Abstract: In embodiments, a wearable cardioverter defibrillator (WCD) system includes a support structure configured to be worn by an ambulatory patient, an energy storage module configured to store an electrical charge, at least one defibrillation electrode held on the patient while the patient is wearing the support structure, and sensors. The sensors may include a rotational measurement module, a magnetic field sensing module, a pulse detector and an ambient air pressure sensor. The sensors may gather multiple data about the patient, which can be used for better understanding of the patient's activities and ultimately a better-informed defibrillation decision.

Abstract: A wearable cardioverter defibrillator (WCD) comprises a plurality of electrocardiography (ECG) electrodes and a plurality of defibrillator electrodes to contact the patient's skin when the WCD is delivering therapy to the patient, a preamplifier coupled to the ECG electrodes to obtain ECG data from the patient. a processor to receive the ECG data from the preamplifier, and a high voltage subsystem to provide a defibrillation voltage to the patient through the plurality of defibrillator electrodes in response to a shock signal received from the processor. In a first power mode of a range of power modes the preamplifier is configured to perform low-fidelity ECG acquisition and the processor is configured to perform simple arrythmia detection analysis, and in a second mode of the range of power modes the preamplifier is configured to perform high-fidelity ECG acquisition and the processor is configured to perform complex arrythmia detection analysis.

Abstract: In embodiments, an external defibrillator has an electrical circuit with a special output stage for the high-voltage defibrillation pulse. The output stage includes switches that can turn on for delivering the pulse, and off during all other times. The output stage also includes a diverting resistance to divert electrical current that could leak into the patient while a capacitor is being charged. An optional detector may notify if a component is malfunctioning. An advantage can be that an external defibrillator may be created according to embodiments that uses, in its output stage, semiconductor switches instead of relays. As semiconductor switches weigh less and occupy less volume than relays, an external defibrillator according to embodiments may have less weight and volume. Especially in wearable defibrillator applications, less weight means less effort to carry and less volume means easier concealment under clothing.

Abstract: A wearable cardioverter defibrillator system supported with a customizable, goal-oriented, companion device. Functionality can be tailored to the goal for a user type. For a patient, the companion device can improve compliance with wear or prescription. Goals can include emotional support, or a specific health, including activity, support. The goal-oriented companion device can receive and process information using machine learning techniques, and interface with a user and other systems and devices.

Abstract: In one embodiment, a method to alert a user of a wearable cardioverter defibrillator (WCD) is described. The method includes determining when a system issue is resolved and issuing an alert when the system issue is resolved. In some embodiments, the method may detect the system issue and issuing a system alert based at least in part on the system issue. The method may then monitor a status of the system issue. In some instances, the method may detect an abnormality in system operation sand determine a severity rating for the abnormality. The method may determine if the abnormality satisfies a time duration threshold based at least in part on the severity rating.

Abstract: A data file system includes one or more files about a patient wearing a wearable cardiac defibrillator (WCD) system that has been assigned to them. The one or more files contain at least one patient identifier of the patient, compliance data about a history of the patient's wearing the WCD system, and possibly other data. The data file system can be accessed through a communication network when the patient uses a communication device. When so accessed, some of the contents can be viewed on a screen of the device, for example in the form of a website. In embodiments, the health care provider and friends and family can view such data and even enter inputs, which may create a situation that motivates the patient to comply better.

Abstract: A wearable cardioverter defibrillator (WCD) comprises a plurality of electrocardiography (ECG) electrodes, a right-leg drive (RLD) electrode, and a plurality of defibrillator electrodes to contact the patient's skin when the WCD is delivering therapy to the patient, a preamplifier coupled to the ECG electrodes and the RLD electrode to obtain ECG data from the patient as one or more ECG vectors, a high voltage subsystem to provide a defibrillation voltage to the patient through the plurality of defibrillator electrodes, and an impedance measurement circuit to measure an impedance across a first pair of ECG electrodes, wherein the impedance measurement circuit is to apply a balancing impedance across a second pair of ECG electrodes when an impedance of the second pair of ECG electrodes is not being measured.

Abstract: A wearable cardioverter defibrillator (WCD) comprises a plurality of electrocardiography (ECG) electrodes, a right-leg drive (RLD) electrode, and a plurality of defibrillator electrodes to contact the patient's skin when the WCD is delivering therapy to the patient, a preamplifier coupled to the ECG electrodes and the RLD electrode to obtain ECG data from the patient as one or more ECG vectors, a processor to receive ECG data from the preamplifier and an abort signal from a user interface, an isolation barrier to isolate the preamplifier from the processor, and a high voltage subsystem to provide a defibrillation voltage to the patient through the defibrillator electrodes in response to a shock signal received from the processor. A shock is provided when an abort signal is not received within a predetermined time period of a shock criterion being met. Less than one false alarm occurs every ten patient-days.

Abstract: A WCD system is configured to detect when a therapy administered to a patient by the WCD system is unsuccessful, and in response determine whether to send notifications to remote non-witness responders. The WCD system may be configured to decide to send such notifications after the WCD system determines it has administered a predetermined number of unsuccessful shocks to the patient. The predetermined number of unsuccessful shocks may be the maximum number of unsuccessful shocks the WCD system will administer to a patient, or every Xth shock (e.g., 3rd shock). The WCD system can be configured to periodically resend the notification. The notifications may be in form of SMS, voice messages, emails, app notifications, etc. sent to cell phones, smartphones, computers, laptops, tablets etc. of the responders either directly, via a server, or via a CAD-coupled server.

Abstract: A wearable cardioverter defibrillator (WCD) including a support structure configured to be worn by an ambulatory patient, an energy storage module configured to store an electrical charge, a discharge circuit coupled to the energy storage module, electrodes configured to render an electrocardiogram (ECG) signal of the patient while the patient is wearing the support structure, a user interface configured to output an alarm in response to a noise alarm signal, and a processor. The processor is configured to receive the ECG signal, determine whether noise is present on the ECG signal, determine from the ECG signal whether a shock criterion is met, and cause the user interface to generate the noise alarm signal when the noise is present on the ECG signal and the shock criterion is met and not generate the noise alarm signal when noise is present on the ECG signal and the shock criterion is not met.

Abstract: A medical device such as an external defibrillator delivers electrical therapy using a special pulse sequence. The special pulse sequence includes a defibrillation shock that is automatically followed by a quick succession of automatic post-shock anti-tachycardia (APSAT) pacing pulses. Because of the pacing pulses, the defibrillation shock can be of lesser energy than an equivalent defibrillation shock of a larger energy. Accordingly, the external defibrillator can be made physically smaller and weigh less, without sacrificing the therapeutic effect of a larger external defibrillator that would deliver a defibrillation shock of higher energy. As such, the defibrillator is easier to configure for transporting, handling, and even wearing.

Abstract: In embodiments, a wearable medical (WM) system includes ECG electrodes, and a support structure that can be worn by an ambulatory patient so as to maintain the ECG electrodes on the patient's body. When thus maintained, the ECG electrodes can be configured to sense an ECG signal of the ambulatory patient. The WM system further includes a memory that stores a reference template, and an output device. The reference template can be made from one or more early portions of the ECG signal of the patient. Then later portions of the ECG signal are sensed and compared against the reference template, to determine if there is a specific problem. If it is so determined, the output device can output an alert.

Abstract: In embodiments, a wearable cardioverter defibrillator (WCD) system is configured to be worn by an ambulatory patient. In the event that the WCD system determines that defibrillation is needed, it delivers a defibrillation shock. To diminish the possibility that the patient will be shocked due to a false positive detection, the WCD system alerts a patient that a defibrillation shock is imminent, and invites them to react to avert it. Alerting may be by a very weak shock, or jolt. Alerting by a jolt can be a last resort warning. An advantage can be that the patient has a higher chance of being alerted by the jolt, especially in the event that the patient is not reacting to other human-perceptible alerts, such as when the patient is riding a motorcycle.

Abstract: In one embodiment, a wearable cardioverter defibrillator (WCD) is described. The WCD includes a support structure that may be worn by a patient. A processor is coupled to the support structure. The wearable cardioverter defibrillator also includes a discharge circuit configured to discharge a stored electrical charge through a body of the patient, the discharge circuit in communication with the processor. The processor may be configured to detect an event occurring at the WCD and determine a severity of the event occurring at the WCD. The processor may activate a multi-sensory alarm based at least in part on the determined event severity.

Abstract: In embodiments, a wearable cardiac defibrillation (WCD) system includes one or more flexible ECG electrodes. The WCD system may have a support structure that is dimensioned to be worn so as to press the electrodes towards the body of the patient. The electrodes may be made from appropriate material so as to flex in order to match a contour of the body of the patient. An advantage over the prior art is that the flexible electrode may make better electrical contact with the patient's skin, and therefore provide a better ECG signal for the WCD system to perform its diagnosis.

Abstract: Embodiments of a wearable cardioverter defibrillator (WCD) system are configured to monitor a patient's ECG for shockable arrhythmias and deliver a shock to the patient in response to such a detection. To monitor the patient's ECG with reduced signal noise to improve the system's performance, the system includes a cable assembly having: a signal line; an inner shield and an outer shield; an ECG electrode electrically connected to the signal line of the cable assembly; and an amplifier having first and second input nodes respectively connected to the signal line and the outer shield of the cable assembly. The amplifier's output node is electrically connected to the inner shield of the cable assembly to reduce the reactive load seen by the patient's heart in driving the ECG sensing circuitry, which reduces the noise on the ECG signal outputted by the amplifier.

Abstract: Embodiments of this disclosure are directed to a wearable cardioverter defibrillator (“WCD”) system design in which a WCD implements an alert prioritization scheme to provide the patient with feedback in an order that is less likely to cause confusion. Different conditions (e.g., device status, equipment condition, or physiologic condition) are prioritized based on an analysis of severity of the condition and timeliness of user action needed. The prioritization scheme defines what alert, if any, is presented to the user by the WCD system as a result of various conditions. Generally stated, an alert for the highest priority condition currently detected is presented to the user and maintained until that condition either changes or becomes surpassed in the prioritization scheme.

Abstract: A wearable cardioverter defibrillator (WCD) having a processor configured to receive a signal indicating a position and/or movement of the ambulatory patient while the ambulatory patient is wearing the support structure receive the ECG signal, determine from an ECG signal whether a shock criterion is met, determine a confirmation time period and/or a response time period based on the position and/or movement of the ambulatory patient, determine from the ECG signal whether the shock criterion is met after the confirmation time period has elapsed, cause the user interface to generate the shock alert signal based on the shock criterion determined after the confirmation time period has elapsed, and control the discharge circuit to discharge the stored electrical charge when a predetermined time period has elapsed after the shock alert signal.

Abstract: In embodiments, a wearable cardioverter defibrillator (WCD) system includes electrodes that render an ECG signal of the patient, and a processor that receives ECG data are derived from the rendered ECG signal. The processor may filter the received ECG data with a matched difference filter to detect QRS complexes, and compute a heart rate from the detected QRS complexes. The matched difference filter itself can have coefficient values associated with a baseline QRS complex, which improves detection.