Method and apparatus for detecting heartbeats

Claim 3

The method according to claim 1, wherein: said last-mentioned analyzing step is responsive to the heartbeat and pacer artifact signals for determining if the shape of a portion of the ECG signal which follows said pacer artifact signal deviates a significant amount from an expected shape for that portion.

Claim 4

The method according to claim 2, wherein, said expected shape in that shape for an ECG signal when there is substantially no heart activity following a pacer artifact.

Claim 5

The method according to claim 3, wherein: said using step inhibits the providing of said heartbeat signal when the shape of said portion of said ECG signal does not substantially deviate from said expected shape.

Claim 6

The method according to claim 1, wherein: said first-mentioned analyzing step comprises analyzing said ECG signal and indicating the detection of the occurrence of a QRS complex.

Claim 7

The method according to claim 5, wherein: said last-mentioned analyzing step analyzes said ECG signal during a time period which includes 30 milliseconds to 70 milliseconds after occurrence of said pacer artifact signal.

Claim 10

The method according to claim 7, wherein: said last-mentioned analyzing step is responsive to said heartbeat and pacer artifact signals for inhibiting use of said heartbeat signal by said heartrate calculating device if the shape of a portion of the ECG signal which follows said pacer artifact signal does not deviate a significant amount from a shape expected for that portion when no heart activity is generated in response to the pacer artifact.

Claim 11

Apparatus for detecting the occurrence of heartbeats in an ECG signal which may also include pacer artifacts, comprising: means for analyzing the ECG signal and providing a heartbeat signal upon detection of the occurrence of a heartbeat; means for analyzing the ECG signal and providing a pacer artifact signal upon detection of the occurrence of a pacer artifact; activity detector means for analyzing the ECG signal and determining if a portion of the ECG signal which follows detection of a pacer artifact has changes in its amplitude level which exceed a predetermined threshold level, thereby indicating the validity of the heartbeat signal, and providing an activity indicating signal in response to said determination; and means for using the activity indicating signal to control the providing of said heartbeat signal by said first-mentioned analyzing means.

Claim 12

Apparatus for detecting the occurrence of heartbeats in an ECG signal which may also include pacer artifacts, comprising: means for analyzing the ECG signal and providing a heartbeat signal upon detection of the occurrence of a heartbeat; means for analyzing the ECG signal and providing a pacer artifact signal upon detection of the occurrence of a pacer artifact; activity detector means for analyzing the ECG signal and determining if a portion of the ECG signal which follows detection of a pacer artifact has changes in its amplitude level which exceed a predetermined threshold level, thereby indicating the validity of the heartbeat signal, and providing an activity indicating signal in response to said determination; and means for using the activity indicating signal to control the providing of said heartbeat signal by said first-mentioned analyzing means.

Claim 13

Apparatus according to claim 9, wherein: said activity detector means is responsive to the ECG signal and pacer artifact signal for evaluating the shape of a portion of the ECG signal which follows the occurrence of said pacer artifact signal.

Claim 14

Apparatus according to claim 10, wherein: said activity detector means includes an amplitude detector for detecting amplitude changes of said ECG signal, a summing means for summing detected amplitude changes of said ECG signal and a threshold circuit responsive to a sum of the detected amplitude changes.

Claim 15

Apparatus according to claim 11, wherein: said activity detector means determines that said heartbeat signal is valid in response to an indication from said threshold circuit that the sum of the ECG signal detected amplitude changes have exceeded a predetermined threshold level during a predetermined time period.

Claim 16

Apparatus according to claim 11, wherein: said activity detector means determines that said heartbeat signal is not valid in response to an indication from said threshold circuit that the sum of the ECG signal detected amplitude changes have not exceeded a predetermined threshold level during a predetermined time period.

Claim 17

Apparatus according to claim 12, wherein: said predetermined threshold level is determined in response to the amplitude of said ECG signal at the beginning of a pacer artifact repolarization tail.

Claim 18

Apparatus according to claim 13, wherein: said predetermined threshold level is determined in response to the amplitude of said ECG signal at the beginning of a pacer artifact repolarization tail.

Claim 19

Apparatus according to claim 11, wherein: said second-mentioned analyzing means also includes means for indicating the polarity of detected pacer artifacts in said ECG signal; and said summing means only sums detected amplitude changes in a portion of said ECG signal which follows a detected pacer artifact and which are opposite in polarity form the polarity of the detected pacer artifact.

Claim 20

Apparatus for detecting the occurrence of heartbeats in an ECG signal which may also include pacer artifacts, comprising: a QRS detector for analyzing the ECG signal in a first signal processing path and providing a QRS detection signal upon detection of a QRS signal complex occurring in said ECG signal; a pacer artifact detector for analyzing the ECG signal and providing a pacer artifact detection signal upon detection of a pacer artifact occurring in said ECG signal; an activity detector means for analyzing the ECG signal in a second signal processing path which is parallel with said first signal processing path for determining if a portion of the ECG signal which follows detection of a pacer artifact has amplitude level changes which exceed a predetermined threshold level, thereby indicating validity of the QRS detection signal, and providing an activity indicating signal in response to said determination; and means for using said activity indicating signal to control the providing of said QRS detection signal to a utilization means.

Claim 21

Apparatus for detecting the occurrence of heartbeats in an ECG signal which may also include pacer artifacts, comprising: a QRS detector for analyzing the ECG signal in a first signal processing path and providing a QRS detection signal upon detection of a QRS signal complex occurring in said ECG signal; a pacer artifact detector for analyzing the ECG signal and providing a pacer artifact detection signal upon detection of a pacer artifact occurring in said ECG signal; an activity detector means for analyzing the ECG signal in a second signal processing path which is parallel with said first signal processing path for determining if a portion of the ECG signal which follows detection of a pacer artifact has amplitude level changes which exceed a predetermined threshold level, thereby indicating validity of the QRS detection signal, and providing an activity indicating signal in response to said determination; and means for using said activity indicating signal to control the providing of said QRS detection signal to a utilization means.

Claim 22

Apparatus according to claim 17, wherein: said activity detector means includes an amplitude detector for detecting changes in amplitude of said ECG signal, a summing means for summing the detected amplitude changes and a threshold circuit responsive to sum of the detected amplitude changes, the output of said threshold circuit providing said activity indicating signal.

Claim 23

Apparatus according to claim 18, wherein: said activity detector means includes comparing means for providing said activity indicating signal when said threshold circuit has summed ECG signal detected amplitude changes which exceed a predetermined threshold level during a predetermined time period.

Claim 24

Apparatus according to claim 19, wherein: said predetermined threshold level is determined in response to the amplitude of said ECG signal at the beginning of a pacer artifact repolarization tail.

Claim 25

Apparatus according to claim 18, wherein: said pacer artifact detector includes means for indicating the polarity of detected pacer artifacts; and said summing means is enabled by said pacer artifact detection signal so as to only sum detected amplitude changes in a portion of said ECG signal which follows a detected pacer artifact and which are opposite in polarity from the polarity indicated for said detected pacer artifact.