Disclosed are a power circuit and an automated external defibrillator including the same. The power circuit may include a battery-driven power source, and a transformer comprising a primary winding and N secondary windings, wherein N is an integer greater than or equal to 2, and wherein the primary winding is electrically coupled to the power source. The power circuit may include N charging and discharging branches, wherein the N charging and discharging branches are respectively connected to the N secondary windings and are cascaded in sequence. The power circuit may include a plurality of electrode plates configured to be connected to an external load, wherein electrode plates of the plurality of electrode plates are electrically coupled to one or more output nodes of the N charging and discharging branches.

A medical device is configured to deliver therapeutic electrical stimulation pulses by generating frequency modulated electrical stimulation pulse signals. The medical device includes a pulse signal source and a modulator. The pulse signal source generates an electrical stimulation pulse signal having a pulse width. The modulator may include a high frequency modulator configured to modulate a frequency of the pulse signal from a starting frequency down to a minimum frequency during the pulse width. The modulator may include a low frequency bias generator to modulate the offset of the pulse signal between a minimum offset and a maximum offset in other examples.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) having a high voltage therapy module is configured to control a high voltage charging circuit to charge a capacitor to a pacing voltage amplitude to deliver charge balanced pacing pulses. The capacitor is chargeable to a shock voltage amplitude that is greater than the pacing voltage amplitude. The ICD is configured to enable switching circuitry of the high voltage therapy module to discharge the capacitor to deliver a first pulse having a first polarity and a leading voltage amplitude corresponding to the pacing voltage amplitude for pacing the patient's heart via a pacing electrode vector selected from extra-cardiovascular electrodes. The high voltage therapy module delivers a second pulse after the first pulse. The second pulse has a second polarity opposite the first polarity and balances the electrical charge delivered during the first pulse.

A patient-worn arrhythmia monitoring and treatment device includes a pair of therapy electrodes and at least one pair of sensing electrodes disposed proximate to the skin and configured to continually sense at least one ECG signal of the patient over an extended period of time. The device includes a therapy delivery circuit coupled to the pair of therapy electrodes and configured to deliver one or more therapeutic pulses. A controller coupled to therapy delivery circuit is configured to analyze the at least one ECG signal and detect one or more treatable arrhythmias and cause the therapy delivery circuit to deliver the one or more therapeutic pulses to the patient. At least one of the one or more therapeutic pulses is formed as a biphasic waveform delivering within 15 percent of 360 J of energy to a patient body having a transthoracic impedance from about 20 to about 200 ohms.

A charging circuit for a capacitor in a defibrillator includes a control enabling a setting of a desired time to charge a capacitor to a desired voltage in the defibrillator. The charging circuit further includes a flyback charge-pump circuit comprising a switch, an energy transfer transformer, an energy storage capacitor and a control. The switch is configured to stop or allow storage of energy in a transformer. The transformer transfers the energy to the capacitor. The flyback charge-pump circuit controls a duty-cycle on the switch so that a current draw from a power source (e.g. battery) is sufficient to enable charging the capacitor to the desired voltage within the desired time set on the control.

A wearable medical device comprising monitoring circuitry to monitor one or more patient parameters of a patient and defibrillation circuitry to provide one or more defibrillation shocks to the patient responsive to a control signal from the monitoring circuitry. The defibrillation circuitry comprises a defibrillation capacitor to provide energy for the one or more defibrillation shocks. The wearable medical device also comprises a power source to provide power to the monitoring circuitry and the defibrillation circuitry. The power source comprises a low current power source (LCPS) to provide power to the monitoring circuitry, and a high current power source (HCPS) to provide power to the defibrillation circuitry.

Defibrillator shock discharge control systems and schemes are described that control the shock discharge based at least in part on discharge capacitor voltage measurement taken after the defibrillation shock has been initiated.

A system to deliver therapeutic energy to a patient, the system including a storage capacitor configured to store and release the therapeutic energy, a boost converter circuit coupled to the storage capacitor, and a current flow control circuit coupled to the boost converter circuit and including a plurality of control circuits configured to control a current output from the current flow control circuit in a therapeutic biphasic voltage waveform upon release of the therapeutic energy from the storage capacitor, wherein the therapeutic biphasic voltage waveform includes a ramped increase in voltage from approximately zero volts to a desired therapeutic voltage level over a time interval greater than 1 millisecond and less than a time associated with a phase switch.

Technologies and implementations for a wearable medical device (WMD). The technologies and implementations facilitate improved comfort and usability of WMDs. Additionally, the technologies and implementations include WMDs having wearable cardioverter defibrillator capabilities.

Disclosed herein is a resuscitation device facilitating the administration of cardiopulmonary resuscitation to a subject, the resuscitation device comprising a housing having a top surface and a bottom surface, said top surface having a concave dell configured to guide on the top surface a hand positioning of a rescuer administrating a cardiopulmonary resuscitation to a subject, and said bottom surface configured to position and stabilize the housing over a sternum of the subject, and wherein the housing is configured to transmit a uniform distribution of the cardiopulmonary resuscitation force to the chest of the subject, said uniform distribution facilitates distributing the cardiopulmonary resuscitation force over a surface area that greater than the area of the top surface that directly receives the cardiopulmonary resuscitation force, thereby facilitating injury and contusion prevention to ribs and the sternum of the subject.