초록 ▼

A system and method are provided, particularly useful for an implantable cardiac pacemaker, for morphological filtering of sensed signals to reliably and accurately identify one or more specified wave portions of the sensed signals. In a first pacemaker embodiment, morphological filtering is done on

A system and method are provided, particularly useful for an implantable cardiac pacemaker, for morphological filtering of sensed signals to reliably and accurately identify one or more specified wave portions of the sensed signals. In a first pacemaker embodiment, morphological filtering is done on the sensed atrial signal, whereby the P-wave peak is discriminated out, with the resulting signal minus the P-wave peak being then subtracted from the inputted atrial signal to provide the atrial peak, thereby effectively eliminating sensing of FFR-wave portions. By setting the morphological filter length to correspond to about the duration of the P-wave peak, or just slightly larger, and by adjusting sampling frequency to correspond to cardiac rate variations, there is provided optimized filtering consistent with low power consumption in an implantable device. In other embodiments, FFR-waves, T-waves, VT, SVT and sinus tachycardia are identified by using templates matched to the wave to be identified. The invention can be performed with either analog or digital embodiments, analog embodiments providing for lower power consumption.

대표청구항 ▼

[ I claim:] [1.] A cardiac pacemaker which utilizes sensed P-waves for control of pacing operation, the cardiac pacemaker further having P-wave sense means operative cyclically, said P-wave sense means comprising:signal means for obtaining an atrial signal from the patient's atrium;sampling means fo

[ I claim:] [1.] A cardiac pacemaker which utilizes sensed P-waves for control of pacing operation, the cardiac pacemaker further having P-wave sense means operative cyclically, said P-wave sense means comprising:signal means for obtaining an atrial signal from the patient's atrium;sampling means for providing a sampled atrial signal;morphological filter means for filtering out the P-wave portion from said sampled atrial signal to obtain a residual signal without said P-wave portion; andsubtracting means for subtracting said residual signal from said sampled signal to obtain a P-wave signal without any substantial FFR-wave portion, andmeans for providing electrical stimulation to a patient's heart.