JP6643414B2 - Wearable defibrillator (WCD) system responsive to high amplitude ECG noise - Google Patents

Description

This patent application claims priority from US Provisional Patent Application No. 62 / 538,145, filed July 28, 2017.

  If a person suffers from some type of cardiac arrhythmia, the result can be reduced blood flow to different parts of the body. Some arrhythmias even result in sudden cardiac arrest (SCA: Sudden Cardiac Arrest). SCA can be fatal if not treated very quickly, eg, temporarily, within 10 minutes.

  Some people are at high risk of SCA. People at higher risk include patients who have had a heart attack, or a previous onset of SCA. A common recommendation is that these people accept an Implantable Cardioverter Defibrillator (ICD). The ICD is surgically implanted in the chest and continuously monitors the patient's electrocardiogram (ECG). If certain types of cardiac arrhythmias are detected, the ICD will deliver an electric shock throughout the heart.

  These individuals may be given a wearable cardioverter defibrillator (WCD) system after it has been identified as having a high risk of SCA and before accepting the ICD. (Early versions of such systems were called wearable defibrillator systems.) WCD systems typically include a harness, vest or other Including clothing. WCD systems further include electronic components, such as defibrillators and electrodes, that are coupled to a harness, vest, or other garment. If the patient wears a WCD system, the external electrodes can then make good electrical contact with the patient's skin and can thus help sense the patient's ECG. If a shockable cardiac arrhythmia is detected, the defibrillator delivers an appropriate electric shock throughout the patient's body and thus throughout the heart.

  In many cases, the patient's ECG contains electrical noise, which can be generated at the interface between the patient's skin and the electrodes. Such noise can make it difficult to accurately diagnose a patient's condition from the ECG and detect whether the patient has a shockable arrhythmia.

  All subjects discussed in this background part of this document are not necessarily prior art and are not presumed to be prior art merely because the subject matter is presented in this background portion. . Further, any reference to any prior art in this description is not an endorsement or any form of suggestion that such prior art forms part of the common general knowledge of any technology in any state, It should not be grasped as such. Along these lines, any perception of a problem in the prior art discussed in this context or associated with such subject matter is treated as prior art unless expressly stated to be prior art. Should not be. Rather, the discussion of any subject matter in this background section should be treated as part of the approach taken by the inventor to a particular problem. This approach can itself be an invention.

US Patent No. 8,024,037 US Patent Application Publication No. 2017/0056682 US Patent No. 8,135,462 US Patent Application Publication No. 2014/0043149

  This description provides examples of wearable cardioverter defibrillator (WCD) systems, storage media capable of storing programs, and methods that may be used to overcome the problems and limitations of the prior art. Can be useful.

  In embodiments, the WCD system is worn and / or carried by a walkable patient. The WCD system analyzes the patient's ECG signal to determine whether the patient should be shocked to restart the patient's heart. If an electric shock is to be delivered, the WCD system will first give a preliminary alarm to the patient, and if the patient is alive, ask to prove that the patient is alive. WCD systems further determine whether an ECG signal contains too much high amplitude (HA) noise, which can distort the analysis of the ECG signal. If too much HA noise is detected for an extended period of time, the WCD system may ultimately alert the patient about the patient's activity so that ECG noise may be reduced. The WCD system may even pause the analysis of the ECG signal so that there are no false alarms until the ECG noise is mitigated.

  Another advantage may be that the patient may be more compliant in actually wearing and / or carrying the WCD system with fewer false alarms.

  These and other features and advantages of the claimed invention take into account the embodiments described and illustrated in this specification, ie, in this written specification and the associated drawings. It will be more readily apparent.

1 is an illustration of components of a sample wearable defibrillator (WCD) system made in accordance with an embodiment. FIG. 2 illustrates a sample component of an external defibrillator, such as an external defibrillator belonging to the system of FIG. 1, made in accordance with an embodiment. FIG. 4 is an illustration of selected components to show how ECG signals sensed by a pair of electrodes can be processed in accordance with an embodiment to obtain heart rate and other information. 5 is a flowchart illustrating a sample method according to the embodiment. Sample time series of ECG parts, sample grouping of these ECG parts, the same ECG part after some of these have been marked for their noise, as a result of the noise / silence ratio, according to embodiments. FIG. 9 is a diagram of the resulting sample development, the resulting sample development of the state of the noise detection flag, and the resulting sample development when the ECG rhythm analysis can be paused from being performed. FIG. 6 illustrates a time diagram of the sample ECG portion of FIG. 5 when a decision to mark if the noise criterion is met is made, according to an embodiment. FIG. 4 illustrates a time diagram to illustrate an example of how a determination may be made as to whether an identified potential R peak in an ECG portion meets a first pseudo-criterion, according to an embodiment. FIG. FIG. 4 illustrates a time diagram to illustrate an example of how a determination may be made as to whether an identified potential R peak in an ECG portion meets a second pseudo-criterion, according to an embodiment. FIG. FIG. 6 is a repetition of FIG. 5 for a specific embodiment where the ECG portion is defined as identified peaks in the sensed ECG signal and they may be QRS complex R peaks.

  As stated above, the present description relates to a wearable defibrillator (WCD) system, a medium for storing instructions, and a method. The embodiment will now be described in more detail.

  A wearable defibrillator (WCD) system made according to embodiments has a plurality of components. These components can be provided separately as modules that can be interconnected or combined with other components and the like.

  FIG. 1 illustrates a patient 82. Patient 82 may also be referred to as a person and / or a wearer because the patient is wearing a component of the WCD system. Patient 82 is ambulatory, which means that patient 82 can roam and is not necessarily bedridden.

  FIG. 1 also illustrates components of a WCD system made according to an embodiment. One such component is a self-supporting structure 170 that can be worn by the patient 82. It will be appreciated that the support structure 170 is only shown generally in FIG. 1 and, in fact, is shown partially conceptually. FIG. 1 is provided merely to illustrate concepts relating to the support structure 170 and as limiting how the support structure 170 is implemented or how the support structure 170 is worn. Should not be interpreted.

  The support structure 170 can be implemented in many different ways. For example, support structure 170 may be implemented in a single component or a combination of multiple components. In embodiments, the support structure 170 may include a vest, half vest, clothing, and the like. In such embodiments, such items may be worn as well as clothing equivalents. In embodiments, support structure 170 may include a harness, one or more belts or straps, and the like. In such embodiments, such items may be worn by the patient around the torso, on the waist, over the shoulders, and the like. In embodiments, the support structure 170 may include a container or housing, which may even be waterproof. In such an embodiment, the support structure may be worn by being attached to the patient with an adhesive material, for example, as shown in US Patent No. 8,024,037. The support structure 170 can even be implemented as described for the support structure of US Patent Application Publication No. 2017/0056682, which is hereby incorporated by reference. Of course, in such embodiments, one of ordinary skill in the art will recognize that additional components of the WCD system may be externally attached to the support structure, for example, as described in U.S. Patent Application Publication No. 2017/0056682. It will be appreciated that instead of being mounted, it may be present within the housing of the support structure. Other examples may exist.

  A WCD system according to an embodiment is configured to defibrillate a patient wearing a WCD system by delivering a charge to the patient's body in the form of an electric shock delivered in one or more pulses. . FIG. 1 shows a sample defibrillator 100 and sample defibrillation electrodes 104, 108, which are coupled to the defibrillator 100 via electrode leads 105. You. The defibrillator 100 and the defibrillation electrodes 104, 108 may be coupled to a support structure 170. Thus, in this manner, many of the components of the defibrillator 100 may be coupled to the support structure 170. If the defibrillation electrodes 104, 108 make good electrical contact with the patient's 82 body, the defibrillator 100 can deliver short, strong electrical pulses 111 throughout the body via the electrodes 104, 108. . Pulse 111 is also known as shock, defibrillation shock, therapy and therapeutic shock. The pulse 111 passes through the heart 85 and is intended to restart the heart 85 to save the life of the patient 82. The pulse 111 can further include one or more pacing pulses and the like.

  Prior art defibrillators typically determine whether to defibrillate based on the patient's ECG signal. However, the external defibrillator 100 can initiate (or refrain from defibrillating) defibrillation based on a wide variety of inputs, and the ECG is only one of them.

  Accordingly, it will be appreciated that a signal, such as a physiological signal containing physiological data, may be obtained from the patient 82. The patient may also be considered as a “user” of the WCD system, but this is not a requirement. That is, for example, a user of a wearable cardioverter-defibrillator (WCD) can be a clinician, such as a physician, nurse, emergency medical technician (EMT), or other similarly positioned individual (or individual). Group). The specific context of these and other related terms within this description should be interpreted accordingly.

  The WCD system may optionally include an external monitoring device 180. Device 180 is referred to as an “external” device, for example, because it may be provided as a stand-alone device, not within the housing of defibrillator 100. Device 180 can be configured to sense or monitor at least one local parameter. The local parameters may be patient 82 parameters, or WCD system parameters, or environmental parameters, as described later in this document. Device 180 may include one or more transducers or sensors configured to render one or more physiological inputs or signals from one or more patient parameters that they sense.

  Optionally, device 180 is physically coupled to support structure 170. Also, device 180 can be communicatively coupled to other components, which are coupled to support structure 170. Such communication may be implemented by a communication module as considered applicable by one of ordinary skill in the art in light of this description.

  FIG. 2 is a diagram showing components of the external defibrillator 200 manufactured according to the embodiment. These components can be included, for example, in the external defibrillator 100 of FIG. The components shown in FIG. 2 can be provided in a housing 201, which can also be referred to as a casing 201.

  External defibrillator 200 is intended for patients who will be wearing external defibrillator 200, such as patient 82 of FIG. Defibrillator 200 may further include a user interface 280 for user 282. User 282 may be patient 82, also known as wearer 82. Alternatively, the user 282 may be a nearby rescuer at the scene, such as an on-site person who may offer assistance, or a trained person. Alternatively, user 282 may be a remotely trained caregiver communicating with the WCD system.

  User interface 280 can be created in many ways. The user interface 280 can include an output device for communicating with a user by outputting images, sounds, or vibrations, and the output device can be visual, audible, or tactile. Images, sounds, vibrations, and anything that can be perceived by the user 282 may be referred to as human perceptible signs. There are many examples of output devices. For example, the output device can be light or a screen displaying what has been sensed, detected, and / or measured, for the rescuer 282 to attempt their resuscitation. Can provide visual feedback or the like. Another output device may be a speaker, which may be configured to emit a voice prompt, beep, loud alarm sound and / or words to alert a person or the like.

  User interface 280 may further include an input device for receiving input from a user. Such an input device may additionally include various controls, for example, a push button, a keyboard, a touch screen, one or more microphones, and the like. The input device can be a cancel switch, which is sometimes referred to as a "I am alive" switch or a "survivor" switch. In some embodiments, activating the cancel switch can prevent imminent transmission of a shock.

  The defibrillator 200 may include an internal monitoring device 281. Device 281 is referred to as an “internal” device because it is incorporated within housing 201. The monitoring device 281 can sense or monitor patient parameters, such as patient physiological parameters, system parameters and / or environmental parameters, all of which may be referred to as patient data. In other words, the internal monitoring device 281 may complement or replace the external monitoring device 180 of FIG. Assigning which of the parameters is to be monitored by which monitoring device 180, 281 can be made according to design considerations. Device 281 may include one or more transducers or sensors configured to render one or more physiological inputs from one or more patient parameters sensed by device 281.

Patient parameters may include physiological parameters of the patient. The patient's physiological parameters may help, for example, by the wearable defibrillation system to detect whether the patient is in need of a shock, and optionally, the patient's medical and / or event history. It may include, but is not limited to, physiological parameters as obtained. Examples of such parameters include the patient's ECG, blood oxygen level, blood flow, blood pressure, blood perfusion, pulsatile changes in light transmission or light reflection properties of perfused tissue, heart sounds, heart wall motion, breath sounds and pulses. . Accordingly, the monitoring devices 180, 281 may include one or more sensors configured to acquire a physiological signal of the patient. Examples of such sensors or transducers are electrodes for detecting ECG data, perfusion sensors, pulse oximeters, devices for detecting blood flow (eg, Doppler devices), sensors for detecting blood pressure (eg, E.g., cuffs), light sensors, illumination detectors and sensors possibly working with light sources to detect color changes in tissue, motion sensors, devices capable of detecting heart wall motion, sound sensors, devices with microphones. , SpO ₂ sensors and the like. In view of the present disclosure, it will be appreciated that such sensors can help detect a patient's pulse, and thus may also be referred to as pulse detection sensors, pulse sensors, and pulse rate sensors. Would. Pulse detection is also taught at least in U.S. Patent No. 8,135,462 to Physio-Control, which is incorporated herein by reference in its entirety. Also, those skilled in the art may implement other techniques for performing pulse detection. In such a case, the transducer includes a suitable sensor and the physiological input is a sensor measurement of the patient parameter. For example, suitable sensors for heart sounds may include a microphone or the like.

In some embodiments, the local parameters tend to be detectable in the monitored physiological parameters of the patient 282. The trend can be detected by comparing the value of the parameter at different times. Parameters whose detected trends are particularly useful for cardiac rehabilitation programs include: a) cardiac function (eg, ejection fraction, stroke volume, cardiac output, etc.); b) heart rate variability during rest or exercise. C) heart rate profile and activity intensity measurements during exercise, as obtained from accelerometer signal profiles and notified by adaptive rate and pacemaker technology; d) heart rate trends; e) SpO ₂ Or perfusion from CO ₂ etc., f) respiratory function, respiratory rate, etc., g) exercise, activity level, etc. Once a trend is detected, the trend can be stored and / or reported over a communication link, possibly with an alert. From this report, a physician monitoring the progress of patient 282 will know about conditions that are not improving or have deteriorated.

  The patient status parameters may include any of the recorded aspects of the patient 282, such as exercise, posture, whether the patient recently spoken, and possibly what the patient said, etc., and optionally, these parameters. Including history. Alternatively, one of these monitoring devices may include a position sensor, such as a Global Positioning System (GPS) position sensor. Such a sensor can detect position, and in addition, speed can be detected as a rate of change of position over time. Many motion detectors output a motion signal that is indicative of the motion of the detector and, therefore, of the patient's body. Patient condition parameters can be very helpful in narrowing down the decision whether an SCA is actually taking place.

  WCD systems made in accordance with embodiments may include a motion detector. In embodiments, the motion detector may be implemented in monitoring device 180 or monitoring device 281. Such motion detectors can be made in many ways as known in the art, for example, by using an accelerometer. In this example, motion detector 287 is implemented within monitoring device 281.

  A motion detector of a WCD system according to embodiments may be configured to detect a motion event. In response, the motion detector may render or generate a motion detection input that may be received by a subsequent device or functionality from the detected motion event or motion. Exercise events can be conveniently defined, for example, as changes in exercise from baseline exercise or rest, and the like. In such cases, the patient parameter sensed is exercise.

  System parameters for a WCD system can include system identification, battery status, system date and time, self-test reporting, recording of entered data, recording of episodes and interventions, and the like.

  Environmental parameters can include ambient temperature and pressure. Additionally, humidity sensors may provide information as to whether it is about to rain. The estimated patient position may also be considered as an environmental parameter. If the monitoring device 180 or 281 includes a GPS position sensor as described above and it is estimated that the patient is wearing a WCD system, the patient position can be estimated.

  The defibrillator 200 typically includes a defibrillation port 210, such as a socket in the housing 201 or the like. Defibrillation port 210 includes electrical nodes 214, 218. The leads of the defibrillation electrodes 204, 208, such as the lead 105 of FIG. 1, can be plugged into the defibrillation port 210 to make electrical contact with the nodes 214, 218, respectively. Alternatively, the defibrillation electrodes 204, 208 can be continuously connected to the defibrillation port 210. In any event, the defibrillation port 210 is used to guide the charge stored in the energy storage module 250, via the electrodes, to the wearer, which will be described more fully later in this document. Can be. The charge will be a shock for defibrillation, pacing, and the like.

  The defibrillator 200 may also optionally have a sensor port 219 in the housing 201, which may also be known as an ECG port. Sensor port 219 can be adapted to plug in sensing electrode 209, which is also known as an ECG electrode and ECG lead. Alternatively, it is possible that the sensing electrode 209 can be continuously connected to the sensor port 219. The sensing electrode 209 may provide an ECG signal, such as a twelve lead signal, or a signal from a different number of leads, particularly if the sensing electrode 209 makes good electrical contact with the patient's body, and specifically with the patient's skin. A type of transducer that can serve to sense. The sensing electrode 209, like the defibrillation electrodes 204, 208, can be mounted inside the support structure 170 to make good electrical contact with the patient.

  Optionally, the WCD system according to embodiments also includes a fluid that the WCD system can automatically place between the electrode and the patient's skin. The fluid can be made conductive, such as by including an electrolyte, to establish better electrical contact between the electrode and the skin. From an electrical point of view, when a fluid is placed, the electrical impedance between the electrode and the skin is reduced. From a mechanical point of view, the fluid may be in the form of a low-viscosity gel so that the fluid does not flow out of the electrode after it has been placed. Fluid can be used for both the defibrillation electrodes 204, 208 and the sensing electrode 209.

  Fluid may initially accumulate in a fluid container not shown in FIG. 2, and the fluid container may be coupled to a support structure. In addition, the WCD system according to the embodiment further includes a fluid placement mechanism 274. The fluid placement mechanism 274 is configured to be positioned near one or both of the patient's locations where at least a portion of the fluid is released from the container and the electrodes are configured to be attached to the patient. Can be. In some embodiments, the fluid placement mechanism 274 is activated prior to discharging in response to receiving an activation signal AS from the processor 230, described more fully later in this document.

  The intent of the WCD system is to shock when needed and not shock when not needed. The ECG signal may provide enough data to make a shock / non-shock decision. The problem is that at any given time, some of these ECG signals may contain noise, while others do not. The noise may be due to patient movement, how well the electrodes make contact with the skin, and the like. The inventor has noted that while some types of ECG noise in a WCD system can be classified as high-frequency (HF) noise, other types of such ECG noise can be classified as high-amplitude (HA): (High-Amplitude) noise. The noise problem for WCD can be further exacerbated by the desire to use a dry, non-adhesive monitoring electrode. A dry, non-adhesive electrode would be more comfortable for the patient to wear over time, but an adhesive to hold the electrode in place and an electrolyte to reduce the impedance of the electrode / skin interface It can generate more noise than conventional ECG monitoring electrodes including gels.

  The defibrillator 200 also includes a measurement circuit 220 as one or more of its sensors or transducers. The measurement circuit 220 senses one or more electrophysiological signals of the patient from the sensor port 219, if provided. Even if the defibrillator 200 lacks the sensor port 219, if the defibrillation electrodes 204, 208 are attached to the patient, the measurement circuit 220 is optionally replaced by the physiologic Target signal can be obtained. In these cases, the physiological inputs reflect ECG measurements. The patient parameter may be an ECG, which may be sensed as a voltage difference between electrode 204 and electrode 208. Also, the patient parameter may be impedance, which may be sensed between the electrodes 204 and 208 and / or between the connections of the sensor port 219. Sensing impedance may be useful, inter alia, to detect whether these electrodes 204, 208 and / or sensing electrode 209 are making good electrical contact with the patient's body. The physiological signals of these patients can be sensed, if available. The measurement circuit 220 may then render or generate information about the physiological signal as a physiological input, data, other signal, or the like. More specifically, the information rendered by the measurement circuit 220 is output from the measurement circuit 220, but may be referred to as an input because this information is received as input by a subsequent device or functionality.

  The defibrillator 200 also includes a processor 230. Processor 230 may be implemented in many ways. Such techniques are not limiting, and include, for example, software executed on a machine, such as a controller, eg, a microcontroller, such as a digital and / or analog processor, eg, a microprocessor and digital signal processor (DSP). Application-specific integrated circuits (ASICs), such as programmable circuits, for example, field programmable gate arrays (FPGAs), field programmable analog arrays (FPAAs), programmable logic devices (PLDs), etc. And any combination of one or more of the above.

  Processor 230 may include, or have access to, non-transitory storage media, such as memory 238, described more fully later in this document. Such a memory may have non-volatile components for storage of machine-readable and machine-executable instructions. Such a set of instructions may also be called a program. The instructions, also referred to as "software," generally increase functionality by performing methods as disclosed herein or as can be understood by one of ordinary skill in the art in view of the disclosed embodiments. provide. In some embodiments, and by convention as used herein, instances of software may be referred to by "modules" and other similar terms. Generally, a module will include a set of instructions to present or implement a particular functionality. Embodiments of the modules and the functionality provided are not limited by the embodiments described in this document. Processor 230 may set flags, clear flags, etc., among other functions.

  Processor 230 may be considered to have many modules. One such module may be a detection module 232. The detection module 232 may include a ventricular fibrillation (VF) detector. The patient's sensed ECG from measurement circuit 220, which may be available as a physiological input, data, or other signal, may be used by a VF detector to determine whether the patient is experiencing VF. Because VF typically results in SCA, detecting VF is beneficial. The detection module 232 may also include a ventricular tachycardia (VT) detector or the like.

  Another such module in processor 230 may be advisory module 234, which generates advice on what to do. The advice may be based on the output of the detection module 232. There may be many types of advice, according to embodiments. In some embodiments, the advisory is, for example, a shock / non-shock decision that processor 230 can make via advisory module 234. The shock / non-shock decision can be made by executing a stored shock recommendation algorithm. The shock advisory algorithm may make a shock / non-shock decision from one or more ECG signals captured according to an embodiment to determine whether a shock criterion has been met. This determination can be made from a rhythm analysis of the captured ECG signal or otherwise.

  In some embodiments, if the decision is to shock, a charge is transmitted to the patient. The transfer of charge is also known as discharge. Shocking may be for defibrillation, pacing, and the like.

  Processor 230 may include additional modules for other functions, such as another module 236. Also, when the internal monitoring device 281 is actually provided, the internal monitoring device 281 may be partially operated by the processor 230 or the like.

  The defibrillator 200 optionally further includes a memory 238, which can function with the processor 230. Memory 238 may be implemented in many ways. Such techniques are not limiting and include, by way of example, volatile memory, non-volatile memory (NVM), read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, Includes smart cards, flash memory devices, any combination thereof, and the like. Therefore, the memory 238 is a non-transitory storage medium. Memory 238, if provided, may include programs for processor 230 that may be capable of being read and executed by processor 230. More specifically, a program may include a set of instructions in the form of code that may be executable when read by processor 230. Execution is performed by physical manipulations of physical quantities, resulting in functions, operations, processes, actions, and / or methods being performed, and / or the processor being capable of executing such functions on other devices or components or blocks. , Operations, processes, actions, and / or methods may be performed. The program may be operable due to the unique needs of the processor 230 and may also include protocols and techniques by which decisions may be made by the advisory module 234. Also, if the user is a nearby rescuer, memory 238 may store a prompt for this user 282. Further, the memory 238 can store data. This data can include, for example, patient data, system data, and environmental data as learned by the internal monitoring device 281 and the external monitoring device 180. The data can be stored in memory 238 before being transmitted from defibrillator 200, or can be stored in defibrillator 200 after being received by defibrillator 200.

  The defibrillator 200 may also include a power supply 240. To enable portability of defibrillator 200, power supply 240 typically includes a battery. Such batteries are typically implemented as battery packs, which may or may not be rechargeable. A combination of rechargeable and non-rechargeable battery packs may be used. Other embodiments of power supply 240 may include an AC power override if AC power is available, an energy storage capacitor, and the like. In some embodiments, power supply 240 is controlled by processor 230. Suitable components may be included to provide charging or replacement of power supply 240.

  The defibrillator 200 may additionally include an energy storage module 250. The energy storage module 250 can be coupled directly to the support structure of the WCD system, for example, or via electrodes and their leads. Module 250 is a place where some electrical energy may be temporarily stored in the form of a charge when preparing for the discharge of the charge for shocking. In embodiments, module 250 may be charged from power supply 240 to a desired amount of energy under the control of processor 230. In a typical implementation, module 250 includes a capacitor 252, which may be a single capacitor, a system of capacitors, or the like. In some embodiments, the energy storage module 250 includes a device that exhibits high power density, such as an ultracapacitor. As described above, the capacitor 252 can store energy for transfer to a patient in the form of a charge.

  The defibrillator 200 further includes a discharge circuit 255. If the decision is to shock, the processor 230 may be configured to control the discharge circuit 255 to discharge the charge stored in the energy storage module 250 through the patient. When so controlled, circuit 255 is communicated to the patient, allowing energy stored in module 250 to be discharged to nodes 214, 218 and from there to defibrillation electrodes 204, 208. Should shock can occur. The circuit 255 can include one or more switches 257. The switch 257 can be made in many ways, for example, by an H-bridge or the like. Circuit 255 may also be controlled via user interface 280.

  The defibrillator 200 optionally connects one or more wired or wireless communication links with other entities, such as a remote support center, emergency medical service (EMS), and the like. A communication module 290 for establishing can be included. The data can include patient data, event information, attempted treatments, performing CPR, system data, environmental data, and the like. For example, as described in US Patent Application Publication No. 2014/0043149, for example, the communication module 290 can access heart rate, respiratory rate, and other vital signs data over the Internet, for example, on a daily basis. It may be transmitted wirelessly to a suitable server. This data can be analyzed directly by the patient's physician and automatically detected by an algorithm designed to detect ongoing illnesses and then notify medical personnel via text, email, phone, etc. Can also be analyzed. Module 290 also includes such interconnected sub-components as may be deemed necessary by those skilled in the art, such as antennas, parts of processors, supporting electronics, telephone outlets or network cables, etc. May be. In this way, data, commands, etc. can be communicated.

  The defibrillator 200 can optionally include other components.

  Here, the operation according to the embodiment will be described in more detail. FIG. 3 shows how the electrodes of the WCD system can sense or capture the patient's ECG signals, and to obtain the patient's heart rate and other information, these sensed ECG signals are FIG. 4 is a conceptual diagram illustrating how it can be used in accordance with an embodiment. The two electrodes 304 and 308 are attached to the patient's torso, not shown. At this point, it will be appreciated that electrical noise can be introduced into the ECG signal. Each of electrodes 304 and 308 has a lead 305. Both electrodes 304 and 308 sense the patient's ECG signal along a single vector. Additional ECG signals may be sensed along additional vectors.

  FIG. 3 also shows measurement circuit 320 and processor 330, which may be configured as described for measurement circuit 220 and processor 230. Filter 325 is optionally implemented in measurement circuit 320 and / or processor 330. Filter 325 may be implemented as an analog filter, a digital filter, or the like. Filter 325 may help overcome some types of ECG noise by suppressing the ECG noise, making it easier to detect, and the like.

  Processor 330 may perform a complete ECG rhythm analysis 335. Such analysis 335 may result in a shock / non-shock decision and the like. At times, prior to analysis 335, processor 330 may calculate heart rate 333 according to an embodiment. If the result of the previous calculation does not meet the confidence criteria, the calculation of heart rate 333 may be repeated. Thus, the calculation of heart rate 333 may be repeated in the same manner or in a different manner, with additional precautions such as, for example, addressing noise in the ECG signal. Further, additional parameters, such as the QRS width, may be calculated for a complete ECG rhythm analysis 335.

  The calculated heart rate 333 and the results of the analysis 335 may be further used in additional ways. For example, they may be stored in memory 238, later downloaded from memory 238, transmitted wirelessly via communication module 290, and displayed by a screen on user interface 280.

  The devices and / or systems referred to in this document perform functions, processes, and / or methods. These functions, processes and / or methods may be implemented by one or more devices including logic circuits. Such a device may alternatively be called a computer or the like. It may be part of a stand-alone device or computer, such as a general-purpose computer, or a device with one or more additional functions. The logic circuitry may include a processor and non-transitory computer-readable storage media, such as memory, of the type described elsewhere in this document. In many cases, it is preferable, for convenience only, to implement and describe the programs as various interconnected discrete software modules or features. These, together with the data, are known individually and collectively as software. In some instances, software is combined with hardware in a mixture called firmware.

  Further, methods and algorithms are described below. These methods and algorithms are not necessarily intrinsically associated with any particular logical device or other apparatus. Rather, they are advantageously implemented by programs for use by computing machines, such as general purpose computers, special purpose computers, microprocessors, processors as described elsewhere in this document, and the like.

  The detailed description includes flowcharts, displayed images, algorithms, and symbolic representations of program operations on at least one computer-readable medium. Simplicity is achieved in that a single set of flowcharts is used to describe both the program and the method. Thus, while the flowcharts have described the methods in terms of boxes, they also describe the programs at the same time.

  Here, the method is described.

  FIG. 4 shows a flowchart 400 for describing the method according to the embodiment. The operations of the flowchart 400 can be largely divided into a first group 401 and a second group 402. First group 401 is distinguished from second group 402 according to the current state of flag 414, and flag 414 is also referred to as noise detection flag 414. According to the in-ellipse annotation 415, in the case of an operation in the first group 401, the flag 414 is cleared and shown in a lowered state. According to the in-ellipse annotation 465, for an operation in the second group 402, the flag 414 is set and shown as raised.

  The current value of the flag 414, ie, whether the current state of the flag 414 is set or cleared, is represented by the value of a parameter maintained in software, or by the state machine and / or related components of the processor 230. May be the value of the parameter to be performed. It is recognized that as the execution of the operations of flowchart 400 alternates between groups 401 and 402, the current value of flag 414 may alternate between a set state and a cleared state. Will.

  Here, each operation of the flowchart 400 will be described.

  The WCD system may begin its operation with operation 410. According to operation 410, the noise detection flag 414 can be cleared, resulting in the orientation of the in-ellipse annotation 415. Flag 414 may be cleared for a number of reasons, for example, in response to the sensed ECG signal meeting a high amplitude (HA) quiet criterion, as will be seen from operation 490 later. Good. Alternatively, the flag 414 may be released after an allowable time has elapsed since the flag 414 was set, for example, as in operation 480. Such a suitable tolerance time may be 0.5 minutes, 1 minute, 5 minutes, 10 minutes, 20 minutes, etc., as will be seen later in the description of operation 470 and operation 480. Alternatively, the flag 414 may be cleared in response to outputting an alarm to the patient 82, as will be seen later in operation 495.

  According to another operation 425, a next ECG portion may be received where processing is taking place, such as at processor 230. A sample ECG portion 519 is shown in FIG.

  FIG. 5 illustrates multiple amounts of sample time evolution according to an embodiment relative to a time axis 558. Sample ECG portion 519 is shown with respect to ECG portion axis 517. Among them, two sample ECG portions 515, 516 are identified for subsequent commentary. Specifically, starting from an ECG signal that can be continuously sensed by the electrodes, an ECG portion of the sensed ECG signal can be defined. Such an ECG portion may be defined in several ways. For example, each ECG portion may be a portion of a sensed ECG signal that processor 230 processes at one time. One ECG portion may be long enough to perform a complete ECG rhythm analysis 335. Thus, one ECG part may contain several QRS complexes. Alternatively, one ECG portion may be shorter. Indeed, in some embodiments, the ECG portion may simply be the identified peak in the ECG signal, which may be the R peak of the QRS complex. The ECG portion may be stored in memory 238 for later analysis, repeat analysis, difference analysis, and the like.

  Although each of the ECG portions 519 is intended to be generally depicted in FIG. 5, in practice they may have waveforms different from those shown in FIG. More specific examples will be given later in this document. In an instance where the ECG signal actually has exactly the appearance seen in FIG. 5, it will be appreciated that the ECG signal may exhibit VT, or even VF, but that need not be the case for FIG. Also, the ECG portion 519 is depicted in a contracted state in FIG. 5, but a slightly expanded version can be seen in FIG.

  Returning to FIG. 4, according to another operation 430, it may be determined whether the sensed ECG signal meets a high amplitude (HA) noise criterion. This may be performed in several ways. In some embodiments, the HA noise criterion is satisfied according to the latest group of ECG portions 519 that meet the noise condition. Such a group may have any suitable number of ECG portions 519, for example, one to ten ECG portions 519 per group. A good number is to have 5 ECG portions 519 per group. Such a sample grouping 580 of the ECG portion 519 is shown in FIG.

  Returning to FIG. 4, if the answer is “No” in operation 430, another operation 435 may determine whether the shock criterion is met. The determination may be made from the sensed ECG signal, for example, as described for operation 335. Further, as described in more detail below, in some embodiments, the HA noise criterion of operation 430 is satisfied by analyzing the ECG segment for whether the ECG segment meets the noise condition. You may. In such embodiments, if the HA noise criterion is not met, it may be determined from only the ECG portion that does not meet the noise condition whether the shock criterion is met for operation 435.

  If the answer is no in operation 435, execution may revert to an earlier operation, such as operation 425. Execution may continue to loop operations 425, 430, 435 indefinitely as long as the HA noise criterion of operation 430 is not met and the patient is healthy.

  If the answer is yes in operation 435, a shock 111 may be delivered to the patient 82 according to the shock operation 411. For shock operation 411, processor 230 causes support structure 170 to be worn by patient 82 to transmit shock 111 to patient 82 in response to the shock criteria being met and noise detection flag 414 being cleared. In the meantime, the discharge circuit 255 may be controlled to discharge the charge stored in the energy storage module 250 through the patient 82. Of course, before the shock action 411 is performed, another process may be warranted, such as the patient being alerted by a preliminary alarm and prompted to demonstrate that the patient is alive.

  If the answer is “yes” in operation 430, the noise detection flag 414 may be set according to another operation 460. Thus, in an embodiment, in operation 430, a noise detection flag is set in response to the sensed ECG signal meeting the HA noise criterion.

  The reader will observe that, beginning with operation 460, execution has now transitioned from the first group 401 of operations to the second group 402 of operations. According to the in-ellipse annotation 465, the flag 414 is shown as being set. While the flag 414 is set, aspects may differ.

  First, in some embodiments, when the noise detection flag 414 is set as in the ellipse annotation 465, the discharge circuit is controlled not to discharge. This may be the case even if it is determined that the shock criterion is met by another action not shown in FIG. In the example of FIG. 4, a shock action similar to shock action 411 does not exist in second group 402 of actions. Further, as described above, the shock operation 411 first gives a preliminary alarm or the like to the patient. Thus, in those embodiments where the discharge circuit is controlled not to discharge if the noise detection flag 414 is set, the patient 82 does not receive such a preliminary alarm.

  Second, in some embodiments, if the noise detection flag is set, it is not even determined whether the shock criterion is met. In the example of FIG. 4, operations similar to operation 435 are not in the second group of operations 402. As such, the patient's ECG may not be monitored while flag 414 is set. (At the same time, however, the patient may continue to be monitored by monitoring devices, motion sensors whose signals may indicate that the patient is engaged in a particular activity, etc.) However, unmonitored ECGs are not To give a possible answer, it may include too much high amplitude noise detected in operation 430. In fact, high amplitude noise tends to obscure the ECG signal. Rhythm analysis 335 during periods of high amplitude noise may produce unpredictable results because it relies on noise over ECG signals.

  Although it is desirable to alert the patient 82 that the activity that causes noise in the ECG signal should be stopped, it is desirable to alert the patient 82 too quickly so as not to unnecessarily disturb the patient 82. Not a good idea. In any case, given sufficient time, high amplitude noise is often mitigated without interference warning the patient.

  Of course, if the large amplitude noise persists for an extended period of time, the patient must be alerted to correct the situation. The noise may be the result of activity on the part of the patient, or may be due to clothing problems, such as being unfit for the body, or electrodes that are too dry. Thus, the allowed time for the purposes of this document is the time during which the WCD system according to the embodiment does not allow the patient to analyze or alert the patient. After that time has elapsed, the WCD system may alert the patient and / or clear flag 414. Some tolerance times are described earlier in this document, and they may even be adjusted by those suggested by other sensors, such as motion sensors.

  According to another optional operation 470, an allowed time countdown may be initiated to implement the allowed time. This may be by a clock or timer, etc. that counts up or down.

  According to another operation 475, a next ECG portion may be received, similar to that described for operation 425. According to another optional operation 480, it may be determined whether the countdown of operation 480 has been completed.

  If the answer is "No" at operation 480, then according to another optional operation 490, it may be determined whether the HA quiet criterion has been met to determine that noise in the ECG signal has been reduced. This can be achieved in several ways.

  First, the HA noise criterion may be met in response to the HA noise criterion no longer being met. For example, another group of the latest ECG portion that is received later may be considered. For example, at least one ECG portion of another group may occur after at least one ECG portion of the group that was initially used to determine that the HA noise criterion was met. Also, the HA silence condition may be satisfied in response to this other group of the latest ECG portion not meeting the HA noise criterion.

  Second, the HA quiet criterion may be met depending on conditions different from the HA noise criterion. For example, the HA quiet criterion may be met in response to another slower group of the latest ECG portion meeting a quiet condition that is not the same or opposite to the noise condition.

  Further, everything else described to determine whether the HA noise criterion is met may be used in the same way to determine whether the HA quiet criterion is met. . This includes those described below for the noisy criterion, the pseudo criterion, etc.

  If the answer is no in operation 490, execution may return to another operation from group 402, such as operation 475. However, if the answer is "yes" in operation 490, execution may return to operation 410, clear noise detection flag 414, and so on.

  If the answer is "yes" at operation 480, an alert may be output to the patient according to another optional operation 495. Thus, the user interface 280 can be configured to output an alert in response to the noise detection flag 414 being set. The alert may relate to correcting a noise situation. The alarm can be output further in response to the noise detection flag being set for an allowed time. Also, different allowance times may be used to warn and leave group 402. For example, before warning or the like through operation 495, the user may leave group 402 more than once. After operation 495, execution may return to operation 410, clear noise detection flag 414, and so on.

  As described above, the algorithm of a WCD system embodiment can make a determination as to whether noise is detected, for example, by determining whether certain conditions and / or criteria are met. Two such criteria have been described previously, the high amplitude (HA) noise criterion of operation 430 and the HA quiet criterion of operation 490. There are more such criteria and conditions. The algorithm according to the embodiment starts by examining the parts of the sensed ECG signal, identifying peaks in these ECG parts, and determining whether these peaks are R peaks of the QRS complex, or large amplitudes. This is because a more detailed examination will follow, trying to determine if the spike is due to high amplitude noise, also known as noise.

  As already described above, in some embodiments, the HA noise criterion of operation 430 is met in response to the latest group of ECG portions meeting the noise condition. Also, the HA quiet criterion of operation 490 is met, such as when another group of the latest ECG portion no longer satisfies the noise condition or meets a different quiet condition.

  In some embodiments, the ECG portion of the group is marked according to meeting the noise criterion, examples of which are given later in this document. The ratio can then be calculated. The ratio can be the number of marked ECG portions of the group to the total number of ECG portions of the group. If the HA noise criterion of operation 430 is met, the ratio can be a so-called noise ratio, and the noise condition can be satisfied as the noise ratio exceeds the threshold noise ratio. On the other hand, if the HA quiet criterion of operation 490 is met, the ratio may be a noise ratio, or a so-called silent ratio. In the latter case, the silence condition may be satisfied depending on the silence ratio being less than the threshold silence ratio. An example will now be described.

  Returning to FIG. 5, the ECG portion 519 includes two consecutive sample ECG portions 515, 516. Grouping 580 is suggested for groups of 5 ECG parts at a time, which is a good number for group size. In some embodiments, the grouping can be fixed, for example, as suggested by grouping 580. At any point in time, the five ECG portions are considered a single group, with no overlap between the groups, then the next five are considered another group, and so on. For example, the earliest group consists of the five leftmost ECG parts that include the ECG part 515 but do not include the ECG part 516. In other embodiments, the grouping may be variable, for example, counting only the five most recent ECG portions at any one time, with overlap between groups. However, the rest of FIG. 5 continues with the grouping 580. This is because the grouping 580 is easier to track visually due to the lack of overlap. Therefore, in the example of FIG. 5, each ECG portion belongs to a single group.

  In FIG. 5, below the grouping 580, the ECG portion 589 repeats the ECG portion 519 next to the vertical axis 587. Also, some of the ECG portions 589 are shown marked by shadow 586. For example, ECG portion 516 is marked by shadow 586, while ECG portion 515 is not. As noted above, such markings may be for those ECG portions 589 that meet the noise criteria. The simple idea about the marked ECG parts is that they are "noisy".

  Here, the aforementioned ratio can be explained in more detail. Diagram 579 shows the time evolution of the sample ratio using two vertical horizontal axes, a noise ratio axis 503 and another noise ratio axis 504, which follows axis 503. Such a ratio can be conveniently defined to have a value between 0 and 1.

  In diagram 579, each of the groupings 580 produces a different value for the noise ratio. Generally, it is observed that there is more ECG portion 589 near the center of time axis 558, marked by shadow 586, due to its noisy nature. When considered in grouping 580, these noisy ECG portions 589 result in noise ratios having higher values of 0.4, 0.6 during the subsequent grouping 580. Further, the noise ratio has a value of zero at the beginning and end of the time axis 558.

  Thus, as described above, the noise condition may be satisfied as the noise ratio exceeds the threshold noise ratio. If more than one is marked in a group of five ECG parts, it is desirable to set a noise flag. Therefore, the threshold noise ratio can be set to a value between 0.2 and 0.4, for example 0.3. A value of 0.3 for the threshold noise ratio is indicated by the dotted line 581 and the time intercept TNF on axis 503.

  It will be observed that noise ratio plot 579 intersects dotted line 581 at time T1. In fact, the time T1 is thus defined. Thus, the HA noise criterion of operation 430 is answered "yes" only at time T1.

  After time T1, the next criterion of interest is the HA quiet criterion of operation 490. This is illustrated in FIG. 5 by the axis 504 for the quietness ratio. In the example of FIG. 5, the silent ratio is calculated in the same manner as the noise ratio.

  Further, as described above, the silent condition may be satisfied if the silent ratio is less than the threshold silent ratio. In some embodiments, the threshold silence ratio can be set below the threshold noise ratio to confirm that the noise has been reduced. For example, the threshold silence ratio can be set to 0.1. Thus, in a group of five consecutive ECG portions 589, if the ECG portions are not marked, a silent condition may be satisfied. A threshold silence ratio value of 0.1 is indicated by dotted line 582 and time intercept TQF on axis 504.

  It will be observed that noise ratio plot 579 intersects dotted line 582 at time T2. In fact, the time T2 is thus defined. Thus, the HA quiet reference of operation 490 is answered "yes" for the first time at time T2. Of course, if the grouping was variable, time T2 would have occurred earlier by one ECG portion. It will further be appreciated that at time T1, according to operation 470, a countdown may have been initiated for an allowed time. In the example of FIG. 5, time T2 has been reached before such countdown was completed in operation 480.

  Thus, diagram 579 provides the answer for time T1 and time T2. Returning to FIG. 4, at time T1, execution moves from the operation group 401 to the operation group 402. At time T2, execution shifts from the operation group 402 to the original operation group 401. Thus, like the in-ellipse annotation 465, the flag 414 is set or raised between time T1 and time T2. Also, like the in-ellipse annotation 415, the flag 414 is cleared or lowered for all other times on the time axis 558.

  FIG. 5 also shows the state of the flag 414 at various times. It will be observed that flag 414 is shown raised between times T1 and T2, and is shown lowered for all other times of time axis 558.

  Further, as described above, in some embodiments, operation 335 is not performed while flag 414 is set or raised. This is also illustrated schematically in the example of FIG. Thus, between time T1 and time T2, there can be no false pre-alarms to the patient due to the wrong decision to shock.

  An example will now be described of how which of the ECG portions 589 can be marked, which means determining whether an ECG portion meets the noise criterion. I do. FIG. 6 shows an ECG portion 619 which repeats the ECG portions 515 and 516 of FIG. In FIG. 6, the ECG portions 515, 516 are shown more fully, but are still somewhat idealized (eg, the baseline level has not changed).

  In some embodiments, the potential R peak 659 of the QRS complex is identified in a particular ECG portion, eg, ECG portions 515,516. As can be seen from FIG. 6, these potential R peaks 659 may be, for example, peaks having a much higher amplitude than their neighboring peaks. Among them, the two sample peaks are 653, 654.

  In addition, some of the identified potential R peaks 659 in the ECG portions 515, 516 may be considered invalid if they meet the spurious criteria described later in this document. In the example of FIG. 6, each of the identified potential R peaks 659 that are deemed invalid are further illustrated with a shadow 656. Potential R peak 653 is acceptable, does not meet the false similarity criterion, and is not marked by a shadow. However, the potential R peak 654 meets the false similarity criterion, and is therefore considered invalid and marked by a shadow 656.

  An efficacy-related percentage can then be defined for the ECG portions 515,516. In each case, the efficacy-related percentage can be the number of potential R peaks in the ECG portion that are considered invalid relative to the total number of identified potential R peaks in the ECG portion. Thus, the efficacy-related percentage will have a value between 0 and 1.

  In such embodiments, a particular ECG portion may meet the noisy criterion, depending on the validity-related percentage exceeding the threshold validity-related percentage. A good threshold efficacy related percentage can be about 1/4. Thus, for practical purposes, the threshold validity-related percentage may be set to 0.24.

  For example, for the ECG portion 515, as in the ellipse annotation 695, the effectiveness-related percentage is 1/5 = 0.2, which is less than 0.24. As such, ECG portion 515 is acceptable and ECG portion 515 is not considered invalid. Thus, ECG portion 515 is repeated as ECG portion 689 without being marked by a shadow, as in FIG.

  In another example, as in the ellipse annotation 696, for the ECG portion 516, the effectiveness-related percentage is 3/7 = 0.43, which is greater than 0.24. As such, ECG portion 516 is not acceptable and is considered invalid. Thus, the ECG portion 516 is repeated as an ECG portion 689, in which the ECG portion 516 is also marked by a shadow 586, as in FIG.

  Determining whether the identified potential R peak 659 in the ECG portions 515, 516 satisfies the spurious criterion can be done in a number of ways. An example will now be described.

  FIG. 7 has a time diagram 715 to show the first pseudo-criterion. The diagram 715 has an R peak amplitude axis 717 and a time axis 758. Diagram 715 shows the identified potential R peaks 753, 754 of the sample, which may be similar to peaks 653, 654.

  In some embodiments, the identified potential R peaks 753, 754 meet the spurious criterion, depending on having an amplitude greater than the threshold amplitude 799. A suitable value for the threshold amplitude is 3 mV. Thus, a potential R peak identified having an amplitude less than the threshold amplitude 799 does not meet the false similarity criterion.

  FIG. 7 also has another time diagram 759 to show similar results as the R peak 659. Diagram 759 also has an R peak amplitude axis 757 and a time axis 758 that repeats from diagram 715.

  As can be seen, the identified potential R peak 753 has an amplitude that is less than the threshold amplitude 799, and thus the false similarity criterion is not met. Thus, the identified potential R peak 753 is repeated in the diagram 759 without being marked by a shadow, as in FIG. However, the identified potential R peak 754 has an amplitude that is greater than the threshold amplitude 799, and thus the quasi-criterion is satisfied. Thus, the identified potential R peak 754 is repeated in diagram 759, where the identified potential R peak 754 is further marked by a shadow 756 as in FIG.

  In some embodiments, the sensed ECG signal is filtered, and thus the filtered ECG portion may be filtered as well. Filtering may be performed, for example, by filter 325. Filter 325 may be a bandpass filter that passes frequencies between 2.75 Hz and 20 Hz. In such embodiments, all of the above may be applied to the filtered ECG signal. In particular, the identified potential R peaks in a particular filtered ECG portion may meet the spurious criterion, depending on having an amplitude greater than the threshold amplitude.

  FIG. 8 has a time diagram 815 to show the second pseudo-criterion. The diagram 815 has an ECG amplitude axis 817 and a time axis 858. Diagram 815 shows the identified potential R peaks 853, 854 of the sample, which may be similar to peaks 653, 654.

  In some embodiments, the ECG segments 830, 840 are defined to have durations 893, 894 that include respective identified potential R peaks 853, 854. In some embodiments, the identified potential R peak (853, 854) is such that the difference between the starting amplitude at the beginning of the ECG segment and the ending amplitude at the end of the ECG segment is greater than the threshold baseline shift 899. Satisfies the pseudo-criterion criteria.

  FIG. 8 also has another time diagram 859 to show similar results as the R peak 659. The diagram 859 also has an ECG amplitude axis 857 and a time axis 858 that is repeated from the diagram 815.

  As can be seen, for the identified potential R peak 853, the difference between the start amplitude at the start 831 of the ECG segment 830 and the end amplitude at the end 832 of the ECG segment 830 is greater than the threshold baseline shift 899. In that case, the simulated criterion will be met. The start point 831 and the end point 832 are further shown projected onto the vertical axis 817, from which it is apparent that their difference is less than the threshold baseline shift 899. As such, for the identified potential R peak 853, the spurious criterion is not met. Thus, the identified potential R peak 853 is repeated in the diagram 859 without being marked by a shadow, as in FIG.

  As can be further seen, for the identified potential R peak 854, the difference between the starting amplitude at the start 841 of the ECG segment 840 and the ending amplitude at the end 842 of the ECG segment 840 is greater than the threshold baseline shift 899. If so, the pseudo-criteria will be met. The start point 841 and the end point 842 are further shown projected onto the vertical axis 817, which reveals that their difference is greater than the threshold baseline shift 899. Thus, for the identified potential R peak 854, the quasi-criterion is satisfied. Thus, the identified potential R peak 854 is repeated in diagram 859, where the identified potential R peak 854 is further marked by shadow 856 as in FIG.

  In some embodiments, the ratio of the threshold baseline shift 899 to the duration 893, 894 of the ECG segments 830, 840 is at least 5 mV / 200 ms. In practice, the duration 893 may be chosen to start 100 milliseconds (ms) prior to the identified potential R peak 853 and end 100 ms after the identified potential R peak 853. . Therefore, the duration 893 can be 200 ms, and the threshold baseline shift 899 can be 5 mV.

  As described above, in some embodiments, an ECG portion is defined as an identified potential R peak in a sensed ECG signal. In such an embodiment, the identified potential R peaks are marked in response to meeting the spurious criteria. The similarity criterion may be as described above and described with reference to FIGS. The noise ratio of the number of identified potential R peaks of the group to the total number of identified potential R peaks of the group may then be calculated. Then, as described above, as the noise ratio exceeds the threshold noise ratio, the noise condition can be satisfied, as is the silent ratio.

  FIG. 9 illustrates multiple amounts of sample time evolution according to an embodiment with respect to a time axis 958. Sample ECG portion 919 is shown with respect to ECG portion axis 917. It will be observed that ECG portion 919 is depicted as a single peak. Two such peaks 953, 954 of the sample are identified, which may be identified from the ECG signal as shown in FIG. 6 for peaks 653, 654. Also, a grouping 980 is shown, and those described above with respect to grouping 580 also apply. Thus, a single group in this example may be a set of peaks detected in the sensed ECG signal, which may be the R peak of each QRS complex.

  Under grouping 980, ECG portion 989 repeats ECG portion 919 next to vertical axis 987. Also, some of the ECG portions 989 are shown marked with shadows 956. For example, ECG portion 954 is marked by shadow 956, while ECG portion 953 is not. Such a marking may be for one of the ECG portions 989 that satisfies the spurious criteria.

  Further, the diagram 979 shows the time evolution of the sample ratio using two vertical horizontal axes, a noise ratio axis 903 and another noise ratio axis 904 following the axis 903. A value of 0.3 for the threshold noise ratio is indicated by the dotted line 981 and the time intercept TNF on axis 903. Noise ratio plot 979 intersects dotted line 981 at time T3. A threshold silence ratio value of 0.1 is indicated by dotted line 982 and time intercept TQF on axis 904. Noise ratio plot 979 intersects dotted line 982 at time T4. The rest of FIG. 9 is similar to that described above with reference to FIG.

  In the method described above, each operation may be performed as a positive act or operation that performs or causes what is described as possible. Such doing or causing to happen may be by the entire system or device, or only by one or more components thereof. It will be appreciated that the methods and operations may be implemented in multiple ways, including the systems, devices and implementations described above. Also, the order of the operations is not limited to that shown, and different orders may be possible according to different embodiments. Examples of such alternative ordering are overlapping, interleaved, interrupted, reordered, evolving, preliminary, complementing, unless the context indicates otherwise. It may include ordering, simultaneous, inversion, or other transformation. Further, in certain embodiments, new operations may be added, or individual operations may be modified or deleted. The added actions may be, for example, from those mentioned while primarily describing a different system, apparatus, device or method.

  Those skilled in the art will be able to practice the invention in light of this description, which should be taken as a whole. Details are included to provide a thorough understanding. In other instances, well-known aspects have not been described in order to not unnecessarily obscure this description.

  Some techniques or techniques described in this document may be known. However, even if so, it is known that such techniques or techniques are applied as described in this document or are applied for the purposes described in this document. Not necessarily.

  This description includes one or more examples, but this fact does not limit how the invention may be implemented. Indeed, the examples, instances, versions or embodiments of the invention may be implemented in accordance with the described details or in different ways, and may be implemented with other existing or future technologies. You may. Other such embodiments, for example, provide or apply features in a different order than the described embodiments, i.e., extract individual features from one embodiment, Inserting features into another embodiment, removing one or more features from an embodiment, or providing features incorporated in such combinations and sub-combinations, while providing features from one embodiment. , And adding features extracted from another embodiment, including combinations and sub-combinations of the features described herein, including embodiments that are equivalent.

  In general, this disclosure reflects a preferred embodiment of the present invention. However, a careful reader will note that certain aspects of the disclosed embodiments fall outside the scope of the appended claims. In that the disclosed embodiments actually fall outside the scope of the appended claims, the disclosed embodiments should be considered as complementary background information and do not constitute a definition of the claimed invention. .

  In this document, the phrases "constructed to" and / or "configured to" refer to structures and / or structures that are essentially tied to the physical characteristics of the element or feature preceding those phrases. Or, it represents one or more actual states of the configuration, and thus goes far beyond merely describing the intended use. Any such elements or features can be implemented in many ways beyond any of the examples set forth in this document, as will be apparent to those of skill in the art after reviewing the present disclosure.

  Regardless of whether it is mentioned in this document or in the application data sheet ("ADS") of this patent application, any and all parent, grandfather, great-grandfather patent applications, etc. Is hereby incorporated by reference, as originally disclosed, to the extent it does not conflict with the present application, including any priority claims made in those applications and in any material incorporated by reference. Have been.

  In this description, a single reference numeral may be used consistently to represent a single item, aspect, component, or process. Further, in drafting this description, similar, if not identical, reference numbers will be used to represent the same or at least similar or related items, aspects, components or other versions or embodiments of the process. As such, further efforts may be taking place. Where efforts were made, such further effort was not required, but was nevertheless done in good faith to promote understanding by the reader. Even if efforts were made in this document, such additional efforts may not be completely consistent with all versions or embodiments enabled by this description. Thus, the description controls the definition of the item, aspect, component or process, rather than its reference number. Any similarity in reference signs may be used to infer similarity in the text, but should not be confused with the particular text or other context where indicated.

  The claims of this document define certain combinations and sub-combinations of elements, features and acts or acts, which are considered new and nonobvious. Additional claims for other such combinations and sub-combinations can be presented in this or a related document. These claims are intended to cover within their scope all changes and modifications that fall within the true spirit and scope of the subject matter described herein. The terms used herein, including the claims, are generally intended as "open" terms. For example, the term "comprising" should be interpreted as "including but not limited to", and the term "comprising" should be interpreted as "having at least" and the like. Where a particular number belongs to a claim, this number is the minimum but not the maximum unless otherwise specified. For example, if a claim describes "a" component or "a" item, it means that the claim can have one or more of this component or item.

In interpreting the claims of this document, we disclose that the terms "means for" or "steps for" are expressly used in the claims. § 112 (f) of the United States Patent Act only when used. Thus, where these terms are not used in a claim, the claim is not intended to be construed by the inventors in accordance with 35 USC 112 (f).

Claims (29)

A wearable defibrillator (WCD) system,
A support structure configured to be worn by a walkable patient;
An energy storage module configured to store a charge;
A discharge circuit coupled to the energy storage module;
An electrode configured to sense an electrocardiogram (ECG) signal of the patient;
A noise detection flag is set according to the sensed ECG signal meeting a high amplitude (HA) noise criterion, and the detected ECG signal meets a high amplitude (HA) noise criterion. In response, cancel the noise detection flag,
Determining from the sensed ECG signal whether a shock criterion is met;
The stored charge while the support structure is being worn by the patient to deliver a shock to the patient in response to the shock criterion being met and the noise detection flag being cleared. A processor configured to control the discharge circuit to discharge through the patient, wherein the discharge circuit sets the noise detection flag even if it is determined that the shock criterion is satisfied. A WCD system that is controlled to not discharge if it has been.   The WCD system according to claim 1, wherein the noise detection flag is released in response to the noise detection flag being set for an allowable time.   3. The WCD system according to claim 2, wherein said tolerable time is at least 0.5 minutes.   The WCD system according to claim 1, wherein if the noise detection flag is set, it is not determined whether the shock criterion is satisfied.   The WCD system according to claim 1, further comprising a user interface configured to output an alarm in response to the noise detection flag being set.   The WCD system according to claim 5, wherein the alarm is output in response to the noise detection flag being set for an allowable time.   7. The WCD system according to claim 6, wherein said tolerable time is at least 0.5 minutes.   The WCD system according to claim 5, wherein the noise detection flag is released in response to the output of the alarm. An ECG portion of the sensed ECG signal is defined;
The WCD system of claim 1, wherein the HA noise criterion is satisfied in response to a group of current ECG portions satisfying a noise condition.   The WCD system according to claim 9, wherein the group has only one ECG part.   10. The WCD system of claim 9, wherein if the HA noise criterion is not met, it is determined from only the ECG portion that does not meet the noise condition whether a shock criterion is met. The ECG portion of the group is marked as meeting the noise criterion,
Calculating a noise ratio of the number of the marked ECG portions of the group to a total number of the ECG portions of the group;
The WCD system of claim 9, wherein the noise condition is satisfied in response to the noise ratio exceeding a threshold noise ratio. Potential R peaks of the QRS complex are identified within certain ECG portions of the group,
The identified potential R peak in the particular ECG portion that satisfies the similarity criterion is considered invalid;
The number of potential R peaks in the particular ECG portion that is deemed invalid relative to the total number of the identified potential R peaks in the particular ECG portion provides a validity for the particular ECG portion. Gender-related proportions are defined,
13. The WCD system of claim 12, wherein the particular ECG portion satisfies the noise criterion in response to the validity-related ratio exceeding a threshold validity ratio.   14. The WCD system of claim 13, wherein the identified potential R peak in the particular ECG portion satisfies the spurious criterion in response to having an amplitude greater than a threshold amplitude. The particular ECG portion is filtered,
15. The WCD system of claim 14, wherein the identified potential R peak in the particular filtered ECG portion satisfies the spurious criterion in response to having an amplitude greater than a threshold amplitude. An ECG segment is defined to have a duration that includes a particular one of the identified potential R peaks within the particular ECG portion;
In response to the difference between the starting amplitude at the beginning of the ECG segment and the ending amplitude at the end of the ECG segment being greater than a threshold baseline shift, the particular identified potential R peak is reduced to the pseudo- 14. The WCD system according to claim 13, which satisfies criteria. Potential R peaks of the QRS complex are identified in the sensed ECG signal;
10. The WCD system of claim 9, wherein the ECG portion is defined as the identified potential R peak. The identified potential R peak is marked in response to meeting the pseudo-criterion criterion;
Calculating the noise ratio of the number of the marked potential R peaks of the group to the total number of the identified potential R peaks of the group;
The WCD system of claim 17, wherein the noise condition is satisfied in response to the noise ratio exceeding a threshold noise ratio.   19. The WCD system of claim 18, wherein the potential R peak identified has an amplitude greater than a threshold amplitude and satisfies the spurious criterion. The sensed ECG signal is filtered;
20. The WCD system of claim 19, wherein the identified potential R-peak has an amplitude greater than a threshold amplitude and satisfies the pseudo-criterion criterion. An ECG segment is defined to have a duration that includes a particular one of the identified potential R peaks within the particular ECG portion;
In response to the difference between the starting amplitude at the beginning of the ECG segment and the ending amplitude at the end of the ECG segment being greater than a threshold baseline shift, the particular identified potential R peak is reduced to the pseudo- 20. The WCD system of claim 18, which satisfies criteria.   The WCD system of claim 1, wherein the HA quiet criterion is met in response to the HA noise criterion failing to be met.   The HA quiet criterion is satisfied in response to another group of the latest ECG portion not meeting the HA noise condition, and at least one ECG portion of the another group is at least one ECG portion of the group. 10. The WCD system of claim 9, wherein the WCD system occurs after an ECG portion.   The HA silence criterion is satisfied in response to another group of the latest ECG portion satisfying a silent condition, wherein at least one ECG portion of the another group occurs after at least one ECG portion of the group. The WCD system according to claim 9, The ECG portion of the group is marked as meeting the noise criterion,
A silent ratio of the marked ECG portion of the group to a total number of the ECG portions of the group is calculated;
25. The WCD system of claim 24, wherein the silent condition is satisfied in response to the silent ratio being less than a threshold silent ratio. Potential R peaks of the QRS complex are identified in certain ECG portions of said another group;
The identified potential R peak in the particular ECG portion that satisfies the similarity criterion is considered invalid;
The number of potential R peaks in the particular ECG portion that is deemed invalid relative to the total number of the identified potential R peaks in the particular ECG portion provides a validity for the particular ECG portion. Gender-related proportions are defined,
26. The WCD system of claim 25, wherein the particular ECG portion satisfies the noise criterion in response to the validity-related ratio exceeding a threshold validity ratio.   28. The WCD system of claim 26, wherein the identified potential R-peak in the particular ECG portion has an amplitude greater than a threshold amplitude and satisfies the pseudo-criterion criterion. The particular ECG portion is filtered,
28. The WCD system of claim 27, wherein identified potential R peaks in the particular filtered ECG portion satisfy the pseudo-criterion criterion in response to having an amplitude greater than a threshold amplitude. An ECG segment is defined to have a duration that includes a particular one of the identified potential R peaks within the particular ECG portion;
In response to the difference between the starting amplitude at the beginning of the ECG segment and the ending amplitude at the end of the ECG segment being greater than a threshold baseline shift, the particular identified potential R peak is reduced to the pseudo- 27. The WCD system of claim 26, wherein the WCD system meets criteria.

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