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US 7,623,921 B2Granted
System and method for verifying capture in a multi-site pacemaker
AssigneeCardiac Pacemakers, Inc.
InventorsRenold J. Russie, Qingsheng Zhu
Life of this patent
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Abstract
An apparatus and method for verifying capture by a selected pacing electrode in a multi-site pacemaker. A switching circuit switches the input of an evoked response sensing channel to an unselected electrode. A pacing pulse is then output by the selected electrode, and the presence or absence of capture is determined from the output of the evoked response sensing channel. In one embodiment, a backup pacing pulse is output by an unselected electrode if a loss of capture is detected.
Claims20
A cardiac pacemaker, comprising:
- a plurality of electrodes disposable near a heart chamber;
- a plurality of pacing channels, wherein each such channel includes a pulse generator connectable to a selected electrode;
- a controller for controlling the operation of the pacemaker;
- an evoked response sensing channel comprising a sense amplifier for sensing an evoked response generated after a pacing pulse;
- a switching circuit operable by the controller for configuring a pacing channel or the evoked response sensing channel with a particular electrode;
- a telemetry interface;
- wherein the controller is programmed to perform a capture verification test upon receiving a command via the telemetry interface to test the sensing/pacing channel for presence or loss of capture, the capture verification test being performed by configuring the evoked response sensing channel with a particular electrode specified for the particular pacing channel to be tested via the switching circuit and sensing whether an evoked response occurs during a capture detection window following the output of a pacing pulse;
- and,
- wherein the controller is programmed to determine a pacing threshold of a sensing/pacing channel upon receiving a command via the telemetry interface by:
- a) performing a capture verification test on the channel;
- b) lowering a pacing pulse energy by a specified amount if capture was present during the preceding capture verification test and raising a pacing pulse energy by a specified amount if capture was absent during the preceding capture verification test;
- c) repeating the capture verification test with the raised or lowered pacing pulse energy;
- and,
- d) determining the pacing threshold as the unlowered pacing pulse energy if the pacing pulse energy was lowered at step b and a loss of capture occurred during the repeated capture verification test, and repeating steps b through d otherwise.
11 more elements
A method for determining a pacing threshold for a pacemaker having multiple pacing channels, comprising:
- a) performing a capture verification test on a pacing channel by configuring an evoked response sensing channel with a particular electrode specified for the particular pacing channel to be tested via a switching circuit, outputting a pacing pulse through the pacing channel, and sensing whether an evoked response occurs during a capture detection window following the output of the pacing pulse via the evoked response sensing channel;
- b) lowering a pacing pulse energy by a specified amount if capture was present during the preceding capture verification test and raising a pacing pulse energy by a specified amount if capture was absent during the preceding capture verification test;
- c) repeating the capture verification test with the raised or lowered pacing pulse energy;
- and,
- d) determining the pacing threshold as the unlowered pacing pulse energy if the pacing pulse energy was lowered at step b and a loss of capture occurred during the repeated capture verification test, and repeating steps b through d otherwise.
2 more elements
Dependencies are inferred from the claim text.