Method and apparatus for multi-state heart failure decompensation detection
AssigneeCardiac Pacemakers, Inc.
InventorsYi Zhang, Pramodsingh Hirasingh Thakur, Robert J. Sweeney
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Abstract
Devices and methods for detecting events indicative of heart failure (HF) decompensation status are described. An ambulatory medical device can determine the present physiologic state as being either a drift state or a stable state, and applies an algorithm to detect HF decompensation event according to the physiologic state. In some embodiments, the ambulatory medical device uses the present physiologic state to estimate one ore more expected future signal characteristics, and to detect HF decompensation event using the one or more expected futures signal characteristics.
Claims20
An ambulatory medical device, comprising:
- a signal sensing circuit, configured to sense a physiologic signal indicative of the patient's heart failure (HF) decompensation status;
- a physiologic state analyzer circuit, including at least one of:
- a timer or a clock configured to determine a current elapsed time since a physiologic state trigger event;
- a drift metric calculator circuit, configured to calculate a drift metric using at least one of:
- a comparison between (1) first measurements of the physiologic signal obtained during a first time window and (2) second measurements of the physiologic signal obtained during a non-overlapping second time window;
- or
- a function of a first or higher order derivative of the physiological signal obtained from two or more non-identical time windows;
- wherein the physiologic state analyzer circuit is configured to determine a physiologic state of the patient using at least one of the elapsed time or the calculated drift metric;
- and
- an HF decompensation event detector circuit, configured to detect an indication of HF decompensation status using the determined physiologic state and the sensed physiologic signal.
A method for detecting an indication of heart failure (HF) decompensation status in a patient having an ambulatory medical device, the method comprising:
- sensing a physiologic signal indicative of the HF decompensation status;
- determining a physiologic state of the patient, wherein the physiologic state is determined using at least one of:
- a time from a physiologic state trigger event;
- or
- a drift metric of the physiologic signal, the drift metric determined using at least one of:
- a comparison between (1) first measurements of the physiologic signal obtained during a first time window and (2) second measurements of the physiologic signal obtained during a non-overlapping second time window;
- or
- a function of a first or higher order derivative of the physiological signal obtained from two or more non-identical time windows;
- and
- detecting the indication of HF decompensation status using the determined physiologic state and the sensed physiologic signal.
A method, comprising:
- sensing a physiologic signal indicative of the HF decompensation status;
- calculating at least one expected future signal characteristic using the sensed physiologic signal;
- comparing the at least one expected future signal characteristic to at least one criterion;
- and
- using the comparison for determining the indication of HF decompensation status.
Dependencies are inferred from the claim text.