A wearable cardioverter defibrillator (“WCD”) system may output a loud sound after detecting and validating a shockable cardiac arrhythmia. In such embodiments, however, the WCD system might not sound a loud alarm before validating the arrhythmia thoroughly, i.e. for a longer time, thus giving the arrhythmia a further chance to self-terminate. The WCD system may thus detect more robustly the cardiac arrhythmias that do not self-terminate quickly. Such arrhythmias that self-terminate quickly may occur from likely harmless events occurring multiple times in the daily life of the patient, such as the patient becoming “winded” from climbing stairs. In embodiments the WCD system may notify the patient only discreetly, or even not at all. The lack of sounding such a loud alarm responsive to such events reduces the overall number of times in which the patient experiences unwanted attention by others, embarrassment, loss of privacy and dignity, and so on.

In embodiments, a wearable cardiac defibrillator system includes an energy storage module configured to store a charge. Two electrodes can be configured to be applied to respective locations of a patient. One or more reservoirs can store one or more conductive fluids. Respective fluid deploying mechanisms can be configured to cause the fluids to be released from one or more of the reservoirs, which decreases the impedance at the patient location, and decreases discomfort for the patient. In some embodiments an impedance is sensed between the two electrodes, and the stored charge is delivered when the sensed impedance meets a discharge condition. In some embodiments, different fluids are released for different patient treatments. In some embodiments, fluid release is controlled to be in at least two doses, with an intervening pause.

Components of wearable cardiac defibrillator (WCD) systems, software, and methods are provided. A WCD system includes a support structure that a patient can wear and electrodes that can capture at least two of the patient's ECG signals. A component includes an energy storage module that can store an electrical charge, a discharge circuit, and a processor that can make a shock/no shock determination, and cause the discharge circuit to discharge the stored charge, if the determination is to shock. In some embodiments, the processor discards at least one of the ECG signals prior to making the shock/no shock determination. The determination can be made from the remaining one or more ECG signals. In some embodiments, the processor makes an aggregate shock/no shock determination from two or more of the ECG signals.

In some embodiments, a wearable cardioverter defibrillator (“WCD”) system may output an opening human-perceptible indication, after detecting a shockable cardiac arrhythmia but before validating it. This may succeed in informing the patient that the WCD system is working, and in particular analyzing a just-detected cardiac arrhythmia. The information may give comfort and confidence to the patient who may be conscious, and be experiencing only ventricular tachycardia but not ventricular fibrillation.

This disclosure relates generally to a computational model for personalizing defibrillation mechanism of wearable cardiac defibrillator (WCD). Cardiac defibrillators are lifesaving therapeutic device with potentially harming capacity if not tuned properly. Hence creation of a personalized energy distribution model based on subject's anatomy, rather than a ‘one size fits all’ approach is preferred. The disclosed model compares the efficiency of standard and nonstandard WCD electrode placement in the torso vest, demonstrating significant differences in defibrillation efficacy associated with different strategies. A new measure is presented for performing such a comparison which combines the DFT and extent of myocardial damage.

The invention relates to a stimulation device for electrotherapy, in particular a defibrillator device and/or external pacemaker device, comprising: at least two contact electrodes (11, 12), which can be applied to the body of a patient at suitable stimulation positions and by means of which current pulses can be applied to the body of the patient (10), the first of the at least two contact electrodes (11, 12) acting as a supply electrode (12) having positive polarity, and the second of the at least two contact electrodes (11, 12) acting as a removal electrode (11) having negative polarity with respect to an emitted current pulse; and a current pulse generator (14), which is or can be connected to the contact electrodes (11, 12) by means of line connections (21, 17). In order to simplify the correct positioning of the contact electrodes on the body of the patient, a signal evaluation unit (15), which is or can be connected to the contact electrodes (11, 12), is provided for determining the application positions of the contact electrodes (11, 12) on the body of the patient (10), by means of which signal evaluation unit the polarity of the electrodes can also be automatically reversed in a preferred embodiment.

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.

A wearable cardioverter defibrillator (WCD) comprises a support structure to be worn by a patient, an energy storage module to store an electrical charge, a discharge circuit coupled to the energy storage module, a measurement circuit, a user interface that includes a speaker, and a processor. The processor is configured to monitor a physiological signal of a patient with the measurement circuit to detect cardiac arrhythmia when the patient is wearing the support structure, determine whether a validation criterion is met in response to detection of a cardiac arrhythmia, provide no alarm with the user interface the validation criterion is being determined, and cause a shock to be delivered to the patient from the energy storage module by the discharge circuit in the event the validation criterion is met.

A system and method for extra cardiac defibrillation is disclosed. In a particular embodiment, an extra cardiac implantable cardioverter defibrillator system includes an implantable defibrillator having a metal case and a defibrillation lead. The defibrillation lead has a connector at its proximal end for coupling to the implantable defibrillator and a first defibrillation coil electrode at a distal portion of the lead. The first defibrillation electrode configured to be disposed in an inferior vena cava.

A method for a wearable cardioverter defibrillator (WCD) system comprises sensing one or more patient parameters from different parts of a body of the patient by the one or more transducers, obtaining a plurality of physiological inputs from the sensed one or more patient parameters, detecting first aspects from each of at least some of the physiological inputs, generating an aggregated first aspect from at least two of the detected first aspects, determining an aggregate analysis score from the aggregated first aspect, and determining whether the aggregate analysis score meets an aggregate shock criterion. The electrical charge is discharged within six minutes from when it is determined that the aggregate shock criterion is met, otherwise the electrical charge is not discharged for at least 19 minutes from when it is determined that the aggregate shock criterion is not met.