses of the first pulse width and the first stimulation voltage set for the value of high energy;
determining whether an end of the current iteration has been reached;
in response to determining the end of the current iteration has not been reached, continuing the current iteration with delivery of a stimulation pulse of increased energy and re-performing the capture test to detect the presence or the absence of a contraction of the heart; and
in response to determining the end of the current iteration has been reached, selecting a last energy value that produced the presence of a contraction as a selected energy value.
1 Assignment
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Accused Products
Abstract
The disclosure relates to a device including a circuit for adjusting the energy of the stimulation pulses, independently controlling the pulse width and the voltage of each stimulation pulse. An iterative search algorithm for determining the optimum energy includes changing both the pulse width and voltage at each new pulse delivered, by setting a high energy value and a low energy value, and delivering a stimulation pulse with the low energy value. A capture test is then carried out. In the presence of a capture, a current iteration is complete and a new iteration is done with the current low energy as a new high energy value. In the absence of capture, the algorithm is terminated with selection of the last energy value that produced the capture as the value of optimum energy.
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Citations
20 Claims
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1. An active implantable medical device for stimulation, resynchronization, and/or defibrillation, comprising:
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a stimulation circuit adapted to deliver stimulation pulses to an electrode in contact with a heart of a patient; a capture test circuit adapted to detect a presence or an absence of a contraction of the heart subsequent to a stimulation pulse; and an energy adjustment circuit adapted to adjust an energy of the stimulation pulses delivered by the stimulation circuit by independently controlling a stimulation voltage and a pulse width of the stimulation pulse for each stimulation pulse delivered; wherein the energy adjustment circuit is configured to implement an iterative algorithm, wherein the iterative algorithm at each current iteration comprises testing to determine whether a contraction of the heart occurs at a plurality of energy values, wherein the testing comprises; setting a value of high energy, wherein the value of high energy includes a first pulse width and a first stimulation voltage; setting a value of low energy, wherein the value of low energy includes a second pulse width and a second stimulation voltage, wherein the second pulse width is less than the first pulse width, and wherein the second stimulation voltage is less than the first stimulation voltage; delivering a stimulation pulse with the value of low energy; and performing a capture test to detect the presence or the absence of a contraction of the heart; and in the presence of a contraction; ending the current iteration; and transitioning to a new iteration, wherein the value of the delivered energy that produced the presence of a contraction is set as a new value of high energy; and in the absence of a contraction; applying consecutive counter-stimulation pulses of the first pulse width and the first stimulation voltage set for the value of high energy; determining whether an end of the current iteration has been reached; in response to determining the end of the current iteration has not been reached, continuing the current iteration with delivery of a stimulation pulse of increased energy and re-performing the capture test to detect the presence or the absence of a contraction of the heart; and in response to determining the end of the current iteration has been reached, selecting a last energy value that produced the presence of a contraction as a selected energy value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for determining an energy for stimulation, resynchronization, and/or defibrillation, comprising:
implementing an iterative algorithm, wherein implementing each current iteration of the iterative algorithm comprises testing to determine whether a contraction of the heart occurs at a plurality of energy values, wherein the testing comprises; setting a value of high energy, wherein the value of high energy includes a first pulse width and a first stimulation voltage; setting a value of low energy, wherein the value of low energy includes a second pulse width and a second stimulation voltage and the second pulse width and second stimulation voltage are less than the first pulse width and first stimulation voltage; delivering a stimulation pulse with the value of low energy; and performing a capture test to detect a presence or an absence of a contraction of a heart of a patient; and in the presence of a contraction; ending the current iteration; and transitioning to a new iteration, wherein the value of the delivered energy that produced the presence of a contraction is set as a new value of high energy; and in the absence of a contraction; applying consecutive counter-stimulation pulses of the first pulse width and the first stimulation voltage set for the value of high energy; determining whether an end of the current iteration has been reached; in response to determining the end of the current iteration has not been reached, continuing the current iteration with delivery of a stimulation pulse of increased energy and re-performing the capture test to detect the presence or the absence of a contraction of the heart; and in response to determining the end of the current iteration has been reached, selecting a last energy value that produced the presence of a contraction as a selected energy value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. An active implantable medical device for stimulation, resynchronization and/or defibrillation, comprising:
circuitry configured to; deliver stimulation pulses to an electrode in contact with a heart of a patient; detect a presence or an absence of a contraction of the heart subsequent to a stimulation pulse; and adjust an energy of the stimulation pulses delivered by the circuitry by independently controlling a stimulation voltage and a pulse width of the stimulation pulse for each stimulation pulse delivered; and determine a selected energy by applying a plurality of iterations, wherein each current iteration comprises testing to determine whether a contraction of the heart occurs at a plurality of energy values, wherein the testing comprises; setting a value of high energy, wherein the value of high energy includes a first pulse width and a first stimulation voltage; setting a value of low energy, wherein the value of low energy includes a second pulse width and a second stimulation voltage and the second pulse width and second stimulation voltage are less than the first pulse width and first stimulation voltage; delivering a stimulation pulse with the value of low energy; and performing a capture test to detect the presence or the absence of a contraction of the heart; and in the presence of a contraction; ending the current iteration; and transitioning to a new iteration, wherein the value of the delivered energy that produced the presence of a contraction is set as a new value of high energy; and in the absence of a contraction; applying consecutive counter-stimulation pulses of the first pulse width and the first stimulation voltage set for the value of high energy; determining whether an end of the current iteration has been reached; in response to determining the end of the current iteration has not been reached, continuing the current iteration with delivery of a stimulation pulse of increased energy and re-performing the capture test to detect the presence or the absence of a contraction of the heart; and in response to determining the end of the current iteration has been reached, selecting a last energy value that produced the presence of a contraction as a selected energy value. - View Dependent Claims (16, 17, 18, 19, 20)
Specification