Implantable pulse generator having rectangular shock waveform

Abstract

To provide an implantable pulse generator comprising an electric circuit.SOLUTION: The electric circuit comprises: a primary energy storage means, at least one secondary energy storage means, and a control unit, where the control unit is configured to activate an electric switch in the electric circuit such that, in a first interval of a first phase of a pulse delivery, the primary energy storage means is discharged via a therapeutic current path, where the electric switch in the electric circuit is activated such that the primary energy storage means and the at least one secondary energy storage means are fixedly connected in series, and where the implantable pulse generator delivers a shock having an approximately rectangular pulse waveform.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to an implantable pulse generator.

[0002] Currently, all implantable cardioverter defibrillators (ICDs) use a capacitor discharge technique, which derives the entire shock energy from a fixed capacitance during defibrillation and is characterized by an exponentially decaying voltage waveform.

[0003] Shock waveforms that minimize shock voltage are already being used in external defibrillators.

[0004] The drawback of the exponential shock waveform is the high peak voltage required for effective defibrillation, especially for non-intravenous defibrillators (subcutaneous ICDS such as the S-ICD™), which can exceed 1300V, requiring appropriate high-voltage components and compliance with design rules. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an implantable pulse generator that can deliver a shock with a high therapeutic effect at a lower shock voltage. [Means for solving the problem]

[0006] This object is achieved by an implantable pulse generator having the features of claim 1 and by a method having the features of claim 11. Suitable embodiments are set out in the dependent claims and the following description.

[0007] According to claim 1, there is provided an implantable pulse generator comprising an electrical circuit, the electrical circuit comprising: a primary energy storage means; at least one secondary energy storage means; a control unit; The control unit activating an electrical switch in the electrical circuit to discharge the primary energy storage means through the therapeutic current pathway during a first interval of the first stage of pulse delivery; configured to activate an electrical switch in the electrical circuit during a second interval of the first stage of pulse delivery such that the at least one secondary energy storage means is discharged through the therapeutic current path; the primary energy storage means and at least one secondary energy storage means are fixedly connected or connectable in series; the implantable pulse generator is configured to deliver a shock having a generally rectangular pulse waveform; the implantable pulse generator comprises a plurality of secondary energy storage means; The control unit, in the second interval: so that the primary energy storage means and all of said secondary energy storage means are sequentially discharged through the therapeutic current pathway; or the primary energy storage means and any of the plurality of secondary energy storage means are discharged via the therapeutic current path; It is further configured to activate an electrical switch in the electrical circuit.

[0008] In particular, the therapeutic current pathway is used to deliver therapeutic electrical pulses to target tissue, preferably cardiac tissue of a patient, preferably to deliver therapeutic electrical shocks for defibrillation of the cardiac tissue.

[0009] Furthermore, in particular the primary energy storage means and the at least one secondary energy storage means are discharged through the therapeutic current path during a second interval of the first stage of pulse delivery.

[0010] Advantageously, the pulse generator according to the present invention achieves shock delivery having a generally rectangular pulse waveform, and in particular, achieves a substantially rectangular voltage or current waveform during pulse delivery. In this way, it is possible to deliver a therapeutically effective (defibrillation) pulse for a defined time while reducing the maximum required shock voltage. Advantageously, the approach according to the present invention allows for more cost-effective designs for implantable cardioverter-defibrillators and the use of existing high-voltage components and platforms, particularly by reducing the maximum required shock voltage.

[0011] The implantable pulse generator according to the invention is therefore particularly suitable for use as a defibrillator, and the electrical circuit according to the invention makes it possible to realize therapeutic voltages of up to 1200 V with the rectangular pulse waveforms described above. In this way, the pulse generator according to the invention can be arranged as one electrode pole and the end of the electrode lead connected to the pulse generator as the other electrode pole, located outside the patient's thorax (subcutaneous ICD). Due to the more compact design possible, a pulse generator configured as a subcutaneous ICD can advantageously be no larger than 70 cm. 3 It has the following volume

[0012] Of course, a pulse generator according to the present invention can achieve a lower treatment voltage, e.g., 600 V, which would allow it to be used as a conventional ICD with the electrode lead ends located intrathoracically and the pulse generator located extrathoracically. Such a lower treatment voltage can be achieved with a smaller energy storage means. Because of the more compact design possible, a pulse generator configured as a conventional ICD can be as small as 35 cm. 3 It can have the following volumes:

[0013] The pulse generator according to the invention can also be used in ICDs in which both the end of the electrode lead and the pulse generator are located in the thorax. In this case, a therapeutic voltage of about 550 V is preferably used, which can be achieved with a pulse generator according to the invention that comprises a smaller energy storage means, in particular a 35 cm 2The following device volumes can be achieved:

[0014] One embodiment of the implantable pulse generator according to the invention provides that the primary energy storage means and the at least one secondary energy storage means are connected in series, in particular fixedly or permanently, i.e., said energy storage means are not disconnected by a switch. As a result of this fixed series connection, the electric circuit according to the invention is advantageously less prone to faults.

[0015] According to an alternative embodiment of the implantable pulse generator of the present invention, it is provided that the primary energy storage means and at least one secondary energy storage means can be connected in series.

[0016] According to an embodiment of the implantable pulse generator according to the invention, it is provided that the activation for the discharge of the at least one secondary energy storage means is performed in a time-controlled or signal-controlled manner.

[0017] This control signal may be derived in-process from analysis of one or more measured voltages or currents measured directly in the energy storage means or in the delivered pulse, for example in the therapeutic current path.

[0018] Thus, according to one embodiment of the implantable pulse generator according to the invention, a device for voltage monitoring is included, which device is particularly configured to determine the voltage of each of the energy storage means of the implantable pulse generator according to the invention, preferably continuously or at predefined intervals.

[0019] The device for voltage monitoring is preferably further configured to send a first signal to the control unit when the voltage of one of the energy storage means of the implantable pulse generator according to the invention falls below a predefined threshold, the first signal advantageously being able to trigger the discharge of further energy storage means via the therapeutic current path.

[0020] The voltage monitoring device is preferably also configured to send a second signal to the control unit if the voltage of one of the energy storage means of the implantable pulse generator according to the present invention does not fall below a predetermined threshold within a predetermined time. The second signal can advantageously inhibit further discharge of the energy storage means through the therapeutic current path. In this design, the voltage monitoring device and the control unit can implement an overvoltage protection system, particularly for the electrical circuit according to the present invention. The presence of a load (voltage drop) or absence of a load (no voltage drop) in the therapeutic current path is established by the voltage measurement. If no load is detected, no further discharge of the energy storage through the therapeutic current path occurs, thereby preventing, for example, a further voltage increase in the therapeutic current path.

[0021] According to a further embodiment, the implantable pulse generator according to the invention comprises a device for measuring the impedance of the surrounding tissue (body tissue). The device for impedance measurement is preferably configured to determine the resistance causing the discharge (observed by a voltage drop) from the voltage ascertained after the start of discharge of the primary energy storage means and / or at least one secondary energy storage means. The voltage can be the treatment voltage, the voltage of an individual energy storage means, or any voltage in the electrical circuit according to the invention. The voltage can be ascertained during the process by the aforementioned device for voltage monitoring.

[0022] According to a further embodiment of the implantable pulse generator according to the invention, it is provided that the time point for the start of the second interval of the first stage is determined from the discharge behavior of the primary energy storage means and / or at least one secondary energy storage means, said time point being selected such that the voltage of a particular energy storage means does not fall below a predetermined threshold, for example 80% of the output voltage.

[0023] A further embodiment of the implantable pulse generator according to the invention provides that the electrical circuit comprises a plurality of secondary energy storage means, and the control unit is configured to operate one or more electrical switches of the electrical circuit during the second interval of the first stage of pulse delivery such that the secondary energy storage means are discharged sequentially or in sequence via the therapeutic current path.

[0024] A further embodiment of the implantable pulse generator according to the invention provides that the primary energy storage means and the plurality of secondary energy storage means are connected in series, in particular fixedly or permanently, i.e. in particular without disconnectable switches between the energy storage means.

[0025] According to an alternative embodiment of the implantable pulse generator of the present invention, it is provided that the primary energy storage means and each of the plurality of secondary energy storage means can be connected in series, and in particular the secondary energy storage means can be connected in parallel.

[0026] In particular, the multiple secondary energy storage means may have essentially the same capacity (i.e., within a tolerance of 20% or less) and / or nominal voltage (i.e., within a tolerance of 10% or less), or may have different capacities and / or nominal voltages. Where there are multiple secondary energy storage means, in each case these are preferably of the same or identical type.

[0027] According to a further embodiment of the implantable pulse generator according to the invention, it is provided that in each case one of the secondary energy storage means is discharged (alternately or all in turn) for a second interval at each time point via the therapeutic current path. Again, each time point is preferably selected so that the voltage of a particular energy storage means does not fall below a predetermined threshold, for example 80% of the output voltage. Similarly, each time point may be selected so that the therapeutic voltage does not fall by more than 20% of the maximum or output voltage.

[0028] The secondary energy storage means in the therapeutic current path is preferably discharged so that the actual pulse waveform (therapeutic voltage / current peaks) varies by no more than 50%, preferably no more than 20%, from the desired ideal rectangular pulse waveform. Such variations, also known as ripple, are manifested as spikes in the voltage waveform.

[0029] As previously mentioned, fluctuations (ripple) can be maintained within the aforementioned boundaries by voltage monitoring, where the exponential partial discharge voltage drop of a particular energy storage means is observed. When the voltage falls below a predefined threshold, charging of another energy storage means is invoked, causing the treatment voltage to rise to the desired maximum voltage and then fall again as the other energy storage means discharges. This is also manifested by additional spikes, or ripples, in the voltage waveform.

[0030] Also, the ripple, or variation, can be controlled in a time-controlled manner as described above. The last secondary energy storage means to which charge is called is preferably discharged until polarity reversal in a biphasic shock (the last spike of the therapy voltage "decays" until polarity reversal of the shock).

[0031] The time to switch to the next energy storage means can be known, for example, from the exponential law of the discharge of the energy storage means, with a known time constant, a known capacitance C, and a resistance R determined as described above such that the charge on the activated energy storage means is equal to the first polarity (+ / - 20%).

[0032] The variation (ripple) from the ideal pulse waveform can be controlled so that the treatment voltage is essentially (±20%) the same voltage, i.e., the peak of the ripple is at the same level (±20%), each time switching to the next storage device.

[0033] Alternatively, variations from the ideal pulse waveform can be monitored so that the treatment voltage is reduced (eg, by up to 20% each time) each time the next energy storage means is switched on.

[0034] The control of the above fluctuations can be time controlled or voltage controlled as described above.

[0035] According to a further embodiment of the implantable pulse generator of the present invention, it is provided that the control unit is further configured to operate at least one electrical switch of the electrical circuit, preferably multiple switches of a bridge circuit (H-bridge), during the second phase of pulse delivery so that the direction of the current in the therapeutic current path is reversed. In this way, a steep voltage drop of the pulse at the end of the first phase can be advantageously realized, generating a biphasic therapeutic pulse. Furthermore, regions of the target tissue that were not sufficiently stimulated during the first phase can be advantageously stimulated during the second phase. At the same time, charge equalization can be advantageously achieved in the target tissue, preferably cardiac tissue.

[0036] According to a further embodiment of the implantable pulse generator according to the invention, the control unit further comprises, during the second phase of pulse delivery: activating an electrical switch in the electrical circuit such that the primary energy storage means is discharged through the therapeutic current pathway; or activating an electrical switch in the electrical circuit so that the primary energy storage means and the secondary energy storage means are discharged through the therapeutic current path; The provided configuration is as follows:

[0037] According to an alternative embodiment of the implantable pulse generator according to the invention, it is provided that the control unit is further configured to operate one or more electrical switches at the end of the first phase of pulse delivery such that the primary and / or secondary energy storage means or means are disconnected from the treatment current path and / or discharged across one or more bleeder resistors connected thereto. Advantageously, a steep voltage drop in the pulse at the end of the first phase can also be achieved in this embodiment, generating a monophasic pulse in the process.

[0038] A further embodiment of the implantable pulse generator according to the invention provides that the primary energy storage means comprises a plurality of individual energy storage means connected in series or in parallel, the number of which is preferably adapted to the required or desired charging capacity. The primary energy storage means preferably comprises at least two individual energy storage means, preferably three individual energy storage means.

[0039] According to a further embodiment of the implantable pulse generator according to the invention it is provided that the individual energy storage means of the primary energy storage means are fixedly connected in series.

[0040] In particular, the individual energy storage means of the primary energy storage means may have essentially the same capacity (i.e., within a tolerance of 20% or less) and / or nominal voltage (i.e., within a tolerance of 10% or less), or may have different capacities and / or nominal voltages.

[0041] According to a further embodiment of the implantable pulse generator according to the invention, the switches of the electric circuit are electronic or semiconductor switches, in particular selected from Insulated-Gate Bipolar Transistors (IGBTs), Anode-Gated Thyristors (AGTs) or a combination of the aforementioned electronic switches.

[0042] According to a further embodiment of the implantable pulse generator of the present invention, it is provided that at least one of the aforementioned switches is electrically connected to a diode, the diode being arranged between one of the energy storage means and the switch. The diode is preferably configured to block current flow in the direction of the energy storage means. A diode is preferably arranged between each switch and the associated energy source, except for the switch from which the last secondary energy source is discharged via the therapeutic current path. Again, each diode is preferably configured to block current flow in the direction of a particular energy storage means. In this way, the switches are advantageously protected against polarity reversal.

[0043] According to a further embodiment of the implantable pulse generator according to the invention it is provided that the plurality of secondary energy storage means consists of two to four secondary energy storage means, preferably three secondary energy storage means.

[0044] An embodiment of the implantable pulse generator according to the invention provides that the energy storage means is a capacitor or a coil. The plurality of energy storage means, e.g., the plurality of secondary energy storage means, may be formed by a capacitor in the process, which comprises a plurality of capacitances, e.g., formed by a plurality of anodes, each of which can be discharged separately.

[0045] According to a further embodiment of the implantable pulse generator according to the invention, it is accordingly provided that the plurality of secondary energy storage means are formed by capacitors comprising at least one first electrode with a first polarity and at least two second electrodes with a second polarity, the first electrode and the at least two second electrodes being each separately electrically contactable from outside the capacitor.

[0046] According to a further embodiment of the implantable pulse generator of the present invention, the primary energy storage means and / or the secondary energy storage means, or the energy storage means, is a capacitor including at least one cathode and at least two anodes, preferably three anodes, each of which can be electrically contacted separately from the outside of the capacitor. The capacitor preferably comprises a conductive housing in which the cathode and the anode are disposed, the housing being electrically connected to the cathode, and the anodes being electrically contactable from the outside of the capacitor or via at least one electrical feedthrough from the capacitor housing. The cathodes are preferably formed by an electrolyte, and the anodes are preferably formed by a valve metal, preferably aluminum, tantalum, or niobium. In particular, each of the anodes can form a dedicated capacitance with the cathode (electrolyte), which preferably ranges from 200 μF to 300 μF, and in particular is approximately 241 μF.

[0047] A further embodiment of the implantable pulse generator according to the invention provides that the electrical circuit comprises primary energy storage means consisting of three of the multi-electrode capacitors described in the preceding paragraph, and secondary energy storage means formed by the capacitors described in the preceding paragraph. In particular, the capacitors configured as secondary energy storage means have at least two, preferably three, anodes which can be individually electrically contacted from the outside of the capacitor, thereby forming at least two, preferably three, capacitances which can be individually discharged.

[0048] According to a further embodiment of the implantable pulse generator according to the invention, the capacitor forming the primary energy storage means, the individual energy storage means or one of the aforementioned secondary energy storage means, or the capacitor is an electrolytic capacitor or a ceramic capacitor or a film capacitor, preferably an aluminium or tantalum electrolytic capacitor, preferably having a capacitance of at least 5 J*cm 3 It is provided that the energy density is

[0049] According to one embodiment of the energy storage means according to the invention, the following is provided: the primary energy storage means has a capacitance in the range of 150 μF to 300 μF and / or a nominal voltage in the range of 250 V to 300 V; and / or The secondary energy storage means each independently have a capacitance between 180µF and 36µF and / or a nominal voltage between 250V and 255V.

[0050] Where the primary energy storage means is formed from a plurality of individual energy storage means, for example two or three, the primary energy storage means preferably has an overall capacitance in the range 150µF to 300µF.

[0051] According to claim 11, there is provided a method for delivering electrical pulses having a substantially rectangular pulse waveform, the method comprising: connecting a charged primary energy storage means to a discharge current path during a first interval of a first stage of pulsing; connecting at least one charged secondary energy storage means to the discharge current path during a second interval of the first stage of the pulse delivery; a primary energy storage means and at least one secondary energy storage means being fixedly connected or connectable in series; Including, during a second interval, the primary energy storage means and, in turn, all secondary energy storage means are discharged via the therapeutic current path; or The primary energy storage means and any of the plurality of secondary energy storage means are discharged through the therapeutic current pathway.

[0052] The method according to the invention can advantageously be implemented using an implantable pulse generator according to the invention as defined in claim 1 or one of the embodiments described above.

[0053] According to one embodiment of the method according to the invention, it is provided that the charged primary energy storage means and the at least one charged secondary energy storage means are fixedly connected in series, i.e. are not disconnected, in particular by a switch.

[0054] According to an alternative embodiment of the method according to the invention, it is provided that the charged primary energy storage means and at least one charged secondary energy storage means can be connected in series.

[0055] According to one embodiment of the method according to the invention, it is provided that the connection of the at least one secondary energy storage means to the discharge current path is signal-controlled or time-controlled.

[0056] According to an embodiment of the method according to the invention, it is provided that in the second interval of the first stage of pulse delivery a plurality of charged secondary energy storage means are connected sequentially or in sequence to the discharge current path.

[0057] According to an embodiment of the method according to the invention, it is provided that the charged primary energy storage means and the plurality of charged secondary energy storage means are fixedly connected in series, i.e. are not disconnected, in particular by a switch.

[0058] An alternative embodiment of the method according to the invention provides that a charged primary energy storage means and a plurality of charged secondary energy storage means can be connected in series.

[0059] According to one embodiment of the method according to the invention, it is provided that only one charged secondary energy storage means is connected to the discharge current path at a time, in particular that several charged secondary energy storage means are connected to the discharge current path in turn in each case. This can be achieved in particular by an electric circuit in which the secondary energy storage means are connected in parallel with each other. In this way, only one secondary energy storage means and one primary energy storage means are connected to the discharge current path at a time.

[0060] According to one embodiment of the method according to the invention, it is provided that a plurality of charged secondary energy storage means are connected in series to the discharge current path, in particular that all secondary energy storage means are connected in series to the discharge current path. This can be realized in particular by an electric circuit in which the primary energy storage means and the secondary energy storage means are respectively connected in series. In this way, the primary energy storage means, the first secondary energy storage means and all further secondary energy storage means are connected in series to the discharge current path in series.

[0061] According to a further embodiment of the method according to the invention, it is provided that the connection of the primary energy storage means with the at least one secondary energy storage means or with a plurality of secondary energy storage means is in each case effected in particular by means of an electronic switch.

[0062] A further embodiment of the method according to the invention provides that in the second stage of pulse delivery the direction of the current in the current path is reversed, which can advantageously be achieved by means of a bridge circuit.

[0063] According to a further embodiment of the method according to the invention, it is provided that in the second stage of pulse delivery: Only the primary energy storage means is connected to the discharge current path, or The primary energy storage means and the secondary energy storage means are connected to the discharge current path.

[0064] Further features and advantages of the invention will be explained below on the basis of the description of the figures of exemplary embodiments. [Brief explanation of the drawings]

[0065] [Figure 1] Figure 1 shows various implantable cardioverter-defibrillator shock waveforms and their effects on the transmembrane voltage of cardiac myocytes. [Figure 2A]FIG. 2A shows an embodiment of a circuit according to the invention consisting of primary and secondary energy storage means connectable in series. [Figure 2B] Figure 2B shows the voltage waveforms associated with the treatment voltage and energy deposition (top) and their effect on the transmembrane voltage of cardiomyocytes (bottom). [Figure 2C] FIG. 2C shows a detailed representation of the embodiment shown in FIG. 2A. [Figure 3A] FIG. 3A shows an alternative embodiment of a circuit according to the invention, consisting of a primary energy storage means connectable in series and a secondary energy storage means connectable in parallel. [Figure 3B] Figure 3B shows the voltage waveforms associated with the treatment voltage and energy deposition (top) and their effect on the transmembrane voltage of cardiomyocytes (bottom). [Figure 4] FIG. 4 shows another embodiment of a circuit according to the invention, which uses a capacitor with multiple externally accessible anodes. DETAILED DESCRIPTION OF THE INVENTION

[0066] Figure 1 shows the current state of the art shock waveform (top graph, blue) for implantable cardioverter-defibrillators (applicable to both transvenous and subcutaneous ICDs). The treatment voltage essentially results from the discharge of a single capacitor, resulting in an exponential decay. This has the drawback of requiring a much higher starting voltage to achieve the same effect on the heart. For comparison, an ideal shock waveform with a rectangular first phase (red) and the shock waveform of our approach, which approximates a rectangular waveform, are shown.

[0067] FIG. 2A shows a preferred embodiment of the circuit according to the present invention, in which the energy storage means C1-C6 are capacitors connected or connectable in series. Capacitors C1-C3, which form the primary energy storage means according to the present invention, can also be implemented as capacitance C0. All capacitors C1-C6 can essentially be charged simultaneously by a charging circuit. To perform therapy, switches S1-S4 are switched in ascending order. Switch i is reopened in this process before switch i+1 is closed. This circuit further feeds an H-bridge (not shown) for generating the second phase. In the second phase, one of the switches (preferably S4) is closed. Instead of switch S4, a diode blocking the current in the direction C0 / C4 can also be placed. FIG. 2B shows the voltage waveform of the therapeutic voltage (blue) that can be achieved with this electrical circuit and the corresponding effect on the transmembrane voltage of the cardiomyocytes, shown in the upper diagram for capacitors C0 (red), C4 (yellow), C5 (purple), and C6 (green), and in the lower diagram. The primary energy storage means C0 formed by the three individual energy storage means C1 to C3 preferably has an overall capacitance in the range of 150 μF to 300 μF, and the secondary energy storage means C4 to C6 each preferably have a capacitance in the range of 180 μF to 360 μF.

[0068] FIG. 2C shows the energy storage means C of the pulse generator according to the invention. 61The embodiment shown in Figure 2A is comprised of an electronic switch and up to six capacitors, designated by symbols C through C. Three of these capacitors, C1, C2, and C3, ensure a sufficiently high starting voltage, while the remaining three, C4, C5, and C6, generate the desired roughly rectangular pulse waveform (sawtooth curve), though in this embodiment, up to four spikes may be present. To make the shock biphasic, a conventional H circuit consisting of electronic switches (IGBTs) Q05 through Q08 is used. This circuit is powered by electronic switches (IGBTs) Q01 through Q04, which activate capacitors C4, C5, and C6. Note that IGBTs Q02 through Q04 are preferably protected from polarity reversal by diodes D7 through D9. The shock is delivered to the body via terminals HV1 and HV2. The capacitors are charged via a high-voltage source connected to HVin and ground.

[0069] FIG. 3A shows a further preferred embodiment of the electrical circuit according to the present invention, comprising capacitors C1-C6 as energy storage means, where activated or activatable energy storage means C4-C6 are connected or connectable in parallel, respectively. Capacitors C1-C3 can also be implemented here as capacitance C0. Essentially, all capacitors are simultaneously charged by a charging circuit. Switches S1-S4 are switched in ascending order to perform treatment. Switch i is then reopened before switch i+1 is closed. This circuit then feeds into an H-bridge to generate a second phase. In the second phase, one of the switches (preferably S1) is closed. FIG. 3B shows, in the upper diagram, the electrical circuit and the voltage waveforms of the treatment voltage (blue) achievable with capacitors C0 (red), C4 (yellow), C5 (purple), and C6 (green), and, in the lower diagram, the corresponding effect on the transmembrane voltage of the cardiomyocytes.

[0070] 4 shows a preferred embodiment of an electric circuit according to the invention, using a parallel approach with capacitors consisting of primary energy storage means C0, C1, C2, C3 and multiple secondary energy storage means C4-C6. In particular, the process uses capacitors each consisting of a cathode K and, for example, three anodes A1, A2, A3, where the cathode K is advantageously externally accessible via a conductive housing, and the anodes are each separately externally accessible and are also electrically insulated from the housing G, for example, via feedthroughs D1, D2, D3. The multiple secondary energy storage means according to the invention are thus implemented as capacitors, providing three capacitances that can each be separately discharged using the three separately accessible anodes A1, A2, A3.

[0071] However, it is also conceivable that the capacitors C1-C3 forming the primary energy storage means according to the present invention may be designed such that the anodes A1, A2, A3 are electrically connected inside the housing G and can be electrically contacted from the outside via a shared anode wire routed to the outside, for example via a feedthrough.

Claims

[Claim 1] 1. An implantable pulse generator comprising an electrical circuit, Primary energy storage means (C ０ , C １ , C ２ , C ３ )and, at least one secondary energy storage means (C ４ , C ５ , C ６ )and, a control unit; Equipped with The control unit During a first interval of a first stage of pulse delivery, the primary energy storage means (C ０ , C １ , C ２ , C ３ ) in the electrical circuit so that it is discharged. １ , Q04) is activated, During the second interval of the first stage of the pulse delivery, the primary energy storage means (C ０ , C １ , C ２ , C ３ ) and said at least one secondary energy storage means (C ４ , C ５ , C ６ ) in the electrical circuit so that the therapeutic current is discharged through the therapeutic current path. ２ , S ３ , S ４ , Q03, Q02, Q01), The primary energy storage means (C ０ , C １ , C ２ , C ３ ) and said at least one secondary energy storage means (C ４ , C ５ , C ６ ) are fixedly connected or connectable in series, the implantable pulse generator is configured to deliver a shock having a generally rectangular pulse waveform; The implantable pulse generator comprises a plurality of secondary energy storage means (C ４ , C ５ , C ６ ) and The control unit, in the second interval, The primary energy storage means (C ０ , C １ , C ２ , C ３ ) and all of the secondary energy storage means (C4, C5, C6) are sequentially discharged through the therapeutic current path, or The primary energy storage means (C ０ , C １ , C ２ , C ３ ) and the plurality of secondary energy storage means (C ４ , C ５ , C ６ ) is discharged through the therapeutic current pathway, The implantable pulse generator is further configured to operate the electrical switches (S2, S3, S4) of said electrical circuit.

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