Several defibrillators, defibrillator architectures, defibrillator components and methods of operating defibrillators are described. In one aspect, a defibrillator (as for example an automated external defibrillator) that can be powered by a mobile communication device such as a smart cellular phone or a tablet computer is described. Utilizing a phone (or other mobile communication device) as the power supply for an external defibrillator allows the external defibrillator to be smaller and, in some circumstance, removes the need for a battery that stores sufficient energy for shock deliverywhich would need to be checked and/or replaced on a regular basis. Additionally, when desired, certain control functionality, computation, data processing, and user instructions can be handled/presented by the mobile communications device thereby further simplifying the defibrillator design and improving the user experience. This architecture takes advantage of the nearly ubiquitous availability of smart phones, tablet computers and other mobile communication devices.

An implantable medical device system is configured to sense cardiac events in response to a cardiac electrical signal crossing a cardiac event sensing threshold. A control circuit is configured to determine a drop time interval based on a heart rate and control a sensing circuit to hold the cardiac event sensing threshold at a threshold value during the drop time interval.

An apparatus comprising: a first garment configured to be worn about a torso of a patient; and a first garment identification component disposed as a part of the first garment, the first garment identification component configured to operably couple with a medical device controller, wherein the medical device controller is configured to identify the first garment based on one or more values provided by the first garment identification component.

An example method is performed by a defibrillator that includes a therapy cable receptacle and an electrocardiogram cable receptacle. The method includes displaying a user interface screen that includes a primary channel for displaying a primary waveform and a secondary channel for displaying secondary data. The method also includes detecting a lack of a patient connection for therapy pads and detecting a patient connection for an ECG lead obtained using an ECG electrode cable. In addition, the method includes displaying a representation of an ECG signal obtained using the ECG electrode cable in the primary channel based on detecting the lack of the patient connection for the therapy pads and detecting the patient connection for the ECG lead.

In one embodiment, a WCD is described. The WCD includes a support structure configured to be worn by a patient and a processor coupled to the support structure. The WCD also includes an energy storage module configured to store an electrical charge and in communication with the processor. The WCD also includes a discharge circuit coupled to the energy storage module, the discharge circuit in communication with the processor and configured to discharge the stored electrical charge through a body of the patient. The processor is configured to detect an event at the WCD, classify the detected event, and determine an alarm onset time of the detected event based at least in part on the event classification. The processor is further configured to issue the alarm after the alarm onset time.

In one embodiment, a method to monitor a patient's heart health is described. The method may include processing at least one electrocardiogram (ECG) signal and diagnosing an episode of nonsustained ventricular tachycardia (NSVT) based at least in part on the processing of the at least one ECG signal. In some embodiments, the NSVT episode may satisfy an NSVT time duration and a QRS criterion. The NSVT time duration may be between 5 seconds and 15 seconds. In some instances, the QRS criterion may be a temporary QRS template of two sequential incoming QRS complexes. In some embodiments, the method may determine a similarity between the temporary QRS template and at least two subsequent QRS complexes by calculating a feature correlation coefficient between the QRS template and the subsequent QRS complexes.

Systems, devices, software and methods are provided, for making a decision as to whether to administer an electric shock to a patient. The decision can be made differently, depending on whether the patient has already been shocked or not.

Methods and devices for adjusting therapy delivery decisions in an implantable cardiac stimulus device. Some example methods and devices use a first counter to track benign cardiac activity during therapy preparations and a second counter to track shockable cardiac activity once therapy is ready. Therapy can then be delivered if or when the second counter exceeds the first counter.

Energy delivered from an implantable medical device to stimulate tissue within a patient's body is controlled. An electrical signal used to stimulate the tissue is changed from a first energy state to a second energy state during a magnetic resonance imaging (MRI) scan. The energy delivered is maintained at the second energy state after the MRI scan. A capture threshold of the tissue is then measured, and the energy delivered to the tissue is adjusted based on the measured capture threshold of the tissue.

Systems, devices, software and methods are provided, for making a decision as to whether to administer an electric shock to a patient. The decision can be made differently, depending on whether the patient has already been shocked or not.