Cardan-mounted charger for pacemakers

Description

[0001] The present invention relates to a charger for contactless charging of an energy storage device of an implant.

[0002] Patent document DE 10 2018 205 940 A1 discloses an electronic pacemaker that is to be fully implanted into the body of a living being. This pacemaker includes an energy storage device that supplies the pacemaker's electronics with electrical energy and can be recharged contactlessly after discharging.

[0003] The contactless recharging of the energy storage device occurs via "indirect" induction with the aid of a magnetized section that responds to an alternating magnetic field in such a way that, once a certain magnetic field strength is reached, a wave of flipping domains (Weiss domains) occurs within it. Due to the rapid change in the magnetic flux, this wave causes a nearby coil to emit a voltage pulse that charges the energy storage device.

[0004] A charger shown in the patent document generates the alternating magnetic field, wherein the charger is arranged on or near a surface of the body of the living being during the charging process and the alternating magnetic field is intended to trigger the magnetization section of the pacemaker in the manner explained.

[0005] The charger contains a multitude of coils to generate the alternating magnetic field. The portion of the alternating magnetic field that penetrates the surface of the body and reaches the magnetized section is part of the weak stray field of the coils.

[0006] This stray field of the coils is also extremely inhomogeneous and decreases sharply with increasing distance from the coil.

[0007] For this reason, recharging the energy storage device, depending on the implantation depth of the pacemaker, requires a meticulous adjustment of the electrical operating parameters of the coils mentioned and a strong stray field with the appropriate direction of the field vector so that the wave of flipping domains in the magnetization section is reliably and periodically generated.

[0008] If the magnetic field in the area of ​​the magnetization section deviates too much from a certain optimal value of the field strength or flux density because it is too weak or too inhomogeneous, the wave necessary for charging is not triggered.

[0009] In order to achieve the necessary field strength or flux density in the stray field, the known charger must have a very high current / voltage resistant design.

[0010] Further prior art can be found in WO2009 / 051539 A1, WO2017 / 025606 A1 and US2012 / 0146575 A1.

[0011] Against this background, the object of the invention is to create a charger for contactless charging of an implant's energy storage device that allows for easier and more reliable generation of the alternating magnetic field required for charging. Furthermore, the object of the invention is to create a charger that is simpler than the prior art, particularly with regard to current and voltage values.

[0012] This object(s) are achieved with a charger according to claim 1. Preferred embodiments of the charger according to the invention are the subject of the dependent claims.

[0013] According to one aspect of the invention, the charger for contactless charging of an energy storage device of an implant implanted in a body of a living being includes the following features: at least one coil extending along a coil axis and configured to generate an alternating magnetic field; wherein When the charger is used as intended, the body is arranged relative to the coil in such a way that the alternating magnetic field, which extends in the area inside the coil along the coil axis, penetrates the body to charge the energy storage device.

[0014] Strictly speaking, the charger's coil generates an alternating electromagnetic field. However, for the purposes of the invention, only the magnetic component of the alternating electromagnetic field is relevant. Therefore, this description refers only to an alternating magnetic field.

[0015] The implant whose energy storage device is intended to be charged by the charging device according to the invention is, for example, a cardiac pacemaker, a brain pacemaker, an organ pacemaker, or an analysis unit. The latter analysis unit is designed, for example, to continuously or at specific intervals determine parameters such as blood pressure and / or blood values. Particularly preferably, the implant is a cardiac pacemaker or pacemaker network located in or on the human heart or implanted at these locations.

[0016] To become independent of the frequency of the alternating magnetic field, an essential element of the implant is a magnetization section with aligned magnetic domains, over which a magnetization reversal wave in the form of continuously reversing magnetic domains passes when the amplitude (B-field) of the alternating magnetic field generated by the charger reaches a certain value in the area of ​​the magnetization section. The magnetization section is, for example, a pulse wire or Wiegand wire.

[0017] A coil located in close proximity to the magnetizing section generates a voltage pulse due to the remagnetization wave and the associated rapid change in the magnetic flux, which supplies energy to, for example, a charging electronics unit and leads to a charging pulse. The charging pulse can be used to charge the energy storage device. The alternating magnetic field generated by the charger triggers the remagnetization wave with each polarity reversal, with charging pulses occurring in equal numbers and charging the energy storage device.

[0018] Alternatively, the implant can be constructed differently, with its energy storage device being charged using conventional induction. For this purpose, the implant has a receiving coil with a preferably specially shaped core. The receiving coil emits charging pulses that depend on the frequency and magnitude of the generated alternating field. The receiving coil is wound around the core in the direction of its longitudinal extension.

[0019] The charger according to the invention is therefore intended for charging using "conventional" induction and / or "indirect" induction. A pacemaker or pacemaker network that utilizes "indirect" induction for charging and has the magnetization section explained above, and whose energy storage devices are charged by generating the magnetization reversal wave, is known from patent documents DE 10 2019 124 435 and EP 3 756 726 A2.

[0020] The statements contained in these patent documents regarding the respective charging pulse generation sections, in particular the magnetization sections including the coils wound around them and emitting the respective voltage pulse, as well as regarding the respective charging electronics are incorporated by reference.

[0021] A frequency f of the alternating magnetic field generated by the charging device according to the invention is in particular between 0.1 kHz ≤ f ≤ 10 kHz, in particular at f = 2 kHz, 3 kHz, 4 kHz, or 5 kHz. The frequency f is preferably adapted to the spatial dimensions and material data of the magnetization section and a related propagation time of the magnetization reversal wave traveling through the magnetization section. The frequencies are suitable for charging the implant in its alternative embodiment based on conventional induction.

[0022] The coil of the charger according to the invention can be designed in various ways. For example, the coil can be circular, rectangular, or square.

[0023] The coil of the charger according to the invention generates a nearly homogeneous alternating magnetic field in the area extending inside the coil along the coil axis, wherein an amplitude of the corresponding magnetic flux density in an entire radial inner area of ​​the coil with respect to the coil axis has such values ​​that i. assuming the same alignment between the magnetic field (direction of the B vector) and the intended direction of travel of the remagnetization wave, each reversal of the alternating magnetic field results in the triggering of the remagnetization wave and thus in the generation of the charging pulse, or ii. assuming the same alignment between the magnetic field (direction of the B vector) and the intended orientation of the core of the receiving coil, which serves for normal induction, each reversal of the alternating magnetic field results in the generation of the charging pulse.

[0024] Due to this field pattern, the exact positioning of the implant in the area within the coil is not important, which makes a meticulous adjustment of the alternating field to the charging conditions, such as the depth of the implant, unnecessary.

[0025] When the charger is used as intended, the body is preferably arranged relative to the coil such that a longitudinal axis of the body runs in the direction of the coil axis and is located within the coil, wherein the alternating magnetic field reaches the location of the implant.

[0026] In this preferred embodiment of the charger, the longitudinal axis of the body of the living being, in particular of a human, runs in the direction of the coil axis. This embodiment is particularly advantageous when the orientation of the intended direction of travel of the magnetization reversal wave passing through the magnetization section or the orientation of the core used for conventional induction coincides with the direction of the body's longitudinal axis. This condition can preferably be achieved by constructing the implant in such a way that the shape or anchoring of the implant leads to this position.

[0027] Preferably, the charger according to the invention further comprises: a suspension that holds the coil and is configured to pivot the coil relative to the body about at least one, preferably two axes, wherein the charger is configured, for example by a control unit, to control the suspension in order to pivot the coil into a specific orientation relative to the body in order to optimize the charging of the energy storage device.

[0028] If the intended direction of travel of the magnetization reversal wave or the orientation of the core used for ordinary induction does not match the direction of the vector of the alternating magnetic field, excessive deviations may lead to a decrease in the charging pulse because the portion of the magnetic field in the direction of the axis of the magnetization section or the core becomes too small.

[0029] The suspension is provided to enable adjustment or adaptation of the direction of travel of the remagnetization wave or the core to the field orientation, or vice versa. The suspension is, for example, a gimbal mount that allows the charger's control unit to pivot the charger's coil around two axes relative to the body of the living being in order to achieve adjustment of the orientation (B-field vector) of the alternating magnetic field generated by the coil to the intended direction of travel of the remagnetization wave or the core.

[0030] Advantageously, pivoting the coil does not result in a change in the amplitude of the magnetic flux density, but only changes its orientation.

[0031] Furthermore, the suspension which holds the coil is preferably displaceable relative to the body and / or a body mount for mounting the body is displaceable relative to the coil, and wherein the charger is set up, the suspension and / or to move the body mount to bring the coil into a specific position relative to the body to optimize charging of the energy storage device.

[0032] For example, the charger includes a linear guide along which the entire coil suspension can be moved, preferably along the body's longitudinal axis. The user can move the suspension along the linear guide either manually or automatically by giving appropriate instructions on a user interface of the control unit.

[0033] The charger is preferably configured to check whether or to what extent the direction of travel of the magnetization reversal wave or of the core used for conventional induction matches the direction of the magnetic field. For example, the charger is capable of wirelessly querying the charge level of the energy storage device at specific intervals and drawing conclusions about the charging efficiency based on the change in the charge level of the energy storage device, the polarity reversal frequency, and a known maximum charging pulse magnitude.

[0034] However, it is preferred that the charger has a receiving unit that is configured to receive a quality signal that is emitted by the implant and reflects the efficiency of the charging, and the charger is configured to pivot the coil into the specific orientation in order to optimize the charging, depending on the quality signal, and / or to bring it into the specific position.

[0035] The quality signal can, for example, be a low-frequency signal that penetrates the human body and, if no antenna is provided for this purpose, the casing or housing of the pacemaker. The quality of the charging pulse is preferably proportional to the value of the integral ( ∫ i dt ) . For good charging pulses, ie with very high quality, the value is up to 1000nC. The signal indicating the quality can, for example, be the value of the integral of the charging pulse current over time ( ∫ i dt ), i.e., its charge content. Alternatively, the quality signal can specify the following ratio: (Charge content of the delivered charge pulse / maximum possible charge content).

[0036] Alternatively, the quality signal may be a binary signal that assumes an OK state when the charging pulse exceeds a certain threshold.

[0037] The control unit controls the suspension, for example the gimbal suspension, while observing the quality signal and determines an optimal position of the coil from various positions of the coil and the corresponding quality signals, into which the control unit finally pivots the coil.

[0038] The following are preferred parameters of the charger according to the invention and / or its coil: The magnetic flux density of the alternating magnetic field along the coil axis preferably has a value B in the following ranges: 2.0mT <= B <= 20.0mT, in particular 2.5mT <= B <= 8.0mT, 3.5mT <= B <= 7.0mT, 4.5mT <= B <= 6.0mT, 4.8mT <= B <= 5.2mT, or 5.0mT = B.

[0039] A diameter of the coil has a value D, which is preferably in the following ranges: 0.6m <= D <= 0.9m, 0.65m <= D <= 0.85m, 0.68m <= D <= 0.8m, or 0.72m = D; and / or a length of the coil preferably has a value I, wherein preferably 0.15m <= I <= 0.5m, 0.2m <= I <= 0.45m, 0.25m <= I <= 0.4m, or 0.33m = l is.

[0040] The coil of the charger may be a continuously wound coil, particularly in the case where the longitudinal axis of the human body is intended to coincide with the coil axis.

[0041] Alternatively, the coil can be pulled apart to form a pair of two partial coils. The dimensions of the partial coils and their spacing are preferably selected such that the pulled apart coil acts like a continuously wound coil, at least in a radial region around the coil axis. An example of a pulled apart coil is a Helmholtz coil. The human body is intended to be positioned between the partial coils, with the longitudinal axis of the body running perpendicular to the coil axis.

[0042] The extended coil can also be held by an adjustable suspension.

[0043] Alternatively, the charger may comprise three separated coils, whose coil axes are preferably arranged in the three spatial coordinates. When the charger is used as intended, the human body and the implant are located between the partial coils of the coil pairs. The alternating magnetic fields generated by the separated coils, each located in a region within the respective coil, overlap between the partial coils and reach the implant implanted in the body.

[0044] A targeted alignment of the alternating magnetic field resulting from the superimposed alternating fields can be achieved by differently controlling the phases and / or amplitudes of the respective coil pairs in order to optimize charging.

[0045] The control of the resulting alternating field can, for example, be based on the quality signal.

[0046] Preferred embodiments of the charger according to the invention are explained below with reference to the attached figures. Figures 1A and 1B show a first preferred embodiment of the charger according to the invention, on the one hand in a perspective view and on the other hand in a view along a Z-axis shown in the figures, wherein the charger includes a coil which is held by a gimbal suspension. Figure 1C shows simulation results of the alternating magnetic field generated by the coil of the charger of the first preferred embodiment of the invention. Figure 1D shows the amplitude of the alternating magnetic field (B-field in mT) in the center of the coil radial to the coil axis. Figure 2A and 2Bshow a second preferred embodiment of the charging device according to the invention, which includes a coil from a coil pair constructed from two partial coils, wherein a suspension holds both partial coils and is configured to pivot and / or displace the partial coils together. Figure 3 shows a third preferred embodiment of the charging device according to the invention, which includes three coils, each of which is constructed from two partial coils, wherein respective coil axes are spatially perpendicular to one another and in an overlay region located between the respective coils, the amplitude and the vector of the alternating magnetic field can be adjusted by controlling the coils.

[0047] The embodiments of the charging device according to the invention explained below serve to charge an energy storage device of an implant that is completely implanted in a human or animal body.

[0048] The implant is generally an entity that performs certain functions when implanted and for this purpose has at least one electronic unit and the energy storage unit that supplies the electronic unit.

[0049] Preferably, the implant may also comprise electrodes for recording body data (body information) and / or delivering impulses to the body and preferably a communication unit that acts as an interface to the outside world.

[0050] The implant is, for example, a cardiac pacemaker, brain pacemaker, bladder pacemaker and / or an analysis unit that records body data such as blood pressure and / or blood values.

[0051] For contactless recharging of the energy storage, the implant has i. a charging pulse generation section with charging electronics, as described, for example, in patent document DE 10 2019 124 435; and / or ii. a receiving coil wound around a preferably specially shaped core, wherein the receiving coil with core enables charging of the energy storage device based on conventional induction.

[0052] An essential element of the charging pulse generating section is a magnetization section, for example a Wiegand wire, with aligned magnetic domains, which can be influenced by the magnetic field component in its axial direction of an electromagnetic alternating field generated by the embodiments of the charging device according to the invention in such a way that a magnetization reversal wave in the form of domino-like flipping domains (Weiss domains) runs over the magnetization section.

[0053] The magnetic reversal wave leads to such a high temporal change in the magnetic flux that a coil arranged in spatial proximity to the magnetization section generates a voltage pulse leading to a charging pulse of the energy storage device.

[0054] This type of recharging of the energy storage device is particularly advantageous in that the frequency of the alternating magnetic field can be reduced to such an extent that no adverse effects, such as skin effects, prevent the alternating magnetic field from penetrating the body and reaching the magnetization section.

[0055] For example, the magnetizing section can be a Wiegand wire around which a coil is wound.

[0056] The speed of the magnetization reversal wave traveling over the Wiegand wire is on the order of 800 m / s during idle operation, with the length of the Wiegand wire contained in the pacemaker ranging from 0.7 to 1.2 cm. This results in a propagation time of the magnetization reversal wave (wave of flipping domains) on the order of 10-20 µs during idle operation.

[0057] Taking these values ​​into account, the charger according to the invention, explained below, generates the alternating magnetic field at a frequency in the range of 0.1 to 10 kHz. In this frequency range, the alternating magnetic field penetrates very deep into the body of the living being and can thus easily reach the magnetization section of the implant for contactless charging.

[0058] The frequency range mentioned is also suitable for charging by means of conventional induction, at least if the aforementioned core runs through the coil.

[0059] The embodiments of the charger according to the invention are explained below under the assumption that the implant is a pacemaker that is completely implanted into / on the human heart. However, the invention is not limited to this.

[0060] The pacemaker has a housing that encapsulates the energy storage device and the corresponding electronics. The pacemaker housing has a volume of approximately 1 cm³.

[0061] Necessary electrodes of the pacemaker are exposed on the surface of the housing and touch sections of the human heart, and / or are designed as anchoring electrodes that are anchored in the human heart and hold the pacemaker in place.

[0062] The pacemaker receives body data, i.e. information about the activity of the heart, via the electrodes and / or can deliver stimulation impulses to the heart.

[0063] The pacemaker's energy storage device is, for example, an electrochemical energy storage device, in particular a rechargeable battery, such as a lithium-ion battery, with a capacity sufficient to supply all of the pacemaker's electronic components with electrical energy for a period of, say, 0.75 to 1.25 years. If it is recharged every 0.5 years, for example, this ensures the supply of energy to all electronic components.

[0064] Charging is carried out contactlessly based on conventional or indirect induction using the charger described in more detail below. (first embodiment)

[0065] With reference to Figures 1A to 1E A first preferred embodiment of the charger according to the invention is explained below.

[0066] The charger 100 according to the first preferred embodiment includes a coil 110 that generates the alternating magnetic field required for charging. The coil 110 has such spatial dimensions that a body holder 120 of the charger 100 intended for a patient P can be accommodated partially within the coil 110.

[0067] In the preferred embodiment of the charger 100, the body holder 120 is a couch on which the patient P lies or is arranged when the charger 100 is used as intended.

[0068] Patient P is a wearer of a schematically indicated pacemaker I, which is completely implanted in the heart of patient P.

[0069] The body support 120 extends in the direction of a Figures 1A and 1Bshown Z-axis through the coil 110. The Z-axis corresponds to a coil axis of the coil 110. When the patient P lies on the body holder 120, as will be described below, a body axis of the patient runs in the direction of the coil axis of the coil 110, whereby the alternating magnetic field located in the area within the coil 110 penetrates the body of the patient P and reaches the pacemaker I to charge the energy storage device.

[0070] The coil 110 is in the preferred embodiment a circular coil with a diameter D, with a corresponding coil plane in the Figures 1A and 1B shown XY plane is perpendicular to the coil axis (Z axis).

[0071] Alternatively, the coil 110 can also be a square or rectangular frame coil. The diameter D is 0.72 m in the first preferred embodiment, but can vary.

[0072] Coil 110, for example, has a single-layer winding with a plurality of turns w, formed from an electrical wire, for example, a copper wire. In the first preferred embodiment, the number of turns w is 10, although this value is merely preferred and may also vary.

[0073] The electrical cable forming the winding preferably has a rectangular cross-section of 320 mm², consisting of a side length of 32 mm pointing in the direction of the Z-axis and a side length of 10 mm perpendicular to it. In addition, there is a 0.5 mm thick electrical insulation covering the surface of the electrical cable.

[0074] This results in a length I of the coil 110 in the direction of its coil axis (Z-axis) of 0.32 m without taking the insulation into account or of 0.33 m with the insulation taken into account, whereby the condition D > I applies to the first preferred embodiment.

[0075] With this design, the inductance L of coil 110 has a value of 87 pH. The invention is not limited to the described design and the stated parameters. In general, it is preferred that the design of coil 110 be such that the inductance lies in the following range: 0.02 mH <= L <= 0.3 mH.

[0076] The coil 110 of the charger 100 according to the invention is preferably operated during the charging of the energy storage device of the pacemaker I in such a way that it generates in its interior the alternating magnetic field with an amplitude (magnetic flux density B) in the range of 2.5 mT <= B <= 8.0 mT, in particular in a range of 5 mT.

[0077] The alternating magnetic field with these values ​​of the magnetic flux density B is located in the area inside the coil 110 and runs along the coil axis of the coil 110.

[0078] The magnetization section contained in the pacemaker I, which is preferably the Wiegand wire already mentioned, shows, at the mentioned values ​​of the magnetic flux density B and a frequency f (polarity reversal frequency) of the alternating magnetic field in the already mentioned range of 0.1 to 10 kHz, in particular at 2 kHz, a reliable behavior in that each polarity reversal of the alternating magnetic field triggers the magnetization reversal wave with a very high probability and thus leads to the charging pulse of the energy storage device.

[0079] The energy storage device can also be charged by conventional induction in this frequency range, especially at frequencies above 2kHz, if the receiving coil of the pacemaker has the appropriate core.

[0080] The explained structure of the charger 100 according to the invention according to the first preferred embodiment is particularly advantageous because electrical operating parameters are of a magnitude that enables problem-free operation of the charger 100 in a normal doctor's office.

[0081] The magnetic flux density B of the alternating magnetic field generated by the coil 110 results from the following relationship: B = μ 0 * I * w / D

[0082] The charger 100 according to the invention preferably generates an alternating electrical current with a strength of I = 300 A in the winding of the coil 110. With the aforementioned w = 10 turns, the above relationship (1) results in a magnetic flux density B of 5.25 mT, which is sufficient for reliable triggering of the Wiegand wire or magnetization section or for sufficient ordinary induction in the stated ranges.

[0083] Taking into account the alternating current resistance of the coil 110, which results from ω*L, with ω=2πf, an alternating voltage necessary for generating the alternating current I follows from U=I*ω*L and is thus 327 V at a frequency f of 2 kHz of the alternating magnetic field.

[0084] Both the value of the alternating current I generated in the winding and the corresponding voltage value U are within the range that can be provided in normal buildings / doctor's offices. Therefore, the charger 100 according to the invention does not necessarily have to be installed in a separate facility, as is the case, for example, for operating an MRI.

[0085] This is advantageously achieved by having the coil 110 of the charger 100 according to the invention be part of a resonant circuit, for example, a parallel resonant circuit. In this way, only the active power (copper losses) needs to be drawn from the grid.

[0086] Figure 1B schematically shows an amplifier 151 and a capacitor 152, which are contained together in a control unit 150 of the charger 100. The capacitor 152, together with the coil 110, forms the aforementioned parallel resonant circuit.

[0087] The parallel resonant circuit is dimensioned such that it resonates during normal operation of the charger 100. Taking into account the inductance of L=87µH of the coil 110, the relationship 1 / (ω*C)=ω*L, which applies to the resonance case, results in a capacitance of the capacitor of C=72.8µF.

[0088] The ohmic resistance R of coil 110 is essentially determined by the material and dimensions of the electrical line forming the winding. In the present first preferred embodiment of the charger 100 according to the invention, the ohmic resistance R of the electrical line of coil 110 is approximately 1.24 mΩ.

[0089] This results in an active power consumption of coil 110 in the example, with a corresponding effective value I eff of the alternating current flowing through coil 110, of 56 W. This active power consumption of the parallel resonant circuit can easily be supplied by a standard power supply in buildings (e.g., 230 V; 50 Hz). This means that the charger 100 according to the invention can be connected to a standard electrical outlet via the control unit 150. Figures 1A and 1B show such a connection cable schematically.

[0090] If the energy storage of the pacemaker I needs to be recharged in the implanted state, the patient P lies down, as shown in Figures 1A and 1B as can be seen, on the lounger 120.

[0091] A spatial position of the patient P or the couch 120 relative to the coil 110 in the Z direction (positive or negative direction of the Z axis) is achieved by the control unit 150 of the charger 100 displacing a suspension 140 of the coil 110, explained below, relative to the couch 120 / the patient P. For this purpose, the charger 100 has a linear guide 130 arranged below the couch 120 and which supports the suspension 140 of the coil 110 displaceably in the Z direction.

[0092] The controller 150 is configured to control the linear guide 130 to move the suspension 140 to a specific position in the Z direction. Alternatively / additionally, the body support / bed 120 can be mounted displaceably, so that the control unit 150 of the charging device 100 can move the body support / bed 120 relative to the coil 110 by controlling adjustment mechanisms to position the patient P.

[0093] When charged as intended, the patient P and the coil 110 have such a spatial relationship to each other that the pacemaker I is located in the area along the coil axis within the coil 110.

[0094] This condition is in Figures 1A and 1B Given that the pacemaker I is located in the cylinder volume V defined by the coil 110, which results from (D / 2) 2< *π*l. The alternating magnetic field running along the coil axis in this area penetrates the body of the patient P and reaches the pacemaker I.

[0095] The magnetic flux density B has adequate values ​​for charging throughout the entire cylinder volume, which is why the specific position of the pacemaker I within the cylinder volume V plays a subordinate role, as long as the alignment of the magnetization section or the core used for the usual induction is correct. This will be seen from the following explanations of the Figures 1C to 1E visible.

[0096] Figures 1C and 1D show the strength and orientation of the magnetic flux density B of the alternating magnetic field generated by the coil 110 when the alternating current of I = 300 A flows through the winding of the coil 110. Figure 1C corresponds to a sectional view of the coil 110, wherein the sectional plane of the Figures 1A and 1B shown ZX plane and contains the center of the coil 110. The center of the coil 110 is also the origin of the Figures 1A and 1B shown coordinate system.

[0097] Figure 1D shows in this context the amplitude of the magnetic flux density B and Figure 1C the corresponding vector representation, where the figures concern the corresponding resulting quantities in space.

[0098] The Figure 1D makes it clear that the amplitude of the magnetic flux density B within the coil 110, especially in the region of the middle plane (XY plane, with Z = 0), has an amplitude exceeding 4.5 mT over the entire diameter D (see areas in Figure 1D ). In addition, what Figure 1C illustrates that the orientation (vector) of the magnetic flux density B in the region of the middle plane is essentially homogeneous, ie the vectors indicating the orientation of the magnetic flux density B run parallel to the coil axis.

[0099] Figure 1Dshows in detail how the amplitude of the resulting magnetic flux density B in the center plane of coil 110 (Z = 0) changes in the radial direction (X and / or Y direction) starting from the coil axis or the origin of the coordinate system. The magnetic flux density B has a resulting magnetic flux density of 4.5 mT at (X, Y, Z) = (0, 0, 0) and increases in the radial direction to approximately 8 mT.

[0100] According to the intended purpose, the charger 100 of the first preferred embodiment is operated such that the pacemaker I is located in the cylinder volume V defined by the coil 110 when the corresponding energy storage device is being charged. However, it is particularly preferred that the patient P, during the intended operation of the charger 100 according to the invention, is arranged relative to the coil 110 such that the pacemaker I is located at a point in the central (X / Y) plane of the coil 110.

[0101] During proper operation of the charger 100, the magnetization section, in particular the Wiegand wire, or the core of the pacemaker I is oriented such that the intended direction of travel of the remagnetization wave or a longitudinal extension of the core coincides with the direction of the coil axis / Z-axis and thus with the main component (Z-component) of the resulting magnetic flux density B. The intended direction of travel corresponds to the direction in which the remagnetization wave should travel across the magnetization section to achieve optimal voltage pulses or charging pulses. For the aforementioned Wiegand wire, this direction of travel generally corresponds to its longitudinal axis.

[0102] The alignment of the magnetization section / direction of travel of the remagnetization wave / longitudinal extension of the core used for conventional induction with the direction of the coil axis is achieved by paying attention to the alignment during implantation of the pacemaker I or the magnetization section contained therein. For example, the pacemaker I has electrodes and / or anchors designed in such a way that the alignment of the magnetization section / longitudinal extension of the core used for conventional induction in the direction of the body axis (and thus in the Z-axis / coil axis) is inevitable upon implantation.

[0103] The orientation of the magnetization section, in particular the orientation of the longitudinal extension of the Wiegand wire, or the longitudinal extension of the core serving for the ordinary induction in the direction of the Z-axis / coil axis, results in each reversal of the alternating electromagnetic field reliably triggering the magnetization reversal wave / ordinary induction, and a desired voltage pulse is generated, which in turn leads to the charging pulse for the energy storage device.

[0104] The explanations regarding the alternating magnetic field generated by coil 110 show that the reliable triggering of the magnetization reversal wave or the reliable induction is independent of where the pacemaker or the magnetization section is located in the cylinder volume V defined by coil 110. This is because within coil 110 there is a sufficiently homogeneous amplitude of the magnetic flux density B with a simultaneous orientation of the B vector pointing in the coil axis (independent of location).

[0105] A meticulous adjustment and adaptation of the strength and orientation of the alternating magnetic field to the position and location of the pacemaker is therefore not necessary.

[0106] Even if the pacemaker I has been implanted into the body of the patient P in such a way that the direction of travel of the magnetization reversal wave or the longitudinal extension of the core points in the direction of the patient's body axis, deviations between the longitudinal extension of the core or the orientation of the magnetization section and thus the direction of travel on the one hand and the coil axis on the other hand may occur during proper operation of the charger 100.

[0107] The reason for this may be, on the one hand, the patient's individual physiological conditions, which lead to a different position of the pacemaker I in the patient's body. On the other hand, simple physical movements of the patient during the charging process can lead to deviations.

[0108] In order to bring and / or maintain the charging of the energy storage device in an optimal state, the suspension 140 is designed to be adjustable.

[0109] On the one hand, the coil 110 can be displaced by the linear guide 130 in the direction of the Z-axis or coil axis.

[0110] On the other hand, the suspension 140 is designed as a gimbal suspension. This allows the coil 110 to be pivoted around the respective Figures 1A and 1B shown X-axis and Y-axis.

[0111] The control unit 150 is configured to use the aforementioned setting options to optimize the charging of the energy storage device.

[0112] Optimizing charging requires determining the extent to which reversing the alternating magnetic field results in the desired, sufficiently high charging pulses. If the alignment of the magnetization wave's intended direction of travel or the core's longitudinal extension deviates too significantly from the coil axis, the generated voltage pulses will decrease in amplitude to such an extent that sufficient charging pulses for the energy storage device can no longer be achieved.

[0113] Pacemaker I preferably generates a quality signal Q as feedback, which reflects the charging efficiency. This quality signal can be actively transmitted or passively interrogated.

[0114] The transmitted quality signal Q can, for example, be a low-frequency signal that penetrates the body of the patient P and, if no external antenna is provided for this purpose, the casing or housing of the pacemaker.

[0115] The quality signal can be queried, for example, by the pacemaker attenuating defined frequencies.

[0116] The quality of the charging pulse is proportional to the value of the integral ( ∫ i dt ) . For good charging pulses, ie with very high quality, the value is up to 1000nC. The signal Q indicating the quality can, for example, be the value of the integral of the charging pulse current over time ( ∫ i dt ), i.e. its charge content.

[0117] The pacemaker's electronics can be configured to transmit the quality-indicating signal Q for each charging pulse or, alternatively, only for those charging pulses that occur consecutively at specific intervals. The intervals can be, for example, 25, 50, 100, 200, 500, 750, or 1000 charging pulses. It is also possible to transmit a value corresponding to the average of all charging pulses occurring in an interval. This can reduce the energy required for active data transmission.

[0118] The control unit 150 has a receiving unit and is configured to evaluate the quality signal Q from the pacemaker I. Based on the quality signal Q, the control unit 150 performs appropriate steps to optimize charging by pivoting the coil 110 about the X / Y axes and / or displacing it in the Z direction until the quality signal indicates an optimal alignment.

[0119] Preferably, the quality signal Q is proportional to the charging efficiency.

[0120] The signal Q indicating the quality of the charging pulse can alternatively be, for example, a binary signal that assumes an OK state when the charging pulse, or its charge content, exceeds a threshold value, and an NG state when the charging pulse does not exceed the threshold value. The threshold value can be, for example, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% of the charge content deliverable by the magnetization section.

[0121] If the quality signal Q is a binary signal, the threshold value for the OK state of the signal is preferably in higher ranges, because the threshold value serves as a criterion for stopping the pivoting of the coil 110 about the respective axes and evaluating the achieved position of the coil as optimal. For this purpose, for example, the extreme positions (change from good to bad or vice versa) are evaluated.

[0122] In general, the charger 100 according to the invention can also be used with implants that do not emit a quality signal Q, but merely have the functionality that allows the control unit 150 to query the charge level of the energy storage device. For the application shown, for example, the corresponding electronics of the pacemaker I can be designed such that the charge level of the corresponding energy storage device can be queried via a transmit and receive function of the pacemaker I.

[0123] Thus, as an alternative to the signal Q indicating the quality, the control unit 150 can draw conclusions about the charging efficiency from repeatedly querying the state of charge of the energy storage device during charging. In detail, the control unit 150 can draw conclusions about the quality / efficiency of the individual charging pulses based on information about a change in the state of charge, the time interval between the queries, a known maximum height of the charging pulses, and the polarity reversal frequency. The time interval at which the control unit 150 queries the state of charge of the energy storage device is preferably 0.5 min, 1.0 min, 1.5 min, 2.0 min, 2.5 min, 3.0 min, 3.5 min, 4.0 min, 4.5 min, and 5.0 min.

[0124] Once the control unit 150 has acquired knowledge of the quality of the charging pulses, it controls the gimbal 140 to pivot the coil 110 about the respective axes (X-axis and / or Y-axis) and / or to translate it along the Z-axis to optimize charging. (second embodiment)

[0125] In the following, a second preferred embodiment of the invention will be described with reference to Figures 2A and 2B explained.

[0126] Figure 2A shows the structure of a charging device 200 according to the second preferred embodiment of the invention, viewed in the direction of the Z-axis, and Figure 2B a perspective view.

[0127] The charger 200 serves to charge an energy storage device of a pacemaker I, which is constructed identically to that described with reference to the first embodiment. Regarding the structure and functionality of the pacemaker I, reference is made to the explanations for the first embodiment.

[0128] The charger 200 includes a coil 210 configured to generate the alternating magnetic field required for the indirect charging of the energy storage device. The coil axis A of the coil 210 extends in Fi gur 2A in the direction of the Y-axis of the coordinate system shown there.

[0129] In contrast to the first preferred embodiment, the winding of the coil 210 is not continuous but is preferably pulled apart in the center of the coil 210, which at the same time corresponds to the origin of the coordinate system, such that the coil 210 forms a coil pair.

[0130] The coil pair includes two circular partial coils 211 and 212, which are arranged axially to each other and have the same diameter D. The partial coils 211 and 212 are arranged at a distance R1 from each other and have the same winding direction.

[0131] The winding of coil 210 runs over a connecting arm 213, thus connecting parts of the winding that form the partial coils 211 and 212. In this embodiment, the connecting arm 213 is a closed ring, which is preferably circular.

[0132] The winding is, as in the first preferred embodiment, single-layered, and the sections of the winding forming the partial coils necessarily have the same winding sense.

[0133] In the present embodiment, the electrical line forming the partial coils 211, 212 preferably has the same cross-sectional dimensions as those in the first preferred embodiment: rectangular with a side length of 32 mm in the direction of the coil axis and a side length of 10 mm in the direction radial to the coil axis. A section of the electrical line that runs over the connecting arm 213 can have the aforementioned cross-sectional dimensions or be dimensioned differently.

[0134] Each of the partial coils 211 and 212 has, for example, a diameter of 160 cm and five turns (w = 5). The distance R1 between the partial coils 211 and 212 preferably corresponds to the radius of the partial coils, ie, 80 cm in the present embodiment, or is preferably smaller than the radius. The diameter D of the partial coils 211 and 212 can be made larger if a larger distance R1 between the partial coils is required.

[0135] A suspension 240 supports the coil 210 by adjustably supporting the ring 213 forming the connecting arm 213, the suspension 240 having adjustment mechanisms for this purpose.

[0136] The adjustment mechanisms include a pivot bearing 241, which allows the connecting arm 213 and thus the coil 210 to be moved in the Fig. 2A and 2B shown position around the X-axis of the coordinate system shown. In addition, the adjustment mechanisms have ball bearings 242, which allow the connecting arm / ring 213, which is connected to a bearing ring 243 via the pivot bearing 241, to be rotated by the total Figures 2A and 2B As can be understood from this, the connecting arm / ring 213 can be rotated so far by the ball bearings 242 supporting the bearing ring 243 that the pivot bearing 241 does not correspond to the Figures 2A and 2Bshown X-axis, but the shown Y-axis.

[0137] The adjustment mechanisms (pivot bearing 241, ball bearing 242) enable the coil 210 to be aligned in a desired orientation relative to the implanted pacemaker I.

[0138] Additionally, the loading device 200 of the second preferred embodiment of the invention can include the linear guide 130, which was already explained with reference to the first preferred embodiment. Reference is made to the corresponding explanations within the context of the first preferred embodiment. As in the first preferred embodiment, the bed 220 can preferably be displaceable in the Z direction. If this is the case, the linear guide 130 is preferably not present.

[0139] A control unit 250, which is configured to perform the functions explained with reference to the first preferred embodiment, is electrically connected to both the suspension 240 and the coil 210. The coil 210 is, as in the first preferred embodiment, part of a Figure 2A not shown parallel resonant circuit, wherein the corresponding other elements of the resonant circuit, such as the amplifier and capacitor already mentioned, are accommodated in the control unit 250.

[0140] A body support 220, which is a couch as in the first preferred embodiment, runs between the partial coils 211 and 212 perpendicular to the plane of the drawing of the Figure 2A in the direction of the Z-axis.

[0141] When the energy storage of the pacemaker I of patient P needs to be charged, the patient P lies down on the couch 220 and is located between the partial coils 211 and 212. The body axis or longitudinal axis of the patient P extends, like the couch 220, in the direction of the Z-axis shown. The patient P is in Figure 2A shown schematically.

[0142] Coil 210 generates a uniform alternating electromagnetic field, even though the winding is not continuous but rather is separated into partial coils 211 and 212. In other words, due to the configurations, dimensions, and spatial relationship explained above, both partial coils 211, 212 act like a single coil with a continuous winding. In the present second embodiment, coil 210 preferably has the structure of a so-called Helmholtz coil.

[0143] Both partial coils 211 and 212 each generate a part of the total alternating magnetic field generated, wherein the magnetic field extending within the coil 210 along the coil axis A passes through the interior spaces of the partial coils 211, 212 and a region between the partial coils 211, 212.

[0144] The area between the partial coils is a superposition area in which the parts of the alternating magnetic field generated by the partial coils superimpose such that the resulting alternating magnetic field extends along the coil axis A.

[0145] The vectors indicating the orientation of the alternating magnetic field, which passes through the interiors of the partial coils 211, 212 and the superposition region located between the partial coils, exhibit parallel paths. Furthermore, the magnetic flux density B in the superposition region has values ​​that exceed 4 mT over long distances.

[0146] These values ​​are sufficient to initiate the described magnetization reversal wave, which runs over the magnetization section or Wiegand wire of the pacemaker I and leads to the charging pulse of the energy storage device, or the usual induction leading to the charging pulse.

[0147] In contrast to the first preferred embodiment, the alternating magnetic field located within the coil along the coil axis A penetrates the body of the patient P not parallel to his body axis running in the Z direction, but perpendicular thereto.

[0148] The charger 200 is therefore intended in particular for the case that the pacemaker I is aligned in the body of the patient P in such a way that the intended direction of travel of the magnetization reversal wave of the magnetization section or the longitudinal extension of the core does not point in the direction of the body axis (Z direction), but deviates significantly therefrom and runs essentially in the Y and / or X direction.

[0149] The adjustment of an optimal position and orientation of the coil 210 with respect to the body of the patient P proceeds similarly to the first preferred embodiment of the charging device according to the invention in that the control unit 250 controls the adjustment mechanisms and / or the linear guide 130 and adjusts and aligns the coil 210 relative to the patient / pacemaker I until optimal charging takes place. (third embodiment)

[0150] Figure 3shows a third preferred embodiment of a charger 300 according to the invention. The charger 300 also serves to charge an energy storage device of an implant I, such as the pacemaker I explained above.

[0151] With regard to the structure and functionalities of the pacemaker I, reference is made to the explanations for the first and second embodiments.

[0152] The charger 300 generates the alternating magnetic field necessary for charging the energy storage device in a similar manner to the coil 210 of the charger 200 according to the second preferred embodiment, but eliminates the need for a suspension for changing the spatial orientation of the alternating magnetic field.

[0153] For this purpose, the charger 300 has a first coil, a second coil and a third coil.

[0154] The first coil includes a first coil pair, which is constructed from a first partial coil 311 and a second partial coil 312, wherein the corresponding coil axis A is in the direction of the Figure 3 shown Y-axis of the corresponding coordinate system.

[0155] The second coil includes a second coil pair, which is equally composed of a first partial coil 221 and a second partial coil 222. The coil axis B of the second coil corresponds to the Figure 3 shown X-axis of the corresponding coordinate system.

[0156] Finally, the charger 300 includes a third coil, which in turn is constructed from a first partial coil 331 and a second partial coil 332. The coil axis C of the third coil corresponds to the Z-axis of the Figure 3 shown coordinate system.

[0157] All coil axes are preferably spatially perpendicular to each other.

[0158] In contrast to the previous embodiments, the coils or partial coils are not circular, but are designed as frame coils with rectangular coil planes.

[0159] All partial coils that form the respective coil pairs of the coils preferably have the same structure with regard to the electrical line and number of turns w forming the corresponding winding, and each have the same winding direction. The dimensions of the electrical line and number of turns w are preferably identical to those of the first and second preferred embodiments.

[0160] A distance between the partial coils 221, 222 in the X-direction is in relation to their dimensions perpendicular to the coil axis A, ie in planes parallel to the Figure 3 shown YZ plane is dimensioned so that the partial coils 221, 222 act as a single coil (Helmholtz coil). This condition preferably applies to all Figure 3 shown partial coils.

[0161] The charger 300 of the third preferred embodiment includes a control unit 350 configured to control each coil pair separately and generate an alternating current in the respective windings. Each coil pair thus generates an individual alternating magnetic field.

[0162] As in the previous embodiments, each of the coils is part of a separate resonant circuit, the elements of which are accommodated in the control unit 350. Regarding the strength of the alternating current generated in each coil and the structure of the resonant circuits, reference is made to the explanations of the previous embodiments.

[0163] When the control unit 350 generates the alternating current in the coil pairs / sub-coils 311 and 312, the individual alternating magnetic field located within the coil along the coil axis A passes through the sub-coils 311, 312 and across the superposition region located between the sub-coils.

[0164] The partial coils 311 and 312 therefore generate the alternating magnetic field in the same way as the coil 210 in the second preferred embodiment. These explanations apply to all Figure 3 shown coil pairs or partial coils of the corresponding coils.

[0165] The individual alternating magnetic fields of all coils overlap in the overlap area to form the alternating magnetic field that reaches Implant I.

[0166] The alternating magnetic field that reaches the pacemaker I has sufficiently high values ​​in the superposition region over wide spatial areas around the coordinate origin to trigger the magnetization section (Wiegand wire) of the pacemaker I to generate the charging pulse or to flow through the core used for normal induction to generate the charging pulse.

[0167] The control unit 350 can change the orientation of the resulting alternating magnetic field by controlling the respective coil pairs or the corresponding partial coils differently and varying the alternating current flowing in the corresponding windings. If the orientation of the resulting alternating magnetic field is not required in space but only in one plane, one of the three coils is dispensable.

[0168] When the charger 300 is used as intended, the patient P is preferably pushed in the direction of the Z-axis through the partial coils 331, 332 until the upper body of the patient P and the pacemaker I are located in the overlapping area. As in the other embodiments, the patient P can be arranged, for example, on a body support or couch.

[0169] All of the above-explained embodiments of the charging device according to the invention have in common that the alternating magnetic field located within the coil(s) along the corresponding coil axis is used to charge the energy storage device. The alternating magnetic field, or its magnetic flux density B, is so strong and largely homogeneous in these regions of the coil(s) over long distances that precise knowledge of the position of the implant (pacemaker) is of secondary importance if the direction of the axis of the magnetization section or the longitudinal extension of the core coincides with the axis of the magnetic field vector to a first approximation.

[0170] In addition, all embodiments allow the vector of the alternating magnetic field to be pivoted / rotated without changing the amplitude of the magnetic flux density B. This allows for a highly reliable alignment of the magnetic field vector in the direction of the longitudinal axis of the core or the axis of the magnetization section and thus in the direction of travel of the remagnetization wave.

Claims

1. Charging device (100, 200, 300) for contactless charging of an energy storage of an implant (I) implanted in a body of a living being, comprising: at least one coil (110, 210) extending along a coil axis and configured to generate an alternating magnetic field; and a body support (120) provided for the body, located within the coil (110, 210) and configured to hold the body spatially relative to the coil (110, 210); wherein the body, with the charger (100, 200, 300) being used as intended, is arranged on the body holder (120) spatially relative to the coil (110, 210) in such a way that the alternating magnetic field, which extends in the area within the coil along the coil axis, penetrates into the body for charging the energy store.

2. Charging device (100, 200, 300) according to claim 1, wherein the body, with the charger being used as intended, is arranged relative to the coil in such a way that a longitudinal axis of the body is directed in the direction of the coil axis and is located inside the coil, the alternating magnetic field reaching the location of the implant.

3. Charging device (100, 200, 300) according to claim 2, further comprising: a suspension which supports the coil and is configured to pivot the coil relative to the body about at least one, preferably two axes, wherein the charging device is configured to control the suspension to pivot the coil, for optimizing the charging of the energy storage, to a certain orientation relative to the body.

4. Charging device (100, 200, 300) according to claim 3, wherein the suspension which supports the coil is displaceable relative to the body and / or a body support for supporting the body is displaceable relative to the coil, and wherein the charging device is configured to displace the suspension and / or the body support in order to bring the coil, for optimizing the charging of the energy storage, into a certain position relative to the body.

5. Charging device (100, 200, 300) according to claim 3 or 4, wherein the charging device comprises a receiver unit configured to either receive or interrogate a quality signal generated in the implant and reflecting the efficiency of the charging, and the charging device being configured, depending on the quality signal, to pivot the coil, for optimizing the charging, into the certain orientation and / or bring it into the certain position.

6. Charging device (100, 200, 300) according to one of the previous claims, wherein a magnetic flux density of the alternating magnetic field along the coil axis comprises a value B, wherein 2.0 mT < = B < = 20.0 mT , preferably 2.5 mT < = B < = 8.0 mT , 3.5 mT < = B < = 7.0 mT , 4.5 mT < = B < = 6.0 mT , 4.8 mT < = B < = 5.2 mT , or 5.0mT = B.

7. Charging device (100, 200, 300) according to one of the claims 1 or 2, wherein the coil is composed of a first pair of coils of two partial coils arranged at a distance R1 from each other on the same axis, which interact in such a way that the alternating magnetic field along the coil axis passes through a superposition area located between the partial coils and through the partial coils, each; wherein preferably R1 is equal to or less than D / 2 and the body, with the charger being used as intended, is arranged relative to the first pair of coils in such a way that the alternating magnetic field located in the superposition area penetrates into the body to charge the energy storage.

8. Charging device (100, 200, 300) according to claim 7, further comprising: a suspension which supports the first pair of coils and is configured to pivot the first pair of coils relative to the body about at least one, preferably two axes, and wherein the charging device is configured to control the suspension to pivot the first pair of coils, for optimizing charging of the energy storage, to a certain orientation relative to the body.

9. Charging device (100, 200, 300) according to claim 8, wherein the charging device is configured to pivot the first pair of coils, for optimizing charging of the energy storage, to the certain orientation relative to the body, depending on a quality signal emitted by the implant and reflecting the efficiency of charging.

10. Charging device (100, 200, 300) according to claim 7, further comprising: a second coil which extends along a coil axis and which is composed of a second pair of coils of two partial coils which are arranged at a distance R2 from one another in such a way that the superposition area is located between the partial coils of the second pair of coils, wherein the coil axes of the first and second coils are transverse, preferably perpendicular, to each other, and the charging device is configured to control the first coil and the second coil, for optimizing the charging of the energy storage, in such a way that one direction of the alternating magnetic field in the superposition area rotates two-dimensionally.

11. Charging device (100, 200, 300) according to claim 10, further comprising: a third coil which extends along a coil axis and which is composed of a third pair of coils of two partial coils which are arranged at a distance R3 from one another in such a way that the superposition area is located between the partial coils of the third pair of coils, wherein the coil axes of the first, second and third coils extend transversely to one another, preferably along spatial coordinates X, Y and Z, and the charging device is configured to control the first coil, the second coil and the third coil, for optimizing the charging of the energy storage, in such a way that the direction of the alternating magnetic field in the superposition area rotates three-dimensionally.

12. Charging device (100, 200, 300) according to claim 10 or 11, wherein the charging device is configured to either receive or interrogate a quality signal generated in the implant reflecting the efficiency of charging, and the charging device being configured to bring the vector of the alternating magnetic field, for optimizing charging of the energy storage, in the superposition area into a defined position.