SYSTEMS AND METHODS TO MONITOR AND TREAT HEART FAILURE CONDITIONS

摘要

An implantable device monitors and treats heart failure, pulmonary edema, and hemodynamic conditions and in some cases applies therapy. In one implementation, the implantable device applies a high-frequency multi-phasic pulse waveform over multiple-vectors through tissue. The waveform has a duration less than the charging time constant of electrode-electrolyte interfaces in vivo to reduce intrusiveness while increasing sensitivity and specificity for trending parameters. The waveform can be multiplexed over multiple vectors and the results cross-correlated or subjected to probabilistic analysis or thresholding schemata to stage heart failure or pulmonary edema. In one implementation, a fractionation morphology of a sensed impedance waveform is used to trend intracardiac pressure to stage heart failure and to regulate cardiac resynchronization therapy. The waveform also provides unintrusive electrode integrity checks and 3-D impedancegrams.

主权项

1. An implantable device, comprising:
a waveform generator to create a waveform for application along each of multiple vectors through a bodily tissue of a patient via electrodes, wherein the duration of each waveform is less than a charging time constant of an electrode-electrolyte interface between each electrode and the bodily tissue and wherein at least one of the vectors is confined to within the patient's heart tissue or pericardium; a multiplexor to apply and process the waveform over the multiple vectors; an impedance measurement module to obtain multiple impedance measurements at least in part via the multiplexor such that one of the multiple impedance measurements is obtained for each of the multiple vectors; and an evaluator to interpret the multiple impedance measurements in order to estimate a bodily parameter of the patient.