Methods and devices for wirelessly providing energy to leadless implants

Abstract

The invention relates to a device (200) for wirelessly providing energy to a leadless implant (100). The device (200) comprises a plurality of inductive charging coils (241) for wirelessly providing the energy according to at least one operating parameter and a controller (220) coupled to the plurality of inductive charging coils (241). The controller (220) is configured to select the at least one operating parameter out of a set of operating parameters of the plurality of inductive charging coils (241).

Description

[0001] METHODS AND DEVICES FOR WIRELESSLY PROVIDING ENERGY TO

[0002] LEADLESS IMPLANTS

[0003] The present invention relates to methods and devices for wirelessly charging leadless implants, in particular to methods and devices for wirelessly charging leadless cardiac implants.

[0004] Implantable medical devices are commonly used today to treat pain, incontinence, heart disease, and so on. In the following, the wording implantable medical device and an implanted medical device will interchangeably be used, and they will be denoted as implant. One example of such an implant is a cardiac implant such as a pacemaker. A pacemaker may be used to treat heart disease and deliver electrical pulses to a patient’s heart (human or animal) to stimulate the heart and to maintain a cardiac rhythm. Other examples of implants are, but are not limited to, sensors (e.g., a pressure sensor for monitoring blood pressure), ventricular assist devices, infusion pumps, and defibrillators.

[0005] Considering a pacemaker, as an exemplary implant, it is traditionally implanted in a subcutaneous location and comprises electrical leads guided from the pacemaker to the heart. In contrast to such traditional pacemakers, leadless pacemakers (also referred to as intracardiac pacemakers) are small enough to be directly implanted into the heart, and therefore, electrical leads are not needed. That was made possible because technology advancements allowed the electronics and the battery for energy supply to be miniaturized to a size that allows a direct implantation of the pacemaker into the ventricle of a patient’s heart. Despite their reduced sizes, leadless pacemakers are capable of providing an equivalent therapy compared to the traditional pacemakers. After injecting the leadless pacemaker via a catheter, the leadless pacemaker resides within the targeted heart chamber. In order to provide energy to the leadless pacemaker, modern leadless pacemakers typically use a battery which may be a rechargeable battery or a non-rechargeable battery. For providing a reasonable operational longevity of leadless pacemakers (e.g., a longevity of a decade) with non-rechargeable batteries, useful, though not necessarily medically critical functions, have been reduced. Different from this compromise of the feature support, a lot of effort has been made in the design and development of non-rechargeable batteries such that they are small enough but still provide sufficient energy. Therefore, many modem leadless pacemakers use non-rechargeable batteries based on a lithium-iodine or carbonmonofluoride chemistry. These batteries are low current drain batteries with a very high energy density. Thus, they can provide a substantial amount of electrical power from a relatively compact sized cell and provide at the same time a reasonable operational longevity. However, a non-rechargeable battery will, by definition, become depleted within a finite period of time and the leadless pacemaker becomes useless. As, during the lifetime of a leadless pacemaker, adipose, vascular, and muscular tissue may grow around the leadless implant, and as it may be unknown how much of these tissues have grown around the leadless pacemaker, it has become emerging practice to abandon the leadless pacemaker within the patient’ s anatomy rather than explanting them. This avoids on the one hand further surgical trauma to the patient, but, on the other hand, causes the undesired effect that abandoned implants may accumulate in a patient’s body.

[0006] In order to extend the operational longevity of leadless pacemakers, and hence, reducing / avoiding the accumulation of abandoned implants in a patient’s body, rechargeable batteries are applied. However, due to limited charging possibilities, the improvements to the above problems are quite restricted. This is caused by the fact that for charging the rechargeable battery, either a venous access procedure, as described in US 2013 / 0303872 Al is necessary or the implant and the charging device need to be properly aligned, as, e.g. described in US 2006 / 00951287 Al and WO 2009 / 140609 Al. These approaches have in common that they may affect a patient’s daily life, and therefore, they may not be well accepted by patients. Hence, the improvements by using rechargeable batteries over non- rechargeable batteries are limited. It will be readily understood by the skilled person that the described existing drawbacks with battery-powered leadless pacemakers are not limited to this particular type of implants. Instead, these drawbacks exist for any battery-powered implant.

[0007] Therefore, there is a need to extend the operational longevity of implants, while providing uncompromised feature support in order to avoid the existing drawbacks discussed above.

[0008] According to an aspect, the above need is at least partly met by a device according to claim 1, a corresponding method and a corresponding computer program according to claims 9 and 14, and a system according to claim 15.

[0009] In one aspect, the present disclosure provides a device for wirelessly charging a leadless implant. The device may comprise a plurality of inductive charging coils for wirelessly providing the energy according to at least one operating parameter and a controller coupled to the plurality of inductive charging coils. The controller may be configured to select the at least one operating parameter out of a set of operating parameters of the plurality of inductive charging coils.

[0010] An underlying idea of the present invention is that a major limitation of prior art approaches for wirelessly providing energy to / charging implants, i.e., by an alternating magnetic or electromagnetic field is that they require for the implant and a charging device (which wirelessly provides energy) to be sufficiently aligned. This means that an inductive charging coil of the implant for wirelessly receiving energy and an inductive charging coil of the charging device for wirelessly providing energy need to be aligned such that their coupling axes are aligned co-axially, i.e., their symmetry axes, which extend along a longitudinal direction of the coils overlap or are at least offset along a common axis. However, already the offset between the coupling axes along a common axis causes a significant decrease in the energy transfer between the inductive charging coil of the implant and the inductive charging coil of the charging device. This efficiency decrease is even more severe, if the coupling axes are not only offset along a common axis but also rotated relative to each other. The latter is quite common, and hence, charging implants wirelessly is quite inefficient, and charging times are quite long. Therefore, existing approaches for wirelessly charging rechargeable batteries, e.g., by means of a venous access procedure or by means of a pillow or a mask, may significantly interfere with a patient’s daily routine, and hence, existing wireless charging approaches may not be well accepted.

[0011] Based on the above, the proposed device for wirelessly charging a rechargeable battery of a leadless implant comprises a plurality of inductive charging coils which may be operated in different ways, i.e., they may wirelessly provide energy according to different operating parameters. There may be one or more operating parameters for one or more or all inductive charging coils of the device. Accordingly, the wireless energy may be operated according to one or more operating parameters out of a set of operating parameters of the charging coils of the device. The selection of one or more operating parameters out of a set of operating parameters is understood to lead to a selection of a subset of the set of available operating parameters. An operating parameter may relate to a single one or a subset of the charging coils of the device. Additionally or alternatively, another operating parameter may relate to all coils collectively. All available operating parameters may define a set of operating parameters for the plurality of inductive charging coils of the device.

[0012] In an example, the set of operating parameters of the plurality of inductive charging coils of the device may comprise at least one of an indication to turn on or off one or more inductive charging coils of the plurality of inductive charging coils, a charging mode, an indication of an energy level, an indication of an energy level change, an indication of a frequency, and an indication of a frequency change. Selecting from the set of operating parameters one or more operating parameters and wirelessly providing energy according to the selected one or more parameters advantageously allows for significantly improving the efficiency of wirelessly charging a leadless implant. This may be achieved, for example, as according to the one or more operating parameters for the plurality of inductive charging coils, the one or more inductive charging coils can be selected which may provide the best inductive coupling between the inductive charging coils of the device and the inductive charging coil of the leadless implant. For example, according to the indication of which one or more inductive charging coils of the set of inductive charging coils are to be turned on and / or off, the one or more inductive charging coils may be turned on for wirelessly providing energy which provide the best inductive coupling, while the others may be turned off. Additionally or alternatively, an energy level and / or a frequency of the wirelessly provided energy can be adjusted by one or more or all inductive charging coils according to the indication of the energy level and / or the indication of the energy level change and / or the indication of the frequency and / or the indication of the frequency change. Additionally or alternatively, this may also comprise selecting a charging mode. Thereby, not only the charging time may efficiently be controlled but also implications such as temperature changes of the device and / or the leadless implant may efficiently be controlled, as will be readily understood by the skilled person, and as will become apparent from the further description.

[0013] In an example, the indication of an energy level may indicate that an induced voltage at the leadless implant may be in a range of 50 mV to 5 V. In another example, an induced current at the leadless implant may be in a range of 1 pA to 100 mA. In a further example, the indication of the energy change may indicate that an induced voltage at the leadless implant changes by 1 V, preferably by 100 mV, more preferably by 10 mV, even more preferably by 1 mV. Additionally or alternatively, the indication of the energy change may indicate that an induced current at the leadless implant changes by 10 mA, preferably by 5 mA, more preferably by 1 mA, even more preferably by 0.1 mA.

[0014] In still a further example, the indication of the frequency may indicate a frequency of the alternating magnetic or electromagnetic field. The frequency may comprise a frequency in the range of 1 kHz to 40 kHz, preferably 5 kHz to 10 kHz. In still a further example, the indication of the frequency change may indicate a change in frequency of 5 kHz, preferably 1 kHz, more preferably 500 Hz, even more preferably 100 Hz.

[0015] In an example, the charging mode may comprise a high-power mode and a low power mode (e.g. a trickle charge mode). In an example, the low power mode slowly recharges the battery of the leadless implant in contrast to pushing a large amount of energy into the leadless implant in the high-power mode. Therefore, the high-power mode may provide a faster charging capability of the rechargeable battery than the low power mode. In an example, in the high-power mode, a voltage of up to 5 V and / or a current of up to 10 mA may be temporarily induced at the leadless implant, wherein temporarily means as long as a temperature limit may not be exceeded associated with the leadless implant as described herein. In a low power mode, 50 mV to 2.5 V, preferably 50 mV to 1.5 V, more preferably 50 mV to 1 V and / or 1 pA to 1 mA, preferably 1 A to 250 pA, more preferably 1 pA to 50 pA may be induced in the leadless implant. The low power mode may minimize the need for focused recharging engagements, e.g., petitioning the patient to sit in a specific place at a specific time on a specific day of the week. The low power mode may also allow for reducing the need to constantly manage the thermal consequences associated with the high-power mode as described herein. The high-power mode may, however, be advantageous in situations, where the battery of the implant has not been recharged for a lengthier than intended duration.

[0016] In a further aspect, the controller may be further configured to receive control information associated with the device and / or the leadless implant.

[0017] In still a further aspect, the controller may be configured to select the at least one operating parameter based, at least in part, on the received control information. Hence, the at least one operating parameter may be selected based on the current needs of the device and / or the leadless implant, e.g. as indicated by the control information.

[0018] In still a further aspect, the control information which may be used to select the at least one operating parameter may comprise temperature information of the device and / or user input received by the device and / or temperature information of the leadless implant and / or an energy level of the leadless implant and / or an energy demand of the leadless implant and / or an indication of a flux linkage between the device and the leadless implant.

[0019] In an example, a leadless implant may be surrounded by adipose, vascular, and muscular tissues as already described above. Heat that may build up in the leadless implant due to processing and / or a charging of a rechargeable battery in the leadless implant may ideally be conducted away through these tissues and / or through blood flow. However, temperatures exceeding certain limits may injure or permanently damage those tissues and eventually organs. The ability of human tissue to withstand hyperthermic conditions may be governed by a complex set of factors including the type of tissue involved, the temperature, and the duration of exposure. While, under normal operating conditions, the leadless implant may have an average temperature of approximately 37 °C, reflective of the average temperature of the surrounding human physiology at the location of the leadless implant, excessive temperature increases that violate the conditions outlined in Section 17.1 of ISO 14708-2 are problematic for patient safety considerations.

[0020] Therefore, the temperature of the leadless implant may be monitored, e.g., by one or more temperature sensors comprised by the leadless implant. This may be particularly important when wirelessly charging a rechargeable battery of the leadless implant. The leadless implant may comprise a number of metallic components. It may further comprise a housing comprising biocompatible metallic material, e.g., titanium. Therefore, depending on how much energy is wirelessly provided and at which frequency the energy is wirelessly provided for charging the rechargeable battery, not only may the battery heat up, but also the metallic components and the housing of the leadless implant may heat up. This may be caused by the fact that through magnetic induction, eddy currents may be induced in the metallic components and / or in the housing. A magnitude of the induced eddy currents may be a function of the frequency and magnitude of the magnetic flux, and the magnitude of the temperature increase in the leadless implant may be a function of the magnitudes of the eddy currents, the resistances of the components carrying the eddy currents, and the total energy transferred during the recharging operation. In an example, a housing comprising glass, lightweight polycarbonate, and / or thermoplastic polymer may be helpful. Additionally or alternatively, the leadless implant may gather temperature information by one or more temperature sensors and provide this information to the device. Therefore, the leadless implant and the device for wirelessly providing energy may comprise wireless data communication means, e.g., a wireless data communication module comprising a wireless data transmitter and a wireless data receiver. Based on this temperature information from the leadless implant, the device for wirelessly providing energy can select corresponding one or more operating parameters for the plurality of inductive charging coils used for wirelessly proving energy in order to control the amount of the wirelessly provided energy, as described herein.

[0021] Additionally or alternatively, a similar temperature information may also be gathered in the device itself. This may be particularly important, if the device may be in physical contact with the patient’s body. Therefore, the explanations with regard to the heating consequences described herein with regard to the leadless implant are also applicable to the device for wirelessly providing energy, as readily understood by the skilled person. In addition or alternatively, the device for wirelessly providing energy may comprise at least one heat dissipation element. In an example, the heat dissipation element may be a thermally conductive fiber. The heat dissipation element advantageously assists in avoiding overheating at physical contact points of the device with the patient.

[0022] Additionally or alternatively, a user input may be gathered by the device. The device may comprise a user interface configured to receive input from the user (patient). Potential user inputs may be a trigger signal to start the charging process, a relative charging speed and / or a selected charging time window.

[0023] Additionally or alternatively, the leadless implant may also communicate, e.g., by a wireless data transmitter, an energy level of its rechargeable battery and / or its energy demand to the device. Depending on the energy level of the leadless implant and / or on the energy demand of the leadless implant, the device for wirelessly providing energy may select the at least one operating parameter for the one or more inductive charging coils of the plurality of charging coils such that the amount of wirelessly provided energy is controlled, as described herein. In an example, the device for wirelessly providing energy may select the at least one operating parameter to enable (turn on) further one or more inductive charging coils for wirelessly providing energy and / or it may increase the wirelessly provided energy by the plurality of inductive charging coils, when the energy level of the leadless implant is low and / or the energy demand of the leadless implant is high. In case that the energy level of the battery is high and / or the energy demand is low, the device for wirelessly providing energy may select the at least one operating parameter to disable (turn off) further one or more inductive charging coils for wirelessly providing energy and / or it may decrease the wirelessly provided energy by the plurality of inductive charging coils.

[0024] Additionally or alternatively, the control information may comprise an indication of a flux linkage between the device and the leadless implant. In an example, the device may determine the indication of flux linkage, e.g., as a function of a resulting inductance of the plurality of inductive charging coils of the device and an inductive charging coil of the leadless implant. In still a further example, a resonator may be used, e.g. by the device, whose frequency may be a function of the resulting inductance. The frequency may then be an indication of the amount of energy transmitted to the leadless implant, e.g., the higher the frequency of the resonator is, the better the flux linkage, i.e., the higher the amount of energy that may be provided to the leadless implant. In an example, the device may turn on a first inductive charging coil and determine a first resulting frequency of the resonator. Then the device may turn off the first inductive charging coil and turn on a second inductive charging coil different from the first inductive charging coil and determine a second resulting frequency of the resonator, and so on. The device may then select the at least one operating parameter for the plurality of inductive charging coils such that the one or more inductive charging coils for which the indication of the amount of energy provided to the leadless implant is highest, i.e., for which the resulting frequency of the resonator is highest, are used for wirelessly providing energy while the other inductive charging coils may not be used.

[0025] In another example, an indication of the amount of energy wirelessly received at the leadless implant may be transmitted to the device as an indicator of the flux linkage. The device may then select the at least one operating parameter based thereon. In one example, the leadless implant may communicate, e.g., by the wireless data transmitter, information such as the induced voltage and / or the induced current to the device for wirelessly providing energy, as described herein. The device may then select the at least one operating parameter for the plurality of inductive charging coils such that the one or more inductive charging coils for which the induced voltage and / or the induced current at the leadless implant is highest.

[0026] In an example, the controller may be configured to select the at least one operating parameter, as described herein, in a startup sequence, upon a patient-triggered event, and / or in a dynamic routine. In a further example, the selecting of the at least one operating parameter may comprise: wirelessly providing energy to the leadless implant by first one or more coils; receiving, in response, first control information, as described herein; wirelessly providing energy to the leadless implant by second one or more coils different from the first coils; receiving, in response, second control information; determining the at least one operating parameter based on the received first and second control information. In still a further example, the device may comprise one or more sensors that are configured to detect that the patient is engaging with the device to select the at least one operating parameter, as described herein, e.g. in a startup sequence. In still a further example, the selection of the at least one parameter may be carried out periodically and / or whenever a changing condition may be detected as part of a dynamic routine. This ensures that the patient always receives the most efficient charging support. In still a further example, the patient my trigger the selecting of the at least one operating parameter, e.g. by pressing a button of the device.

[0027] In an example, an inductive charging coil of the plurality of charging coils of the device for wirelessly providing energy may be a loop of any shape, e.g., it may be a ring-shaped loop, a square-shaped loop or it may have any other shape. The shape may depend on the form or shape of the device, thereby allowing an optimum integration of the plurality of inductive charging coils in the device. In a further example, a ring-shaped loop may have a diameter of 5 cm, preferably 8 cm, even more preferably 10 cm. The larger the size of the loop, the more efficient the wireless energy transfer between the device and the leadless implant may be. The loop may comprise one or preferably more windings.

[0028] In an example, the plurality of coils may be arranged regularly in a (for example, two- dimensional or three-dimensional) matrix-like structure. For example, two successive inductive charging coils may essentially abut, wherein “essentially” is to be understood as being produced within the achievable technical tolerance, as known to the skilled person. In addition or alternatively, the plurality of coils may be arranged irregularly. In an example, one or more of the inductive charging coils of the plurality of inductive charging coils may be arranged such that its / their coupling axis / axes is / are not aligned with the coupling axes of at least one of the remaining inductive charging coils, i.e., they are not co-axial. In an example, the one or more non-aligned coupling axes may be perpendicular. In an example, the plurality of inductive charging coils may form one or more arrays. An array may comprise two or more inductive charging coils. The two or more inductive charging coils of the array may be operated such that an alternating magnetic or electromagnetic field is directed into a specific direction. In an example, the device may comprise two inductive charging coils, preferably three coils, more preferably multiples of three coils. In addition or alternatively, the at least two inductive charging coils may be arranged essentially perpendicularly to each other, i.e., their coupling axes may essentially be perpendicular to each other. Two essentially perpendicular inductive charging coils advantageously allow to provide an alternating magnetic or electromagnetic field in any direction in a two- dimensional space. Three essentially perpendicular inductive charging coils advantageously allow to provide an alternating magnetic or electromagnetic field in any direction in a three- dimensional space. In a further example, the plurality of inductive charging coils may be arranged in arrays, wherein each array may comprise two essentially perpendicular inductive charging coils, preferably three essentially perpendicular inductive charging coils. In other words, the individual charging coils may be arranged in any possible orientation with respect to each other and with respect to the surface of the device.

[0029] In one aspect, the device for wirelessly providing energy may be a garment or wearable. In an example, it could be a vest that could be worn as either an undergarment or, beyond supporting medical needs, for purposes of warmth in cooler weather, a brassiere, a bathrobe, a shirt, a jacket, blankets, a tie, and so on. In the case of garments or wearables, it may be possible to have the simple act of hanging one’s clothing onto a clothing rack or docking a wearable serve as a convenient way to have them ready and available for patient use. In addition or alternatively, the device for wirelessly providing energy may be a mattress, a blanket, a heart monitor strap, a seatbelt, a shoulder strap, and so on. It may also be any accessory used in daily life. These realizations of the device advantageously allow a seamless integration in a patient’s daily routine, and thereby, minimize the impact they have on the patient. In preferred support modalities, the patient would have a multitude of such external charging resources in effect to maximize engagements with their implanted device subject to the spectrum of intended routines typical to their day.

[0030] In a further aspect, the device may comprise an energy supply. The energy supply may be a rechargeable battery. It may also be a non-rechargeable battery. In addition or alternatively, the energy supply may comprise a plug to connect the device to the mains voltage, to a car battery or any other external battery or energy source for providing energy to the device and / or recharging the rechargeable battery of the device.

[0031] In another aspect, a leadless implant is provided. The leadless implant may comprise a rechargeable battery. The leadless implant may also comprise a non-rechargeable battery. The leadless implant may also comprise at least one inductive charging coil for wirelessly receiving energy. The wirelessly received energy may be, at least in part, used for charging the rechargeable battery. The recharging may be carried out as described herein. The wirelessly received energy may also be used for the processing carried out by the leadless implant. In a further example, the wirelessly received energy may in addition or alternatively be used to charge a capacitor which may be used to capture any energy that may not be used for charging the rechargeable battery and / or for processing carried out by the leadless implant. The capacitor may be a further energy supply of the leadless implant.

[0032] The leadless implant may comprise any of the further features described herein with reference to a leadless implant, e.g. one or more temperature sensors, wireless communication means for transmitting control information (e.g. concerning the charging state and / or process, about an energy demand and / or an energy level and / or an indication of a flux linkage) to the device, etc.

[0033] In a further aspect, the leadless implant may comprise two inductive charging coils, more preferably three inductive charging coils. In an example, the two or three inductive charging coils may be arranged essentially perpendicularly to each other. As described herein, two or three inductive charging coils arranged essentially perpendicular to each other advantageously allow for wirelessly receiving energy from any direction in a two- dimensional or three-dimensional space, respectively. Thereby, the efficiency for wirelessly providing energy to the leadless implant significantly increases.

[0034] In another aspect, an inductive charging coil of the leadless implant may be a loop of any shape, e.g., it may be a ring-shaped loop, a square-shaped loop or it may have any other shape. The shape may depend on the form or shape of the leadless implant. In a further example, a ring-shaped loop may have a diameter of less than 8 mm, preferably less than 7 mm, more preferably less than 6 mm. The loop may comprise one or preferrably more windings.

[0035] In another aspect, the leadless implant may be a leadless cardiac implant, preferably a leadless pacemaker, a cardiac monitor or a pressure sensor. In another aspect, a method may be provided for wirelessly providing energy to a leadless implant by a device comprising a plurality of inductive charging coils. The method may comprise selecting at least one operating parameter out of a set of operating parameters of the plurality of inductive charging coils, and wirelessly providing the energy to the leadless implant by the plurality of inductive charging coils according to the selected at least one operating parameter. The method may optionally also comprise further steps, which are described herein with reference to a device for wirelessly providing energy to the leadless implant.

[0036] In a further aspect, a computer program (product) may be provided, the computer program (product) comprising instructions for carrying out the steps and / or implementing the means described herein. For example, the instructions may be stored on a memory medium and it may cause a processor to implement the individual steps. The memory medium and / or the processor may be comprised by a device for wirelessly providing energy to the leadless implant according to the present invention. The device for wirelessly providing energy to the leadless implant of the present invention may generally comprise the computer program (product) of the present invention.

[0037] In a further aspect, a system may be provided. The system may comprise a leadless (cardiac) implant comprising at least one first inductive charging coil configured to wirelessly receive energy, and a device comprising a plurality of second inductive charging coils configured to wirelessly provide energy to the leadless cardiac implant. The leadless cardiac implant may optionally comprise any features as described herein with reference to a leadless implant. The device configured to wirelessly provide energy to the leadless cardiac implant may in addition or alternatively comprise any features as described herein with reference to a device for wirelessly providing energy to a leadless implant.

[0038] In a further aspect, methods may be provided for wirelessly receiving energy from a device comprising a plurality of inductive charging coils by a leadless implant and for carrying out steps as described herein with regard to a system. The methods may optionally also comprise steps, which are described herein with reference to a device for wirelessly providing energy to the leadless implant and a leadless implant.

[0039] In a further aspect, computer programs or computer program products comprising instructions for carrying out the steps and / or implementing the means described herein may be provided. As described herein, the computer program instructions may be stored on a memory medium and it may cause a processor to implement the individual steps. The memory medium and / or the processor may be comprised by a leadless implant and a system of the present invention.

[0040] It is noted that the methods as described herein may include all aspects described herein, even if not expressly described as method steps but rather with reference to an apparatus (or device). Moreover, the devices as outlined herein may include means for implementing all aspects as outlined herein, even if these may rather be described in the context of method steps.

[0041] Whether described as method steps, computer program and / or other means, the functions described herein may be implemented in hardware, software, firmware, and / or combinations thereof. If implemented in software / firmware, the functions may be stored on or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, FPGA, CD / DVD or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. In order to better understand the present invention and to appreciate its practical applications, the following figures are provided and referenced hereafter. It should be noted that the figures are given as examples only and in no way limit the scope of the invention.

[0042] Fig. 1 schematically shows an example of a leadless implant in form of a leadless pacemaker;

[0043] Fig. 2 presents schematically an example of a device for wirelessly providing energy according to the invention;

[0044] Fig. 3 a schematically shows a portion of a device for wirelessly providing energy according to the invention comprising two co-aligned inductive charging coils;

[0045] Fig. 3b schematically shows a portion of a device for wirelessly providing energy according to the invention comprising two inductive charging coils, wherein coupling axes of the two inductive charging coils are essentially perpendicular;

[0046] Fig. 4a presents an example use case of the present invention, where a patient rests on a mattress, and the mattress being an embodiment of the device for wirelessly providing energy according to Fig. 2;

[0047] Fig. 4b presents a further example use case of the present invention, where a patient wears a vest, and the vest being an embodiment of the device for wirelessly providing energy according to Fig. 2.

[0048] In the following, the present disclosure will be more fully described hereinafter with reference to the accompanying figures, in which exemplary embodiments of the invention are illustrated. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and will convey the scope of the invention to persons skilled in the art. In Fig. 1, an example of a leadless pacemaker 100 is shown, which may be an example of a leadless implant, as described herein.

[0049] In this example, the leadless pacemaker 100 comprises a sealed housing 105 and fixation elements 110, 111 disposed at a proximal and a distal end of the housing 105, respectively. The sealed housing 105 may be of a cylindrical shape. The cylindrical housing 105 may have a diameter of approximately 7 mm such that the leadless pacemaker is small enough to be inserted into a ventricle of a heart by means of a catheter (not shown), as will be apparent to the person skilled in the art. The housing 105 may comprise biocompatible metallic material such as titanium. The housing 105 may also comprise glass, a lightweight polycarbonate, and / or thermoplastic polymer, as described herein. Fixation elements 110 at the distal end of the housing 105 may be any suitable elements for fixating the leadless pacemaker 100 in cardiac tissue. Fixation element 111 may be any suitable element for releasably fixing the leadless pacemaker to the catheter (not shown). They may be formed of or comprise any suitable material and include any suitable shape as known to the skilled person. Examples of fixation elements are screws, hooks (also termed tines), barbs and sutures. The leadless pacemaker may include a single distal fixation element 110 (e.g. a single screw or helix-type fixation element) or more than one distal fixation element (a plurality of fixation elements, e.g. a plurality of tines).

[0050] Within the housing 105, the leadless pacemaker 100 may comprise an energy supply 120, electronic components 130, and elements 140 for receiving energy wirelessly. The energy supply may comprise a rechargeable battery 125 as described herein. The energy supply may additionally comprise a non-rechargeable battery (not shown). The electronic components 130 may comprise a controller 131 and a wireless data communication module 132. The elements 140 for receiving energy wirelessly may comprise a single inductive charging coil 141. The elements 140 may also comprise two inductive charging coils 141 or the elements 140 may even comprise three inductive charging coils 141. The two or three inductive charging coils 141 may be arranged that their coupling axes, as described with regard to Fig. 3, are not aligned. In an example, the two or three inductive charging coils 141 may be arranged that their coupling axes are perpendicular, as described with regard to Fig. 3b. The elements 140 may provide the wirelessly received energy to the rechargeable battery 125 of the energy supply 120 for charging. The elements 140 may also provide only a portion of the wirelessly received energy to the rechargeable battery 125 of the energy supply 120. Another portion or the wirelessly received energy may also be used for the electronic components 130. A still further portion of the wirelessly received energy, which may not be needed for charging the rechargeable battery 125 and / or for the electronic components 130, may be used to charge, e.g., a capacitor (not shown) which may be a further energy supply for the leadless pacemaker 100. This may be helpful to not wasting any of the wirelessly received energy. The controller 131 of the electronic components 130 may be configured to control the portions of the wirelessly received energy, as described above.

[0051] The controller may further be configured to gather control information such as temperature information of the leadless pacemaker 100, which may be obtained via one or more temperature sensors (not shown). As will be appreciated by the skilled person, the temperature information may be used by device 200 (as shown in Fig. 2) to avoid an overheating of the leadless pacemaker such that damage to organs is avoided, as described herein. The control information may also comprise information such as a voltage level and / or a current level of the wirelessly received energy and / or an energy level of the battery 125 (e.g., a voltage level) and / or an energy demand of the electronic components 130 for carrying out certain tasks, as described herein. This gathered information may be provided to the wireless data communication module 132 for communication to a device 200 (as shown in Fig. 2) for wirelessly providing energy to the leadless pacemaker 100. The wireless data communication module 132 may comprise a wireless data transmitter and a wireless data receiver (not shown) for comminating with the device 200.

[0052] In Fig. 2, an example of a device 200 for wirelessly providing energy to a leadless implant 100, e.g., the leadless pacemaker, as depicted in Fig. 1, is schematically illustrated. The device 200 may comprise an energy supply 210. The energy supply 210 may comprise a rechargeable battery. It may also comprise a non-rechargeable battery. The energy supply 210 may also comprise a plug 215. The plug 215 may be suitable for connecting it to any external power source such as the mains voltage, a car battery, and / or any other external battery or energy source. Thereby, the rechargeable battery of the energy supply 210 may be charged and / or energy may be provided to power the device 200 via the external energy source.

[0053] The device 200 may further comprise a controller 220, and possibly also a wireless data communication module 230. In accordance with the present invention, the device 200 also comprises elements 240 for wirelessly providing energy to the leadless implant, as also described with respect to Fig. 1. The elements 240 may comprise a plurality of inductive charging coils 241 for wirelessly providing energy the leadless implant 100 via an alternating magnetic or electromagnetic field. The device 200 may comprise at least two inductive charging coils 241. The device 200 may also comprise any other number of inductive charging coils 241. As illustrated in Fig. 2, the plurality of inductive charging coils 241 may be arranged in a matrix-like structure, where the plurality of inductive charging coils 241 abut or wherein a space between two successive inductive charging coils 241 is essentially the same. As will be appreciated by the person skilled in the art, any arrangement of the inductive charging coils 241 may be possible. In contrast to the discussed regular arrangement, an irregular arrangement may be possible. Two or more of the coils may also overlap fully or partially.. Even more so, two or more of the coils may be arranged such that their coupling axes are not aligned, as described herein. For example, the device may comprise two inductive charging coils 241 which may be arranged such that their coupling axes are essentially perpendicular, as described with regard to Fig. 3b. To briefly illustrate how such an arrangement would look like: If the device would be in the form of a blanket or mattress, one charging coil would be oriented having the plane of the coil windings essentially parallel to the plane of the blanket or mattress (like a spring in a mattress) and one charging coil would be oriented having the plane of the coil windings essentially perpendicular to the plane of the blanket or mattress (like a spring lying in the mattress). Further details are described in Fig. 3b. In another example, the device 200 may comprise three inductive charging coils 241 which may be arranged such that their coupling axes are essentially perpendicular. In a further example, the plurality of inductive charging coils 241 may be arranged in arrays. In an example, two or more inductive charging coils 241 may form an array. In an example, the two or more inductive charging coils 241 may be consecutive inductive charging coils 241. In a further example, an array may be formed of two inductive charging coils 241 which may be arranged such that their coupling axes are essentially perpendicular, as described with regard to Fig. 3b. In a further example, an array may be formed of three inductive charging coils 241 which may be arranged such that their coupling axes are essentially perpendicular. In a further example, the plurality of inductive charging coils 241 may be arranged in arrays of two or three inductive charging coils 241, wherein the two or three inductive charging coils may be arranged such that their coupling axes are essentially perpendicular.

[0054] In the example of Fig. 2, the plurality of inductive charging coils 241 wirelessly provide energy in form of an alternating magnetic or electromagnetic field, as described above, according to at least one operating parameter. The controller 220 may select the operating parameter from a set of operating parameters of the plurality of inductive charging coils 241. In an example, the controller 220 of the device 200 may be configured to select the at least one operating parameter as follows: The controller 220 may wirelessly provide energy to the leadless implant 100 by a first inductive charging coil 241. In response, the controller 220 may receive first control information. Then, the controller may wirelessly provide energy to the leadless implant 100 by a second inductive charging coil 241 different from the first inductive charging coil 241. In response, the controller 220 may receive second control information. The controller 241 may proceed with this procedure until energy is provided wirelessly to the leadless implant 100 by any of the inductive charging coils 241, and corresponding control information is received. The controller 241 may then determine the at least one operating parameter based on the received control information. As described herein, this routine may be carried out by the controller 220 as a startup sequence, as a patient-triggered event, and / or as a dynamic routine. As further described herein, the controller 220 may carry out the routine as a startup sequence, e.g., when the controller 241 receives information from a sensor (not shown) or any other element that detects that a patient is engaging with the device 200. In an example, this sensor or element may be a pressure sensor. In a further example, the routine may be carried out as a user-triggered event, e.g., when the user of the device 200 (a patient) presses a button. As will be appreciated by the skilled person, any other means may be provided to the patient such that he / she is able to trigger the routine. In a still further example, the routine may be a dynamic routine, e.g., the routine may be carried out periodically, e.g., every hour. The skilled person understands that any other interval may be foreseen to carry out the routine dynamically, e.g., whenever a changing condition is detected, e.g., as described with regard to Fig. 4.

[0055] In an example, the received control information by the controller 220 may comprise an indication of a flux linkage between the plurality of inductive charging coils 241 of the device 200 and the inductive charging coil 141 of the leadless implant 100. In an example, the device 200 may determine the indication of flux linkage as a function of the resulting inductance of the inductive charging coil 241 of the device 200 for wirelessly providing energy and the inductive charging coil 141 of the leadless implant 100. In an example, the device 200 may determine the indication of flux linkage as a function of the reflected or transmitted power. The corresponding signatures may serve as an indication of the flux linkage loading. In an example, the controller 220 may comprise a resonator (not shown), whose frequency may be a function of the resulting inductance. The frequency of the resonator may then be an indication of the flux linkage, i.e., an indication of the amount of energy that is wirelessly provided to the leadless implant 100. In an example, the indication of the flux linkage may be the higher, i.e., the amount of energy wirelessly provided to the leadless implant 100 may be the higher, the higher the frequency of the resonator is.

[0056] In another example, the received control information by the controller may additionally or alternatively comprise temperature information of the device 200. The temperature information may be obtained by one or more temperature sensors (not shown). As will be appreciated by the skilled person, the temperature information may be used by device 200 to avoid an overheating at physical contact points of the device 200 with the patient, as described herein.

[0057] In a further example, the controller 220 may receive control information from the leadless implant 100, as described above with respect to leadless implant 100. In order to exchange control information between device 200 and leadless implant 100, the device 200 may comprise a wireless data communication module 230, similarly as described above with regard to the leadless implant 100. In still another example, the controller 220 may use the control information to select the at least one operating parameter from a set of operating parameters for operating the inductive charging coils 241, as described herein. In an example, the set of operating parameters of the plurality of inductive charging coils 241 of the device 200 may comprise at least one of an indication to turn on or off one or more inductive charging coils 241 of the plurality of inductive charging coils 241, a charging mode, an indication of an energy level, an indication of an energy level change, an indication of a frequency, and an indication of a frequency change. For example, according to the operating parameters, the controller 220 may turn on and / or off one or more inductive charging coils 241 of the set of inductive charging coils 241. Additionally or alternatively, the controller 220 may adjust an energy level and / or a frequency of the wirelessly provided energy by one or more or all inductive charging coils 241 according to the indication of the energy level and / or the indication of the energy level change and / or the indication of the frequency and / or the indication of the frequency change. In an example, the indication of an energy may indicate that an induced voltage at the leadless implant 100 may be in a range of 50 mV to 5 V. In another example, the induced current at the leadless implant 100 may be in a range of 1 pA to 10 mA. In a further example, the indication of the energy change may indicate that the induced voltage at the leadless implant 100 changes by 1 V, by 100 mV, by 10 mV, or by 1 mV. Additionally or alternatively, the indication of the energy change may indicate that the induced current at the leadless implant 100 changes by 10 mA, by 5 mA, by 1 mA, by 0.1 mA. In still a further example, the indication of the frequency may indicate that the alternating magnetic or electromagnetic field comprises a frequency in the range of 1 kHz to 40 kHz, or 5 kHz to 10 kHz. In still a further example, the indication of the frequency change may indicate a change of the frequency of the alternating magnetic or electromagnetic field by 5 kHz, by 1 kHz, by 500 Hz, or by 100 Hz.

[0058] Additionally or alternatively, the controller 220 may select a charging mode. In an example, the charging mode may comprise a high-power mode and a low power mode. In an example, in the high-power mode, a voltage of up to 5 V and / or a current of up to 100 mA may be temporarily induced at the leadless implant 100, wherein temporarily means as long as a temperature limit may not be exceeded in the leadless implant 100 and / or the device, as described herein. In a low power mode, 50 mV to 2.5 V, or 50 mV to 1.5 V, or 50 mV to 1 V, or 5 mA to 20 mA, or 2.5 mA to 10 mA, or 1.5 mA to 5 mA may be induced at the inductive charging coil 141 of the leadless implant 100.

[0059] In still a further example, the device 200 may additionally or alternatively also comprise one or more heat dissipation elements (not shown). In an example, the one or more heat dissipation elements may comprise a thermally conductive fiber. As will be appreciated by the skilled person, any heat dissipation element may be used for device 200 which assists in avoiding overheating at physical contact points of the device 200 with the patient, as described herein.

[0060] In the example of Fig. 3, portions 300a and 300b of the device 200 are depicted. Portion 300a shows an arrangement of two inductive charging coils 310a, 320a, whereby the cross section of the two charging coils is shown. The two charging coils 310a and 320a comprise several coil windings around the respective central axes 311a and 321a. The two inductive charging coils 310a and 320a are arranged such that their coupling axes (e.g. the central axes of the wounded coil) 311a and 321a are co-aligned, though offset with respect to a common axis 331a. The coupling axis 31 la, 321a of an inductive charging coil 310a, 320a is defined as the symmetry axis of the inductive charging coil 310a, 320a along a longitudinal direction of the inductive charging coil 310a, 320a, as can be verified from Fig. 3a. Accordingly, two inductive charging coils are co-aligned if their coupling axes are translated (shifted) in a general three-dimensional space relative to each other (e.g. if they are parallel). Two inductive charging coils are considered to be not aligned if their coupling axes are not only translated (shifted) but also rotated in a general three-dimensional space relative to each other.

[0061] Portion 300b shows an arrangement of two inductive charging coils 310b and 320b, wherein the two inductive charging coils 310b and 320b are arranged such that their coupling axes 311b and 321b are essentially perpendicular. Again the cross section of the two charging coils 310b and 320b is shown. The two charging coils 310b and 320b comprise several coil windings around the respective central axes 311b and 321b. Accordingly, in the example of Fig. 3b, the inductive charging coils 310b and 320b are not aligned, as their coupling axes 311b and 321b are translated and rotated in a two-dimensional space x-y. In the example of Fig. 4a, an example use case 400a of the present invention is shown. In this example, the device 200 may be a mattress 420a comprising a plurality of inductive charging coils 430a. In the depicted example, the plurality of inductive charging coils 430a may be arranged in a matrix-like structure. However, as described already with respect to Fig. 2, any arrangement and any number of inductive charging coils 430a may be considered. In this example, a patient 410a having a leadless implant (not shown) may rest on the mattress 420a. During the time the patient 410a rests on mattress 420a, the leadless implant may be charged via the mattress 420a, as described herein. The mattress 420a may only be partly equipped with inductive charging coils 430a or completely equipped with inductive charging coils 430a, i.e., the full three-dimensional space provided by the mattress may be used to provide inductive charging coils 430. In a further example, the mattress 420a may be adapted to the specific needs of the patient 410a. In an example, the inductive charging coils 430a may be arranged in areas that are most closely to the patient’ s one or more leadless implants (not shown), when the patient 410a rests on the mattress 420a. In a further example, the inductive charging coils 430a may be arranged such as to ensure that the patient 410a still receives charging support even when the patent 410a shifts positions on the mattress 420a. In still a further example, the mattress 420a may additionally be equipped with a sensor, such as a pressure sensor (not shown), which may be configured to provide information about the patient engaging with the mattress 420a, as described herein. The sensor may also provide information about the patient 410a shifting a position on the mattress 420a. This information may also be used for carrying out a routine for selecting the at least one operating parameter as part of a dynamic routine, as described herein.

[0062] In the example of Fig. 4b, another example use case 400b of the present invention is shown. In this example, the device 200 may be a vest 420b comprising a plurality of inductive charging coils 430b. In the depicted example, the plurality of inductive charging coils 430b may be arranged irregularly. In the example, the inductive charging coils 430b are arranged regularly in a vertical direction, and they are arranged irregularly in a horizontal direction. The inductive charging coils 430b may be arranged on the front of the vest 420b and / or on the back of the vest 420b. However, as described already with respect to Fig. 2, any arrangement and any number of inductive charging coils 420a may be considered. Similarly as described above with respect to Fig. 4a, for the arrangement of the inductive charging coils 420a, also the specific needs of the patient 410b may be taken into consideration. In this example, a patient 410b having a leadless implant (not shown) may wear the vest 420b as either an undergarment or, beyond supporting medical needs, for purposes of warmth in cooler weather. During the time the patient 410b carries the vest 420b, the leadless implant may be recharged via the vest 420b, as described herein. The vest may be further equipped with any sensor (not shown) to detect when the patient uses the vest such that the leadless implant (not shown) of the patient 410b is wirelessly provided with energy. In an example, the applied sensor may detect closing the front of the vest by a Velcro fastener 421b or pulling tight key cinch(es) 422b.

Claims

Claims1. A device (200) for wirelessly charging a leadless implant (100), the device (200) comprising: a plurality of inductive charging coils (241) for wirelessly providing the energy according to at least one operating parameter; and a controller (220) coupled to the plurality of inductive charging coils (241); wherein the controller (220) is configured to select the at least one operating parameter out of a set of operating parameters of the plurality of inductive charging coils (241).

2. The device (200) of claim 1, wherein the controller (220) is further configured to receive control information associated with at least one of: the device (200) and the leadless implant (100).

3. The device (200) of claim 2, wherein the control information comprises at least one of: temperature information of the device (200), user input received by the device (200), temperature information of the leadless implant (100), an energy level of the leadless implant (100), an energy demand of the leadless implant (100), and an indication of flux linkage between the device (200) and the leadless implant (100).

4. The device (200) of claim 2 or 3, wherein the controller (220) is further configured to select the at least one operating parameter based, at least in part, on the received control information.

5. The device (200) of any of the preceding claims, further comprising at least one heat dissipation element.

6. The device (200) of any of the preceding claims, further comprising an energy supply (210).

7. The device (200) of any of the preceding claims, further comprising:one or more temperature sensors configured to provide temperature information of the device.

8. The device (200) of any of the preceding claims, wherein the device (200) is a garment (420b).

9. A method for wirelessly charging a leadless implant (100) by a device (200) comprising a plurality of inductive charging coils (241), the method comprising: selecting at least one operating parameter out of a set of operating parameters of the plurality of inductive charging coils (241); wirelessly providing the energy to the leadless implant (100) by the plurality of inductive charging coils (241) according to the selected at least one operating parameter.

10. The method of claim 9, further comprising: receiving control information associated with at least one of: the device (200) and the leadless implant (100).

11. The method of claim 10, wherein the control information comprises at least one of: temperature information of the device (200), temperature information of the leadless implant (100), an energy level of the leadless implant (100), an energy demand of the leadless implant (100), and an indication of flux linkage between the device (200) and the leadless implant (100).

12. The method of claim 10 or 11, further comprising: selecting the at least one operating parameter based, at least in part, on the received control information.

13. The method of any of claims 9 to 12, wherein the set of operating parameters of the plurality of inductive charging coils (241) comprises at least one of: an indication to turn on or off one or more inductive charging coils (241) of the plurality of inductive charging coils (241), a charging mode, an indication of an energy level, an indicationof an energy level change, an indication of a frequency, an indication of a frequency change.

14. A computer program comprising instructions for causing a device (200) to execute the steps of any of claims 9 to 13.

15. A system comprising: a leadless cardiac implant (100) comprising at least one first inductive charging coil (141) configured to wirelessly receive energy; and a device (200) comprising a plurality of second inductive charging coils (241) configured to wirelessly provide energy to the leadless cardiac implant (100).

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