pacemaker

Abstract

The invention relates to a leadless endocardial or intravascular pacemaker. It has a housing (1) with an anchoring device (2). Located in the housing are a sensor unit (3), a control unit (4), a stimulation pulse generator (5), a pulse emitter (6), and an energy storage unit (7). Furthermore, the leadless endocardial or intravascular pacemaker is configured for communication with an external unit (8). The leadless endocardial or intravascular pacemaker is characterized in that more than 50% of the capacity of the energy storage unit (7) is available for generating the pulses in the stimulation pulse generator (5).

Description

The invention relates to a probeless endocardial or intravascular pacemaker, which is characterized in that it comprises in a housing with anchoring unit a sensor unit, a control unit, a stimulation pulse generator, a pulse transmitter and an energy storage unit. The pacemaker is configured for communication with an external unit.The first pacemaker, fully and permanently embedded in the human body, was implanted in 1958. The pacemaker concept developed then consists of a major component, also called "aggregate", which is implanted infra-clavicularly in a pocket. This unit contains a battery, a control unit and the connectors for probes. These probes are advanced via venous accesses to the right heart and anchored there in the right atrium and or in the right ventricle. The probes serve both as sensors to detect the heart action and as electrodes to deliver the pulse generated by the pulse generator of the control unit to the myocardium. This basic concept was developed further in the following years by a multiplicity of improvements, but in principle remained unchanged.The problem zones of this conventional pacemaker therapy are hematomes and infections in the region of the "aggregate" and dislocations, fractures and infections in the region of the probes.To counteract these weaknesses, the development of the probeless pacemakers occurred at the beginning of the 21st century.EP 1 714 670 A1 describes a probeless endocardial or intravascular pacemaker having a sealed housing. A battery and a pacemaker control connected to the battery and a stimulation pulse generator are arranged in this housing. Furthermore, the pacemaker described therein is characterized in that the housing is elongated and has a length of less than 70 mm and a cross-sectional area of less than 100 mm 2. It carries at least two electrodes, each directed outwards and having an electrically conductive surface. The electrodes are therefore designed as stimulation electrodes. They are electrically connected at least temporarily to the stimulation pulse generator via an electrical connection arranged in the interior of the housing.The essential development of this pacemaker concept according to EP 1 714 670 A1 consists in accommodating all the components of a conventional pacemaker, except for the probes and the connectors, in a single, hermetically sealed housing. This miniaturization of the pacemaker, achieved by miniaturization of the components, makes it possible to implant it completely in the right heart.The first probeless endocardial pacemaker was deployed to a patient in 2013.In the next few years, the concept of the probeless endocardial pacemaker has been further improved by a variety of developments. Currently, about one million of these pacemaker types are implanted worldwide, demonstrating the success of this new therapy. However, the concept of the probeless endocardial pacemaker has deficiencies which can be overcome by further developments.The essential limitation of currently implantable probeless endocardial or intravascular pacemakers is primarily the limited battery capacity available.Since probeless endocardial pacemakers are advanced via veins into the right heart and anchored there, the dimensions of the pacemaker housing cannot be increased as desired, for example in order to use a larger energy storage unit / battery with correspondingly higher capacity. Therefore, a longer operating time of the probeless endocardial pacemaker, besides an increase in the energy storage density of lithium-ion batteries, can only be achieved by a more effective utilization of the battery capacity present.A longer battery life is of importance in particular in the case of intracardially or intravascularly implanted probeless heart pacemakers, since the recovery of an implant with a depleted energy storage unit / battery is associated with certain risks. This risk increases with increasing duration of retention of the implant in the patient's body, since as a rule the entire housing of the implanted pacemaker overwax from the endothelium of the heart over the course of time and the implant is therefore as a rule encapsulated right in the myocardium.Furthermore, approximately 20% of patients supplied with a probeless endocardial pacemaker develop cardiomyopathies which can lead to heart failure because of the unphysiological ventricular stimulation situation in the right ventricle. Therefore, stimulation utilizing portions of the natural conduction system of the heart is desirable (so-called conduction system pacing). Direct HIS burst stimulation is considered to be the "most ideal" method of ventricular stimulation by a pacemaker. However, the electrical pulse required for this requires more energy than the direct ventricular stimulation, as a result of which the energy storage unit / battery present in the pacemaker is loaded more heavily.In current probeless endocardial pacemakers, half of the battery capacity (typically 120 mA) is consumed by the cardiac activity sensing sensor, the control unit and the pacing pulse generator. The remaining 50% are delivered as impulse energy to the myocardium via the electrode.It is an object of the invention to provide a probeless endocardial or intravascular pacemaker which makes more effective use of the capacity of the energy storage unit incorporated in the pacemaker housing. The function duration is thus to be extended. The aim is, depending on the age of the patient and the time of implantation, to achieve transit times which make it superfluous to recover an endocardially implanted pacemaker with the energy storage unit used. It is a further object of the invention to provide a pacemaker which can generate a stronger pulse via the stimulation pulse generator. The aim is to enable physiological stimulation of the heart via the HIS bundle. By using the invention in this way, the cardiomyopathies which are to be expected-in the case of non-physiological pulse positioning-can be reduced or even completely avoided.This object is achieved according to the invention in that more than 50% of the capacity of the energy storage unit is available for generating the pulses in the stimulation pulse generator.It follows from this that less than 50% of the capacity of the energy storage unit is required for the energy consumption of the control unit, of the sensor and of the preprocessing unit and of the post-processing unit.In conventional probeless endocardial or intravascular pacemakers, the available battery capacity is consumed approximately 50% by the sensor and control electronics of the pacemaker, so that only approximately 50% is available for the generation of the stimulation pulses.According to the invention, this ratio of 50% for the intrinsic consumption of the sensor and control electronics of a heart pacemaker is shifted by the invention such that the sensor and the control unit require significantly less electricity for their operation and therefore a larger proportion of the available capacity of the energy storage unit is available for the pulse provision. The battery capacity thus obtained can either be used for the emission of normal-strength pulses or it is used to generate stronger pulses. In the first case, the pacemaker is extended in the transit time; in the second case, the pacemaker is not expected to be extended in the transit time; however, due to the higher pulse strength, it is possible to allow the heart to be stimulated via parts of the physiological conduction system (HIS burst stimulation).The probeless endocardial or intravascular pacemaker control unit includes a pre-processing unit. In this, the signals provided by the sensor unit are modulated.In this case, specific properties of the carrier signal are changed by the modulation of the signals in such a way that the information content of the signal is encoded for transmission to the control unit and for storage and processing in the control unit.For this purpose, the carrier signal can be present in the form of a high-frequency sine wave or in the form of a continuous signal. The frequency, the current intensity and / or the voltage of the carrier signal are determined such that the transmission via the transmission channel takes place particularly quickly and reliably.The modulation changes, for example, one or more properties of the signal depending on the properties of the sensor unit. For this purpose, the amplitude and / or the frequency and / or the phase is preferably modulated.The control unit of the probeless endocardial or intravascular pacemaker further includes a post-processing unit. In this, the signals delivered from the control unit to the stimulation pulse generator are modulated.Furthermore, the probeless endocardial or intravascular pacemaker presented here includes an external unit for communication or for programming the control unit.The external unit for the controller is a component used in many technical systems and devices to develop, manipulate, or update the software or programmed logic that enables control of the system. The function of such an external unit is to enable developers to create and transmit the desired programs or instructions for the control unit. The basic functions and features are described below:For example, adjustments in a version chronology may be stored in the external entity. Furthermore, the control algorithms for the control unit can be adapted to the current requirements of the patient.In a variant of the invention, the code adaptations can additionally be transmitted to a development platform via various interfaces such as USB, Ethernet or serial connections.The external unit can also comprise functions for versioning and storing codes, for example.In one embodiment of the invention, the external unit of the control unit is used to carry out firmware updates which are provided, for example, via external interfaces.The external unit may also implement security mechanisms and access checks, for example, in order to ensure exclusively authorized access to the control unit.In a variant of the invention, the control unit of the probeless endocardial or intravascular pacemaker allows adaptive learning. This makes it possible to react, for example, to changing physical loads on the patient in an adapted manner.The sensor unit of the probeless endocardial or intravascular pacemaker comprises, for example, at least one combination of one or more memristors and one or more piezoelectric elements.In one example, the control unit of the probeless endocardial or intravascular pacemaker comprises a system and / or structure of programmable resistance elements. These elements may be memristors, for example.In one embodiment of the invention, the control unit of the probeless endocardial or intravascular pacemaker comprises one or a plurality of memristors.In one embodiment of the invention, the control unit of the probeless endocardial or intravascular pacemaker is configured as a neuromorphic machine. This can be done on the basis of a structure of programmable resistor elements, preferably memristors.Neuromorphic technology enables the control unit of the probeless endocardial or intravascular pacemaker to learn independently and adapt to the needs of the patient and thus always achieve the most physiological possible stimulation.A memristor is an electrical component designed as a kind of non-linear resistance element. Memristors have the particular property that they can store information about the electric charge or the current flowing into them and retain this information even if the current supply is interrupted. This behavior has the advantage that they form a kind of synaptic memory.Memristors remain in a certain state and store information about the electric charge introduced into them. This makes them a non-volatile memory in a probeless endocardial or intravascular pacemaker.The electrical conductivity of a memristor is non-linearly dependent on the applied voltage or current. Rather, it varies depending on the previous state, in particular on the number and the intensity of the input systems, e.g. the signals of the sensor unit.Thus, the control unit of the probeless endocardial or intravascular pacemaker with neuromorphic technology can be implemented, for example, as an in-memory computing architecture. In-memory computing is an alternative to the von Neumann architecture.The neuromorphic architecture of the control unit of the probeless endocardial or intravascular pacemaker is particularly energy efficient, so that the capacity of the energy storage unit can be used for the majority of the stimulation pulses.The control unit of the probeless endocardial or intravascular pacemaker may event driven and / or spike data, comparable to biological neuronal networks. The control unit of the module responds in real time to changing physiological conditions of the patient.In one embodiment, the control unit of the probeless endocardial or intravascular pacemaker is a neuromorphic machine that uses memristors as synaptic elements. These memristors have adaptive learning and synaptic plasticity, which also make it possible to adapt to different physiological conditions of the patient.The memristive neuromorphic control unit of the probeless endocardial or intravascular pacemaker adjusts in real time to the changing physiological conditions of the patient.In a variant of the invention, the control unit is integrated into the sensor unit.The neuromorphic architecture of the control unit of the probeless endocardial or intravascular pacemaker is particularly energy-efficient, so that the capacity of the energy storage unit is only minimally loaded by the intrinsic consumption of the control unit.The housing of the probeless endocardial or intravascular pacemaker is dimensioned such that it can be advanced through the usual venous accesses to the right heart and does not cause disturbances in the physiological function of the heart in the interior of the heart. Furthermore, the housing has anchoring devices which make it possible to anchor the probeless endocardial or intravascular pacemaker securely in the myocardium or in a larger blood vessel. These anchoring devices can be implemented according to the prior art.The sensor unit of the probeless endocardial or intravascular pacemaker can be implemented as a thermosensor or as an accelerator according to the prior art. The signals generated by these sensor variants are modulated in a preprocessing unit such that they can be processed by the control unit.The impulse transmitter of the probeless endocardial or intravascular pacemaker is equipped as a steroid-emitting electrode according to the prior art. It has an electrically conductive surface and is connected to the stimulating pulse generator via an electrical connection.The probeless endocardial or intravascular pacemaker described herein allows stimulation of the heart following established conventional therapy, but with the advantage of a longer device life and the advantages thereof for the patient as set forth in the discussion of this invention.Moreover, it is also suitable for allowing stimulation via the HIS bundle. The use of a portion of the natural cardiac conduction system in cardiac stimulation provides further advantages to the patient, which have also been demonstrated in the discussion of this invention.Further features of the invention are evident from the description of an exemplary embodiment on the basis of a drawing and from the drawing itself.This shows FIG. 1 is a block diagram of a probeless endocardial or intravascular pacemaker, FIG. 2 is a schematic illustration of heart anatomy with physiological conduction components and an alternative placement of probeless endocardial or intravascular pacemakers.List of reference numbers:1 Housing 2 Anchoring device 3 Sensor unit 4 Control unit 5 Stimulation pulse generator 6 Pulse transmitter 7 Energy storage unit 8 External unit 9 Preprocessing unit 10 Post-processing unit 11 AV node 12 Left atrium 13 HIS bundle 14 Left ventricle 15 Tawara leg left 16 Purkinje fibers 17 Tawara leg right 18 Right ventricle 19 Right atrium 20 Intermodial bundle 21 Sinus nodeFigure 1 is a schematic illustration in block diagram form of a probeless endocardial or intravascular pacemaker.In the embodiment shown, the pacemaker comprises a cylindrical housing 1 which is elongated and has a length of less than 40 mm and a cross-sectional area of less than 40 mm 2.On one of the two base surfaces of the cylinder there is arranged a pulse emitter 6, the electrically conductive and steroid emitting surface of which points outwards.At the end of the cylindrical housing 1 at which the pulse transmitter 6 is arranged, there is also an anchoring device 2 of the probeless endocardial or intravascular pacemaker.The pulse transmitter 6 is electrically connected to a stimulation pulse generator 5 inside the housing 1.The stimulation pulse generator 5 receives its signals from a post-processing unit 10. The post-processing unit 10 modulates the signals generated by the control unit ( 4) such that the stimulation pulse generator 5 can be controlled in a suitable manner.A control unit 4 processes the signals generated by a preprocessing unit 9. These signals are the modulation of signals which are conducted from a sensor unit 3 to a preprocessing unit 9.The sensor unit 3 can be designed as an accelerator or as a temperature sensor.The components sensor unit 3, preprocessing unit 9, control unit 4 and post-processing unit 10 can be embodied as an integrated component.An energy storage unit 7 is arranged on the side of the cylindrical housing 1 opposite the pulse transmitter 6. There are electrical connections to the components installed in the housing 1. An external unit 8 is located outside the probeless endocardial or intravascular pacemaker. The external unit 8 makes it possible to communicate with the control unit 4 of the probeless endocardial or intravascular pacemaker via differently designed wireless interfaces.In FIG. 2, a schematic representation of the heart anatomy relevant here with the components of the physiological conduction of excitation in the heart is shown.It also shows the alternative placement of probeless endocardial or intravascular pacemakers.In this case, placement of the probeless endocardial or intravascular pacemaker in the region of position A corresponds to conventional therapy with direct stimulation of the myocardium of the right ventricle.When the probeless endocardial or intravascular pacemaker is placed in the region of position B, stimulation of the HIS beam is made possible. The HIS beam belongs to the physiological part of the excitation system of the heart. The stimulation pulse generated there by a probeless endocardial or intravascular pacemaker is physiologically transmitted via the two Tawara legs and the subsequent Purkinje fibers.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 1 714 670 A1 [0005, 0006]

Claims

Probeless endocardial or intravascular pacemaker having a housing (1) with an anchoring device (2), a sensor unit (3), a control unit (4), a stimulation pulse generator (5), a pulse transmitter (6), an energy storage unit (7), wherein the pacemaker is configured for communication with an external unit (8), characterized in that more than 50% of the capacity of the energy storage unit (7) is available for generating the pulses in the stimulation pulse generator (5).Pacemaker according to claim 1, characterised in that less than 50% of the capacity of the energy storage unit (7) is required for the energy consumption of the control unit (4), the sensor unit (3) as well as the preprocessing unit (9) and the post-processing unit (10).Pacemaker according to one of claims 1 or 2, characterised in that the pacemaker comprises a preprocessing unit (9) for modulating the signals from the sensor unit (3) to the control unit (4).Pacemaker according to one of claims 1 to 3, characterised in that the pacemaker comprises a post-processing unit (10) for modulating signals from the control unit (4) to the stimulation pulse generator (5).Pacemaker according to one of Claims 1 to 4, characterized in that the external unit (8) is set up for programming the control unit.Pacemaker according to one of Claims 1 to 5, characterized in that the control unit (4) is set up for adaptive learning.Pacemaker according to one of claims 1 to 6, characterized in that the control unit (4) comprises a structure of programmable resistance elements.Pacemaker according to one of Claims 1 to 7, characterized in that the control unit (4) is integrated into the sensor unit (3).Pacemaker according to one of Claims 1 to 8, characterized in that the control unit (4) has neuromorphic technology.Pacemaker according to one of claims 1 to 9, characterised in that the housing (1) is elongated and has a length of less than 40 mm and a cross-sectional area of less than 40 mm 2.Pacemaker according to one of claims 1 to 10, characterised in that the sensor unit (3) comprises at least one thermosensor and / or at least one accelerator.Pacemaker according to one of Claims 1 to 11, characterized in that the pulse emitter (6) has an outwardly directed, electrically conductive surface and is designed as a stimulation electrode. The pulse transmitter is then electrically connected at least temporarily to the stimulation pulse generator (5) via an electrical connection arranged in the interior of the housing.Use of a pacemaker according to any one of claims 1 to 12 for stimulation via the physiological conduction system of the heart, preferably for stimulation via the HIS bundle.

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