| 摘要 |
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. |
| 主权项 |
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:
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 the 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; andperforming a capture test to detect the presence or the absence of a contraction of the heart; andin the presence of a contraction:
ending the current iteration; andtransitioning to a new iteration, wherein the value of low energy is set as a new value of high energy; andin 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; andselecting a last energy value that produced the presence of a contraction as a selected energy value. |
