Third heart sound activity index for heart failure monitoring
AssigneeCardiac Pacemakers, Inc.
InventorsKrzysztof Z. Siejko, Laura Green, Gerrard M. Carlson
Life of this patent
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Abstract
A cardiac rhythm management system provides for the trending of a third heart sound (S3) index. The S3 index is a ratio, or an estimate of the ratio, of the number of S3 beats to the number of all heart beats, where the S3 beats are each a heart beat during which an occurrence of S3 is detected. An implantable sensor such as an accelerometer or a microphone senses an acoustic signal indicative heart sounds including S3. An S3 detector detects occurrences of S3 from the acoustic signal. A heart sound processing system trends the S3 index on a periodic basis to allow continuous monitoring of the S3 activity level, which is indicative of conditions related to heart failure.
Claims43
A heart sound processing system, comprising:
- a cardiac signal input to receive a cardiac signal indicative of heart beats;
- a beat counter, coupled to the cardiac signal input, to count the heart beats;
- an acoustic signal input to receive an acoustic signal indicative of at least third heart sounds (S3);
- a heart sound detector, coupled to the acoustic signal input, to detect S3;
- a heart sound counter, coupled to the heart sound detector, to count S3 beats each being a heart beat during which one of S3 is detected;
- and
- a heart sound analyzer coupled to the beat counter and the heart sound counter, the heart sound analyzer including a ratio calculator to calculate an S3 index being a ratio of a number of the S3 beats counted during a predetermined time period to the number of the heart beats counted during the predetermined time period.
A cardiac rhythm management system, comprising:
- means for counting heart beats from a cardiac signal;
- means for detecting third heart sounds (S3) from an acoustic signal;
- means for counting S3 beats each being a heart beat during which one of the S3 is detected;
- and
- means for calculating an S3 index being a ratio of a number of the S3 beats counted during a predetermined time period to a number of the heart beats counted during the predetermined time period.
A heart sound processing method, comprising:
- receiving a cardiac signal indicative of cardiac events;
- receiving an acoustic signal indicative of at least third heart sounds (S3);
- detecting the cardiac events from the cardiac signal;
- counting heart beats based on the cardiac events;
- detecting S3 from the acoustic signal;
- counting S3 beats each being a heart beat during which an occurrence of S3 is detected;
- and
- producing a trend of an S3 index, wherein the S3 index is a ratio of a number of the S3 beats counted during a predetermined time period to a number of the heart beats counted during the predetermined time period.
Dependencies are inferred from the claim text.