System and method for a radio power resonator having a core cavity

Abstract

According to the present disclosure, there is provided a resonator for use in a wireless power transfer system. The resonator of the present disclosure includes a core having a front surface, a back surface, and an annular sidewall extending between the front surface and the back surface, the front surface having an annular groove and a post portion surrounded by the annular groove formed therein, and the back surface having a cavity formed therein, the post portion and the cavity being aligned with a longitudinal axis of the core. The resonator of the present disclosure further includes a coil element disposed within the annular groove in the front surface of the core.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority based on U.S. Provisional Patent Application No. 63 / 036,010, filed on June 8, 2020. The entire disclosure content of the above application is incorporated herein by reference.

[0002] (Technical Field) The present disclosure generally relates to a wireless power transmission system, and more particularly, to a wireless power transmission resonator having a cavity formed in a core of a resonator.

Background Art

[0003] A ventricular assist device (VAD), known as a VAD, is an implantable blood pump and is generally used in patients suffering from conditions where the heart cannot provide sufficient circulation, such as heart failure or congestive heart failure, for both short - term (i.e., days or months) and long - term (i.e., years or lifetime) applications. Patients with heart failure can use a VAD while waiting for a heart transplant or as long - term destination therapy. In another example, a patient can use a VAD during the recovery period after heart surgery. Thus, a VAD can assist a weakened heart (i.e., partially assist) or effectively replace the function of the natural heart.

[0004] For power supply to a VAD, a wireless power transmission system can be used. A wireless power transmission system generally includes an external transmitting resonator and an implantable receiving resonator configured to be implanted in a patient's body. Such a wireless power transmission system is also referred to as a transcutaneous energy transmission system (TETS). [[ID=二十五]] [[ID=二十六]]

[0005] [[ID=二十七]] To improve the operation of wireless power transmission systems, it is generally desirable to reduce the heat generated by the resonator and to miniaturize the resonator. In particular, it is beneficial to reduce the amount of heat generated during the operation of implanted receiving resonators and to miniaturize implanted receiving resonators. [Overview of the project] [Means for solving the problem]

[0006] This disclosure relates to a resonator for use in a wireless power transmission system. The resonator of this disclosure includes a core having a front, a back, and an annular side wall extending between the front and back, wherein the front has an annular groove and a post portion surrounded by the annular groove, and the back has a cavity, the post portion and the cavity being aligned with the longitudinal axis of the core. The resonator of this disclosure further includes a coil element disposed within the annular groove on the front of the core.

[0007] Furthermore, this disclosure relates to a wireless power transmission system. The wireless power transmission system of this disclosure comprises a power supply, a transmitting resonator electrically connected to the power supply, a load, and an implanted receiving resonator electrically connected to the load, wherein the implanted receiving resonator is configured to receive wireless power from the transmitting resonator. The implanted receiving resonator includes a core having a front, a back, and an annular side wall extending between the front and back, wherein the front has an annular groove and a post portion surrounded by the annular groove, and the back has a cavity, wherein the post portion and the cavity are aligned with the longitudinal axis of the core. The implanted receiving resonator further includes a coil element disposed in the annular groove on the front of the core.

[0008] The present disclosure also relates to a method for assembling a wireless power transmission system. The method of the present disclosure includes the steps of electrically connecting a power source to an external transmitting resonator and electrically connecting a load to an implanted receiving resonator, wherein the implanted receiving resonator is configured to receive wireless power from the external transmitting resonator, and the implanted receiving resonator includes a core having a front, a back, and an annular side wall extending between the front and back, the front having an annular groove and a post portion surrounded by the annular groove, and the back having a cavity, the post portion and the cavity being aligned with the longitudinal axis of the core, and a coil element disposed within the annular groove. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a simplified electrical circuit diagram of one embodiment of the wireless power transmission system of the present disclosure. [Figure 2] Figure 2 shows how the wireless power transmission system from Figure 1 is used to supply power to a ventricular assist device (VAD). [Figure 3] Figure 3 is a front perspective view of one embodiment of the resonator 300 that can be used to implement the system shown in Figure 1. [Figure 4] Figure 4 is a perspective view of the rear side of the resonator shown in Figure 3. [Figure 5] Figure 5 is a cross-sectional view of the resonator shown in Figures 3 and 4, and is a cross-sectional view along the line 5-5 in Figure 4. [Figure 6] Figure 6 is a rear perspective view of another resonator that can be used to implement the system shown in Figure 1. [Modes for carrying out the invention]

[0010] This disclosure relates to a system and method for a wireless power resonator. Furthermore, this disclosure relates to a resonator for use in a wireless power transmission system. The resonator of this disclosure includes a core having a front, a back, and an annular sidewall extending between the front and back, wherein the front has an annular groove and a post portion surrounded by the annular groove, and the back has a cavity, the post portion and the cavity aligned with the longitudinal axis of the core. The resonator of this disclosure further includes a coil element disposed within the annular groove on the front of the core.

[0011] Referring next to the drawings, Figure 1 shows a simplified electrical circuit of the wireless power transmission system 100 of the present disclosure. The system 100 comprises an external transmitting resonator 102 and an implantable receiving resonator 104. In the system shown in Figure 1, a power supply Vs is electrically connected to the transmitting resonator 102, and power is supplied to the transmitting resonator 102 from the power supply Vs. The receiving resonator 104 is connected to a load 106 (e.g., an implantable medical device). The receiving resonator 104 and the load 106 may be electrically connected by switching elements or rectifying elements (not shown).

[0012] In this exemplary embodiment, the transmitting resonator 102 includes a coil Lx connected to the power supply Vs by a capacitor Cx. The receiving resonator 104 also includes a coil Ly connected to the load 106 by a capacitor Cy. The coils Lx (inductor Lx) and Ly (inductor Ly) are connected by a coupling coefficient k. Mxy is the mutual inductance between the two coils. The mutual inductance Mxy has the relationship with the coupling coefficient k shown in equation (1) below.

[0013]

number

[0014] During operation, the transmitting resonator 102 wirelessly transmits power supplied from the power supply Vs. The receiving resonator 104 receives the power wirelessly transmitted from the transmitting resonator 102 and supplies the received power to the load 106.

[0015] Figure 2 shows one embodiment in which power is wirelessly transmitted from an external coil 202 (e.g., the transmitting resonator 102 shown in Figure 1) to an implanted coil 204 (e.g., the receiving resonator 104 shown in Figure 1) implanted in the body of a patient 200. The implanted coil 204 uses the power received from the external coil 202 to power an implanted device 206. For example, the implanted device 206 may be a pacemaker or a cardiac pump (e.g., a left ventricular assist device (LVAD)). In some embodiments, the implanted coil 204 and / or the implanted device 206 may have a battery or be connected to a battery.

[0016] In one embodiment, the external coil 202 is communicatively connected to the computer device 210, for example, via a wired or wireless connection, so that it can send and receive signals with the computer device 210. In some embodiments, the computer device 210 also serves as the power source for the external coil 202. In other embodiments, the external coil 202 is connected to another power source (not shown). The computer device 210 comprises a memory device 214 and a processor 212 communicatively connected to the memory device 214. In some embodiments, computer executable instructions are stored in the memory device 214.

[0017] The computer device 210 further comprises a user interface (UI) 216. The user interface (UI) 216 presents information to the user (e.g., patient 200). Examples of the user interface (UI) 216 include a display adapter (not shown) connected to a display device such as a cathode ray tube (CRT), liquid crystal display (LCD), organic LED (OLED) display, and / or "electronic ink" display. In some embodiments, the user interface (UI) 216 includes one or more display devices. Furthermore, in some embodiments, the presentation interface generates audible and / or computer-generated audio content without generating visual content. In an exemplary embodiment, the user interface (UI) 216 displays one or more representations or images designed to assist the patient 200 in positioning the external coil 202 so that the connection between the external coil 202 and the implanted coil 204 is optimal. In some embodiments, the computer device 210 may be a wearable device. For example, in one embodiment, the computer device 210 is a wristwatch, and the user interface (UI) 216 is displayed on the wristwatch.

[0018] Figure 3 is a front perspective view of one embodiment of the resonator 300 of the present disclosure that can be used to implement the system 100 shown in Figure 1. The resonator 300 of the present disclosure can be used, for example, to implement an external transmitting resonator 102, an implanted receiving resonator 104, an external coil 202, and / or an implanted coil 204. Figure 4 is a rear perspective view of the resonator 300 shown in Figure 3. Figure 5 is a cross-sectional view of the resonator 300 shown in Figures 3 and 4, and is a cross-sectional view along line 5-5 in Figure 4.

[0019] As shown in FIGS. 3 to 5, the resonator 300 of the present disclosure includes a core 302 and a coil element 304. The core 302 has a front surface 305, a back surface 306, and an annular side wall 308 extending between the front surface 305 and the back surface 306. An annular groove 310 is formed in the front surface 305, whereby a central post portion 312 is formed in the central portion of the front surface 305.

[0020] When the resonator 300 (including the core 302 and the coil element 304) is connected to a capacitor (for example, a capacitor on a printed circuit board electrically connected to the coil element 304), it functions as a wireless power resonator. However, those skilled in the art will understand that the resonator 300 not connected to a capacitor constitutes a coil assembly. Therefore, as used herein, the term "resonator" does not require connecting the resonator to a capacitor to form a wireless power resonator. On the contrary, as used herein, the term "resonator" has a broad enough scope to include a coil assembly including a core and a coil element not connected to a capacitor, as shown in FIG. 3.

[0021] The core 302 can be formed from a ferrite material such as nickel-based or manganese-based ferrite. Nickel-based ferrite generally has low electrical conductivity and low loss. On the other hand, manganese-based ferrite has a high permeability (however, the loss is within an acceptable range), facilitates the confinement of magnetic flux lines, reduces the leakage magnetic field entering a nearby conductor (for example, a titanium housing or copper of a nearby PCB), and prevents loss. In other embodiments, other types of ferrite materials may be used. For example, in some embodiments, magnesium-based ferrite (for example, MgCuZn, which is more performance-efficient than nickel-based or manganese-based ferrite in a frequency range of about 1 megahertz (MHz)) may be used.

[0022] In the illustrated embodiment, the coil element 304 is disposed within the annular groove 310 and surrounds the central post portion 312. The resonator 300 can be, for example, a litz wire resonator or a laminated plate resonator. In the case of a litz wire type resonator, the coil element 304 includes loops of a plurality of litz wires. In the case of a laminated plate type resonator, the coil element 304 includes a laminated plate formed by alternately laminating a plurality of dielectric layers and conductive layers. The dielectric layer can be formed from, for example, ceramic, plastic, glass, and / or mica.

[0023] The coil element 304 is electrically connected to, for example, a power source (when functioning as a transmitting resonator) or a load 106 (when functioning as a receiving resonator). During operation, when power is supplied to the resonator 300 operating as a transmitting resonator, a current flows through the coil element 304, thereby forming an induced current loop. On the condition that the resonance frequency of the first resonator 300 overlaps with the resonance frequency of the second resonator 300, power can be wirelessly transmitted from the first resonator 300 to the second resonator 300 by this induced current loop. In the illustrated embodiment, the coil element 304 has a plurality of terminals 314 that penetrate the core 302 and extend to the back surface 306. The terminals 314 of the coil element 304 facilitate electrically connecting the coil element 304 to a power source or a load as required.

[0024] As shown in FIGS. 3 to 5, a cavity 320 is formed in the back surface 306 of the core 302. In the illustrated embodiment, the cavity 320 is a substantially cylindrical cavity having a certain depth 322 and a certain diameter 324. The depth 322 of the cavity 320 can be, for example, about 4 mm (millimeters). Also, the diameter 324 of the cavity 320 can be, for example, about 20 mm. Alternatively, the cavity 320 can have any suitable dimensions. Further, the cavity 320 is aligned with the longitudinal axis 326 of the resonator 300 (together with the post portion 312).

[0025] The cavity 320 is defined by a cavity side wall 332 and a cavity bottom wall 330. In the illustrated embodiment, the cavity side wall 332 is substantially annular and oriented perpendicular to the cavity bottom wall 330, and the cavity side wall 332 and the cavity bottom wall 330 intersect at a rounded or chamfered boundary 334. In other embodiments, the cavity side wall 332 and the cavity bottom wall 330 may have any suitable orientation. For example, in some embodiments, the boundary 334 forms a right angle between the cavity side wall 332 and the cavity bottom wall 330.

[0026] As described herein, the resonator 300 of the present disclosure having a cavity 320 offers several advantages compared to conventional resonators without a cavity 320 (i.e., resonators having a continuous planar back surface). Notably, the cavity 320 can be utilized whether the resonator 300 is a receiving resonator or a transmitting resonator.

[0027] For example, the resonator 300 of the present disclosure having a cavity 320 generates less heat during operation (e.g., during wireless power transfer) compared to a conventional resonator without a cavity 320. For instance, in computer modeling simulations, a conventional implanted resonator without a cavity 320 (i.e., a conventional resonator functioning as a receiving resonator) increased the temperature of the local tissue adjacent to the resonator by 5.68°C, while the resonator 300 of the present disclosure having a cavity 320 increased the temperature of the local tissue by only 5.44°C. This reduction in temperature rise is at least partially attributable to the removal of some of the material from the core 302.

[0028] Computer modeling simulations revealed that the reduction in temperature rise was due to an increase in heat on the back of the resonator 300 (i.e., near the back surface 306). Specifically, in the absence of cavity 320, the front of the receiving resonator faces the transmitting resonator and is therefore normally hotter than the back. In the presence of cavity 320, heat from the front of the resonator 300 is dissipated (induced) to the back, resulting in an increase in heat on the back of the resonator 300 but a decrease in heat on the front, thus reducing the overall heat of the resonator 300.

[0029] Generally, reducing the amount of heat generated by an implantable device is desirable because it reduces the impact the implantable device has on adjacent tissues. A resonator 300 having a cavity 320 is lighter in weight than a corresponding resonator without a cavity 320 (because the core material 302 is not present in the cavity 320). The cavity 320 may be filled with air or other suitable gas. For example, in some embodiments, the cavity 320 is filled with a gas that facilitates heat transfer from the front to the back of the resonator 300.

[0030] Of note is that forming a cavity 320 in the resonator 300 does not significantly affect the electromagnetic properties of the resonator 300. In other words, forming a cavity 320 in the resonator 300 does not impair the radio power transmission and reception capability of the resonator 300. This is because the magnetic field strength at the location of the cavity 320 is relatively low. That is, due to the shape of the resonator 300, only a relatively weak magnetic field is generated at the location of the cavity 320 during operation. For example, in one experimental simulation, the magnetic field strength inside the cavity 320 was 5 microtesla (μT), while the magnetic field strength outside the annular sidewall 308 was approximately 50 times that. Furthermore, by changing the shape of the resonator 300, the cavity 320 can be used to easily eliminate or reduce standing waves of closed-loop magnetic field lines that may be generated during the operation of the resonator 300.

[0031] In at least some embodiments, one or more electronic components (not shown) are placed within the cavity 320. Because the magnetic field strength within the cavity 320 is relatively low, the electronic components placed within the cavity 320 are substantially shielded when the resonator 300 is operating. In other words, when electronic components are placed within the cavity 320, the operation of the resonator 300 does not electromagnetically impair or otherwise interfere with the operation of those electronic components. Electronic components placed within the cavity 320 can be electrically connected to the coil element 304 (for example, via terminal 314). Examples of electronic components placed within the cavity 320 include rectifier circuits (e.g., field-effect transistors, diodes), matching capacitors, and series inductors. Alternatively, the electronic components may be any suitable electronic components.

[0032] If the electronic components placed within the cavity 320 generate heat (for example, about 300 milliwatts (mW)), the cavity 320 may be filled with insulating material to dissipate (induce) the heat generated by the electronic components to the back of the resonator 300. Simulations have shown that such insulating material can reduce the maximum temperature of the tissue adjacent to the resonator 300 by at least 0.11°C. The greater the heat generated by the electronic components, the greater the benefit of such insulating material.

[0033] Placing electronic components within the cavity 320 makes it easier to reduce the overall size of the resonator 300. In other words, if the electronic components are not placed in the cavity 320 (for example, in embodiments where the resonator does not have a cavity 320), these electronic components must be placed outside the core 302, thus increasing the size of the resonator 300.

[0034] In some embodiments, the resonator 300 includes a cover (not shown) that surrounds and protects the electronic components located within the cavity 320. Such a cover may be substantially coplanar with the back surface 306 and may be made of the same material as the core 302.

[0035] Those skilled in the art will understand that the dimensions and structure of the resonator 300 described herein are merely examples. For example, in some embodiments, the dimensions of the core 302 and cavity 320 may be modified to minimize losses (for example, at a given operating frequency of the resonator 300).

[0036] Figure 6 is a rear perspective view of another resonator 600. Unless otherwise specified, resonator 600 is substantially similar to resonator 300, and the same reference numerals are used to indicate similar components. In this embodiment, in addition to the cavity 320, a recess 604 is formed on the rear surface 306 of resonator 600. The recess 604 is generally wider than the cavity 320 but shallower than the cavity 320. Therefore, relatively thin components such as printed circuit boards (PCBs) connected to terminals 314 can be placed in the recess 604.

[0037] The embodiments described herein relate to systems and methods for wireless power transmission resonators. The disclosure also relates to resonators for use in wireless power transmission systems. The resonator of the disclosure includes a core having a front, a back, and an annular side wall extending between the front and back, wherein the front has an annular groove and a post portion surrounded by the annular groove, and the back has a cavity, wherein the post portion and the cavity are aligned with the longitudinal axis of the core. The resonator of the disclosure further includes a coil element disposed in the annular groove on the front of the core.

[0038] While the embodiments and examples disclosed herein have been described with reference to specific embodiments, it should be understood that these embodiments and examples are merely illustrative of the principles and applications of the disclosure. Therefore, it should be understood that various modifications can be made to the exemplary embodiments and examples, and other configurations can be devised, without departing from the spirit and scope of the disclosure as defined by the claims. Accordingly, this application is intended to encompass modifications and variations of these embodiments and their equivalents.

[0039] This specification discloses, with reference to examples, the scope of the present invention, including the best mode, and enables those skilled in the art to practice the present invention (including the fabrication and use of any apparatus or system, and the implementation of any incorporated method). The patentable technical scope of the present invention is defined by the statements in the claims and also includes other embodiments that a person skilled in the art could conceive. Such other embodiments are included in the scope of the claims if they include components that are not different from the language of the claims, or components that are substantially equivalent to the language of the claims.

Claims

1. A resonator for use in wireless power transmission systems, A core having a front surface, a back surface, and an annular side wall extending between the front surface and the back surface, wherein the front surface has an annular groove and a post portion surrounded by the annular groove, the annular groove extending from the front surface to the bottom wall of the annular groove, and a cavity formed on the back surface, the cavity extending from the back surface to a cavity bottom wall closer to the front surface than the bottom wall of the annular groove, the post portion and the cavity being aligned with the longitudinal axis of the core, The coil element is disposed within the annular groove, The coil element is a resonator comprising a plurality of terminals extending to the back surface through at least one through-hole penetrating the core, wherein the at least one through-hole includes a through-hole through which two or more terminals of the plurality of terminals pass at different radial positions of the core.

2. The resonator according to claim 1, A resonator further comprising at least one electronic component disposed within the cavity.

3. The resonator according to claim 2, A resonator in which the cavity is filled with an insulating material configured to dissipate heat generated from at least one electronic component to the back of the resonator.

4. The resonator according to claim 1, The cavity is a resonator having a diameter of approximately 20 mm and a depth of approximately 4 mm.

5. The resonator according to claim 1, The resonator in question is a resonator that includes an implanted receiving resonator.

6. The resonator according to claim 1, The resonator in question is a resonator that includes an external transmitting resonator.

7. The resonator according to claim 1, The coil element is a resonator comprising multiple laminates.

8. The resonator according to claim 1, The coil element is a resonator containing multiple Litz wire loops.

9. The resonator according to claim 1, A recess is formed on the back surface of the core, The recess is a resonator that is shallower than the cavity.

10. The resonator according to claim 1, A resonator in which the cavity is filled with a gas that facilitates heat transfer from the front to the back of the resonator.

11. A wireless power transmission system, Power supply and A transmitting resonator electrically connected to the aforementioned power supply, Load and The system comprises an implantable receiving resonator electrically connected to the aforementioned load, The implanted receiving resonator is configured to receive radio power from the transmitting resonator, and The aforementioned implanted receiving resonator is A core having a front surface, a back surface, and an annular side wall extending between the front surface and the back surface, wherein the front surface has an annular groove and a post portion surrounded by the annular groove, the annular groove extending from the front surface to the bottom wall of the annular groove, and a cavity formed on the back surface, the cavity extending from the back surface to a cavity bottom wall closer to the front surface than the bottom wall of the annular groove, the post portion and the cavity being aligned with the longitudinal axis of the core, The coil element is disposed within the annular groove, The coil element includes a plurality of terminals extending to the back surface through at least one through-hole penetrating the core, wherein the at least one through-hole includes a through-hole through which two or more terminals of the plurality of terminals pass at different positions radially in the core. Wireless power transmission system.

12. A wireless power transmission system according to claim 11, The resonator further comprises at least one electronic component located within the cavity, in a wireless power transmission system.

13. A wireless power transmission system according to claim 11, The cavity is defined by an annular cavity side wall and a cavity bottom wall, and is a wireless power transmission system.

14. A wireless power transmission system according to claim 13, The cavity is a wireless power transmission system having a diameter of approximately 20 mm and a depth of approximately 4 mm.

15. A wireless power transmission system according to claim 11, The coil element is a wireless power transmission system comprising multiple laminates.

16. A wireless power transmission system according to claim 11, The coil element is a wireless power transmission system that includes multiple Litz wire loops.

17. A wireless power transmission system according to claim 11, A recess is formed on the back surface of the core, The recess is shallower than the cavity, and is part of a wireless power transmission system.

18. A wireless power transmission system according to claim 11, A wireless power transmission system in which the cavity is filled with a gas that facilitates heat transfer from the front to the back of the resonator.

19. A method for assembling a wireless power transmission system, The steps include electrically connecting the power supply to the external transmitting resonator, The steps include electrically connecting a load to an implantable receiving resonator, The implanted receiving resonator is configured to receive radio power from the external transmitting resonator, and The aforementioned implanted receiving resonator is A core having a front surface, a back surface, and an annular side wall extending between the front surface and the back surface, wherein the front surface has an annular groove and a post portion surrounded by the annular groove, the annular groove extending from the front surface to the bottom wall of the annular groove, and a cavity formed on the back surface, the cavity extending from the back surface to a cavity bottom wall closer to the front surface than the bottom wall of the annular groove, the post portion and the cavity being aligned with the longitudinal axis of the core, The coil element is disposed within the annular groove, The coil element includes a plurality of terminals extending to the back surface through at least one through-hole penetrating the core, wherein the at least one through-hole includes a through-hole through which two or more terminals of the plurality of terminals pass at different positions radially in the core. method.

20. The method according to claim 19, A method further comprising the step of placing at least one electronic component within the cavity.

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