Patent ID: 7826896
Filing Date: 2010-11-02
Classification: A61B,A61N

Abstract:
1. A method for monitoring a plurality of physiological factors contributing to physiological conditions of a patient in an implantable medical device, wherein the plurality of physiological factors are selected from the group consisting of lung resistivity, blood resistivity, heart muscle resistivity, skeletal muscle resistivity, heart volume and lung volume, and wherein one or more of the plurality of physiological factors contribute to the impedance of a vector, the method comprising: determining a first impedance across each of a plurality of vectors; determining a second impedance across each of the plurality of vectors subsequent to determining the first impedance; for each of the plurality of vectors, determining a difference value between the first impedance for the vector and the second impedance for the vector; determining, based on an identification of a first physiological factor of the plurality of physiological factors and first minimally contributing physiological factors of the plurality of physiological factors associated with the first physiological factor, a relative change in tissue resistivity corresponding to the first physiological factor based on at least some of the determined difference values and physiological factors of the plurality of physiological factors other than the first minimally contributing physiological factors; and, evaluating the relative change in tissue resistivity corresponding to the first physiological factor to determine whether the first physiological factor is an indicator of a medical condition, wherein, for each of the first minimally contributing physiological factors, a sensitivity of at least two of the plurality of vectors to the first physiological factor is substantially similar.