Systems and methods to monitor and treat heart failure conditions
First Claim
1. An implantable device, comprising:
- multiple electrodes configured to apply a multi-phasic pulse waveform over multiple vectors, wherein the multi-phasic pulse waveform is generated from a source and a sink having different magnitudes;
a waveform generator for generating and applying the multi-phasic pulse waveform over the multiple vectors through tissue of a human being, wherein the multi-phasic pulse waveform has a duration less than a charging time constant of electrode-electrolyte interfaces in the tissue;
an impedance measurement module configured to obtain one impedance measurement for each of the multiple vectors; and
an evaluator configured to process impedance measurements for the multiple vectors in order to estimate a status of a bodily parameter of the human being.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
103 Citations
24 Claims
-
1. An implantable device, comprising:
-
multiple electrodes configured to apply a multi-phasic pulse waveform over multiple vectors, wherein the multi-phasic pulse waveform is generated from a source and a sink having different magnitudes; a waveform generator for generating and applying the multi-phasic pulse waveform over the multiple vectors through tissue of a human being, wherein the multi-phasic pulse waveform has a duration less than a charging time constant of electrode-electrolyte interfaces in the tissue; an impedance measurement module configured to obtain one impedance measurement for each of the multiple vectors; and an evaluator configured to process impedance measurements for the multiple vectors in order to estimate a status of a bodily parameter of the human being. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. An implantable device, comprising:
-
a waveform generator for generating and applying a multi-phasic pulse waveform over multiple vectors through tissue of a human being, wherein the multi-phasic pulse waveform possesses alternate positive and negative phases generated by a source and a sink having different magnitudes such that the multi-phasic pulse waveform also possesses an additive net-zero charge and an additive net-zero voltage and has a duration less than a charging time constant of electrode-electrolyte interfaces in the tissue; an impedance measurement module configured to obtain one impedance measurement for each of the multiple vectors; and an evaluator configured to process impedance measurements for the multiple vectors in order to estimate a status of a bodily parameter of the human being. - View Dependent Claims (16, 17, 18, 19, 20)
-
-
21. An implantable device, comprising:
-
a processing circuit comprising electronics; a waveform generator for generating and applying a multi-phasic pulse waveform over multiple vectors through a tissue of a human being, wherein the multi-phasic pulse waveform possesses alternating positive and negative phases and having null phases located between successive ones of the alternating positive and negative phases, the null phases having a duration sufficient to allow the electronics in the processing circuit of the implantable device to settle and the multi-phasic pulse waveform has a duration less than a charging time constant of electrode-electrolyte interfaces in the tissue; an impedance measurement module configured to obtain one impedance measurement for each of the multiple vectors; and an evaluator configured to process the multiple impedance measurements in order to estimate a status of a bodily parameter of the human being. - View Dependent Claims (22, 23, 24)
-
Specification