# US 2021/0330239 A1 · Method and system for adaptive-sensing of electrical cardiac signals

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0330239 A1
- Document ID: US20210330239A1
- Status: Published application
- Kind: A1
- Application number: 17/192,171
- Filed: 2021-03-04
- Published: 2021-10-28
- Earliest claimed: 2020-04-22
- Assignees: Pacesetter, Inc.
- Applicants: Pacesetter, Inc.
- Inventors: Hanbiao Wang; Xing Pei; Kyungmoo Ryu
- Web page: https://patentgrep.com/patent/US20210330239A1

## CPC

- A61B 5/29: for permanent or long-term implantation
- A61B 5/366: Detecting abnormal QRS complex, e.g. widening
- A61B 5/308: for electrocardiography [ECG]
- A61B 5/349: Detecting specific parameters of the electrocardiograph cycle
- A61B 5/352: Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
- A61B 5/353: Detecting P-waves
- A61B 5/355: Detecting T-waves
- A61B 5/7225: {Details of analogue processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation (input circuits for detecting, measuring, or recording bioelectric or biomagnetic signals A61B5/30; specific diagnostic methods using bioelectric or biomagnetic signals A61B5/316)}
- A61N 1/36507: {controlled by gradient or slope of the heart potential}
- A61N 1/39622: {Pacing therapy}
- G16H 40/63: for local operation
- G16H 40/67: for remote operation
- G16H 50/30: for calculating health indices; for individual health risk assessment
- G16H 50/70: for mining of medical data, e.g. analysing previous cases of other patients
- A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)
- G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA

## Abstract

Computer implemented methods and systems for monitoring cardiac activity (CA) signals, for a series of beats, over first and second sensing channels having different first and second detection thresholds, respectively. The methods and systems also include analyzing the CA signals over the first and second sensing channels utilizing the first and second detection thresholds, respectively, during an event prediction window to detect a presence of sensed events. The methods and systems also include determining amplitudes of the sensed events detected. The methods and systems also include calculating at least one of an amplitude distribution or amplitude trend for the sensed events detected over the first and second channels and adjusting at least one of the first or second detection thresholds based on the at least one of the amplitude distribution or amplitude trend.

## Claims

### Claim 1

A computer implemented method, wherein under control of one or more processors configured with specific executable instructions, the method comprises:
monitoring cardiac activity (CA) signals, for a series of beats, over first and second sensing channels having different first and second detection thresholds, respectively;
analyzing the CA signals over the first and second sensing channels utilizing the first and second detection thresholds, respectively, during an event prediction window to detect a presence of sensed events;
determining amplitudes of the sensed events detected;
calculating at least one of an amplitude distribution or amplitude trend for the sensed events detected over the first and second channels; and
adjusting at least one of the first or second detection thresholds based on the at least one of the amplitude distribution or amplitude trend.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first and second detection thresholds represent a primary detection threshold and an upper guard threshold, respectively, and wherein the analyzing the CA signals includes determining whether the CA signals for a current beat of interest (BOI) exceed at least one of the primary detection threshold or the upper guard threshold, the upper guard threshold being greater than the primary detection threshold.

### Claim 3 (depends on 2)

The method of claim 2, wherein, responsive to the CA signals of the current BOI exceeding the upper guard threshold, the method further comprises:
declaring that the sensed event is present within the current BOI; and
increasing at least one of the primary detection threshold or the upper guard threshold for a subsequent BOI.

### Claim 4 (depends on 3)

The method of claim 3, wherein the increasing the at least one of the primary detection threshold or the upper guard threshold includes increasing the at least one of the primary detection threshold or the upper guard threshold based on an amplitude of the CA signals of the current BOI within the event prediction window.

### Claim 5 (depends on 2)

The method of claim 2, wherein, responsive to the CA signals of the current BOI not exceeding the upper guard threshold but exceeding the primary detection threshold, the method further comprises:
declaring that the sensed event is present within the current BOI; and
decreasing at least one of the primary detection threshold or the upper guard threshold for a subsequent BOI.

### Claim 6 (depends on 1)

The method of claim 1, further comprising:
calculating at least one of an interval distribution or interval trend for events-of-interest from the CA signals; and
estimating a time of the event prediction window for detecting the sensed events based on the at least one of the interval distribution or interval trend.

### Claim 7 (depends on 1)

The method of claim 1, further comprising at least a third detection threshold, wherein the first, second, and third detection thresholds are distributed within a sensitivity range;
wherein the analyzing the CA signals includes determining whether the CA signals for a current beat of interest (BOI) exceeds the first, second, or third detection thresholds; and
wherein the method further comprises increasing or decreasing one or more of the first, second, or third detection thresholds based on a total number of the first, second, or third detection thresholds being exceeded.

### Claim 8 (depends on 1)

The method of claim 1, wherein the sensed event is at least one of an R-wave, a P-wave, or a T-wave.

### Claim 9 (depends on 1)

The method of claim 1, further comprising processing the CA signals through first and second filtering circuits, the first filtering circuit amplifying a first event-of-interest and the second filtering circuit amplifying a different second event-of-interest.

### Claim 10 (depends on 9)

The method of claim 9, wherein the first filtering circuit selectively amplifies an R-wave or T-wave more than a P-wave and the second filtering circuit selectively amplifies the P-wave more than the R-wave or T-wave.

### Claim 11

A system for detecting cardiac activity (CA) signals, comprising:
memory to store specific executable instructions;
one or more processors configured to execute the specific executable instructions for:
monitoring cardiac activity (CA) signals, for a series of beats, over first and second sensing channels having different first and second detection thresholds, respectively;
analyzing the CA signals over the first and second sensing channels utilizing the first and second detection thresholds, respectively, during an event prediction window to detect a presence of sensed events;
determining amplitudes of the sensed events detected;
calculating at least one of an amplitude distribution or amplitude trend for the sensed events detected over the first and second channels; and
adjusting at least one of the first or second detection thresholds based on the at least one of the amplitude distribution or amplitude trend.

### Claim 12 (depends on 11)

The system of claim 11, wherein the first and second detection thresholds represent a primary detection threshold and an upper guard threshold, respectively, and wherein the analyzing the CA signals includes determining whether the CA signals for a current beat of interest (BOI) exceed at least one of the primary detection threshold or the upper guard threshold, the upper guard threshold being greater than the primary detection threshold.

### Claim 13 (depends on 12)

The system of claim 12, wherein, when the CA signals of the current BOI exceed the upper guard threshold, the one or more processors are configured to:
declare that the sensed event is present within the current BOI; and
increase at least one of the primary detection threshold or the upper guard threshold for a subsequent BOI.

### Claim 14 (depends on 13)

The system of claim 13, wherein the one or more processors are further configured to increase the at least one of the primary detection threshold or the upper guard threshold based on the amplitude of the CA signals of the current BOI within the event prediction window.

### Claim 15 (depends on 12)

The system of claim 12, wherein, when the CA signals of the current BOI do not exceed the upper guard threshold but do exceed the primary detection threshold, the one or more processors are configured to:
declare that the sensed event is present within the current BOI; and
decrease at least one of the primary detection threshold or the upper guard threshold for a subsequent BOI.

### Claim 16 (depends on 11)

The system of claim 11, wherein the one or more processors are configured to:
calculate at least one of an interval distribution or interval trend for events-of-interest from the CA signals; and
estimate a time of the event prediction window for detecting the sensed events based on the at least one of the interval distribution or interval trend.

### Claim 17 (depends on 11)

The system of claim 11, further comprising at least a third detection threshold, wherein the first, second, and third detection thresholds are distributed within a sensitivity range;
wherein the one or more processors are configured to:
determine whether the CA signals for a current beat of interest (BOI) exceed the first, second, or third detection thresholds; and
increase or decrease one or more of the first, second, or third detection thresholds based on a total number of the first, second, or third detection thresholds that are exceeded.

### Claim 18 (depends on 11)

The system of claim 11, wherein the sensed event is at least one of an R-wave, a P-wave, or a T-wave.

### Claim 19 (depends on 11)

The system of claim 11, further comprising first and second filtering circuits within the first and second sensing channels, the first filtering circuit configured to amplify a first event-of-interest and the second filtering circuit configured to amplify a different second event-of-interest, the first and second events of interest representing different first and second sensed events.

### Claim 20 (depends on 19)

The system of claim 19, wherein the first filtering circuit selectively amplifies an R-wave or T-wave more than a P-wave and the second filtering circuit selectively amplifies the P-wave more than the R-wave or the T-wave.