Patent ID: 9560980
Date: 2017-02-07
CPC Classifications: A61B,G16H

Claim:
1. A method for determining a risk of a patient experiencing a heart failure decompensation event in the near future, the method comprising: storing, by a medical device implanted in the patient, an electrode vector parameter indicating an electrode vector of a plurality of electrode vectors, each of the electrode vectors being a different combination of electrodes; using, by the medical device, a plurality of electrode vectors to generate a plurality of intrathoracic impedance measurements; performing, by the medical device, a vector selection operation on a first recurring basis, wherein each time the medical device performs the vector selection operation, the medical device: performing, by the medical device, a risk assessment operation on a second recurring basis, wherein each time the medical device performs the risk assessment operation, the medical device determines the risk based at least in part on intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter; calculating, based on the intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, an initial risk score during the risk assessment operation, the risk score being correlated with a likelihood of the patient experiencing the heart failure decompensation event in the near future; recalculating the risk score using one or more intrathoracic impedance measurements generated using electrode vectors other than the electrode vector indicated by the electrode vector parameter; and responsive to determining that one of, but not both of, the initial risk score and the recalculated risk score exceeds a predetermined risk threshold, performing the vector selection operation.