Patent ID: 8868175
Filing Date: 2014-10-21
Classification: A61B

Abstract:
1. A method of estimating stroke volume of the heart, comprising: a) making a first set of electrical measurements of the chest, at a first phase of the cardiac cycle; b) estimating a first volume of the heart from data of the first set of electrical measurements; c) making a second set of electrical measurements of the chest, at a second phase of the cardiac cycle; d) estimating a second volume of the heart from data of the second set of electrical measurements; e) finding a difference between the first and second volumes of the heart; and f) using the difference between the first and second volumes of the heart to estimate the stroke volume of the heart; wherein estimating the first volume of the heart comprises generating a first impedance image of the chest from the data of the first set of electrical measurements, and estimating the second volume of the heart comprises generating a second impedance image of the chest from the data of the second set of electrical measurements, and generating the second impedance image of the chest comprises putting constraints on differences between the second impedance image and the first impedance image, but not constraining the volume of the heart to be the same in the first and second impedance images.