System and method for powering a device

Abstract

A system for powering a device, the system comprising a wireless power transmitter configured to transmit a first power signal, and a receiver unit configured to receive the first power signal, convert the first power signal into a second power signal for wirelessly powering the device, and transmit a second power signal for powering the device through inductive coupling.

Description

Technical Field

[0001] The present invention relates to a system for powering a device, and more particularly, although not limited thereto, to charging implantable devices and related methods.

Background Art

[0002] When wirelessly charging a device, it is necessary to consider different transmission environments (e.g., air or soft tissue) through which power is transmitted. When the device is in close proximity to an inductive charging module, there may be little or no air between the charging module of the device and the charging circuit. However, over greater distances or, in the case of implantable devices, through soft tissue, when transmitting power wirelessly, the transmission environment requires optimization of the antenna used to transmit the wireless power.

[0003] For implantable devices, inductive charging can be relied upon to transmit power through soft tissue (e.g., fat, muscle, and bone) to power or recharge the device when the implantable device is placed in close proximity to an inductive charging module. However, in many situations, the implantable device requires the patient to be stationary or the wireless charger to remain in a fixed position relative to the device. This may be undesirable if the patient remains connected to a main power source or if the power source needs to be carried with the patient. When the patient moves within a space, the implantable device may not be close enough to the wireless charger, which makes inductive charging impractical or impossible. More generally, wirelessly powering a device moving within a space is difficult because the distance between the charging coil and the patient changes.

Summary of the Invention

[0004] The present invention seeks to address at least some of these problems.

[0005] A system for powering a device, the system comprising a wireless power transmitter configured to transmit a first power signal, and a receiver unit configured to receive the first power signal, convert the first power signal into a second power signal for wirelessly powering the device, and transmit a second power signal for powering the device through inductive coupling.

[0006] The first power signal may be any one of an acoustic signal, an ultrasonic signal, or a microwave signal.

[0007] The wireless power transmitter may be configured to transmit the first power signal using a phased array.

[0008] The receiver unit may comprise a near-field transmitter configured to transmit the second power signal.

[0009] The second power signal may be a low-voltage power signal having, for example, a voltage of less than 10V and / or a current of less than 10mA.

[0010] The wireless power transmitter may be configured to receive a location identification signal indicating the location of the receiver unit. The wireless power transmitter may be configured to direct the first power signal towards the receiver unit based on the location identification signal.

[0011] Viewed from a further independent aspect, there is also provided a system for powering a device, the system comprising a wireless power transmitter configured to transmit a first power signal, and a receiver unit configured to receive the first power signal for powering a device operably connected to the receiver unit, wherein the wireless power transmitter is configured to receive a location identification signal indicating the location of the receiver unit and is configured to direct the first power signal towards the receiver unit based on the location identification signal.

[0012] The receiver unit may be configured to transmit a location identification signal. The location identification signal may be a BLE (Bluetooth (Registered Trademark) Low Energy) signal.

[0013] The wireless power transmitter may comprise an adaptive phased array transmitter. The wireless power transmitter may comprise a far-field transmitter configured to transmit a first power signal. The wireless power transmitter may be configured to transmit the first power signal in a plurality of directions.

[0014] The receiver may be embedded within the fabric layer. The charging system may comprise a wearable. The wearable may comprise a fabric layer.

[0015] The receiver unit may comprise an adhesive layer for attaching the receiver unit to an outer surface. The adhesive layer may be configured to adhere the receiver unit to the skin.

[0016] Viewed from a further independent aspect, there is also provided a receiver unit adapted for use in a charging system according to any of the preceding claims.

[0017] Viewed from a further independent aspect, there is also provided a method of wirelessly powering a device. The method includes wirelessly transmitting a first power signal from a wireless power transmitter to a receiver unit, converting, by the receiver unit, the first power signal into a second power signal for wirelessly powering the device, and powering the device by inductive coupling using the second power signal.

[0018] Viewed from a further independent aspect, there is also provided a method of wirelessly powering a device. The method includes receiving, by the wireless power transmitter, a location signal indicating the location of the receiver unit, and directing, by the wireless power transmitter, a first power signal towards the receiver unit based on the location signal.

[0019] The first power signal may be transmitted using a phased array.

[0020] The location signal may be a BLE signal.

[0021] A location-specific signal can be transmitted from the receiver unit.

[0022] Embodiments of the present invention are further described below with reference to the following attached drawings.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

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Figure 8

Figure 9

Modes for Carrying Out the Invention

[0024] Referring to FIG. 1, an exemplary system 100 for powering a device 10 is provided. The illustrated system 100 includes a wireless power transmitter 105 having an antenna 110 for transmitting a first power signal 115. Although a single antenna is shown, it is clear that a plurality of antennas 110 may be used, for example, to provide a phased array power transmitter. The phased array power transmitter may be implemented as any dynamic phased array, fixed phased array, active phased array, or passive phased array as known in the art.

[0025] The first power signal 115 is transmitted through a first transmission environment 1 (e.g., air) by a first modality, e.g., ultrasonic or microwave, and received by the receiver unit 200. The wireless power transmitter 105 can radiate the first power signal 115 omnidirectionally or generate a beam directed in a predetermined direction. In some cases, the wireless power transmitter 105 can sweep the beam over an area. In some cases, the wireless power transmitter 105 is a far-field transmitter.

[0026] The receiver unit 200 includes a receiving antenna 210, a transmitting antenna 215, and a controller 205 operably connected to the receiving antenna 210 and the transmitting antenna 215. The transmitting antenna 215 can include a transmitting coil or the like for forming an inductive coupling between the receiver unit 200 and the device 10 to wirelessly power the device 10 by sending a second power signal 220. The receiver unit 200 converts the received power signal 220 into a direct current or alternating current that can be used to power the transmitting coil 215. The second power signal 220 is transmitted by a second transmission modality different from the first modality. In some cases, the receiver unit 200 includes a near-field transmitter for transmitting the second power signal 220.

[0027] The system uses two different transmission modalities and utilizes the most appropriate transmission modality for each step. For example, the transmission of the first power signal 115 through air 1 may be considered the first step, and the transmission of the second power signal 220 through soft tissue 5 may be considered the second step. This two-step approach is particularly suitable for powering implantable devices as described below, but it will be apparent that this approach may also be applied to non-implantable devices where power is transmitted over multiple different transmission environments, such as portable electronic devices. In particular, it will also be apparent that three or more different transmission modalities may be used to wirelessly transmit power to the device 10 when different transmission modalities are more suitable for transmitting power through different transmission environments.

[0028] Figure 2 shows a receiver unit 200 embedded in a fabric layer of an article of clothing 225, such as a sleeve or a sock. In Figure 2, the device is implanted in a patient, and the article of clothing 225 has the receiver unit 200 disposed on the outer knee surface in close proximity to the implantable device 10 and includes a rechargeable battery (not shown). Embedding the receiver unit 200 in the article of clothing is advantageous because the device 10 can be charged while the patient can wear the article of clothing 225 for an extended period of time, such as overnight.

[0029] Figure 3 shows a first power signal 115 that travels through a first transmission environment (e.g., air 1) and reaches the receiver unit 200, and a second power signal 220 that travels through the soft tissue 5 of the patient's leg (a second transmission environment). In one example, a phased array microwave or ultrasonic signal is used to transmit the first power signal 115 to the receiver unit 200, which converts this into an electromagnetic signal in order to inductively charge the device 10.

[0030] A phased power signal 115, for example, a phase-controlled microwave or ultrasonic signal, is particularly advantageous because the first power signal 115 can reach the receiver unit 200 with sufficient power, thereby enabling the receiver unit 200 to convert the first power signal 115 for dielectric charging within the implantable device 10 via electromagnetic coupling. This eliminates the need for a separate power source for powering the implantable device 10 and provides a charging system that is much more flexible than existing systems for charging implantable devices. Preferably, the receiver unit 200 does not have a separate power source. The power induced by the receiver unit 200 may be a low-voltage signal. This is not a problem when the implantable device 10 remains in the vicinity (e.g., 3 - 4 m) of the wireless power transmitter 105 for an extended period, such as overnight, while the patient is lying in a substantially fixed position relative to the wireless power transmitter 105. The low-voltage signal is typically a few volts (e.g., less than 10 V) and / or a few milliamperes (e.g., less than 100 mA). The tolerance of the present system can accommodate movement of the patient within the bed in the room. An implantable device 10 implanted in the patient's knee joint is shown, but this is merely illustrative, and it will be apparent that the present system can be used to power or charge devices 10 implanted at other locations within the body or devices 10 placed on the body surface without being implanted within the body. As described above, the device may be a portable electronic device such as a mobile phone.

[0031] FIG. 4 is a schematic diagram of a third exemplary system in which the receiver unit 200 has an adhesive layer 230 (see also FIG. 5) for attaching the receiver unit 200 to the skin surface 7 of the patient. The receiver unit 200 having the adhesive layer 230 can be easily provided as a patch that can be simply attached to the skin surface 7 near the implantable device 10. This ensures that the receiver unit 200 remains in a relatively fixed position relative to the implantable device 10 when the patient moves relative to the wireless power transmitter 105.

[0032] FIG. 6 is a schematic diagram of a fourth exemplary system in which a plurality of devices 10A, 10B are moving within a room. Each of the devices 10A, 10B has a respective receiver unit 200A, 200B fixed thereto using, for example, a layer of material (such as within the wearable 225) or an adhesive layer 230 to fix the receiver unit 200 to the device 10 as described above. Since the devices 10A, 10B remain within the room, they remain relatively close to the wireless power transmitter 105, for example within 4 m. In this case, the wireless power transmitter 105 can power or charge both devices 10A, 10B simultaneously.

[0033] FIG. 7 shows an exemplary method 400 for powering a device 10. The method 400 includes steps of wirelessly transmitting a first power signal 115 to a receiver unit 200 (step 405), converting the first power signal 115 to a second power signal 220 for wirelessly powering the device 10 (step 410), and powering the device 10 by inductive coupling using the second power signal 220 (step 415). As an example, the device 10 may be a sensor-based implantable device. In some cases, the device 10 includes, for example, a rechargeable battery having a capacity of 25 mAh and a charging circuit for charging the rechargeable battery.

[0034] In some cases, the receiver unit 200 includes a plurality of charging coils (not shown) for powering the device 10. Although a charging system 100 is described herein, it will be apparent that in some cases, the system 100 may be for powering a device without a rechargeable battery.

[0035] In some cases, the wireless power transmitter 105 may be attached to the wall of a room, or may be placed on or fixed to the structure within the room. By way of example, the wireless power transmitter 105 may be fixed to the bed frame of a patient wearing an article of clothing that houses the receiver unit 200 as described above. In this case, the first power signal 115 is transmitted to the article of clothing 225 through any bedding and mattress on the bed frame. Typically, this distance is too far to transmit power via inductive coupling, but is possible using the far-field techniques described herein. The first power signal 115 may be converted to power the transmission antenna 215 to transmit a second power signal 220 to the implantable device 10 via an inductive coupling closer to the receiver unit 200.

[0036] The receiver unit 200 can also transmit a localization signal 240 from a Bluetooth module 235, preferably a Bluetooth Low Energy unit. The localization signal 240 can be detected by the wireless power transmitter 105, and the first power signal 115 can be directed towards the source of the localization signal 240 (i.e., beamforming). This localization guided beamforming advantageously increases the power transmitted to the receiver unit 200 as compared to the radial first power signal 115. The Received Signal Strength Indicator (RSSI) is one form of a localization signal, but this is not essential, and it will be apparent that other localization signals or localization parameters may be used in addition to or instead of this. Similarly, although the receiver unit 200 has been described as providing the localization signal 240, the Bluetooth module 235 may be part of the device 10 being powered, or the receiver unit 200 or a stand-alone device separate from the device 10 being powered, so this is not essential. It will also be apparent that a plurality of devices (i.e., any combination of the device 10, the receiver unit 200, and stand-alone devices) may provide the localization signal 240.

[0037] In some cases, the receiver unit 200 does not convert the first power signal 115 into a second power signal 220 of a modality different from the first power signal 115. That is, the second power signal 220 may be of the same modality as the first power signal 115. This can be useful when the receiver unit 200 is used to direct the first power signal 115 towards itself so that the charging efficiency of the device 10 can be increased. When a plurality of devices 10A, 10B are present in a space, each device 10A, 10B may be localized in the manner described herein to provide a plurality of beams for powering each device 10A, 10B.

[0038] FIG. 9 is a schematic diagram of an alternative method 500 for powering device 10. Method 500 includes step 505 of transmitting a first power signal 115 in a first direction, step 510 of receiving a location identification signal 240 indicating the location of device 10 (e.g., transmitted from device 10 itself, a stand-alone device (not shown), or receiver module 200), and step 515 of directing the first power signal 115 based on the location identification signal 240 (e.g., towards the source of the location identification signal 240 which can be any of device 10, a stand-alone device, or receiver module 200). The directed first power signal 115 may be in a second direction different from the first direction. It is clear that if there are multiple devices 10A, 10B, the signals for powering each device (e.g., device 10A) may be directed independently of the signals for powering the remaining devices (e.g., device 10B). Since wireless power transmitter 105 only needs to start transmitting the first power signal after receiving the location identification signal 240, step 505 is not essential.

[0039] Throughout the description and claims of this specification, the terms "comprise" and "contain" and their variants mean "include but are not limited to", and they are not intended to (and do not) exclude other parts, additives, components, integers, or steps. Throughout the description and claims of this specification, the singular form includes the plural form unless the context otherwise requires. In particular, when an indefinite article is used, this specification should be understood to consider not only the singular form but also the plural form unless the context otherwise requires.

[0040] Features, integers, characteristics, or groups described in connection with a particular aspect, embodiment, or example of the present invention are to be understood as applicable to any other aspect, embodiment, or example described herein, unless they are inconsistent therewith. All features disclosed in this specification (including the appended claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not limited to the details of any of the foregoing embodiments. The invention extends to any novel one or any novel combination of features disclosed in this specification (including the appended claims, abstract, and drawings), or to any novel one or any novel combination of any method or process so disclosed.

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