An implantable system includes an implantable medical device (IMD) and a non-transvenous lead that is configured to be implanted outside of a heart. The IMD includes an output configured to be connected at least to the lead, a current generator (CG) circuit configured to generate pacing pulses, a switching circuit coupled between the CG circuit and the output, one or more capacitors coupled in parallel with the CG circuit and the switching circuit, and a control circuit coupled to the CG circuit. The control circuit is configured to manage the CG circuit to generate the pacing pulses with a constant current at the output.

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.

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.

Provided are a defibrillation catheter system, a defibrillation power supply device, and a method for controlling the device during observation of intracardiac potential and defibrillation. A defibrillation catheter system 1 includes a catheter 20; a first power supply part 6A and a second power supply part 6B connected to the catheter 20; and an electrocardiograph 40 measuring an intracardiac potential, wherein the catheter 20 is provided with a first electrode group 21 having at least a 1-1 electrode and a 1-2 electrode and a second electrode group 22 having at least a 2-1 electrode and a 2-2 electrode, the first and second electrode groups 21 and 22 are connected to the electrocardiograph 40, the 1-1 electrode and the 2-1 electrode are connected to the first power supply part 6A, and the 1-2 electrode and the 2-2 electrode are connected to the second power supply part 6B.

A novel therapeutic biphasic or multiphasic pulse waveform and method are provided. The novel therapeutic biphasic or multiphasic pulse waveform may be used in a defibrillator, or in another medical device that delivers therapeutic electrical stimulation pulses to a patient.

Provided are a defibrillation catheter system, a defibrillation power supply device, and a method for controlling the device during observation of intracardiac potential and defibrillation. A defibrillation catheter system 1 includes a catheter 20; a power supply part 6 connected to the catheter 20; an electrocardiograph 40 measuring an intracardiac potential; a first electrode 21 and a second electrode 22 provided on the catheter; and a changeover part 7 connected to the power supply part 6, the changeover part 7 switching between a first mode for measuring the intracardiac potential and a second mode for applying the voltage while the intracardiac potential is measured, wherein the first electrode 21 and the second electrode 22 are connected to the power supply part 6 through the changeover part 7, and the first electrode 21 and the second electrode 22 are connected to the electrocardiograph 40.

An implantable medical device for generating electrical stimulations, wherein the medical device is embodied to generate and emit, during a first stimulation phase, at least one first stimulation that has a first amplitude by means of energy from an energy storage element, and wherein the medical device is embodied, during a second stimulation phase following the first stimulation phase, to generate and emit at least one second stimulation that has a second amplitude by means of energy from the energy storage element, wherein the energy storage element is charged at least prior to the generation of the at least one first stimulation and after the generation of the at least one first stimulation, and wherein the medical device is embodied not to completely discharge the energy storage element by generating the at least one first stimulation. The invention furthermore relates to a method for controlling such a device.

A system and method to deliver a therapeutic quantity of energy to a patient. The system includes a capacitor having a rated energy storage capacity substantially equal to the therapeutic quantity of energy, a boost converter coupled with the capacitor and constructed to release energy from the capacitor at a substantially constant current for a time interval, and an H-bridge circuit coupled with the boost converter and constructed to apply the substantially constant current in a biphasic voltage waveform to the patient. The method includes storing a quantity of energy substantially equal to the therapeutic quantity of energy in a capacitor, releasing the quantity of energy at a relatively constant current during a time interval using a boost converter coupled with the capacitor, and delivering a portion of the quantity energy in a direction to the patient using an H-bridge circuit coupled with the boost converter.

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.