Method and apparatus for improving specificity of atrial tachycardia detection techniques in dual-unipolar or dual-bipolar implantable cardiac stimulation systems
First Claim
1. In an implantable cardiac stimulation device coupled to cardiac leads from which atrial and ventricular channel signals are generated, a method comprising:
- tracking refractory periods within both the atrial and ventricular channel signals; and
determining an atrial rate using unipolar sensing outside the refractory periods and using combined unipolar/bipolar sensing within the refractory periods.
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Accused Products
Abstract
Techniques are provided for allowing Automatic Mode Switching (AMS) to be exploited within dual unipolar systems employing Combipolar sensing. Relative refractory windows are opened within both the atrial and ventricular refractory periods for the purposes of determining the atrial rate using Combipolar sensing logic. In this manner, T-waves occurring during the relative refractory windows are excluded from the atrial rate calculation, whereas any P-waves occurring during the relative refractory windows are counted, thereby achieving a more accurate atrial rate calculation, particularly at high atrial rates, and thus permitting AMS to be enabled along with Combipolar sensing in the dual unipolar lead system. An alternative technique is provided for use in dual unipolar systems not initially set to a Combipolar Sensing mode, which also achieves more accurate atrial rate calculation at high atrial rates. Additional techniques are provided for use in dual bipolar systems. An improved Combipolar sensing logic is also provided.
63 Citations
19 Claims
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1. In an implantable cardiac stimulation device coupled to cardiac leads from which atrial and ventricular channel signals are generated, a method comprising:
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tracking refractory periods within both the atrial and ventricular channel signals; and determining an atrial rate using unipolar sensing outside the refractory periods and using combined unipolar/bipolar sensing within the refractory periods. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. In an implantable cardiac stimulation device, a system comprising:
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a ventricular sense amplifier operative to sense ventricular channel signals; and an atrial sense amplifier operative to sense atrial channel signals; a control unit operative to track refractory periods within atrial and ventricular channel signals; and an atrial rate determination unit programmed to determine an atrial rate using unipolar sensing outside the refractory periods and using combined unipolar/bipolar sensing within the refractory periods. - View Dependent Claims (16, 17, 18)
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19. In an implantable cardiac stimulation device, a system comprising:
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means for sensing ventricular channel signals; means for sensing atrial channel signals; means for tracking refractory periods within atrial and ventricular channel signals; and means programmed for determining an atrial rate using unipolar sensing outside the refractory periods and using combined unipolar/bipolar sensing within the refractory periods.
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Specification