Method and apparatus for determining cardiac performance in a patient with a conductance catheter
AssigneeBoard of Regents, The University of Texas System
InventorsMarc D. Feldman, Jonathan W. Valvano, John A. Pearce, Chia-Ling Wei
Life of this patent
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Abstract
An apparatus for determining cardiac performance in the patient involving a conductance catheter (12) for measuring conductance and blood volume in a heart chamber of the patient. The apparatus includes a processor (14) for determining instantaneous volume of the ventricle by applying a non-linear relationship between the measured conductance and the volume of blood in the heart chamber to identify mechanical strength of the chamber. The processor (14) is in communication with the conductance catheter (12).
Claims47
An apparatus for determining cardiac performance in the patient comprising:
- a plurality of electrodes adapted to be placed in the patient and in communication with a heart chamber of the patient for measuring conductance and blood volume in the heart chamber of the patient;
- and
- a processor for determining instantaneous volume of the ventricle by applying a non-linear relationship between the measured conductance and the volume of blood in the heart chamber to identify mechanical strength of the chamber, the processor in communication with the electrodes.
A method for determining cardiac performance in the patient comprising the steps of:
- measuring conductance and blood volume in a heart chamber of the patient with a plurality of electrodes disposed in the patient and in communication with the heart chamber;
- and
- determining instantaneous volume of the ventricle by applying a non-linear relationship between the measured conductance and the volume of blood in the heart chamber to identify mechanical strength of the chamber with a processor, the processor in communication with the electrodes.
An apparatus for determining cardiac performance in a patient comprising:
- a plurality of electrodes adapted to be placed in the patient and in communication with a heart chamber of the patient for measuring conductance in the heart chamber of the patient, where the conductance includes contributions from blood and muscle with respect to the heart chamber;
- and
- a processor for determining instantaneous volume of the heart chamber by removing the muscle contribution from the conductance, the processor in communication with the electrodes.
A method for determining cardiac performance in a patient comprising:
- measuring conductance in a heart chamber of the patient with a plurality of electrodes disposed in the patient and in communication with the heart chamber, where the conductance includes contributions from blood and muscle with respect to the heart chamber;
- and
- determining instantaneous volume of the heart chamber by removing the muscle contribution from the conductance with a processor, the processor in communication with the electrodes.
An apparatus for determining cardiac performance in the patient comprising:
- a plurality of electrodes adapted to be placed in the patient and in communication with a heart chamber of the patient for measuring conductance in a heart chamber of the patient;
- and
- a processor for determining instantaneous volume of the heart chamber according to
- Vol
-
- (
- t
- )
- =
- [
- β
-
- (
- G
- )
- ]
- [
- L
- 2
- σ
- b
- ]
-
- [
- Y
-
- (
- t
- )
- -
- Y
- p
- ]
- where:
- β(G)=the field geometry calibration function (dimensionless), Y(t)=the measured combined admittance, and Yp=the parallel leakage admittance, dominated by cardiac muscle, the processor in communication with the conductance catheter.
A method for determining cardiac performance in the patient comprising the steps of:
- measuring conductance and blood volume in a heart chamber of the patient with a plurality of electrodes disposed in the patient and in communication with the heart chamber;
- and
- determining instantaneous volume of the ventricle according to
- Vol
-
- (
- t
- )
- =
- [
- β
-
- (
- G
- )
- ]
- [
- L
- 2
- σ
- b
- ]
-
- [
- Y
-
- (
- t
- )
- -
- Y
- p
- ]
- where:
- β(G)=the field geometry calibration function (dimensionless), Y(t)=the measured combined admittance, and Yp=the parallel leakage admittance, dominated by cardiac muscle, to identify mechanical strength of the chamber with a processor, the processor in communication with the conductance catheter.
Dependencies are inferred from the claim text.