Implantable cardioverter defibrillator device comprising a pulse generation circuitry

Abstract

An implantable cardioverter defibrillator device (1) comprises a generator device (10) comprising a processing circuitry (102) and a pulse generation circuitry (103). At least one lead (11) comprises an electrode pole arrangement including a shock electrode (115) for emitting a defibrillation shock pulse (DP). The pulse generation circuitry (103) comprises an energy supply arrangement (105) containing at least one energy storage device (C1-C7) which is dischargeable to form the defibrillation shock pulse (DP), and an output circuit (107) for outputting the defibrillation shock pulse (DP) to the shock electrode (115) of the electrode pole arrangement. The processing circuitry (102) is configured to control the pulse generation circuitry (103) to produce the defibrillation shock pulse (DP) based on a discharging of the at least one energy storage device (C1-C7) and to generate, subsequent to the generation of the defibrillation shock pulse (DP), a sequence of post-shock stimulation pulses (O1…On) based on a residual energy stored in the at least one energy storage device (C1-C7) subsequent to the generation of the defibrillation shock pulse (DP).

Description

[0001] Implantable cardioverter defibrillator device comprising a pulse generation circuitry

[0002] The instant invention concerns an implantable cardioverter defibrillator device and a method for operating an implantable cardioverter defibrillator device.

[0003] An implantable cardioverter defibrillator device generally comprises a generator device comprising a processing circuitry and a pulse generation circuitry. The implantable cardioverter defibrillator device in addition comprises an electrode pole arrangement including a shock electrode for emitting a defibrillation shock pulse. The pulse generation circuitry comprises an energy supply arrangement containing at least one energy storage device which is dischargeable to form said defibrillation shock pulse, and an output circuit for outputting said defibrillation shock pulse to the shock electrode of the electrode pole arrangement.

[0004] The implantable cardioverter defibrillator device in particular is designed for emitting electrical shocks in case life-threatening arrhythmias of a patient’s heart are detected. By means of an electrical shock a defibrillation shall be achieved in order to reset the cardiac rhythm back to a normal state.

[0005] By emitting a defibrillation shock pulse a cardiac rhythm shall be reset. For generating the defibrillation shock pulse, herein, one or multiple electrical energy storage devices, for example capacitors, of an energy supply arrangement are discharged, such that based on the discharging a high energy defibrillation shock pulse is produced and output via the shock electrode of the lead connected to the generator device.

[0006] Subsequent to emitting a defibrillation shock pulse, it must be made sure that cardiac activity restarts at a normal or close-to normal rhythm. For this it may be necessary to initiate a so- called post-shock therapy in which a stimulation is provided causing cardiac activity to intrinsically restart if it does not start automatically.

[0007] There is a desire to be able, in an efficient way, to provide for a post-shock therapy after outputting a defibrillation shock pulse in an implantable cardioverter defibrillator device, in particular a non-transvenous implantable cardioverter defibrillator device, which at best does not increase complexity of the circuitry used within the implantable cardioverter defibrillator device.

[0008] It is an object of the instant invention to provide an implantable cardioverter defibrillator device and a method for operating an implantable cardioverter defibrillator device which allow in an easy and efficient way to perform a post-shock therapy subsequent to a defibrillation shock pulse.

[0009] This object is achieved by an implantable cardioverter defibrillator device according to the features of claim 1.

[0010] Accordingly, an implantable cardioverter defibrillator device comprises a generator device comprising a processing circuitry and a pulse generation circuitry. At least one lead comprises an electrode pole arrangement including a shock electrode for emitting a defibrillation shock pulse. The pulse generation circuitry comprises an energy supply arrangement containing at least one energy storage device which is dischargeable to form said defibrillation shock pulse, and an output circuit for outputting said defibrillation shock pulse to the shock electrode of the electrode pole arrangement. The processing circuitry is configured to control the pulse generation circuitry to produce the defibrillation shock pulse based on a discharging of the at least one energy storage device and to generate, subsequent to the generation of the defibrillation shock pulse, a sequence of post-shock stimulation pulses based on a residual energy stored in said at least one energy storage device subsequent to the generation of said defibrillation shock pulse.

[0011] The implantable cardioverter defibrillator device comprises a pulse generation circuitry which comprises an energy supply arrangement and an output circuit. The energy supply arrangement is formed by one or multiple energy storage devices, for example capacitors, which may be caused to discharge in order to supply energy to form the defibrillation shock pulse.

[0012] The implantable cardioverter defibrillator device may in particular be a non-transvenous implantable cardioverter defibrillator device (in short non-transvenous ICD), which is designed for implantation external to a patient’s heart. In a non-transvenous implantable cardioverter defibrillator device, a generator device may for example be implanted subcutaneously in a patient. A lead, in a connected state, extends from the generator device, the lead being implanted such that it fully rests outside of the patient’s heart. The lead may for example extend from the generator device towards a location in the region of the patient’ s sternum, in particular between the patient’s sternum and the patient’s heart, the shock electrode hence being placed outside of the patient’s heart for emitting an electrical shock pulse at a location external to the patient’s heart.

[0013] The term “non-transvenous” in this respect in particular shall express that the lead of the non-transvenous implantable cardioverter defibrillator device does not extend transvenously into the heart, but fully rests outside of the patient’s heart.

[0014] In another embodiment, the implantable cardioverter defibrillator device may be designed for a transvenous implantation, i.e., by implanting a lead to extend transvenously into the heart.

[0015] The implantable cardioverter defibrillator device generally is configured to emit a defibrillation shock pulse for achieving a defibrillation. The implantable cardioverter defibrillator device may serve for monitoring and treating potentially life-threatening arrhythmias of a patient's heart. If the implantable cardioverter defibrillator device is a non- transvenous implantable cardioverter defibrillator device, the shock electrode in an implanted state of the defibrillator device is placed outside of the heart of the patient, for example in the region of the sternum of the patient, such that a shock pulse for achieving a defibrillation is generated outside of the heart. In case a potentially life-threatening tachycardic arrhythmia, for example a ventricular fibrillation, is detected, the processing circuitry controls the pulse generation circuitry to generate a defibrillation shock pulse which is output via the output circuit to the shock electrode of the electrode lead connected to the generator device. By means of the defibrillation shock pulse, generated at high energy by using stored energy of the energy supply arrangement, the arithmetic cardiac rhythm shall be reset to a normal rate such that e.g. a fibrillation state is terminated.

[0016] The defibrillation shock pulse is generated by discharging the at least one energy storage device of the energy supply arrangement, for example formed by an arrangement of capacitors which, in a charged state, store energy as supplied for example from a battery. Herein, in order to ensure that intrinsic cardiac activity resumes beneficially at a normal or close to a normal rate subsequent to outputting a defibrillation shock pulse, the processing circuitry of the generator device is configured to control the pulse generation circuitry to generate a sequence of post-shock fibrillation pulses subsequent to generating the defibrillation shock pulse. The sequence of post-shock stimulation pulses is generated based on a residual energy stored in the at least one energy storage device of the energy supply arrangement, such that for generating the post-shock stimulation pulses energy is used which is left in the at least one energy storage device after the generation of the defibrillation shock pulse.

[0017] Generally, for generating a high energy defibrillation shock pulse, the at least one energy storage device of the energy supply arrangement is first charged and then discharged. For this, the at least one energy storage device of the energy supply arrangement is connected to an energy supply of the generator device, such as an electrochemical battery. For charging, hence, energy is supplied to the at least one energy storage device, and subsequently the at least one energy storage device is discharged to generate the defibrillation shock pulse to perform a defibrillation action.

[0018] It herein is proposed that, for generating the defibrillation shock pulse, not the entire energy as stored in the at least one energy storage device of the energy supply arrangement is used, but only a portion. For generating the defibrillation shock pulse, the at least one energy storage device hence is discharged only partially, such that residual energy remains in the at least one energy storage device, which subsequently to producing the defibrillation shock pulse may be used for generating a sequence of post-shock stimulation pulses.

[0019] The post-shock stimulation pulses hence are produced from energy stored in the at least one energy storage device of the energy supply arrangement. Prior to producing the post-shock stimulation pulses, herein, the at least one energy storage device is not recharged, for example from a battery of the generator device, but a remaining filling level of the at least one energy storage device after generation of the defibrillation shock pulse is used to generate and output the post-shock stimulation pulses.

[0020] As the pulse generation circuitry hence is used both for producing the defibrillation shock pulse and for generating the post-shock stimulation pulses, no additional circuitry is required. As prior to generating the defibrillation shock pulse and the post-shock stimulation pulses the at least one energy storage device is charged and does not need to be recharged in between the defibrillation shock pulse and the sequence of post-shock stimulation pulses, processing becomes easy and time efficient, as the post-shock stimulation pulses can be generated immediately after or at a desired time distance closely after outputting the defibrillation shock pulse.

[0021] A post-shock therapy hence becomes possible with substantially the same circuitry as required for producing the defibrillation shock pulse. The design of an implantable cardioverter defibrillator device, including also a post-shock therapy, thus may be eased, and manufacturing costs may be reduced.

[0022] In one embodiment, the output circuit is configured to output the sequence of post-shock stimulation pulses to the shock electrode or to at least one other electrode pole of the electrode pole arrangement for emitting the sequence of post-shock stimulation pulses. For example, the post-shock stimulation pulses may be output using the shock electrode of the lead, which also is used to output the defibrillation shock pulse. In another embodiment, one or multiple other electrode poles arranged on the lead on which also the shock electrode is arranged or on another lead connected to the generator device are used to output the postshock stimulation pulses.

[0023] In one embodiment, the processing circuitry is configured to control the pulse generation circuitry to generate the sequence of post-shock stimulation pulses at a rate in between 20 bpm and 100 bpm, in particular 30 bpm and 60 bpm. Post-shock stimulation pulses hence are output at a brady cardie rate, which is lower than a normal cardiac rate.

[0024] For example, the processing circuitry may be configured to control the pulse generation circuitry to generate the sequence of post-shock stimulation pulses in a VVI mode. Signals hence are sensed in the ventricle, and post-shock stimulation pulses are output for achieving a ventricular stimulation. If intrinsic cardiac activity is sensed subsequent to generating and outputting the defibrillation shock pulse, however, the generation and outputting of the postshock stimulation pulses is inhibited, such that intrinsic activity has preference over stimulated activity.

[0025] In one embodiment, the processing circuitry is configured to control the pulse generation circuitry to generate the sequence of post-shock stimulation pulses for a maximum duration smaller than 5 minutes, preferably smaller than 2 minutes, for example for a maximum duration of 1 minute or 30 seconds. During the outputting of the post-shock stimulation pulses it may be sensed whether intrinsic cardiac activity restarts, upon which a further generation and outputting of stimulation signals may be inhibited. The generation of the post-shock stimulation pulses however in any case is terminated after reaching the maximum duration.

[0026] In one embodiment, the processing circuitry is configured to control the pulse generation circuitry to terminate the defibrillation shock pulse based on a discharging level of the at least one energy storage device. As sufficient energy shall remain in the at least one energy storage device after generating and outputting the defibrillation shock pulse, it is monitored, during the generation of the defibrillation shock pulse, to what level the at least one energy storage device has discharged. If it is found that the charging level of the at least one energy storage device has dropped to or below a predefined minimum, generation of the defibrillation shock pulse is terminated, such that sufficient energy remains for, potentially, producing post-shock stimulation pulses.

[0027] For example, the processing circuitry may be configured to control the pulse generation circuitry to terminate the defibrillation shock pulse if an output voltage of the at least one energy storage device becomes smaller than a predefined termination threshold. If the output voltage of the at least one energy storage device has dropped to or below a predefined termination threshold voltage, the defibrillation shock pulse is terminated, such that it is ensured that the voltage of the at least one energy storage device does not drop below the value of the termination threshold and hence a sufficient voltage level is still available at the at least one energy storage device for producing the post-shock stimulation pulses.

[0028] In one embodiment, the processing circuitry is configured to control the pulse generation circuitry to generate the post-shock stimulation pulses of the sequence of post-shock stimulation pulses at a voltage amplitude equal to or smaller than the output voltage of the at least one energy storage device at the time of terminating the defibrillation shock pulse. In the course of discharging the at least one energy storage device for generating the defibrillation shock pulse the available output voltage of the at least one energy storage device decays. Hence, the post-shock stimulation pulses are produced at a reduced voltage level which is equal to or smaller than the output voltage of the at least one energy storage device at the time of terminating the defibrillation shock pulse.

[0029] As when generating and outputting the post-shock stimulation pulses the at least one energy storage device further discharges, in one embodiment the processing circuitry is configured to control the pulse generation circuitry to generate the post-shock stimulation pulses at a varying amplitude and / or pulse width. For example, the voltage amplitude of the post-shock stimulation pulses may decay, due to the decaying charging level of the at least one energy storage device during generation of the post-shock stimulation pulses. To compensate for the decaying voltage amplitude, herein, the pulse width may be increased in the course of generating the sequence of post-shock stimulation pulses, such that the lower the voltage amplitude the larger the pulse width becomes. In one embodiment, the pulse generation circuitry comprises a limiting circuit arranged electrically in between the energy supply arrangement and the output circuit. The limiting circuit is configured to limit a current and / or / voltage of the sequence of post-shock stimulation pulses, such that the post-shock stimulation pulses are produced at a reduced current and / or voltage in comparison to the output voltage and / or current available at the at least one energy storage device at the time of terminating the defibrillation shock pulse.

[0030] The limiting circuit may in particular be a current limiting circuit for limiting a current supplied from the at least one energy storage device. The limiting circuit, in one embodiment, is arranged electrically in between the energy supply arrangement of the output circuit such that a current supplied from the energy supply arrangement of flows through the limiting circuit towards the output circuit. The limiting circuit comprises at least one current limiting component which is controlled by the processing circuitry of the generator device in order to perform a modulation of the current flowing through the limiting circuit. The modulation in particular may be a pulse width modulation (PWM), with a modulation depth between for example 25% to 100% (100% corresponding to a 0 amplitude in between pulses). In that the limiting circuit limits the current flowing to the output circuit and hence limits the power of the post-shock stimulation pulses fed by means of the output circuit to the electrode arrangement, post-shock stimulation pulses may be generated which comprise a reduced voltage level and a reduced power.

[0031] The current limiting component serves to reduce and hence limit the amplitude of a current flowing through a conduction path in which the current limiting component is arranged. The limiting effect of the current limiting component may be controlled, in that for example a resistance value of the current limiting component may be controlled, or the current limiting component may be selectively activated (such that a current flows through the current limiting component) or deactivated (such that the current does not flow through the current limiting component).

[0032] By using the limiting circuit, a power and voltage level of post-shock stimulation pulses may be controlled such that an excessive voltage level and power is avoided, while producing pulses of sufficient energy to induce a desired stimulation. By means of the limiting circuit a control means in between the energy supply arrangement and the output circuit is provided, which may allow for an easy and effective control and hence a reliable operation of the pulse generation circuitry.

[0033] In that the limiting circuit is arranged electrically in between the energy supply arrangement and the output circuit, a single limiting circuit may be used for controlling a current flow to the output circuit. The limiting circuit is arranged in an electrical conduction path in between the energy supply arrangement and the output circuit such that a current from the energy supply arrangement flows through the limiting circuit to the output circuit and is modulated by controlling the limiting circuit.

[0034] In one embodiment, the processing circuitry is configured to control the limiting circuit to modulate the current flowing through the limiting circuit to generate the post-shock stimulation pulses according to a modulation scheme. A current for producing the post-shock stimulation pulses hence flows through and is modulated by the limiting circuit.

[0035] In one embodiment, the processing circuitry is configured to control the limiting circuit to set an effective voltage level of the post-shock stimulation pulses using a pulse width modulation. In particular, the processing circuitry may control the limiting circuit such that a sequence (burst) of pulses is produced to form the post-shock stimulation pulses. A modulation depth may be in a range between 25% to 100%. If a modulation depth of 100% is employed, pulses are selectively switched on and off by controlling the limiting circuit. If a modulation depth less than 100% is used, the current limiting component may be switched between different resistance values such that pulses of varying amplitude are generated for producing the post-shock stimulation pulses.

[0036] By controlling the limiting circuit, post-shock stimulation pulses of varying widths and at varying distances may be produced. The pulse width may, in one embodiment, be time- controlled. In another embodiment, the pulse width may be voltage-controlled. In a preferred embodiment, at least the majority (>50%, >80% >95%) of the post-shock stimulation pulses shall guaranty a desired effectiveness. According to electro-physiology the effectiveness is governed by an electrical charge dose provided by a respective pulse. The electrical charge dose results from the integral over time of the electrical current provided by the pulse. The current is a result of the pulse voltage driving charge through the living body resistance. To control the electrical charge dose, hence, the pulse width may be controlled. Because an available voltage level provided by the energy supply arrangement decreases during application due to a discharging of capacitors, the pulse width may be adapted accordingly.

[0037] Another way to control effectiveness is to adapt a total duration of the sequence of postshock stimulation pulses. If there is an increased charge loss during one pulse due to a lower body resistance, the distance in between subsequent pulses may be increased in order to stretch the pulse train to obtain effective outputs (sufficient charge per pulse) over a sufficiently long duration. The duration of the pulse train is programmable in one embodiment.

[0038] In another embodiment, the pulse width is set based on the peak voltage of the instant pulse itself or the peak voltage of at least one prior pulse. According to one embodiment the width calculation is based on an extrapolation of the progression of prior pulse peak voltages (optionally including the peak voltage of the instant pulse which has just started). The extrapolation may be performed by applying a linear or exponential extrapolation. In one embodiment, the pulse width is set based on a voltage decay that occurs during a pulse.

[0039] In one embodiment, the at least one current limiting component comprises a resistance, an inductance, or a semiconductor component. A semiconductor component for providing for a current limiting may for example be a current limiting diode. The current limiting component may be a passive component or an active current limiting arrangement including active and passive elements such as transistors and resistors.

[0040] The current limiting component may be controllable, for example to control a resistance value of the current limiting component.

[0041] In one embodiment, the limiting circuit comprises a controllable component which is controllable by the processing circuitry. The controllable component may for example be a switch, such as a semiconductor switch, for example a transistor such as an FET, an IGBT or an AGT. The controllable component may in particular be controlled by the processing circuitry in order to selectively open and close a conduction path in which the current limiting component is arranged such that the current limiting opponent may be selectively activated or deactivated.

[0042] In one embodiment, the limiting circuit comprises a switch, wherein the current limiting component is arranged in a first path and the switch is arranged in a second path electrically in parallel to the first path. By controlling the switch, for example using the processing circuitry, current may be supplied via the first path or the second path. If the switch is closed, current (predominantly) flows through the second path and hence not through the current limiting component. If the switch is opened, current flows through the current limiting component in the first path. The current limiting component in addition may be controllable in order to modulate the current flowing through the current limiting component.

[0043] For controlling the limiting circuit, a driver may be used which functions at floating potential on its secondary side. Floating potential means that there is no galvanic connection between the primary and the secondary side. Such driver functioning at floating potential on its secondary side is used to control e.g. an arrangement of switches. By use of such a driver the processing circuitry can be implemented using low voltage electronics. Low voltage electronics may use a voltage level as supplied directly from a battery. The battery voltage may be in the range of 1.5 V to 15 V, for example at 3 V, 6 V or 9 V. Switches in turn may operate at voltage levels dictated by the energy supply arrangement. While the processing circuitry generates commands for actuating the switches, the driver translates the commands to a secondary side electrical potential completely isolated from a primary side electrical potential. The translation is done for example by means of optical radiation, magnetic induction, or mechanic transmission (also including vibrations, including acoustics). In a preferred implementation the driver may for example be an optocoupler. Another option for a driver may be an inductively coupled high-side driver.

[0044] A resistor of the limiting circuit may be used as a dump resistor for draining off energy which is not used for producing the post-shock stimulation pulses. The resistor may for example comprise an intermediate terminal (e.g. realized as a series connection of two resistors) such that e.g. only a portion of the resistor is used as a limiting resistance for the current limiting, whereas the entire resistor may be used for draining off energy (dumping).

[0045] In one embodiment, the output circuit is formed by an H bridge comprising switches to selectively form conduction paths for outputting the defibrillation shock pulse and / or the sequence of post-shock stimulation pulses in a first polarity or in a second, opposite polarity. In the H bridge, for example four switches may be used, wherein a first conduction path may be formed by a first pair of switches to connect terminals of the H bridge circuit to inject a pulse into the patient at a first polarity, and a second conduction path may be formed by a second pair of switches to connect the terminals of the H bridge to inject a pulse of a second, opposite polarity into the patient. By selectively switching the switches, the connection paths may be selectively opened or closed in order to selectively output a pulse of a particular polarity.

[0046] In one embodiment, the pulse generation circuitry comprises a multiplicity of energy storage devices, for example in the shape of capacitors, functionally connected to at least one switching device. The processing circuitry herein is configured to control the at least one switching device to supply energy for generating the defibrillation shock pulse and the postshock stimulation pulses using all of the multiplicity of energy storage devices or a combination of some of the multiplicity of energy storage devices.

[0047] The pulse generation circuitry may be controlled to produce one or multiple of the defibrillation shock pulse and the post-shock stimulation pulses as rectangular or approximately rectangular pulses. Alternatively, one or multiple of the defibrillation shock pulse and the post-shock stimulation pulses may be shaped to exhibit a rising ramp.

[0048] The post-shock stimulation pulses may each exhibit a single phase. The post-shock stimulation pulses may, in another embodiment, each exhibit multiple phases. Within the multiple phases polarities of the respective post-shock stimulation pulse may change.

[0049] The pulse generation circuitry may be controlled to produce one or multiple of the defibrillation shock pulse and the post-shock stimulation pulses as single or multiple phase pulses exhibiting a shape according to a condensator discharge, in particular a shape according to an exponential decrease.

[0050] In one embodiment the implantable cardioverter defibrillator device comprises a sensing arrangement for sensing electrocardiogram signals. Sensed signals are forwarded to the processing circuitry, which processes the signals in order to e.g. identify ventricular contraction events in a sensed electrocardiogram signal. Based on a sensed cardiac activity (or a lack of it), then, the defibrillation shock pulse and, subsequently, post-shock stimulation pulses may be generated.

[0051] The sensing arrangement may comprise multiple electrode poles. One or multiple electrode poles of the sensing arrangement herein may be placed on the lead carrying the shock electrode. For example, one electrode pole may be placed on the lead at a position proximal to the shock electrode. Another electrode pole may be placed on the lead at a position distal to the shock electrode.

[0052] Further electrode poles may be placed on further leads connected to the generator device. Alternatively or in addition, one or multiple electrode poles may be formed by a housing of the generator device. Yet alternatively or in addition, the shock electrode may be used as a sense electrode pole for sensing electrocardiogram signals.

[0053] In one embodiment, the sensing arrangement comprises three or more electrode poles. The three or more electrode poles form multiple pairs of electrode poles which may be used for sensing electrocardiogram signals. The different pairs span sense vectors which, each by itself, may be used to sense an electrocardiogram signal. The different sense vectors herein may exhibit a different spatial sensitivity with respect to electrocardiogram signals and hence may be used to sense information in a multichannel processing. Signals received by means of the different sense vectors as spanned by different pairs of electrode poles may be combined in order to sense ventricular activity and to derive information from electrocardiogram signals.

[0054] The generator device may have a volume smaller than 70 cm3. The implantable cardioverter defibrillator device may be MRI compatible.

[0055] The implantable cardioverter defibrillator device may comprise a communication interface for communicating with an external device, for example within a home-monitoring system. The communication interface may for example employ a common communication scheme such as a MICS communication or a BLE communication.

[0056] In another aspect, in a method for operating an implantable cardioverter defibrillator device the implantable cardioverter defibrillator device comprises a generator device and at least one lead comprising an electrode pole arrangement including a shock electrode for emitting a defibrillation shock pulse. The method comprises: generating, by controlling a pulse generation circuitry of the generator device using a processing circuitry of the generator device, said defibrillation shock pulse based on a discharging of at least one energy storage device of an energy supply arrangement of the pulse generation circuitry; outputting, using an output circuit of the pulse generation circuitry, said defibrillation shock pulse to the shock electrode of the electrode pole arrangement; and generating, by controlling the pulse generation circuitry using the processing circuitry, a sequence of post-shock stimulation pulses subsequent to the generation of said defibrillation shock pulse based on a residual energy stored in said at least one energy storage device subsequent to the generation of said defibrillation shock pulse.

[0057] The advantages and advantageous embodiments described above for the implantable cardioverter defibrillator device equally apply also to the method, such that it shall be referred to the above in this respect.

[0058] The idea of the invention shall subsequently be described in more detail with reference to the embodiments as shown in the drawings. Herein:

[0059] Fig. 1 shows a schematic drawing of an implantable cardioverter defibrillator device in an implanted state in a patient; Fig. 2 shows the cardioverter defibrillator device of Fig. 1, illustrating sense vectors spanned by different pairs of electrode poles of a sensing arrangement of the device;

[0060] Fig. 3 shows an example of a defibrillation shock pulse followed by a sequence of postshock stimulation pulses;

[0061] Fig. 4 shows a schematic drawing of an embodiment of a pulse generation circuitry comprising an energy storage arrangement, a limiting circuit and an output circuit;

[0062] Fig. 5 shows another embodiment of a pulse generation circuitry;

[0063] Fig. 6 shows an example of a sequence of post-shock stimulation pulses produced by a pulse generation circuitry;

[0064] Fig. 7 shows an example of a pulse generation circuitry for generating a defibrillation shock pulse followed by a sequence of post-shock stimulation pulses;

[0065] Fig. 8 shows another example of a pulse generation circuitry for generating a defibrillation shock pulse followed by a sequence of post-shock stimulation pulses; and

[0066] Fig. 9 shows yet another example of a pulse generation circuitry for generating a defibrillation shock pulse followed by a sequence of post-shock stimulation pulses.

[0067] Subsequently, embodiments of the invention shall be described in detail with reference to the drawings. In the drawings, like reference numerals designate like structural elements.

[0068] It is to be noted that the embodiments are not limiting for the invention, but merely represent illustrative examples.

[0069] Referring to Fig. 1, in a setup of a therapy system an implantable cardioverter defibrillator device 1 is designed as a non-transvenous implantable cardioverter defibrillator device 1. The non-transvenous implantable cardioverter defibrillator device 1 is implanted such that the implantable cardioverter defibrillator device 1 is completely external to the heart H, the implantable cardioverter defibrillator device 1 comprising a generator device 10 encapsulated within a housing 100, and a lead 11 connected to the generator device 10 at a proximal end 111 and carrying electrode poles 113, 114 as well as a shock electrode 115 in the shape of a coil formed on a distal portion close to a distal end 112 of the lead 11. The electrode poles 113, 114, for example formed as ring electrodes on either side of the shock electrode 115, serve to sense cardiac signals for processing within the generator device 10 of the implantable cardioverter defibrillator device 1, such that based on sensed signals an arrhythmia may be identified and a shock pulse may be generated for providing for a defibrillation therapy.

[0070] The implantable cardioverter defibrillator device 1, in the embodiment of Fig. 1, is designed for a non-transvenous implantation, that is an implantation external to the patient’s heart H. In particular, the lead 11 connected to the generator device 10 shall rest outside of the patient’s heart H and shall not extend transven ously into the heart, the shock electrode 115 hence, in an implanted state, being placed outside of the heart H for providing for a defibrillation therapy.

[0071] For example, the generator device 10 may be implanted subcutaneously in a patient. The lead 11, with a lead body 110, may extend from the generator device 10 towards the sternum of the patient, the lead 11 for example tunneling through tissue in the region of the sternum and being placed beneath the sternum of the patient.

[0072] The implantable cardioverter defibrillator device 1 may comprise a communication interface for communicating with an external device 2, for example within a home-monitoring system.

[0073] Referring now to Fig. 2, the generator device 10 generally comprises a processing circuitry 102 for controlling operation of the implantable cardioverter defibrillator device 1. In addition, the generator device 10 comprises a pulse generation circuitry 103 and an energy supply 104, in particular in the shape of an electrochemical battery. The processing circuitry 102 in particular serves to process signals sensed via a sensing arrangement formed by the electrode poles 113, 114 arranged on the lead 11 and additional poles, such as the shock electrode 115 and the housing 100 of the generator device 10. The different poles of the sensing arrangement form pairs of electrode poles in between which sense vectors A, B, C, D are spanned, as illustrated in Fig. 2, the different sense vectors A, B, C, D allowing to sense electrocardiogram signals from the patient’s heart H with a different spatial sensitivity, hence allowing to sense and process information from the patient’s heart H in a multichannel processing.

[0074] The implantable cardioverter defibrillator device 1 as shown in Figs. 1 and 2 in particular shall be configured to perform a defibrillation therapy.

[0075] Referring now to Fig. 3, the implantable cardioverter defibrillator device 1, when sensing a tachycardic ventricular arrhythmia, shall be configured to output a defibrillation shock pulse DP using the shock electrode 115 such that the tachycardic rhythm is reset to a normal rhythm, hence terminating the cardiac arrhythmia. The defibrillation pulse DP, for this, may be biphasic, wherein for generating the defibrillation shock pulse DP one or multiple energy storage devices of an energy supply arrangement of the pulse generation circuitry 103 are discharged and a high energy defibrillation pulse DP is generated and output using the shock electrode 115.

[0076] If, subsequent to a defibrillation shock pulse DP, it is found that intrinsic cardiac contractions do not restart automatically after a resetting action of the high energy defibrillation shock pulse DP, the implantable cardioverter defibrillator device 1 is enabled to perform a postshock therapy PS in which a sequence of post-shock stimulation pulses Oi...Onare generated.

[0077] Using the pulse generation circuitry 103, the post-shock stimulation pulses Oi...Onare output e.g. at a bradycardic rate, for example at a rate in between 30 bpm and 60 bpm for a maximum duration for example below 2 minutes, for example up to 1 minute or 30 seconds. The post-shock stimulation pulses Oi.. Onexhibit, in comparison to the defibrillation shock pulse DP, a reduced energy and shall trigger intrinsic cardiac contractions such that normal cardiac activity resumes.

[0078] Beneficially, the implantable cardioverter defibrillator device 1 is configured to produce the post-shock stimulation pulses Oi...Ononly if intrinsic cardiac activity does not start automatically after the defibrillation shock pulse DP. If intrinsic activity is sensed following the defibrillation shock pulse DP, a post-shock stimulation therapy PS may be inhibited in a so-called VVI mode.

[0079] Referring now to Fig. 4, in one embodiment a pulse generation circuitry 103 comprises an energy supply arrangement 105 comprising one or multiple energy storage devices, for example in the shape of capacitors, a limiting circuit 106 and an output circuit 107, for example in the shape of an H bridge comprising switches to selectively form therapeutic conduction paths via terminals Tl, T2 for outputting pulses of a particular polarity into the body of the patient.

[0080] Making use of the pulse generation circuitry 103 as shown, in an embodiment, in Fig. 4, a defibrillation shock pulse DP and subsequently a sequence of post-shock stimulation pulses Oi. . .On may be generated for performing a defibrillation therapy followed by a subsequent post-shock bradycardic stimulation therapy. Herein, the defibrillation shock pulse DP and the subsequent train of post-shock stimulation pulses Oi.. Onare generated using the same energy supply arrangement 105 comprising one or multiple energy storage devices, such as capacitors, without charging the energy supply arrangement 105 anew following the generation of the defibrillation shock pulse DP.

[0081] Generally, the energy supply arrangement 105 is enabled to allow for a fast discharging to produce a high-energy, high-voltage defibrillation shock pulse DP. Prior to generating the defibrillation shock pulse DP, the energy supply arrangement 105, namely the energy storage devices such as the capacitors of the energy supply arrangement 105, are charged from energy supplied from the general energy supply 104 of the generator device 10, for example a battery, such that the energy supply arrangement 105 is in a charged state prior to generating the defibrillation shock pulse DP. During the generation of the defibrillation shock pulse DP, the energy supply arrangement 105 is discharged, such that the stored energy reduces and the available output voltage of the energy supply arrangement 105 decays. As, in between the generation of the defibrillation shock pulse DP and the subsequent post-shock stimulation pulses Oi . . . On, the energy supply arrangement 105 is not recharged, the generation of the defibrillation shock pulse DP is controlled by the processing circuitry 102 such that the generation of the defibrillation shock pulse DP is terminated once a predefined discharging level of the energy supply arrangement 105 has been reached.

[0082] For example, during the generation and the outputting of the defibrillation shock pulse DP the output voltage of the energy supply arrangement 105 is monitored. If it is found that the output voltage of the energy supply arrangement 105 has dropped to or below a predefined termination threshold voltage, the generation of the defibrillation shock pulse DP is terminated, such that a substantial charging level remains in the energy supply arrangement 105 for a potential subsequent generation of post-shock stimulation pulses Oi.. On.

[0083] Referring now again to Fig. 3, the initial voltage level VI of the first (negative) phase of the defibrillation shock pulse DP may correspond to the maximum voltage of the energy supply arrangement 105 in its charged state. In the course of the first phase, the voltage decays to a voltage level V2, for example corresponding to 50% of the maximum voltage VI, upon which the second phase of the defibrillation shock pulse DP with opposite polarity is produced starting at the voltage level V3 approximately corresponding to the amount of the voltage V2. Once the voltage level of the second phase has dropped to a voltage level V4 which is at or below the predefined termination threshold, the generation of the defibrillation shock pulse DP is terminated, such that a sufficient filling level remains in the energy supply arrangement 105 for a subsequent generation of post-shock stimulation pulses Oi.. On.

[0084] If it now is found that a post-shock therapy PS is indicated, post-shock stimulation pulses Oi... On are generated from the residual energy left in the energy supply arrangement 105 after generation of the defibrillation shock pulse DP, wherein a voltage and / or current of the post-shock stimulation pulses Oi...Onmay be limited by using the limiting circuit 106 of Fig. 4 such that a voltage amplitude of the post-shock stimulation pulses Oi.. Onis reduced in comparison to the voltage level V4 at the time of termination of the defibrillation shock pulse DP.

[0085] The limiting circuit 106 comprises a current limiting component 120 having for example a resistance 124 and a switch 123. The limiting circuit 106 is arranged electrically in between the energy supply arrangement 105 and the output circuit 107, such that a current is supplied from the energy supply arrangement 105 to the output circuit 107 via the limiting circuit 106.

[0086] The limiting circuit 106 is controllable by the processing circuitry 102. In particular, by controlling the limiting circuit 106 a current flow through the limiting circuit 106 is modulated in order to produce the post-shock stimulation pulses Oi . . . Onto be output by the output circuit 107 subsequent to a prior defibrillation shock pulse DP.

[0087] The control of the output circuit 106 in particular may take place by controlling the switch 123 to assume an open or a closed state. Alternatively or in addition, the resistance 124 may be controllable such that a resistance value may be selectively adapted.

[0088] The processing circuitry 102 may in particular control the limiting circuit 106 to apply a pulse width modulation to produce the post-shock stimulation pulses Oi...On. The pulse width modulation may be achieved by controlling the switch 123. Alternatively or in addition the resistance 124 may be controlled. The pulse width modulation may have a modulation depth for example between 25% to 100%.

[0089] The switch 123 may for example be a semiconductor switch, such as a transistor, for example an FET, IGBT, or AGT.

[0090] Referring now to Fig. 5, the limiting circuit 106 may comprise two paths Pl, P2, wherein in a first path Pl the current limiting component 120 is arranged and in the other, second path P2, in parallel to the first path Pl, a switch 121 and a circuit component 122, for example a resistor, may be placed. By controlling the switch 121 a current may selectively flow via the first path Pl and hence via the current limiting component 120, or via the second path P2 and hence via the circuit component 122. In particular, when the switch 121 is opened, a current flows through the current limiting component 120. If instead the switch 121 is closed, a current predominantly flows via the circuit component 122 to the output circuit 107.

[0091] By means of the switch 121, hence, the current limiting component 120 may selectively be activated or deactivated. For example, by activating the current limiting component 120 post-shock stimulation pulses Oi...Onmay be produced, the post-shock stimulation pulses Oi... On having a reduced voltage level and a reduced power in comparison to a prior defibrillation shock pulse DP. By deactivating the current limiting component 120, in turn, a defibrillation shock pulse DP having an increased voltage level and an increased power may be produced.

[0092] Referring now to Fig. 6, by using the limiting circuit 106, in particular by supplying current through the current limiting component 120 and the resistor 124 arranged therein, a sequence of post-shock stimulation pulses Oi, O2 ... Onmay be produced which are set to a desired pulse width Wi, W2, Wnand voltage level Ai, A2, An. The post-shock stimulation pulses Oi, O2 . . . On may differ in their pulse width Wi, W2, Wn. Alternatively or in addition, a distance Bi, B2 between neighboring pulses may vary. Yet alternatively or in addition, a maximum pulse amplitude Ai, A2, Anmay vary.

[0093] The post-shock stimulation pulses Oi, O2 . . . Onmay have an equal polarity or may have a differing polarity. By means of the H bridge the post-shock stimulation pulses Oi, O2 . . . Oncan be shaped as monophasic or biphasic pulses. The train of post-shock stimulation pulses Oi, O2 . . . On may comprise a mix of both monophasic and biphasic pulses.

[0094] As visible from Fig. 6, each pulse Oi, O2 ... Onmay exhibit a decaying ramp, due to a discharging of the energy supply arrangement 105, comprising for example an arrangement of capacitors, as shall be explained in more detail below with reference to Figs. 7 to 9. In addition, the peak amplitude Ai, A2, Anof a pulse Oi, O2 ... Onin comparison to a prior pulse Oi, O2 ... On may be reduced, also due to a decaying charging level of the energy supply arrangement 105 during operation. The pulse width Wi, W2, Wnas well as the distance Bi, B2 between neighboring pulses Oi, O2 ... Onmay be controlled e.g. based on the peak voltage Ai, A2, Anof a pulse Oi, O2 ... Onor a prior pulse Oi, O2 ... Onor based on a voltage level at the end of the pulse Oi, O2 . . . Onor a prior pulse Oi, O2 . . . On.

[0095] For example, the pulse width Wi, W2, Wnmay be set based on an extrapolation of the progression of prior pulse peak voltages Ai, A2, An(optionally including the peak voltage of the instant pulse which has just started). The extrapolation may be performed by applying a linear or exponential extrapolation. In one embodiment, the pulse width Wi, W2, Wnis set based on a voltage decay that occurs during a pulse Oi, O2 . . . On.

[0096] Referring now to Fig. 7, the energy supply arrangement 105 may be implemented by an arrangement of energy storage devices formed by capacitors Cl to C7, which are functionally connected to an arrangement of switching devices S5 to S8. The capacitors Cl to C7 are in operative electrical connection to the energy supply 104, formed by a battery, of the generator device 10 and may be charged by the energy supply 104 in order to generate electrical pulses for emission by an electrode arrangement of one or multiple leads 11 connected to the generator device 10.

[0097] In the embodiment of Fig. 7, the capacitors Cl to C7 are connected to each other in an electrical series connection. Switching devices S5 to S8 selectively connect the capacitors Cl to C7 to an output circuit 107 formed by a so-called H bridge comprising switching devices SI to S4. R represents an effective body impedance, the switching devices SI to S4 selectively forming therapeutic current paths for emitting electrical pulses of a desired polarity into the patient’s body.

[0098] By means of the switching devices S5 to S8 the electrical voltage in particular of the defibrillation shock pulse DP may be set. If only the switching device S5 is closed, the defibrillation shock pulse DP is formed by the charge of the capacitors Cl to C4, which discharge via the electrical path formed by the closed switching device S5. The electrical pulse is fed through the H bridge, wherein either the combination of switching devices S3, S2 or the combination of switching devices S4, SI is closed in order to form an electrical pulse at a particular polarity for emission into the body of the patient. In order to set the voltage level of the electrical output pulse, either one of the switching devices S5 to S8 is closed. If the switching device S6 instead of the switching device S5 is closed, the electrical pulse is formed by discharging the combination of the capacitors Cl to C5. If instead the switching device S7 is closed, the charge of the capacitor C6 is added. If the switching device S8 is closed, the electrical pulse is formed by the combination of all capacitors Cl to C7.

[0099] By combining all capacitors Cl to C7 by closing (only) the switching device S8, a maximum voltage for the electrical pulse may be set.

[0100] In one embodiment, an output pulse for example serving as a defibrillation shock pulse DP is formed by the combination of all capacitors Cl to C7 by closing the switching device S8 (and leaving the switching devices S5 to S7 open). For forming the defibrillation shock pulse DP, herein, the capacitors Cl to C7 are charged by the energy supply 104 of the generator device 10 to such a level that the voltage of the defibrillation shock pulse DP is set to a desired level.

[0101] Herein, as visible in Fig. 7, in the electrical conduction path formed by the switch S8 a limiting circuit 106 is arranged, such that when the switch S8 is closed the current is supplied from the energy supply arrangement 105 via the limiting circuit 106 to the output circuit 107. The limiting circuit 106 herein comprises a current limiting component 120, for example including a resistance 124 and a controllable component 123, for example a switch, as explained above in accordance with the embodiments of Figs. 4 and 5. The current limiting component 120 is arranged in a first path Pl, wherein in a second path P2 in parallel to the first path Pl a switch 121 is arranged for selectively activating or deactivating the current limiting component 120. In particular, when the switch 121 is opened, current is supplied via the current limiting component 120 to the output circuit 107. If instead the switch 121 is closed, current flows predominantly via the second path P2 and hence does not flow through the current limiting component 120 to the output circuit 107. By means of the limiting circuit 106 a current as supplied from the energy supply arrangement 105 may be limited, such that an excessive pulse amplitude is avoided. For example, post-shock stimulation pulses Oi...Onmay be formed by modulation by controlling the limiting circuit 106 using the processing circuitry 102.

[0102] Referring now to Fig. 8, in another embodiment the energy supply arrangement 105 comprises energy storage devices in the shape of capacitors Cl to C7, which each may be charged with electrical energy supplied from the energy supply 104 (Fig. 2) in the shape of a battery. The pulse generation circuitry 103 in addition comprises switching devices S5-S7, which serve to selectively couple the energy storage devices Cl to C7 to an output circuit 107 in the shape of an H bridge comprising switching devices SI to S4 for selectively forming a therapeutic current path via an associated diode D1-D3 for injecting a shock pulse into a patient, represented in the schematic circuit diagram of Fig. 8 by an effective body impedance R.

[0103] In the embodiment of Fig. 8, electrical pulses may be formed by selectively switching the switching devices S5 to S7 to a closed position. Herein, if all switching devices S5 to S7 are open, an electrical pulse is formed by the combination of the capacitors Cl to C4. By closing the switching device S5, the capacitor C5 is added to the combination, such that an electrical pulse is formed by discharging the combination of the capacitors Cl to C5. By closing also the switching device S6, the capacitor C6 is added. By closing all switching devices S5 to S7, an electrical pulse of a maximum voltage level is produced from the combination of all capacitors Cl to C7 along the electrical conduction path via diode D3 towards the output circuit 107 formed by the switching devices SI to S4.

[0104] By combining all capacitors Cl to C7 by closing all switching devices S5 to S7, hence, a maximum voltage for the electrical pulse may be set. A defibrillation shock pulse DP may be formed by the combination of all capacitors Cl to C7 by closing the switching devices S5 to S7. The capacitors Cl to C7 may be charged by the energy supply 104 of the generator device 10 to such a level that the voltage of the defibrillation shock pulse DP is set to a desired level. In the embodiment of Fig. 8, a limiting circuit 106 is arranged in the conduction path linked to capacitor C7 such that, when the switch S7 is closed, current flows through the limiting circuit 106. Again, as described above in connection with the embodiment of Fig. 7, the limiting circuit 106 comprises a current limiting component 120 in a first path Pl and a switch 121 in a second path P2 in parallel to the first path Pl. By controlling the switch 121 using the processing circuitry 102 the current limiting component 120 may selectively be activated or deactivated in order to limit a current flowing to the output circuit 107 or not.

[0105] In addition, it shall be referred to the description in relation to the embodiment of Fig. 8 and the embodiments of Figs. 4 and 5.

[0106] Referring now to Fig. 9, in another embodiment the energy supply arrangement 105 and the output circuit 107 substantially matches the embodiment of Fig. 8. The embodiment of Fig. 9 however differs from the embodiment of Fig. 8 in the placement of the limiting circuit 106.

[0107] Namely, in the embodiment of Fig. 9 the limiting circuit 106 is not arranged in the path of capacitor C7 and switch S7, as in the embodiment of Fig. 8, but is arranged immediately prior to the output circuit 107. A current supplied from the energy supply arrangement 105 hence in any case, independent of whether none, some or all of the switches S5, S6 or S7 are closed, flows through the limiting circuit 106, which again comprises a current limiting component 120 in a first path Pl and a switch 121 for selectively activating or deactivating the current limiting component 120 in a second path P2 in parallel to the first path Pl.

[0108] The functionality of the limiting circuit 106 in the embodiment of Fig. 9 otherwise is the same as described above in connection with the embodiments of Figs. 4, 5, 7, and 8.

[0109] In the exemplary embodiments described above, a resistor of the limiting circuit 106 may be used as a dump resistor for draining off energy which is not used for producing post-shock stimulation pulses Oi . . . On.

[0110] For example, in the embodiment of Fig. 7 a dumping may be implemented by using a resistor implementing the current limiting component 120 as a dump resistor. For the dumping, switches S5, S6, S7 and switch 121 are switched to an open position. To perform the dumping, switch S8 is closed together with switches SI, S3 (or S2, S4).

[0111] In the embodiment of Fig. 8, a dumping is achieved by using a resistor implementing the current limiting component 120 as dump resistor. To perform the dump, the switch 121 is opened, and the switches S5, S6, S7 are closed together with switches SI, S3 (or S2, S4).

[0112] In the embodiment of Fig. 9, a dumping may be done by using a resistor implementing the current limiting component 120 as dump resistor. To perform the dump, the switch 121 is opened, and the switches S5, S6, S7 are closed together with switches SI, S3 (or S2, S4).

[0113] In the embodiment of Fig. 9, also a partial dump by dumping a remaining charge of capacitors C1-C4 only may be performed. To perform the partial dump, the switches 121, S5, S6, S7 are opened, and switches SI, S3 (or S2, S4) are closed. Subsequently, also the upper capacitors C5, C6, C7 may be dumped sequentially by sequentially closing the switches S5, S6 and S7. Herein, to prevent a reverse charging of the respective lower capacitor, the capacitors may be protected by a reverse oriented diode in parallel to the capacitor or a group of capacitors. “Reverse oriented” means that the anode of the diode is oriented towards the ground (or the normally negative charged plate of the capacitor).

[0114] The idea underlying the invention is not limited to the embodiments described above, but may be implemented in an entirely different fashion.

[0115] An implantable cardioverter defibrillator device may comprise one or multiple leads, with one or multiple electrode poles arranged on each lead. List of reference numerals

[0116] 1 Non-transvenous implantable cardioverter defibrillator device

[0117] 10 Generator device

[0118] 100 Housing

[0119] 101 Connection block

[0120] 102 Processing circuitry

[0121] 103 Pulse generation circuitry

[0122] 104 Energy supply (battery)

[0123] 105 Energy supply arrangement

[0124] 106 Limiting circuit

[0125] 107 Output circuit

[0126] 11 Electrode lead

[0127] 110 Lead body

[0128] 111 Proximal end

[0129] 112 Distal end

[0130] 113, 114 Electrode pole

[0131] 115 Shock electrode (coil)

[0132] 120 Current limiting component

[0133] 121 Switch device

[0134] 122 Circuit component

[0135] 123 Controllable component

[0136] 124 Resistance

[0137] 2 External device

[0138] A-D Reception vector

[0139] Ai ... AnAmplitude

[0140] Bi, B2 Distance

[0141] C1-C7 Capacitors

[0142] D1-D3 Diode

[0143] DP Defibrillation shock pulse

[0144] H Heart 01. . On Post-shock stimulation pulses

[0145] Pl, P2 Conducting path

[0146] PS Post-shock stimulation

[0147] R Resistance S1-S8 Switches

[0148] Tl, T2 Terminal

[0149] Wl, W2, Wn Pulse width

Claims

Claims1. An implantable cardioverter defibrillator device (1), comprising a generator device (10) comprising a processing circuitry (102) and a pulse generation circuitry (103); and at least one lead (11) comprising an electrode pole arrangement including a shock electrode (115) for emitting a defibrillation shock pulse (DP); wherein said pulse generation circuitry (103) comprises an energy supply arrangement (105) containing at least one energy storage device (C1-C7) which is dischargeable to form said defibrillation shock pulse (DP), and an output circuit (107) for outputting said defibrillation shock pulse (DP) to the shock electrode (115) of the electrode pole arrangement; characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to produce said defibrillation shock pulse (DP) based on a discharging of said at least one energy storage device (C1-C7) and to generate, subsequent to the generation of said defibrillation shock pulse (DP), a sequence of post-shock stimulation pulses (Oi.. On) based on a residual energy stored in said at least one energy storage device (C1-C7) subsequent to the generation of said defibrillation shock pulse (DP).

2. The implantable cardioverter defibrillator device (1) according to claim 1, characterized in that the output circuit (107) is configured to output the sequence of post-shock stimulation pulses (Oi.. On) to the shock electrode (115) or to at least one other electrode pole (113, 114) of said electrode pole arrangement for emitting the sequence of post-shock stimulation pulses (Oi.. On).

3. The implantable cardioverter defibrillator device (1) according to claim 1 or 2, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to generate the sequence of post-shock stimulation pulses (Oi . . . On) at a rate in between 20 bpm and 100 bpm, in particular 30 bpm and 60 bpm.

4. The implantable cardioverter defibrillator device (1) according to one of claims 1 to 3, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to generate the sequence of post-shock stimulation pulses (Oi... On) for a maximum duration smaller than 5 minutes, preferably smaller than 2 minutes.

5. The implantable cardioverter defibrillator device (1) according to one of the preceding claims, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to terminate said defibrillation shock pulse (DP) based on a discharging level of the at least one energy storage device (C1-C7).

6. The implantable cardioverter defibrillator device (1) according to claim 5, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to terminate said defibrillation shock pulse (DP) if an output voltage of the at least one energy storage device (C1-C7) becomes smaller than a predefined termination threshold.

7. The implantable cardioverter defibrillator device (1) according to claim 6, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to generate the post-shock stimulation pulses (Oi...On) of said sequence of post-shock stimulation pulses (Oi.. On) at a voltage amplitude equal to or smaller than said output voltage of the at least one energy storage device (C1-C7) at the time of terminating said defibrillation shock pulse (DP).

8. The implantable cardioverter defibrillator device (1) according to one of the preceding claims, characterized in that said processing circuitry (102) is configured to control the pulse generation circuitry (103) to generate the post-shock stimulation pulses (Oi... On) of said sequence of post-shock stimulation pulses (Oi...On) at a varying amplitude (Ai . . . An) and / or pulse width (W i . . . Wn).

9. The implantable cardioverter defibrillator device (1) according to one of the preceding claims, characterized in that said pulse generation circuitry (103) comprises a limitingcircuit (106) arranged electrically in between the energy supply arrangement (105) and the output circuit (107) and configured to limit a current and / or voltage of said sequence of post-shock stimulation pulses (Oi.. On).

10. The implantable cardioverter defibrillator device (1) according to claim 9, characterized in that the limiting circuit (106) is a limiting circuit arranged electrically in between the energy supply arrangement (105) and the output circuit (107) such that a current supplied from the energy supply arrangement (105) flows through the limiting circuit (106) towards the output circuit (107), wherein said limiting circuit (106) comprises at least one current limiting component (120), wherein the limiting circuit (106) is controllable by the processing circuitry (102) to modulate a current flowing through the limiting circuit (106).

11. The implantable cardioverter defibrillator device (1) according to claim 10, characterized in that the at least one current limiting component (120) comprises a resistance (124), an inductance, or a semiconductor component.

12. The implantable cardioverter defibrillator device (1) according to one of claims 9 to11, characterized in that said processing circuitry (102) is configured to control the limiting circuit (106) to modulate said current flowing through the limiting circuit (106) to generate said sequence of post-shock stimulation pulses (Oi...On) according to a modulation scheme.

13. The implantable cardioverter defibrillator device (1) according to one of claims 9 to12, characterized in that said processing circuitry (102) is configured to control the limiting circuit (106) to set an effective voltage level of said sequence of post-shock stimulation pulses (Oi . . . On) using a pulse width modulation.

14. The implantable cardioverter defibrillator device (1) according to one of the preceding claims, characterized in that the energy supply arrangement (105) comprises a multiplicity of energy storage devices (C1-C7) functionally connected to at least one switching device (S5-S8), wherein the processing circuitry (102) is configured tocontrol the at least one switching device (S5-S8) to supply energy for generating said defibrillation pulse (DP) and said post-shock stimulation pulses (Oi.. On) using all of said multiplicity of energy storage devices (C1-C7) or a combination of some of said multiplicity of energy storage devices (C1-C7).

15. A method for operating an implantable cardioverter defibrillator device (1), said implantable cardioverter defibrillator device (1) comprising a generator device (10) and at least one lead (11) comprising an electrode pole arrangement including a shock electrode (115) for emitting a defibrillation shock pulse (DP), the method comprising: generating, by controlling a pulse generation circuitry (103) of the generator device (10) using a processing circuitry (102) of the generator device (10), said defibrillation shock pulse (DP) based on a discharging of at least one energy storage device (C1-C7) of an energy supply arrangement (105) of the pulse generation circuitry (103); and outputting, using an output circuit (107) of the pulse generation circuitry (103), said defibrillation shock pulse (DP) to the shock electrode (115) of the electrode pole arrangement; characterized by generating, by controlling the pulse generation circuitry (103) using the processing circuitry (102), a sequence of post-shock stimulation pulses (Oi... On) subsequent to the generation of said defibrillation shock pulse (DP) based on a residual energy stored in said at least one energy storage device (C1-C7) subsequent to the generation of said defibrillation shock pulse (DP).

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