# US 12,599,330 B2 · Wearable medical device with zoneless arrhythmia detection

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- Number: US 12,599,330 B2
- Document ID: US12599330B2
- Status: Granted
- Kind: B2
- Application number: 17/591,526
- Filed: 2022-02-02
- Published: 2022-08-04
- Granted: 2026-04-14
- Earliest claimed: 2021-02-02
- Assignees: West Affum Holdings DAC
- Applicants: West Affum Holdings Dac
- Inventors: Jaeho Kim; Pamela F. Breske
- Web page: https://patentgrep.com/patent/US12599330B2

## CPC

- A61B 5/361: Detecting fibrillation
- A61B 5/256: Wearable electrodes, e.g. having straps or bands
- A61B 5/282: Holders for multiple electrodes (for introduction into the body A61B5/287)
- A61B 5/366: Detecting abnormal QRS complex, e.g. widening
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61B 5/6802: {Sensor mounted on worn items}
- A61B 5/7264: {Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems}
- A61N 1/0484: {Garment electrodes worn by the patient}
- A61N 1/36031: {using physiological parameters for adjustment}
- A61N 1/3904: {External heart defibrillators [EHD]}
- 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)

## Abstract

Embodiments of a wearable monitoring device system can include a wearable monitoring device comprising one or more patient physiological sensors and a detector to zonelessly detect arrhythmias from physiological signals sensed by the one or more sensors, and optionally other signals. In embodiments the detector includes a processor configured with a sudden rate change onset (SRCO) algorithm, one or more arrythmia detection algorithms and, optionally, a noise detection algorithm. In embodiments, in response to detecting SRCO, the wearable monitoring device or a remote system that receives data from the wearable medical device determines whether the patient has an arrhythmia from physiological signals sensed by the one or more sensors.

## Claims

### Claim 1

A wearable cardioverter defibrillator (WCD) system, comprising:
a support structure to be worn by a patient;
an energy storage module to store an electrical charge;
at least one therapy electrode coupled to the support structure;
at least one sensor, coupled to the support structure, configured to generate an electrocardiogram (ECG) of the patient when the patient is wearing the support structure; and
a processor, communicatively coupled to the at least one sensor, configured to:
receive the ECG of the patient from the at least one sensor;
determine, based on the received ECG, whether a heart rate and/or QRS width of the patient is within a predefined ventricular fibrillation (VF) zone, wherein the predefined VF zone corresponds to one or more ranges of the heart rate and/or the QRS width indicating VF;
in response to a determination that the heart rate and/or the QRS width of the patient is outside the predefined VF zone, perform a sudden rate change onset (SRCO) detection of the received ECG, wherein to perform the SRCO detection, the processor is configured to:
detect a first heart parameter value from the received ECG at a first time,
detect a second heart parameter value from the received ECG at a second time, wherein the first heart parameter value and the second heart parameter value comprise one of a heart rate (HR), R-R interval, average HR, or an average R-R interval,
determine a difference between the first heart parameter value and the second heart parameter value, and
detect the SRCO of the received ECG based, at least in part, on comparison of absolute value of the difference between the first heart parameter value and the second heart parameter value with a predetermined threshold;
responsive to the detected SRCO, perform a process to determine whether the received ECG is indicative of VF; and
cause the energy storage module to discharge at least a portion of the stored electrical charge to the patient using the at least one therapy electrode, at least in part, in response to a determination that VF is indicated.

### Claim 2 (depends on 1)

The WCD system of claim 1, wherein the processor is further configured to determine whether the received ECG is indicative of one or more of pulseless ventricular tachycardia (PVT), monomorphic ventricular tachycardia (MVT), or noise in response to the detected SRCO.

### Claim 3 (depends on 1)

The WCD system of claim 1, wherein responsive to the detected SRCO, the processor is configured to:
save the first heart parameter value, wherein the first heart parameter is detected before the SRCO;
determine whether the received ECG of the patient is indicative of supraventricular tachycardia (SVT);
responsive to a determination that the received ECG of the patient is indicative of SVT, determine whether a current heart parameter value determined from the received ECG of the patient is less than the saved value;
responsive to a determination that the current value is less than the saved value, detect whether the received ECG of the patient is indicative of a subsequent SRCO; and
responsive to a determination that the current value is not less than the saved value, determine whether the received ECG of the patient remains indicative of SVT.

### Claim 4 (depends on 3)

The WCD system of claim 3, wherein:
responsive to the received ECG of the patient being not indicative of SVT, the process further includes:
determining whether the received ECG of the patient is indicative of monomorphic ventricular tachycardia (MVT),
wherein the process determines that the received ECG of the patient is determined to be indicative of VF when the received ECG of the patient is not indicative of MVT.

### Claim 5 (depends on 4)

The WCD system of claim 4, wherein responsive to the received ECG being not indicative of MVT, the process further includes:
determining whether the received ECG of the patient is noisy.

### Claim 6 (depends on 5)

The WCD system of claim 5, wherein the process determines that the received ECG of the patient is determined to be indicative of VF when the received ECG of the patient is determined to not be noisy.

### Claim 7 (depends on 5)

The WCD system of claim 5, wherein the processor is further configured to:
determine whether a physiological parameter of the patient sensed by the at least one sensor is indicative of the patient being conscious; and
classify the received ECG of the patient as VF in response to the sensed physiological parameter being not indicative of the patient being conscious.

### Claim 8 (depends on 7)

The WCD system of claim 7, wherein the sensed physiological parameter comprises a vital sign.

### Claim 9 (depends on 1)

The WCD system of claim 1, wherein the processor is further configured to:
not perform the SRCO detection in response to the heart rate and/or the QRS width being within the predefined VF zone.

### Claim 10 (depends on 1)

The WCD system of claim 1, wherein the first heart parameter value is determined by taking an average of a first group of heart parameter values.

### Claim 11 (depends on 10)

The WCD system of claim 10, wherein the second heart parameter value is determined by taking an average of a second group of heart parameter values, the second group having the same number of heart parameter values as the first group.

### Claim 12 (depends on 1)

The WCD system of claim 1, wherein the WCD system further comprises an outside monitoring device configured to monitor at least one local parameter.

### Claim 13 (depends on 12)

The WCD system of claim 12, wherein the at least one local parameter includes at least one of a parameter of the patient, a parameter of the WCD system, or a parameter of the environment surrounding the patient.

### Claim 14 (depends on 1)

The WCD system of claim 1, wherein the first heart parameter value and the second heart parameter value correspond to the HR, wherein the predetermined threshold is a change of eighty beats per minute over twelve HR samples, wherein the first time and the second time correspond to a first and a last of the twelve HR samples respectively, and wherein the HR samples are generated at intervals of 2.4 seconds.

### Claim 15 (depends on 1)

The WCD system of claim 1, wherein the first heart parameter value and the second heart parameter value correspond to the R-R interval, wherein the predetermined threshold is 200 milliseconds over twelve R-R interval samples, and wherein the first time and the second time correspond to a first and a last of the twelve R-R interval samples respectively.

### Claim 16 (depends on 1)

The WCD system of claim 1, wherein the first heart parameter value and the second heart parameter value correspond to the HR, wherein the predetermined threshold is a change in a range of 10 beats per minute to 50 beats per minute over a number of HR samples, wherein the number of HR samples ranges from 10 samples to 20 samples, and wherein the first time and the second time correspond to a first and a last of the number of HR samples respectively.

### Claim 17 (depends on 1)

The WCD system of claim 1, wherein the comparison of the absolute value of the difference between the first heart parameter value and the second heart parameter value with the predetermined threshold comprises the absolute value of the difference between the first heart parameter value and the second heart parameter value exceeding the predetermined threshold.

### Claim 18 (depends on 1)

The WCD system of claim 1, wherein the processor is configured to detect the SRCO of the received ECG based, at least in part, on the comparison of the absolute value of the difference between the first heart parameter value and the second heart parameter value over a timing value with the predetermined threshold, and wherein the timing value comprises a time duration, a number of samples, or a number of heart beats.

### Claim 19 (depends on 1)

The WCD system of claim 1, wherein the predetermined threshold is based on a running average of HR or R-R interval measurements.

### Claim 20 (depends on 19)

The WCD system of claim 19, wherein the predetermined threshold is a change in the running average of fifty-five beats per minute over twenty HR samples.