Patent Publication Number: US-2023148701-A1

Title: Wireless charging assemblies for sensorized insoles, methods for charging sensorized insoles, and footwear systems including sensorized insoles

Description:
FIELD 
     This document relates to sensorized insoles, such as insoles that include pressure and/or temperature sensors. More specifically, this document relates to wireless charging assemblies for sensorized insoles, methods for charging sensorized insoles, and footwear systems including sensorized insoles. 
     BACKGROUND 
     U.S. Pat. No. 8,058,837 (Beers et al.) discloses an article of footwear and a footwear housing. The footwear housing includes a charging station that can be used to charge a battery in the footwear housing. 
     U.S. Patent Application Publication No. 2014/0354218 (Kaynar et al.) discloses a magnetic mounting system configured to charge a personal electronic device with integrated conductive charging of the personal electronic device. The system includes a case configured to connect to the personal electronic device. The case is attached to a printed circuit board, wiring, and a plurality of metal plates. A housing is arranged proximate the casing. The housing includes a plurality of magnets and a plurality of pins. Aligning the plurality of magnets with the plurality of pins detachably couples the case to the housing. Aligning the plurality of pins and the printed circuit board provides electricity from the plurality of pins to the printed circuit board when the case is attached to the housing to charge the personal electronic device in the case. 
     SUMMARY 
     The following summary is intended to introduce the reader to various aspects of the detailed description, but not to define or delimit any invention. 
     Footwear systems are disclosed. According to some aspects, a footwear system includes at least a first sensorized insole. The first sensorized insole has a first insole bulk having a first foot-facing upper surface, at least a first sensor embedded in the first insole bulk for measuring a parameter of a user&#39;s first foot, at least a first battery embedded in the first insole bulk for providing energy to the first sensor, and at least a first wireless charging receiver pod embedded in the first insole bulk and spaced from the first foot-facing upper surface for wirelessly receiving energy and providing energy to the first battery. The system further includes a charger for providing energy to the first wireless charging receiver pod. The charger includes a first cable for connecting to an energy source, and at least a first wireless charging transmitter pod electrically connected to the first cable for receiving energy from the first cable and wirelessly transmitting energy to the first wireless charging receiver pod. The first wireless charging transmitter pod is positionable against the first foot-facing upper surface to wirelessly provide energy to the first wireless charging receiver pod through the first insole bulk. 
     In some examples, the footwear system further includes a second sensorized insole. The second sensorized insole can include a second insole bulk having a second foot-facing upper surface, at least a second sensor embedded in the second insole bulk for measuring a parameter of a user&#39;s second foot, at least a second battery embedded in the second insole bulk for providing energy to the second sensor, and at least a second wireless charging receiver pod embedded in the second insole bulk and spaced from the second foot-facing upper surface for wirelessly receiving energy and providing energy to the second battery. The charger can further include at least a second wireless charging transmitter pod that is electrically connected to a second cable for receiving energy from the energy source and for wirelessly transmitting energy to the second wireless charging receiver pod. The second wireless charging transmitter pod can be positionable against the second foot-facing upper surface to wirelessly provide energy to the second wireless charging receiver pod through the second insole bulk. 
     In some examples, the first wireless charging transmitter pod is further positionable against the second foot-facing upper surface to wirelessly provide energy to the second wireless charging receiver pod through the second insole bulk. The second wireless charging transmitter pod can further be positionable against the first foot-facing upper surface to wirelessly provide energy to the first wireless charging receiver pod through the first insole bulk. 
     In some examples, the first wireless charging receiver pod includes a first receiver coil, and the first receiver coil is spaced from the first foot-facing upper surface by a first spacing. The second wireless charging receiver pod can include a second receiver coil, and the second receiver coil can be spaced from the second foot-facing upper surface by a second spacing that is different from the first spacing. The first spacing can be, for example, between about 1 mm and about 18 mm, the second spacing can be, for example, between about 1 mm and about 18 mm, and the first spacing and the second spacing can in some examples differ by about 4 mm. 
     In some examples, the first wireless charging transmitter pod is configured to emit a first electromagnetic field and to dither the first electromagnetic field. The second wireless charging transmitter pod can further be configured to emit a second electromagnetic field and to dither the second electromagnetic field. The first transmitter pod and second transmitter pod can be configured to dither asynchronously. 
     In some examples, the first wireless charging transmitter pod includes a first transmitter coil and a first set of transmitter magnets arranged around the transmitter coil. The first wireless charging receiver pod can further include a first receiver coil and a first set of receiver magnets arranged around the first receiver coil for magnetically coupling with the first set of transmitter magnets. In some examples, a height of each receiver magnet is less than a height of each transmitter magnet, and a diameter of each receiver magnet is greater than a diameter of each transmitter magnet. In some examples, the first set of transmitter magnets includes a greater number of magnets than the first set of receiver magnets. For example, the first set of transmitter magnets can include between 7 and 15 transmitter magnets spaced around the first transmitter coil, and the first set of receiver magnets can include between 2 and 6 receiver magnets spaced around the first receiver coil. For further example, the first set of transmitter magnets can include 11 transmitter magnets spaced around the first transmitter coil, and the first set of receiver magnets can include 2 receiver magnets positioned on opposite sides of the first receiver coil. 
     In some examples, the first wireless charging receiver pod includes a first receiver coil that is spaced from the first foot-facing upper surface by a first spacing, and the first wireless charging transmitter pod is configured to detect the first spacing and emit an electromagnetic field of a frequency that is tuned to the first spacing. The first wireless charging transmitter pod can be configured to detect the first spacing by emitting a series of stimulation pulses to the first receiver coil and receiving a series of response pulses back from the first receiver coil. The first spacing can be, for example, between about 1 mm and about 18 mm. 
     In some examples, the charger comprises the energy source, and the energy source is a battery. 
     Methods for charging sensorized insoles are also disclosed. According to some aspects, a method for charging one or more sensorized insoles includes: a) with a first sensorized insole received in a first shoe, inserting a first wireless charging transmitter pod through a foot-receiving opening of the first shoe and positioning the first wireless charging transmitter pod against a first foot-facing upper surface of a first insole bulk of the first sensorized insole; and b) transferring energy through the first insole bulk, from the first wireless charging transmitter pod to a first wireless charging receiver pod embedded in the first insole bulk. 
     In some examples, the method further includes: c) with a second sensorized insole received in a second shoe, inserting a second wireless charging transmitter pod through a foot-receiving opening of the second shoe, and positioning the second wireless charging transmitter pod against a second foot-facing upper surface of a second insole bulk of the second sensorized insole; and d) transferring energy through the second insole bulk of the second sensorized insole, from the second wireless charging transmitter pod to a second wireless charging receiver pod embedded in the second insole bulk. 
     In some examples, step a) includes magnetically coupling the first wireless charging transmitter pod to the first wireless charging receiver pod, and step c) includes magnetically coupling the second wireless charging transmitter pod to the second wireless charging receiver pod. 
     In some examples, step b) includes transferring energy from an energy source to the first wireless charging transmitter pod via a first cable, and step d) includes transferring energy from the energy source to the second wireless charging transmitter pod via a second cable. 
     In some examples, the first wireless charging receiver pod includes a first receiver coil that is spaced from the first foot-facing upper surface by a first spacing, the second wireless charging receiver pod includes a second receiver coil that is spaced from the second foot-facing upper surface by a second spacing that is different from the first spacing, and the method further includes: e) removing the first wireless charging transmitter pod from the first shoe and removing the second wireless charging transmitter pod from the second shoe; f) inserting the second wireless charging transmitter pod through the foot-receiving opening of the first shoe, positioning the second wireless charging transmitter pod against the first foot-facing upper surface, and magnetically coupling the second wireless charging transmitter pod to the first wireless charging receiver pod; and g) transferring energy from the second wireless charging transmitter pod to the first wireless charging receiver pod through the first insole bulk. 
     In some examples, the first wireless charging receiver pod includes a first receiver coil that is spaced from the first foot-facing upper surface by a first spacing, and step d) includes detecting the first spacing and emitting an electromagnetic field of a frequency that is tuned to the first spacing. Detecting the first spacing can include emitting a series of stimulation pulses from the first transmitter coil to the first receiver coil and receiving a series of response pulses back from the first receiver coil. 
     In some examples, step b) includes emitting a first electromagnetic field from the first wireless charging transmitter pod and dithering the first electromagnetic field. Step d) can include emitting a second electromagnetic field from the second wireless charging transmitter pod, and dithering the second electromagnetic field asynchronously with the first electromagnetic field. 
     Wireless charging assemblies for sensorized insoles are also disclosed. According to some aspects, a wireless charging assembly for a sensorized insole includes a wireless charging transmitter pod having a transmitter coil and a set of transmitter magnets arranged around the transmitter coil, and a wireless charging receiver pod having a receiver coil and a set of receiver magnets arranged around the receiver coil for magnetically coupling with the set of transmitter magnets to hold the wireless charging transmitter pod in proximity to the wireless charging receiver pod. A height of each receiver magnet is greater than a height of each transmitter magnet, and a diameter of each receiver magnet is less than a diameter of each transmitter magnet. 
     In some examples, the set of transmitter magnets includes a greater number of magnets than the set of receiver magnets. For example, the set of transmitter magnets can include between 7 and 15 transmitter magnets spaced around the transmitter coil, and the set of receiver magnets can include between 2 and 6 receiver magnets spaced around the receiver coil. For further example, the set of transmitter magnets can include 11 transmitter magnets spaced around the transmitter coil, and the set of receiver magnets can include 2 receiver magnets positioned on opposite sides of the receiver coil. 
     Methods for providing a footwear system are also disclosed. According to some aspects, a method for providing a footwear system includes: a) custom manufacturing a sensorized insole for a user by assessing the user&#39;s foot and custom fashioning an insole bulk based on the assessment. Custom fashioning the insole includes embedding in the insole bulk at least one sensor, at least one battery for providing energy to the sensor, and at least one wireless charging receiver pod for wirelessly receiving energy and providing the energy to the battery. The insole bulk has a foot-facing upper surface, and the wireless charging receiver pod is embedded in the insole bulk so that a receiver coil of the wireless charging receiver pod is spaced from the foot-facing upper surface by a spacing that is at least partially determined by the assessment. The method further includes b) providing a wireless charging transmitter pod that is configured to wirelessly transmit energy to the wireless charging receiver pod through the insole bulk by positioning the wireless charging transmitter pod against the foot facing upper surface. The wireless charging transmitter pod is configured to detect the spacing and emit an electromagnetic field of a frequency that is tuned to the spacing. 
     In some examples, the wireless charging transmitter pod is configured to detect the spacing by emitting a series of stimulation pulses to the receiver coil and receiving a series of response pulses back from the receiver coil. 
     In some examples, the spacing is between about 1 mm and about 18 mm. 
     In some examples, the wireless charging transmitter pod is configured to first recognize a presence of the receiver coil, and then detect the spacing. 
     Methods for charging a footwear system are also disclosed. According to some aspects, a method for charging a footwear system includes: a) detecting a spacing between a foot-facing upper surface of an insole bulk and a receiver coil of a wireless charging receiver pod embedded in the insole bulk; and b) providing energy to the wireless charging receiver pod by emitting an electromagnetic field through the insole bulk at a frequency that is tuned to the spacing. 
     In some examples, step a) includes emitting a series of stimulation pulses from a transmitter coil of a wireless charging transmitter pod to the receiver coil, and receiving a series of response pulses back from the receiver coil. Step b) can include selecting the frequency based on the series of response pulses. 
     In some examples, the spacing is between about 1 mm and about 18 mm. 
     In some examples, step a) includes first detecting a presence of the receiver coil, and then detecting the spacing. 
     Methods for charging one or more sensorized insoles are disclosed. According to some aspects, a method for charging one or more sensorized insoles includes: a) positioning a first wireless charging transmitter pod against a first sensorized insole; and b) transferring energy from the first wireless charging transmitter pod to a first wireless charging receiver pod embedded in the first sensorized insole by emitting a first electromagnetic field from the first wireless charging transmitter pod and dithering the first electromagnetic field. 
     In some examples, the method further includes: c) positioning a second wireless charging transmitter pod against a second sensorized insole; and d) transferring energy from the second wireless charging transmitter pod to a second wireless charging receiver pod embedded in the second sensorized insole by emitting a second electromagnetic field from the second wireless charging transmitter pod and dithering the second electromagnetic field. 
     In some examples, step d) includes dithering the second electromagnetic field asynchronously with the first electromagnetic field. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the present specification and are not intended to limit the scope of what is taught in any way. In the drawings: 
         FIG.  1 A  is a perspective view of an example footwear system, showing a charger in position to be coupled to a pair of sensorized insoles within a pair of shoes; 
         FIG.  1 B  is a perspective view of the footwear system of  FIG.  1 A , showing the charger coupled to the insoles; 
         FIG.  2    is a perspective view of a sensorized insole with a transmitter pod of the charger of  FIGS.  1 A and  1 B  coupled thereto; 
         FIG.  3    is a cross section taken along line  3 - 3  in  FIG.  2   ; 
         FIG.  4    is an exploded view of the sensorized insole and transmitter pod of  FIG.  2   ; 
         FIG.  5    is an enlarged perspective view of the transmitter pod of  FIGS.  2 ,  3 , and  4   ; 
         FIG.  6    is a rear perspective view of the transmitter pod of  FIG.  5   , with a housing thereof removed; 
         FIG.  7    is a front perspective view of the transmitter pod of  FIG.  5   , with a housing thereof removed; 
         FIG.  8    is a perspective view of a receiver pod of the sensorized insole of  FIGS.  2 ,  3 , and  4   ; and 
         FIG.  9    is an exploded view of the receiver pod of  FIG.  8   . 
     
    
    
     DETAILED DESCRIPTION 
     Various apparatuses or processes or compositions will be described below to provide an example of an embodiment of the claimed subject matter. No embodiment described below limits any claim and any claim may cover processes or apparatuses or compositions that differ from those described below. The claims are not limited to apparatuses or processes or compositions having all of the features of any one apparatus or process or composition described below or to features common to multiple or all of the apparatuses or processes or compositions described below. It is possible that an apparatus or process or composition described below is not an embodiment of any exclusive right granted by issuance of this patent application. Any subject matter described below and for which an exclusive right is not granted by issuance of this patent application may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document. 
     As used herein, the term ‘about’ indicates that a referenced value may vary by plus or minus 5%. For example, a reference to a length of ‘about 10 mm’ indicates that the length may be between 9.5 mm and 10.5 mm. 
     In this document, unless specified otherwise, all ranges are inclusive of the bounds of the range. For example, the statement that a length may be ‘between 5 mm and 15 mm’ indicates that the length may be 5 mm, or 15 mm, or any number therebetween. 
     Generally disclosed herein are wireless charging assemblies for sensorized insoles (such as but not limited to sensory insoles for the prevention of diabetic foot ulcers, such as those sold by Orpyx Medical Technologies Inc. and described in U.S. Pat. No. 10,004,428), and related systems and methods. 
     The wireless charging assemblies may in some examples be relatively easy to use, particularly for users of limited dexterity and/or mobility. For example, the wireless charging assemblies may be used without necessarily requiring that the sensorized insole(s) be removed from the user&#39;s shoe(s), and without necessarily requiring a plug or receptacle of the wireless charging assembly to be mated to a corresponding plug or receptacle of the sensorized insole. That is, in some examples, with the sensorized insole in a shoe, the user may simply drop or place a transmitter pod of the wireless charging assembly into the shoe. The transmitter pod may then magnetically couple to a receiver pod that is embedded in the insole, and commence charging the sensorized insole via an LC (inductor capacitor) circuit. 
     Furthermore, the wireless charging assemblies may be configured to wirelessly charge sensorized insoles of various thickness, where in use the transmitter pod and receiver pod are not necessarily spaced apart by a pre-set distance. That is, in some instances, the sensorized insoles may be in the form of custom orthotics, which are custom manufactured to fit a user&#39;s foot. In such instances, each sensorized insole may have a thickness that is customized to fit the foot of the user. Even for a given user, the sensorized insole for the user&#39;s left foot may be of a different thickness than the sensorized insole for the user&#39;s right foot. As will be described in further detail below, the wireless charging assemblies may be configured to detect and adjust for the thickness of the insole, in order to effectively charge a given sensorized insole. 
     Furthermore, the wireless charging assemblies may be configured to have a minimized or reduced peak emission. Particularly, the wireless charging assemblies may include a pair of transmitter pods (i.e. one for each sensorized insole of a pair). The transmitter pods may be configured to transfer energy at an oscillating frequency, to reduce the peak emission of the system. Furthermore, the transmitter pods may be configured to oscillate frequency asynchronously, to even further reduce the peak emission. 
     Referring now to  FIGS.  1 A and  1 B , an example footwear system  100  is shown. The footwear system  100  includes a first shoe  102  and a second shoe  104  (i.e. a left shoe and a right shoe of a pair). A first sensorized insole  106  (shown in  FIGS.  2  to  4   ) is received in the first shoe  102 , and a second sensorized insole (not shown) is received in the second shoe  104 . When the shoes  102 , 104  are being worn, the first sensorized insole  106  and second sensorized insole may be used to collect data (e.g. regarding the wearer&#39;s health, activity, movement, or gait). When the shoes  102 , 104  are not being worn, the batteries of the first sensorized insole  106  and the second sensorized insole may be electrically charged by a wireless charging assembly  108 , which is described in further detail below. 
     Referring now to  FIGS.  2  and  3   , the first sensorized insole  106  and a portion of the wireless charging assembly  108  are shown in greater detail. For brevity, only the first sensorized insole  106  and the related features of the wireless charging assembly  108  are shown. The second sensorized insole is similar to the first sensorized insole  106 , and is not shown. Furthermore, although the first sensorized insole  106  may be charged while remaining in the first shoe  102  (as shown in  FIGS.  1 A and  1 B ), for clarity, the first shoe  102  is not shown in  FIGS.  2  and  3   . 
     Referring still to  FIGS.  2  and  3   , the first sensorized insole  106  includes an insole bulk  110  (also referred to herein as a ‘first insole bulk’), which may be made up of one or more layers such as a cushion layer, a support layer, a gel layer, an anti-odor layer, a thermal insulation layer, and/or a foam layer. In the example shown, the first sensorized insole  106  is in the form of an orthotic that is custom manufactured for a user. For example, the user&#39;s foot may be assessed (e.g. by a podiatrist, optionally using plaster casting or  3 D scanning), and the insole bulk  110  may be custom fashioned based on the assessment, for example in order to support the user&#39;s foot, improve foot function, relieve pain, and/or relieve pressure. In the example shown, the insole bulk  110  includes a top layer  112  and a base layer  114 . The top layer  112  may in turn include multiple sub-layers, such as an upper finishing layer (not shown), a middle comfort layer (not shown), and a contoured layer (not shown). Likewise, the base layer  114  may include multiple sub-layers. Various sub-layers are described in international patent application no. PCT/CA2020/051520 (publication no. WO 2021/092676), which is incorporated herein by reference in its entirety. 
     In other examples, the sensorized insoles may be another type of insole, such as a generic insole (e.g. a comfort insole, an athletic insole, a shock-absorbing insole, or a gel insole). Furthermore the sensorized insoles may in some examples be integral with the shoes. 
     Referring still to  FIGS.  2  and  3   , the insole bulk  110  has a foot-facing upper surface  116  (also referred to herein as a ‘first foot-facing upper surface’), and a ground-facing lower surface  118  (also referred to herein as a ‘first ground-facing lower surface’). In use, the foot-facing upper surface  116  faces upwardly towards a user&#39;s foot (e.g. contacts the user&#39;s skin or sock), and the ground-facing lower surface  118  faces downwardly (e.g. contacts the inner surface of the shoe  102 ). 
     Various sensors may be embedded in the insole bulk  110 , for measuring a parameter of a user&#39;s first foot (e.g. a parameter relating to the user&#39;s health, activity, movement, gait, or location). Furthermore, one or more batteries may be embedded in the insole bulk  110 , for providing energy to the sensor(s). The sensors may in some examples include one or more of: a heart rate sensor, a blood pressure sensor, an oxygen saturation sensor, an oxygen sensor, a respiratory rate sensor, a blood flow sensor, a cardiac output sensor, a perfusion sensor, a pressure sensor, a temperature sensor, a weight sensor, a body mass index sensor, a moisture sensor, a hydration sensor, a perspiration rate sensor, sweat electrolyte sensor, a bacterial load sensor, an inductance sensor, a resistance sensor, a dielectric sensor, a capacitance sensor, a conductance sensor, an impairment sensor, a sleep sensor, a fatigue sensor, an electrocardiogram sensor, an electromyography sensor, an electroencephalogram sensor, an odor sensor, a taste sensor, a stress sensor, a shear sensor, a respiratory flow rate sensor, a lung function sensor, a GPS, an accelerometer, a gyroscope, a magnetometer, an altimeter, a compass, an image capturing sensor, a limb positioning measurement device, a light sensor, an oxygen sensor, another type of sensor that measures a physiologic(al) characteristic indicative of the functions and activities of a living organism, and combinations thereof. 
     Referring to  FIG.  4   , in the example shown, both a pressure sensor array  120  and a temperature sensor array  122  are embedded in the insole bulk  110 . The pressure sensor array  120  includes a plurality of pressure sensors  124  (only two of which are labelled) printed on flexible polymer film  126 . Likewise, the temperature sensor array  122  includes a plurality of temperature sensors  128  (only two of which are labelled) printed on flexible polymer film  130 . Furthermore, a circuit board  132  is embedded in the insole bulk  110 , together with a carbon fiber shield  134  and a rigid support  136 . The carbon fiber shield  134  serves to distribute pressure to protect the circuit board  132 , and the rigid support  136  maintains the carbon fiber shield  134  in position above the circuit board  132 . A pair of batteries  138   a ,  138   b  are further embedded in the insole bulk  110 , for providing energy to the sensors  124 ,  128 . As will be described below, the batteries  138   a ,  138   b  are chargeable by the wireless charging assembly  108 . Such sensor arrays, batteries, and circuit boards are described in international patent application no. PCT/CA2020/051520 (publication no. WO 2021/092676), which is incorporated herein by reference in its entirety. 
     As used herein, the term ‘embedded’ indicates that at least a portion of the referenced part is positioned between the layers of the insole bulk  110 , or within one or more layers of the insole bulk  110 . For example, the referenced part can be nested in a pocket of a first layer, and then covered by a second layer. In the example shown, the pressure sensor array  120 , temperature sensor array  122 , and circuit board  132  are sandwiched between the top layer  112  and the base layer  114  of the insole bulk  110 , while the batteries  138   a ,  138   b  are nested in a pocket of the base layer  114 . 
     As used herein, the term “battery” can refer to any portable and chargeable energy storage device, such as chemical battery (e.g. a lithium ion battery) or a super capacitor. 
     Similarly to the first sensorized insole  106 , the second sensorized insole (not shown) may include a second insole bulk, a second foot-facing upper surface, a second ground-facing lower surface, at least a second sensor embedded in the insole bulk, and at least a second battery embedded in the second insole bulk. 
     The wireless charging assembly  108  is configured to charge the batteries  138   a ,  138   b  of the first sensorized insole  106  and the batteries of the second sensorized insole. Referring back to  FIGS.  1 A to  3   , in the example shown, the wireless charging assembly  108  includes a charger  140  that in turn includes first  142  and second  144  transmitter pods (also referred to herein as ‘wireless charging transmitter pods’). The wireless charging assembly  108  further includes a first receiver pod  146  and a second receiver pod (not shown) (also referred to herein as ‘wireless charging receiver pods’), which are embedded in the first insole bulk  110  and the second insole bulk, respectively. The first transmitter pod  142  can wirelessly transmit energy to either of the first receiver pod  146  and the second receiver pod, and the second transmitter pod  144  can wirelessly transmit energy to either of the first receiver pod  146  and the second receiver pod. The first receiver pod  146  wirelessly receives the energy and provides the energy to the batteries  138   a ,  138   b  of the first sensorized insole  106 , and the second receiver pod wirelessly receives the energy and provides the energy to the batteries of the second sensorized insole. 
     More specifically, referring still to  FIGS.  2  and  3   , the first receiver pod  146  is embedded in the first insole bulk  110 , and is spaced from the first foot-facing upper surface  116 . In the example shown, the first receiver pod  146  is nested in a pocket of the base layer  114 , and is covered by the top layer  112 . The first transmitter pod  142  is positionable against the first foot-facing upper surface  116 , and wirelessly transmits energy to the first receiver pod  146  through the first insole bulk  110  (i.e. through the top layer  112 , in the example shown). Likewise, the second transmitter pod  144  (shown in  FIG.  1 A ) wirelessly transmits energy to the second receiver pod (not shown), and the second receiver pod wirelessly receives the energy and provides the energy to the batteries (not shown) of the second sensorized insole (not shown). Similarly to the first receiver pod  146 , the second receiver pod is embedded in the second insole bulk and is spaced from the second foot-facing upper surface, and the second transmitter pod is positionable against the second foot-facing upper surface to wirelessly provide energy to the second wireless charging receiver pod through the second insole bulk. 
     The first transmitter pod  142  and the first receiver pod  146  are described in greater detail below. For brevity the second transmitter pod  144  and second receiver pod are not shown or described in detail; however, the second transmitter pod  144  is similar to the first transmitter pod  142 , and the second receiver pod is similar to the first receiver pod  146 . 
     Referring now to  FIGS.  5  to  7   , the first transmitter pod  142  will be described in greater detail. In the example shown, the first transmitter pod  142  includes a housing  148  (shown in  FIG.  5   ). The housing  148  can be sized so that the first transmitter pod  142  can readily pass through a foot-receiving opening  150  of the first shoe  102  or a foot receiving opening  151  of the second shoe  104  (shown in  FIGS.  1 A and  1 B ), and so that the first transmitter pod  142  can generally fit within the heel cup (not shown) of the first shoe  102  or second shoe  104  and sit generally flat against the foot-facing upper surface  116 . That is, the first transmitter pod  142  may have a relatively small diameter. For example the first transmitter pod  142  may have a diameter of between 20 mm and 40 mm (e.g. about 30 mm) and height of between 10 mm and 20 mm (e.g. about 16 mm). 
     Referring to  FIG.  6   , the housing  148  (not shown in  FIG.  6   ) houses a receptacle  152  (also referred to herein as a ‘first receptacle’) which in the example shown is a micro-USB port, a circuit board (not visible)(also referred to herein as a ‘first circuit board’), a light pipe  154  (also referred to herein as a ‘first light pipe’), and a shield  156  (also referred to herein as a ‘first shield’). Referring to  FIG.  7   , the housing  148  further houses a transmitter coil  158  (also referred to herein as a ‘first transmitter coil’), and a set of transmitter magnets  160  (also referred to herein as a ‘first set of transmitter magnets’, only two of which are labelled) that are arranged around the transmitter coil  158 . The transmitter coil  158  is configured to receive a current from an energy source, and wirelessly induce a current in a receiver coil  176  of the first receiver pod  146  (described below). The transmitter magnets  160  are configured to magnetically couple the first transmitter pod  142  to the first receiver pod  146 , to hold the first transmitter pod  142  in proximity to the first receiver pod  146 . The first set of transmitter magnets  160  may include, for example, between 7 and 15 transmitter magnets  160 . In the example shown, the first set of transmitter magnets  160  includes 11 transmitter magnets  160 . The transmitter magnets  160  may be, for example, N38 rare earth magnets. The size of the transmitter magnets  160  may be selected to maximize magnetic coupling to the first receiver pod  146 , while minimizing the diameter of the first transmitter pod  142  (i.e. so that the first transmitter pod  142  can readily pass through the foot-receiving opening  150 ,  151 ). For example, the transmitter magnets  160  may have a diameter of between about 2 mm and about 8 mm and a height of between about 3 mm and about 10 mm. 
     The second transmitter pod  144  is configured similarly to the first transmitter pod  142 , and includes a second housing (not shown) that is configured so that the second transmitter pod  144  can readily pass through the foot-receiving opening  150  of the first shoe  102  or the foot-receiving opening  151  of the second shoe  104 , a second receptacle (not shown), a second circuit board (not shown), a second light pipe (not shown), a second shield (not shown), a second transmitter coil (not shown), and a second set of transmitter magnets arranged around the second transmitter coil (not shown). 
     Referring back to  FIG.  5   , in the example shown, the first transmitter pod  142  is electrically connected to a first cable  162  via the receptacle  152  (shown in  FIG.  6   ). Referring back to  FIG.  1   , the charger  140  further includes a second cable  164 , which is electrically connectable to the second transmitter pod  144 . The first  162  and second  164  cables are connectable to an energy source (e.g. wall outlet  166 ), so that the first  142  and second  144  transmitter pods receive energy from the energy source via the first  162  and second  164  cables, respectively. More specifically, in the example shown, the first cable  162  and the second cable  164  are joined to a third cable  168  at a Y-junction  170 , and the third cable  168  is electrically connectable to a plug  172  that can plug into the wall outlet  166 . 
     In alternative examples, the energy source can itself be a battery, to allow for portability of the charger. 
     Referring now to  FIGS.  8  and  9   , the first receiver pod  146  will be described in more detail. In the example shown, the first receiver pod  146  includes a housing  174  (also referred to herein as a ‘first housing’). The housing  174  is sized so that the first receiver pod  146  can be embedded in the insole bulk  110  without being readily detectable by a user (i.e. without the user feeling an object under their foot). That is, the first receiver pod  146  may have a relatively small thickness. For example the first receiver pod  146  may have a thickness of between about 2 mm and about 5 mm (e.g. about 3.75 mm). 
     Referring still to  FIGS.  8  and  9   , the housing  174  supports a receiver coil  176  (also referred to herein as a ‘first receiver coil’), and a set of receiver magnets  178  (also referred to herein as a ‘first set of receiver magnets’). The receiver coil  176  is configured to wirelessly receive energy by having a current induced therein by the transmitter coil  158 . The receiver magnets  178  are configured to magnetically couple to the transmitter magnets  160  (shown in  FIGS.  6  and  7   ), to hold the first receiver pod  146  in proximity to the first transmitter pod  142 , so that the transmitter coil  158  can induce a current in the receiver coil  176 . The first set of receiver magnets  178  may include, for example, between 2 and 6 receiver magnets  178 . In the example shown, the first set of receiver magnets includes 2 receiver magnets  178  positioned on opposite sides of the receiver coil  176 . The receiver magnets  178  may be, for example, N52 rare earth magnets. The size of the receiver magnets  178  may be selected to maximize magnetic coupling to the transmitter magnets  160 , while minimizing the thickness of receiver pod  146  (i.e. so that the receiver pod  146  is generally not felt under the user&#39;s foot). For example, the receiver magnets  178  may have a diameter of between about 3 mm and about 12 mm and a height of between about 2 mm and about 5 mm. 
     In the example shown, the size constraints of the transmitter pod  142  are different from the size constraints of the receiver pod  146 , as the transmitter pod  142  is configured to readily pass through the foot-receiving opening  150  of the first shoe  102  and the foot-receiving opening  151  of the second shoe  104  (and also to fit within the heel cup of the first  102  and second  104  shoes and sit flat against the foot facing upper surface  116 ), while the receiver pod  146  is configured to be embedded in the insole bulk  110  while remaining generally undetectable. As such, the height of each transmitter magnet  160  is greater than the height of each receiver magnet  178 , and the diameter of each transmitter magnet  160  is less than a diameter of each receiver magnet  170 . Furthermore, the set of transmitter magnets  160  includes a greater number of magnets than the set of receiver magnets  178 . Nevertheless, the set of transmitter magnets  160  can magnetically couple to the set of receiver magnets  178 , to hold the receiver pod  146  in proximity to the transmitter pod  142 , so that the transmitter coil  158  can induce a current in the receiver coil  176 . 
     In alternative examples, in addition to or as an alternative to the transmitter magnets  160  and receiver magnets  178 , other mechanisms may be used to align the transmitter pod  142  to the receiver pod  146  and hold the transmitter pod  142  in proximity to the receiver pod  146 . For example, a visual indicator (e.g. in the form of a target) may be provided on the foot-facing upper surface  116 , to guide a user in placing the transmitter pod  142  in proximity to the receiver pod  146 . For further example, a set of grooves (or another mechanical feature) may be provided for guiding a user in placing the transmitter pod  142  in proximity to the receiver pod  146  and mating the transmitter pod  142  to the insole  106 . 
     Referring still to  FIGS.  8  and  9   , in the example shown, the receiver pod  146  further includes a carbon fiber shield  180  (also referred to herein as a ‘first carbon fiber shield’), which supports the receiver coil  176  and protects the receiver coil  176  from deformation that may occur during use of the sensorized insoles. The receiver pod  146  further includes a receptacle  182  (also referred to herein as a ‘first receptacle’) in the form of a micro-USB port, which is used to electrically connect the receiver coil  179  to the batteries  138   a ,  138   b  (shown in  FIG.  4   ). 
     Referring back to  FIG.  3   , in use of the first sensorized insole  106 , when the transmitter pod  142  is positioned against the foot-facing upper surface  116  and magnetically coupled to the receiver pod  146 , energy is transferred from the transmitter coil  158  of the transmitter pod  142  to the receiver coil  176  of the receiver pod  146 . Particularly, energy is transferred through the insole bulk  110 , via an inductor capacitor circuit. In the example shown, the receiver coil  176  is spaced from the foot-facing upper surface  116  by a spacing  184  (also referred to herein as a ‘first spacing’), which is defined by the thickness of the portion of the top layer  112  that overlies the receiver coil  176 . Likewise, in the second sensorized insole (not shown), the second receiver coil is spaced from the second foot-facing upper surface by a second spacing. As noted above, in the example shown, the first sensorized insole  106  and the second sensorized insole (not shown) are in the form of custom orthotics, which are custom manufactured to fit a user&#39;s feet. Accordingly, the size of first spacing  184  may be unique to each user, as the thickness of the top layer  112  of the first sensorized insole  106  is determined at least in part by the assessment of the user&#39;s foot. Likewise, the size of the second spacing (not shown) may be unique to each user, as the thickness of the top layer of the second sensorized insole is determined at least in part by the assessment of the user&#39;s foot. For example, for a user with high arches, the top layer  112  may be relatively thick and the spacing  184  may thus be relatively large. On the contrary, for a user with relatively low arches, the top layer  112  may be relatively thin and the spacing  184  may thus be relatively small. Furthermore, even for a given user, the first spacing  184  may be different from the second spacing (e.g. in the case where a user&#39;s left foot has a different arch height from the user&#39;s right foot). More specifically, the first spacing  184  and the second spacing may on average be about 6 mm, but may vary between about 1 mm (e.g. where the top layer  112  includes only an upper finishing layer and the middle comfort layer and contour layer are omitted) and up to 18 mm. Accordingly, the first spacing  184  may differ between users by up to 17 mm, or more commonly, by up to about 4 mm. Furthermore, the first spacing  184  and the second spacing may differ between feet by up to 17 mm, or more commonly, by up to about 4 mm. 
     In order to account for the variable nature of the first spacing  184  and the second spacing, the first transmitter pod  142  is configured to detect the spacing of the insole to which it is coupled, and adjust its output accordingly, in order to effectively transfer energy at a given spacing. Likewise, the second transmitter pod  144  is configured to detect the spacing of the insole to which it is coupled, and adjust its output accordingly, in order to effectively transfer energy at a given spacing. That is, when coupled to the first sensorized insole  106 , the first transmitter pod  142  will detect the first spacing  184 , and emit an electromagnetic field of a frequency that is tuned to the first spacing  184 . In order to do this, the first transmitter pod  142  is configured to emit a series of stimulation pulses to the receiver coil  176 , receive a series of response pulses back from the receiver coil  176 , and adjust the output thereof based on the response pulses. More specifically, the transmitter coil  158  is configured to send out a series of stimulation pulses (also referred to as ‘pings’) of a narrow band that is close to the resonant frequency of the circuit. When these stimulation pulses are received by the receiver coil  176 , response pulses are emitted, and the response pulses are detected by the transmitter coil  158 . When the response pulses are detected, the transmitter pod  142  recognizes the presence of the receiver coil  176  in proximity to the transmitter coil  158 , and begins to emit pings at a broader band. The receiver coil  176  will continue to emit response pulses, and based on the response pulses, the transmitter pod  142  will determine an operating frequency (i.e. a highest efficiency frequency). The transmitter pod  142  will then select that frequency and begin transferring energy at that frequency. For example, if the transmitter coil  158  has a diameter of about 18 mm, and the transmitter coil  158  and receiver coil  176  are spaced apart by between about 1 mm and 18 mm, the operating frequency may be between about 0.43 MHz and 0.45 MHz. The second transmitter pod  144  operates in a similar fashion. 
     Because the transmitter pods  142 ,  144  are configured to adjust their output based on the spacing of the sensorized insole to which they are coupled, the transmitter pods  142 ,  144  can be manufactured in bulk, even though the sensorized insoles themselves may be custom manufactured for each user. Furthermore, because the transmitter pods  142 ,  144  are configured to adjust their output based on the spacing of the sensorized insole to which they are coupled, the user need not necessarily have a transmitter pod that is designated for a left sensorized insole and a transmitter pod that is designated for a right sensorized insole. Rather, the first transmitter pod  142  and second transmitter pod  144  can be interchangeable. That is, the first transmitter pod  142  can be positioned against either the foot-facing upper surface  116  of the first sensorized insole  106  to wirelessly provide energy to the first receiver pod  146  through the first insole bulk  110 , or against the foot-facing upper surface of the second sensorized insole to wirelessly provide energy to the second wireless charging receiver pod through the second insole bulk. Likewise, the second transmitter pod  144  can be positioned against either the second foot-facing upper surface to wirelessly provide energy to the second wireless charging receiver pod through the second insole bulk, or against the first foot-facing upper surface  116  to wirelessly provide energy to the first wireless charging receiver pod through the first insole bulk  110 . 
     In addition, in order to minimize or reduce conducted emissions from the wireless charging assembly  108 , the electromagnetic field emitted from the first transmitter pod  142  (also referred to herein as a ‘first electromagnetic field’) may be dithered, and the electromagnetic field emitted from the second transmitter pod  144  (also referred to herein as a ‘second electromagnetic field’) may be dithered. That is, energy may be transferred at a frequency that oscillates slightly around the operating frequency, to reduce the peak emission of the system. Furthermore, the second electromagnetic field may be dithered asynchronously with the first electromagnetic field, to even further reduce peak emissions. 
     In order to mitigate any issues caused by the generation of heat during charging, the first transmitter pod  142  may be configured to detect the temperature in the vicinity of the transmitter coil  158 , and turn off for a preset time period (e.g. about 20 seconds) if the temperature exceeds a predetermined threshold (e.g. a temperature of about 50 degrees Celsius). The second transmitter pod  144  may be similarly configured. 
     In general, in use, the first sensorized insole  106  and the second sensorized insole can be positioned in a user&#39;s shoes  102 ,  104 , and the shoes  102 ,  104  can be worn. When the shoes  102   104  are removed from the user&#39;s feet, the first sensorized insole  106  and second sensorized insole can be charged. As noted above, the user need not necessarily remove the first sensorized insole  106  and second sensorized insole from the shoes  102 ,  104 ; the first sensorized insole  106  and second sensorized insole can remain in the shoes  102 ,  104  during charging. That is, with the first sensorized insole  106  remaining in the first shoe  102  and the second sensorized insole remaining in the second shoe  104 , the user can insert the first transmitter pod  142  through the foot-receiving opening  150  of the first shoe  102  and position the first transmitter pod  142  against the first foot-facing upper surface  116  of the first insole bulk  110 , and insert the second transmitter pod  144  through the foot-receiving opening  151  of the second shoe  104  and position the second transmitter pod  144  against the second foot-facing upper surface of the second insole bulk. This can be achieved, for example, by simply dropping the first transmitter pod  142  into the first shoe  102  and allowing the first transmitter pod  142  to magnetically couple to the first receiver pod  146 , and dropping the second transmitter pod  144  into the second shoe  104  and allowing the second transmitter pod  144  to magnetically couple to the second receiver pod. As noted above, the transmitter pods  142 ,  144  are each configured to charge the first sensorized insole  106  and the second sensorized insole, even if the first sensorized insole  106  and the second sensorized insole have different thicknesses. Accordingly, the user can drop either transmitter pod  142 ,  144  into either shoe  102 ,  104  (i.e. the transmitter pods  142 ,  144  could be removed from the shoes  102 ,  104  and swapped, so that the second transmitter pod  144  is inserted through the foot-receiving opening  150  of the first shoe  102 , positioned against the foot-facing upper surface  116  of the first insole bulk  110 , and magnetically coupled to the first receiver pod  146 ). Energy will then be transferred from the energy source (i.e. the wall outlet  166 ) to the first  142  and second  144  transmitter pods via the cables  162 ,  164 ,  168 , and from the first  142  and second  144  transmitter pods to the first  146  and second receiver pods, respectively. 
     While the above description provides examples of one or more processes or apparatuses or compositions, it will be appreciated that other processes or apparatuses or compositions may be within the scope of the accompanying claims. 
     To the extent any amendments, characterizations, or other assertions previously made (in this or in any related patent applications or patents, including any parent, sibling, or child) with respect to any art, prior or otherwise, could be construed as a disclaimer of any subject matter supported by the present disclosure of this application, Applicant hereby rescinds and retracts such disclaimer. Applicant also respectfully submits that any prior art previously considered in any related patent applications or patents, including any parent, sibling, or child, may need to be re-visited.