×

METHODS AND APPARATUS FOR MONITORING P-WAVE DURATION AND END AND QRS DURATION WITH AN IMPLANTABLE MEDICAL DEVICE

  • US 20090234412A1
  • Filed: 03/13/2008
  • Published: 09/17/2009
  • Est. Priority Date: 03/13/2008
  • Status: Active Grant
First Claim
Patent Images

1. An apparatus for monitoring a subject, comprising:

  • means for sensing an intrinsic or a paced atrial event of a subject with a pair of electrodes coupled to an IMD;

    means for collecting a first portion of a PQRST signal with the pair of electrodes;

    means for filtering the first portion of the PQRST signal (band pass);

    means for calculating a time derivative of the first portion of the PQRST signal;

    means for rectifying the derivative signal;

    means for locating at least one peak for the rectified signal (maximum amplitude or near-maximum amplitude);

    means for setting a reference threshold based at least in part upon the amplitude of the rectified signal; and

    means for translating a temporal window (10-20 ms) from the at least one peak;

    means for declaring that the end of a P-wave (PWend) has been located when the rectified signal within the translated temporal window has sub-threshold values; and

    means for measuring a P-wave duration (PWd) defined as the time elapsed between the detected atrial event and the PWend; and

    means for one of storing the PWd in a memory structure of an IMD and comparing the measured duration to a previously measured PWd value of the subject.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×