Method of automatic evoked response sensing vector selection using evoked response waveform analysis

• US 20040088018A1
• Filed: 10/31/2002
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Sawchuk, Robert T., Heinks, Michael W., Graden, David W.
• Granted Patent: US 7,123,963 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

A cardiac pacing device and method for automatically selecting an optimal evoked response sensing vector based on an evaluation of the evoked response signal quality are provided. Electrode switching circuitry allows selection of multiple sensing electrode vectors. Capture detection circuitry provides capture and loss of capture signal characteristics determined during a pacing threshold search to be used in determining evoked response signal quality parameters. An optimal evoked response sensing vector is selected based on evoked response signal quality parameters meeting predetermined criteria for reliable evoked response sensing.

Claims

1. A method for automatically selecting evoked response sensing electrodes and setting a sensing threshold comprising:

selecting an evoked response sensing electrode pair;

delivering a sequence of test pulses including at least a first test pulse having a pulse energy exceeding the capture threshold and at least one second test pulse having a pulse energy less than the capture threshold;

setting a capture detection time window following each test pulse during which a signal is sensed,

determining a signal characteristic of the sensed signal occurring during the capture detection window following each test pulse,

determining the quality of the signal based on the signal characteristic; and

either accepting or rejecting the sensing electrode configuration based on the quality of the sensed evoked response signal.

2. A system implemented in an implantable medical device, the system comprising:

first means for selecting an optimal evoked response sensing vector;

second means for selecting multiple sensing electrode vectors; and

means for detecting capture;

said first and second means for selecting and said means for detecting being in cooperative relations to enable selection of an optimal evoked response sensing vector.