Oral care devices and methods

Abstract

An oral care device (8) is adapted to generate an RF field for performing an oral cleaning function. The device comprises a cleaning unit (10) for reception in the oral cavity, the cleaning unit (10) comprising a conductor arrangement (18, 19) driven by a drive signal to generate an RF field for cleaning surfaces in the oral cavity. A method is also provided for sensing an electrical or electromagnetic signal generated by the interaction of RF energy with an object in the oral cavity, the electrical or electromagnetic signal being used to perform a sensing function using the same RF system components used to generate the RF field for cleaning or treatment.

Description

Technical Field

[0001] The present invention relates to an oral care device, in particular to an oral care device using electromagnetic radiation for cleaning and / or treatment functions. Background Art

[0002] Electromagnetic emission can be used to provide a cleaning function in the oral cavity. In particular, the oral care device can include a cleaning and / or treatment unit, such as a head, for insertion into the oral cavity of a user, the cleaning unit comprising, in part, one or more conductive elements coupled to an RF signal generator. The signal generator drives the conductive element with an RF signal, which causes the RF radiation to be emitted by the element.

[0003] US10 / 201701B2 describes a prior art electric toothbrush. The toothbrush comprises a platen, an RF generator, two RF electrodes, and a dielectric barrier in the form of a silicone rubber strip located between the two RF electrodes. The toothbrush also comprises bristles. The dielectric barrier has a height extending to the level of the distal tip of the bristles. The barrier forces the RF waves transmitted between the electrodes and the generated RF field to pass through the top of the barrier, thereby reaching the area where the bristles engage with the tooth and gum surface during use.

[0004] According to US10 / 201701B2, when the RF field interacts with the tooth and gum surfaces, it provides a cleaning function by loosening the bond between impurities and surfaces in the oral cavity. In particular, the RF field generated in this way can remove dental plaque and also calculus. Tooth staining can also be reduced.

[0005] The distal tips of the bristles rub the tooth surface in the usual manner to clean the teeth, while at the same time the RF electrodes emit RF waves which provide a cleaning action at the same surface being brushed at the level of the bristle tips.

[0006] Metal and non-metal restorations (crowns, implants, bridges, fillings) or appliances (braces) are often more susceptible to biofilm formation and more difficult to clean. 50% of orthodontic patients develop white spots due to failure to properly clean orthodontic appliances. Detection of these foreign bodies and plaque buildup on these areas is needed to optimize cleaning. Summary of the invention

[0007] The invention is defined by the claims.

[0008] According to an example of one aspect of the present invention, there is provided an oral care device, the oral care device comprising:

[0009] a cleaning unit for receipt in an oral cavity of a user, the cleaning unit comprising at least one conductor arrangement adapted to generate an RF field in response to receipt of an RF drive signal;

[0010] an RF generator arranged to provide an RF drive signal to the at least one conductor arrangement to generate an RF field, the RF field being suitable for performing an oral cleaning or treatment function during use; and

[0011] A controller is arranged to receive and process sensed electrical or electromagnetic signals resulting from the interaction of the generated RF field with foreign matter in the oral cavity.

[0012] Embodiments of the invention are based on providing an RF-based oral care device that additionally includes functionality for sensing, the sensing being based, for example, on the same system components as used to generate the RF field. The device settings can then be adapted based on the sensed interaction. Thus, additional sensing capabilities are enabled, but without requiring a change in the form factor of the device.

[0013] The oral care device uses RF energy to provide cleaning and / or therapeutic functions in the oral cavity.

[0014] The sensed electrical or electromagnetic signal (i.e., sensed data) can be used for a wide range of purposes. For example, it can be used to sense the presence of foreign matter in the oral cavity based on the electrical characteristics of the sensed signal. According to one or more embodiments, this can be used to adapt the cleaning and / or treatment functions of the device based on the detection.

[0015] Although the cleaning unit is cited above, it should be understood that the cleaning unit can provide cleaning and / or treatment functions. Therefore, the reference to the cleaning unit in the present disclosure can be understood as a reference to the cleaning and / or treatment unit. The cleaning unit can be, for example, a detachable component that is releasably coupleable to a body portion or a control unit portion of the device that accommodates the RF generator and the controller. According to another aspect, the body portion or the control unit portion can be separately provided and is suitable for being electrically and mechanically coupled to the cleaning and / or treatment unit to provide an RF drive signal to at least one conductor arrangement and receive a signal from at least one conductor arrangement.

[0016] The conductor arrangement comprises at least one electrical conductor operable to generate an electromagnetic field in response to being excited by an RF drive signal. For example, it may comprise one or more electrodes or one or more coils.

[0017] The device may include a component for sensing an electrical or electromagnetic signal caused by the interaction of the generated RF field with a foreign object in the oral cavity. The component may be provided at least in part by a conductor arrangement. The component may be provided by an RF generator circuit including an RF generator and a conductor arrangement. In a further example, the component may be provided by a separate dedicated sensing arrangement including one or more sensing elements.

[0018] According to some embodiments, the electrical signal or electromagnetic signal may be sensed using at least one conductor arrangement.Here, advantageously, the same component(s) used for transmitting the RF field are also used for sensing the return signal.

[0019] According to some embodiments, the controller may be adapted to adjust the operation of the oral care device based on the received and processed signals.

[0020] The controller may be adapted to cyclically or continuously adjust the operation of the oral care device (eg, throughout or during generation of the RF field by the RF generator) based on the received and processed signals.

[0021] Adjustments to the operation of the oral care device may be performed dynamically and in real time during operation. Cyclic or continuous adjustments may be performed throughout an operation session, for example, throughout the period of RF generation by the RF generator.

[0022] A control or feedback loop or path may be implemented between the controller and the RF generator so that operation of the oral care device may be automatically adjusted based on the sensed data.

[0023] The controller may be adapted to detect (solid) foreign matter in the RF field based on receiving and processing sensed electrical or electromagnetic signals resulting from interaction of the generated RF field with foreign matter in the oral cavity.

[0024] According to one or more embodiments, at least one conductor arrangement and an RF generator may together form an RF generating circuit, and wherein the sensing of the electrical or electromagnetic signal is based on detecting changes in one or more electrical characteristics of the RF generating circuit, such as voltage or impedance changes at electrodes of the conductor arrangement.

[0025] Here, therefore, the same circuitry used to generate the signal can be re-used for sensing while still being able to simultaneously perform its primary function (provision of RF energy).

[0026] According to one or more embodiments, the controller may be adapted to process the sensed electrical or electromagnetic signals to detect the presence of an object or entity in the RF field.It may be adapted to detect the presence of a solid object or entity in the RF field.

[0027] According to one or more embodiments, the controller may be adapted to process the sensed electrical or electromagnetic signals to determine or identify an object or entity present in the generated RF field.Here, the controller is able to perform different identifications of the object.

[0028] This may be based on a characteristic of the sensed interaction signal, such as voltage, current, impedance magnitude, frequency or phase.

[0029] This detection may enable differentiation between metallic and non-metallic objects.

[0030] According to at least one set of embodiments, the oral care device may be operable in a plurality of mechanical and / or fluid cleaning and / or treatment modes, and wherein the controller is adapted to configure or select the mode based on the sensed electrical or electromagnetic signal.

[0031] Here, the cleaning or treatment operation of the device is adapted based on the results of the sensing.For example, the sensing information may indicate the type of body or structure in the RF field, and based on this, the most appropriate mode may be selected.

[0032] Cleaning and / or treatment modes may be configured or selected by adapting device settings (e.g., RF frequency, duty cycle, drive train amplitude, motion, floss characteristics), for example, to allow for a personalized or optimized treatment process.

[0033] For example, the duration of cleaning and / or treatment may be configured based on the sensed signal.

[0034] The device may also have a user training mode. For example, the training mode involves sending and displaying sensor measurement data to a remote device, or giving feedback / suggestions to allow the user to personalize or customize the oral care process.

[0035] According to embodiments of the present invention, at least two main sensing approaches may be followed: complex impedance based sensing (preferably but not limited to capacitance based sensing) and inductance based sensing.

[0036] Capacitance-based sensing will be discussed first.

[0037] According to one or more embodiments, the conductor arrangement may include at least one pair of electrodes, the electrodes being spaced apart from each other and adapted to generate an RF field in a region around and between the electrodes in response to receipt of an alternating drive signal applied to the electrodes.

[0038] An alternating drive signal may be applied between the electrodes, thereby inducing an alternating potential difference between the electrodes. Thus, the pair of electrodes effectively forms a capacitor arrangement coupled across the AC supply voltage.

[0039] This embodiment effectively provides a capacitive sensing arrangement and allows detection of foreign matter based on changes in effective capacitance between electrodes, directly or indirectly. This can be detected based on, for example, analyzing the electrical characteristics of a circuit including the electrodes. These electrical characteristics can include, for example, one or more of voltage, current, and impedance. In some examples, detection can be based on changes in electrical characteristics of a drive signal to the detection electrodes. Preferably, the analysis involves current measurement. In some examples, this can be performed simultaneously with signal generation.

[0040] According to one or more embodiments, the oral cleaning unit may include a support structure having a support surface, and wherein at least one pair of electrodes is arranged to protrude outwardly from the support surface.

[0041] For example, this arrangement allows detection of objects that enter the space between the protruding electrodes.

[0042] The proximal end of each protruding member may be coupled to the support surface at respective locations on the support surface that are spaced apart to define a gap between the pair of electrodes.

[0043] According to one or more embodiments, the cleaning unit may include at least one pair of protruding members extending outward from a surface of the support body, each protruding member including one electrode of the at least one pair of electrodes, the protruding members being spaced apart from each other.

[0044] The cleaning unit may further include a plurality of bristles for cleaning teeth, the bristles extending outwardly from a supporting surface of the cleaning unit in the same general direction as the protruding members.

[0045] According to one or more embodiments, sensing of an electrical or electromagnetic signal may be based on sensing changes in the complex impedance of a generator circuit.

[0046] This embodiment may enable more robust or reliable detection of objects or entities in the RF field, as distinct from non-object related artifacts that may be present in the generator circuit signal.

[0047] Instead, by measuring changes in the total complex impedance of the sensed signal (including both resistive and reactive components), object detection can be made more robust to motion artifacts.

[0048] Another primary sensing method according to one or more embodiments is inductive type sensing.

[0049] For example, according to one or more embodiments, at least one conductor arrangement may include at least one induction coil or loop, wherein sensing the electrical or electromagnetic signal includes sensing an impedance change of the circuit including the at least one coil.

[0050] This can be the generator circuit or a separate sensing circuit.

[0051] In some examples, the conductor arrangement may include a single induction coil or loop for both RF field generation and sensing.

[0052] Alternatively, the coil may be driven according to a transmit / receive duty cycle, wherein the coil alternates between a signal generating phase or mode and a signal sensing phase or mode.

[0053] Alternatively, in other examples, simultaneous sensing and signal generation can be achieved based on monitoring changes in the impedance of the generator circuit while driving the coil with the drive signal. Simultaneous sensing and generation can be based on detecting changes in the amplitude, frequency or phase of the generator circuit drive signal, for example.

[0054] According to some examples, the cleaning unit may include a support structure having an outer support surface, and wherein the at least one induction coil is integrated in the support structure below the support surface, such as embedded in the support structure below the support surface.

[0055] According to one or more embodiments, the controller may be adapted to process the sensed electrical or electromagnetic signals to detect the presence of a metal object.

[0056] In some examples, the controller may be adapted to determine whether a metal object is exposed or unexposed (eg, a metal implant).

[0057] According to one or more embodiments, the oral care device may further include a body portion housing the RF generator and the controller, the body portion being mechanically and electrically coupled to the cleaning unit. The body portion may form a handle for the device. According to another aspect of the invention, the body portion may be provided by itself.

[0058] In some examples, the cleaning unit can be releasably couplable with the body portion. For example, it can be in the form of a head for an oral care device, such as a toothbrush, an oral rinsing device, a dental flossing device, a (partial) toothbrush mouthpiece, a multi-surface cleaning device, or any other type of oral cleaning and / or treatment device.

[0059] According to one or more embodiments, the cleaning unit may further include a plurality of bristles extending outwardly from a supporting surface of the cleaning unit for cleaning teeth. The device may be, for example, a toothbrush device or an interface unit including bristles.

[0060] According to one or more embodiments, the device may further include a mechanical oscillating mechanism arranged to oscillate the support surface of the cleaning unit at a first frequency, and wherein the oscillation of the first frequency causes the bristles to oscillate. The oscillating system may use a combination of motions and frequencies of different dimensions (e.g., a knocking up and down motion combined with a rotational or sweeping motion). More complex motions are also possible.

[0061] According to an example of another aspect of the present invention, there is provided a method, the method comprising:

[0062] generating and providing an RF drive signal to at least one conductor arrangement of an oral cleaning unit, the cleaning unit being adapted to be received in an oral cavity of a user, and the conductor arrangement being adapted to generate an RF field in response to receipt of the RF drive signal, and the RF field being adapted to perform an oral cleaning and / or treatment function during use;

[0063] sensing electrical or electromagnetic signals caused by the interaction of the RF field with foreign matter in the oral cavity, and

[0064] Receive and process sensed electrical and electromagnetic signals.

[0065] In some examples, the sensing may be performed using at least one conductor arrangement for generating an RF field.

[0066] The method may also include adjusting operation of the oral care device based on the received and processed signals.

[0067] The method may also include an initial step of inserting the oral cleaning unit into the user's oral cavity, and performing the remaining steps of the method while the cleaning unit is received in the user's oral cavity.

[0068] According to an example of another aspect of the present invention, there is provided a computer program product comprising a computer program code, the computer program code being executable on a processor or a computer,

[0069] Wherein when the processor or computer is operably coupled to an RF generator of an oral care device, the RF generator is operably coupled to at least one conductor arrangement, the code is configured to cause the processor to perform a method according to any example or embodiment summarized above or described below or according to any claim of the present application.

[0070] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] For a better understanding of the invention, and in order to more clearly show how the same may be put into practice, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0072] Figure 1 illustrates components of a first example oral care device according to one or more embodiments;

[0073] Figure 2 illustrates a plan view of an example cleaning unit of an oral care device;

[0074] Figure 3 illustrates components of another example oral care device according to one or more embodiments;

[0075] Figure 4illustrates electrode placement in a cleaning unit of another example oral care device according to one or more embodiments;

[0076] FIG5 illustrates the principle of capacitive sensing according to one or more embodiments;

[0077] Figure 6 illustrates a cleaning unit according to an example oral care device operating according to the principles of inductive sensing;

[0078] Figure 7 illustrates the principle of inductive sensing according to one or more embodiments;

[0079] Figure 8 illustrates a circuit arrangement of two induction coils of an example oral care device;

[0080] Fig. 9 illustrates a circuit arrangement with a single induction coil for an example oral care device;

[0081] Fig.10 Adapting a cleaning mode based on sensed object detection is illustrated;

[0082] Fig.11 A graph illustrating the relationship between the sensed interaction signal strength detected at the coil or electrode and the distance to the detection object is shown; and

[0083] Fig.12 Example methods are shown in block diagram form. DETAILED DESCRIPTION

[0084] The present invention will be described with reference to the accompanying drawings.

[0085] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, system and method, are for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects and advantages of the apparatus, system and method of the present invention will be better understood from the following description, the appended claims and the accompanying drawings. It should be understood that the drawings are only schematic diagrams and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to indicate the same or similar components.

[0086] The present invention provides an oral care device adapted to generate an RF field for performing an oral cleaning function. The device comprises a cleaning unit for receiving in the oral cavity, the cleaning unit comprising a conductor arrangement driven by a drive signal to generate an RF field for cleaning surfaces in the oral cavity. A method for sensing an electrical signal or an electromagnetic signal generated by the interaction of RF energy with a foreign object in the oral cavity is also provided, the electrical signal or the electromagnetic signal being used to perform the sensing function.

[0087] Thus, embodiments are based on utilizing RF cleaning fields to advantageously perform sensing concurrently with cleaning.In some embodiments, the sensed interaction signal may be used to inform the device of the nature or mode of cleaning.

[0088] For example, metallic and nonmetallic dental restorations (e.g., crowns, bridges, dentures, inlays, implants, screws, fillings) or appliances (wires, braces) are very common in the oral cavity. These foreign materials often result in sites that are more susceptible to the formation of dental biofilm and / or accumulation of dental plaque and are more difficult to clean with conventional cleaning processes (e.g., brushing, flossing). These materials in the oral cavity may provide a harbour for bacteria to accumulate and multiply and avoid removal using standard oral cleaning equipment.

[0089] This can lead to local oral health problems such as gingivitis and caries. In the case of orthodontic patients, white spot lesions often form. An estimated 50% of orthodontic patients have white spots on their teeth due to failure to properly clean orthodontic equipment. These white spot lesions are caused, for example, by localized softening of the enamel caused by poor cleaning around brackets.

[0090] As mentioned above, RF fields are an advantageous cleaning solution or adjunct to mechanical cleaning because such fields can penetrate into surfaces and crevices that are difficult to reach with physical cleaning means such as bristles, dental floss, or even cleaning with fluids.

[0091] Advantageously, in such an RF oral care device also includes a component for sensing an object present in the field, adjacent to the device RF transmitter. It would be useful if the form and modality of such a sensing component were capable of distinguishing between different types of foreign matter within the oral cavity. This information could be communicated to a user operating the device to help them maneuver the device around the mouth or adapt the cleaning mode performed depending on the type of foreign matter or structure engaged by the device. In some cases, it would be valuable if the device itself included a component for adapting the cleaning action or operation based on the sensing results.

[0092] Embodiments of the present invention are directed to addressing one or more of these problems.

[0093] According to an example of one aspect of the present invention, there is provided an oral care device, the oral care device comprising:

[0094] a cleaning unit for receipt in an oral cavity of a user, the cleaning unit comprising at least one conductor arrangement adapted to generate an RF field in response to receipt of an RF drive signal;

[0095] an RF generator arranged to provide an RF drive signal to the at least one conductor arrangement to generate an RF field suitable for performing an oral cleaning or treatment function when the cleaning unit is received in the oral cavity;

[0096] The device is further adapted to sense electrical or electromagnetic signals caused by the interaction of the generated RF field with foreign matter in the oral cavity, and

[0097] The apparatus also includes a controller arranged to receive and process the sensed electrical and electromagnetic signals.

[0098] The oral care device uses RF energy to provide cleaning and / or therapeutic functions in the oral cavity.

[0099] Although reference is made to a cleaning unit, it should be understood that the cleaning unit may provide cleaning and / or treatment functions. Therefore, references to a cleaning unit in the present disclosure may be understood as references to a cleaning and / or treatment unit.

[0100] Figure 1 Components of a first example oral care device 8 are schematically illustrated, according to one or more embodiments.

[0101] The device 8 comprises a cleaning unit 10 for reception in the oral cavity of a user. The cleaning unit comprises a support structure or body 12 having a support surface 13. The cleaning unit comprises a conductor arrangement, in this case in the form of a pair of electrodes 18a, 18b, which are spaced apart from each other and are adapted to generate an RF field in response to receipt of an RF drive signal.

[0102] In this example, at least one pair of electrodes 18 a , 18 b is arranged to protrude outwardly from the support surface 13 .

[0103] The proximal end of each electrode 18a, 18b is coupled to the support surface 13 at respective locations on the support surface, the respective locations being spaced apart so as to define a gap between the pair of electrodes. In further examples, more than one pair of electrodes may be provided.

[0104] In this particular example, the cleaning unit 10 includes a pair of protruding members 14a, 14b extending outwardly from the surface 13 of the support body 12, and each of the electrodes 18a, 18b includes one of the protruding members. For example, each protruding member 14a, 14b can take the form of or include a sheet-like structure. This example is shown in Figure 2 As shown in, for example, Figure 2 A top-down (planar) view of an example of a cleaning unit 10 is shown. Each protruding member defines a plane, and the members are arranged so that their respective planes are parallel and the major planar surfaces of the members are opposite to each other. However, this is not required, and in other examples, the protruding member may define, for example, a rod or shaft-shaped member. The electrodes may, for example, be integrated into the brush filaments or bristles, or they may be separate elements.

[0105] In some examples, the protruding members may be flexible and thus they may be resiliently deflected, for example, in response to appropriate mechanical interactions or forces. This allows the RF intensity distribution of the RF field generated by the electrodes to be dispersed across a wider area, or simply allows the high intensity area to be moved to cover different areas as the user moves the cleaning unit over the teeth (e.g., where the cleaning unit is the head of a toothbrush, it may be moved over the teeth).

[0106] exist Figure 1 In the example of FIG. 1 , the electrodes 18a, 18b are integrated within (eg, embedded in) the protruding members 14a, 14b. However, in other examples, they may be carried, for example, on the surface of the protruding members.

[0107] A protruding member is not necessary and the electrode may instead be provided on itself, for example protruding from the surface 13 .

[0108] In some examples, the cleaning unit 10 may also include a plurality of mechanical cleaning elements (eg, bristles, posts, protective cups) for cleaning teeth, which extend outwardly from the supporting surface 13 of the cleaning unit in the same direction as the electrodes. However, this is not required.

[0109] The device 8 further comprises an RF generator 22 electrically coupled to the electrodes 18a, 18b and arranged to provide an RF drive signal to the pair of electrodes to induce generation of an RF field. The RF field is suitable for performing an oral cleaning function when the cleaning unit is received in the oral cavity.

[0110] For example, the RF field may be used at any frequency in the range of 3 kHz - 300 GHz, such as 500 kHz - 30 MHz.

[0111] The electrodes 18a, 18b are adapted to generate an RF field in a region around and between the electrodes in response to receipt of an alternating drive signal applied to the electrodes by an RF generator 22.

[0112] An alternating drive signal may be applied between the electrodes 18a, 18b, thereby inducing an alternating potential difference between the electrodes. Thus, the pair of electrodes effectively forms a capacitor arrangement coupled across an AC supply current or voltage source from an RF generator.

[0113] The device 8 also includes components that allow sensing of electrical or electromagnetic signals caused by the interaction of the generated RF field with foreign matter in the oral cavity. Figure 1 In the example of , a sensing unit 24 is provided, and the sensing unit 24 is electrically coupled to the pair of electrodes 18a, 18b. The sensing unit 24 is adapted to sense changes in electrical characteristics of an interaction signal generated by the interaction of the RF field with the foreign matter. For example, the interaction signal is received from or transmitted to the electrode.

[0114] exist Figure 1 In the example of , the sensing unit 24 is electrically connected in parallel with the pair of electrodes (and with the RF generator), which means that it can detect changes in the voltage between the electrodes.

[0115] In other examples, the sensing unit 24 may be provided in a different electrical arrangement, such as being connected in series with one or more of the electrodes 18a, 18b. For example, one example of such an arrangement is Figure 3 It is shown in Figure 3 Depicted with Figure 1 The same example device differs in the configuration of the sensing unit 24. Figure 3 In the embodiment of the present invention, the RF generator is a voltage generator 22, and the interaction signal is measured using a current sensor 24 including an RF generating circuit. Figure 1 shows a current generator combined with a voltage sensor, while Figure 3 The use of a voltage generator in combination with a current sensor is shown.

[0116] In each case, the device 8 also comprises a controller 28 arranged to receive and process the sensed electrical and electromagnetic signals from the sensing unit 24 .

[0117] Preferably, the controller 28 may also be communicatively or operatively coupled to the RF generator 22 such that analysis results of the sensed interaction signal from the sensing unit 24 may be used to inform the RF drive scheme implemented by the RF generator.

[0118] In some examples, controller 28 may be adapted to control operation of RF generator 22 based on the sensed interaction signal.

[0119] The conductor arrangement including the electrodes 18a, 18b and the RF generator 22 may be understood to together form an RF generator circuit. Figure 1 and Figure 3 In the example, the sensing unit 24 is arranged to be electrically connected to the circuit so that the sensing of the electrical or electromagnetic signal returned from the oral cavity can be based on the detection of changes in one or more electrical characteristics of the RF generating circuit.

[0120] Hence, here the same circuitry used to generate the signal is used for sensing.However, this is not required, and in further examples separate sensing circuitry may be provided electrically coupled to the electrodes 18a, 18b, the sensing circuitry being arranged to sense the signal received at the electrodes.

[0121] Furthermore, it should be noted that although Figure 1 and Figure 3In the example of , the same conductor arrangement (at least one pair of electrodes 18a, 18b) is used to sense electrical or electromagnetic signals from the oral cavity, but this is not necessary but preferred, and in other examples, a separate conductor arrangement may be provided for sensing, or a separate one or more electrodes may be provided for sensing. This may provide a simpler method for achieving simultaneous sensing and signal generation. However, using the same Figure 1 and Figure 3 In the example of FIG. 5 , it is advantageous to use the same electrodes 18a, 18b for sensing and RF field generation because it minimizes the number of components.

[0122] In operation, the RF generator 22 generates a drive signal that is provided to at least one pair of electrodes 18a, 18b. The drive signal causes the electrodes to generate an RF field in the space between and around the electrodes.

[0123] In some examples, signal generation and signal sensing can be performed alternately in a duty cycle operation, such that before the RF generator 22 is disabled, an RF field is generated within a portion of the duty cycle, and the sensing unit 28 senses electrical characteristics in the electrode circuit to detect any return signal. Alternatively, sensing and RF field generation can be performed simultaneously based on monitoring changes in the drive signal to the electrodes during RF field generation. For example, changes in capacitance between the electrodes sensed by changes in voltage between the electrodes can be used to provide a sensed interaction signal.

[0124] According to one or more embodiments, the controller 28 may be adapted to process the sensed electrical or electromagnetic interaction signals to determine or identify an object or entity present in the generated RF field. For example, it may be adapted to distinguish between oral tissue and an artificial object or foreign body. It may be used to determine the type of artificial object or foreign body present in the field, such as the type of restoration or implant. As a non-limiting example, this may include, for example, a determination as to whether the object is a crown, bridge, denture, inlay, implant, screw, filling, or any other type of dental restoration. It may be feasible to determine that the object is made of a polymer or metal material and thereby distinguish it from intact enamel.

[0125] Such identification of a foreign object or matter in the RF field may be based, for example, on electrical characteristics of the sensed signal, such as complex impedance, voltage, current, amplitude, and / or frequency of the signal. For example, different foreign objects and different structures may have different RF absorption characteristics, so that the amplitude or power of the return RF waves sensed at the electrodes 18a, 18b may be used to identify the material, shape, or structure of the foreign object.

[0126] In some examples, the device may include a memory communicatively coupled to the controller, the memory storing a reference data set, such as a lookup table, recording reference signal characteristics for each of a plurality of different possible objects or entities. These may be organic, such as different types of oral structures (different teeth, etc.), or man-made / foreign objects. Thus, the system is able to distinguish between tissue and different types of man-made / foreign objects.

[0127] According to one or more embodiments, the controller 28 may be adapted to adjust device operating parameters or cleaning and / or treatment functions or change the operating mode of the device based on the sensed interaction signals from the sensing unit 24. For example, based on the type of object or body detected in the RF field, the cleaning mode may be adjusted to provide the most appropriate cleaning or treatment. For example, as described above, certain dental restoration features are prone to collecting biofilm and bacteria. Thus, for example, in response to detecting such features within the RF field, a more intense cleaning mode may be triggered, or the duration of the cleaning cycle may be increased.

[0128] Sensing-based adaptation of the functionality of the oral care device may include, but is not limited to, adaptation of RF field generation settings (eg, RF frequency or duty cycle) and settings related to other cleaning or therapeutic functions of the device.

[0129] For example, according to one or more embodiments, the cleaning unit may include bristles for cleaning teeth, and the device may include a mechanical oscillation mechanism arranged to oscillate the cleaning unit to cause oscillation of the bristles. In some examples, the amplitude and / or frequency of the mechanical oscillation may be adjusted based on the interaction signal detected by the sensing unit 24.

[0130] According to one or more examples, device 8 may be a flossing device, and wherein characteristics of the flossing function may be adjusted based on the sensed interaction signal.

[0131] According to at least one set of embodiments, oral care device 8 may be operable in a plurality of mechanical and / or fluid cleaning or treatment modes, and wherein controller 28 is adapted to configure or select a cleaning or treatment mode based on the sensed electrical or electromagnetic interaction signal.

[0132] For example, the sensing information may indicate the type of objects or structures present in the RF field, and based on this, the most appropriate cleaning or treatment mode may be selected.

[0133] The adaptation of device functionality based on sensing will be discussed in more detail below.

[0134] According to one or more embodiments, the controller 28 may be adapted to trigger certain response actions based on the sensed signals.

[0135] The responsive action may include generating information output based on the processing of the sensed data by the controller 28. For example, the sensed data may be transmitted to a remote device, such as via a wireless data communication channel. Sensory feedback, such as acoustic, tactile, or visual feedback, may be generated for the user based on the sensed information.

[0136] A control or feedback loop or path may be implemented between controller 28 and RF generator 22 so that the operation of oral care device 8 can be automatically adjusted based on the sensed data ( Figure 1 and Figure 3 ). For example, based on detecting the presence of one or more metal objects in the oral cavity, the cleaning process or routine can be adjusted accordingly and individually to achieve specialized cleaning or treatment actions, such as more intense cleaning or a different cleaning mode, at the metal-containing sites identified in the oral cavity. In some cases, feedback can be generated for the user to indicate locations that have been identified as requiring special attention.

[0137] According to one or more embodiments, the controller 28 may include a wireless communication interface to allow transmission and reception of data and / or control signals. The wireless communication interface may operate using any type of wireless communication protocol, such as Wi-Fi or Bluetooth.

[0138] The sensing functionality of the device can be implemented in different ways. In particular, according to embodiments of the present invention, at least two main sensing methods can be followed: capacitance-based sensing and inductance-based sensing.

[0139] Discussed above Figure 1 and Figure 3 Examples of operate on complex impedance, such as capacitive type sensing methods.

[0140] Here, the conductor arrangement comprises at least one pair of electrodes 18a, 18b, the electrodes being spaced apart from one another and adapted to generate an RF field in a region around and between the electrodes in response to receipt of an alternating drive signal applied to the electrodes.

[0141] An alternating drive signal may be applied between the electrodes 18a, 18b, thereby inducing an alternating potential difference between the electrodes. Thus, the pair of electrodes effectively forms a capacitor arrangement coupled across the RF power generator.

[0142] This embodiment effectively provides a capacitive sensing arrangement and allows sensing of foreign matter introduced between electrodes based on directly or indirectly detecting changes in the effective capacitance between the electrodes. For example, this can be detected by analyzing the electrical characteristics of the RF generating circuit by the sensing unit 24. These electrical characteristics may include, for example, one or more of voltage, current, and impedance. In some examples, this can be detected based on changes in the electrical characteristics of the drive signal that detects the electrodes. In some examples, this can be performed simultaneously with signal generation.

[0143] Despite Figure 1-Figure 2 and Figure 3 In the example of the at least one pair of electrodes 18a, 18b are arranged to protrude outwardly from the support surface 13 of the cleaning unit 10, but this is not important and in alternative examples the electrodes may be embedded below the support surface of the support structure 12. An example of such an alternative arrangement is Figure 4 For ease of illustration, the controller 28, the signal generator 22 and the sensing unit 24 are not shown, but these features may be Figure 1 or Figure 3 The features are the same as in .

[0144] An arrangement comprising protruding electrodes 18a, 18b allows detection of objects brought into the space between the protruding electrodes.An arrangement with embedded electrodes (or annular coils) allows, for example, detection of objects entering the space or region above and between the electrodes.

[0145] In either case, when an object or structure (e.g., foreign matter) enters the space between the locations of the RF electrodes 18a, 18b, the total effective capacitance between the electrodes changes and this results in detectable changes in voltage, current, impedance and / or other electrical characteristics of the circuit including the electrodes.

[0146] This is schematically illustrated in FIG. 5 . Figure 5a The effective capacitance between the electrodes (18a, 18b) is shown when there is no object or body in the RF field. The total effective capacitance C T Equal to the capacitance C1 between the electrodes themselves. Figure 5b 1 shows the situation when an object or body 32 enters the RF field. Here, additional effective capacitance is introduced, which includes a first object capacitance C2 across the space between the first electrode 18a and the object 32, and a second object capacitance C3 across the space between the object and the second electrode 18b. As a result, the total effective capacitance between the electrodes 18a, 18b increases to

[0147]

[0148] The sensing unit 24 (not shown in FIG. 5 ) may detect such changes based on detecting, for example, changes in voltage, current or impedance of a circuit comprising the electrodes 18 a, 18 b. The electrical characteristic(s) sensed by the sensing unit 24 may depend on the type of RF generator 22 used. For example, if the RF generator is a current generator, a voltage sensor may be implemented, whereas if the RF generator is a voltage generator, a current sensor may be used.

[0149] As previously mentioned, optionally, the measurement signals from the sensing unit 24 may therefore be used by the controller 28 (which may be a microcontroller, for example) to adapt the settings of the RF generator 22 or other cleaning components of the apparatus 8 .

[0150] Experiments performed by the present inventors have shown that using capacitive sensing methods, for example, it is possible to distinguish between metallic and non-metallic fillings, and also between metallic and non-metallic filled teeth.

[0151] In particular, the measured capacitance of different teeth with different types of fillings (metal, polymer, no filling) results in different measured capacitances. In general, the effective capacitance between the electrodes 18a, 18b is higher for more conductive objects. Specific ranges of relevant measurable capacitances for different foreign objects in the oral cavity can be measured in advance and stored as reference data, e.g. in a look-up table, which can then be retrieved from a memory, e.g. during operation, to allow the type of object in the field of the device to be determined.

[0152] According to one or more specific examples, sensing of an electrical or electromagnetic signal may be based on sensing a change in a complex impedance of a generator circuit.

[0153] This embodiment can achieve more robust or reliable detection of objects or entities in the RF field, which is different from non-object related artifacts that may be present in the generator circuit signal. By measuring the change in the total complex impedance (including the resistive and reactive parts) of the sensed signal, the moving object detection can be made more robust to motion artifacts.

[0154] The complex impedance may be expressed as Z=R+jX, where R is the resistance and X is the reactance.This may be measured based on sensing changes in the amplitude and / or phase of a current in a circuit comprising the electrodes 18a, 18b.

[0155] Another primary sensing method according to one or more embodiments is inductive type sensing.

[0156] For example, according to one or more embodiments, the cleaning unit 10 may include a conductor arrangement in the form of at least one induction coil or loop.

[0157] The sensing of the electrical or electromagnetic signal may comprise sensing a change in the inductance of a circuit comprising at least one coil. This may be a generator circuit or a separate sensing circuit.

[0158] Inductive sensing is based on the principle of electromagnetic induction based on eddy currents. A coil or loop antenna is driven by an alternating current (e.g., at the resonant frequency of the coil), thereby inducing an alternating magnetic field. The coil can be driven, for example, at an RF frequency to generate an RF field with a cleaning function. The same field can be used for sensing.

[0159] The generated RF field penetrates beneath the surface of foreign matter that enters it. For conductive foreign matter (including metal objects, and water containing foreign matter and matter), the magnetic field induces eddy currents in the material beneath the surface. These eddy currents in turn generate a secondary magnetic field that can be detected at the cleaning unit 10 using a second induction coil or based on measuring the induced changes in the electrical characteristics of the primary generator coil current.

[0160] Therefore, sensing can be more specific and robust in the presence of water.

[0161] Furthermore, while capacitive (or impedance) type sensing is primarily limited to sensing at the surface of a foreign object, inductive sensing allows penetration beneath the surface of an object. The eddy currents induce a magnetic field that is out of phase with the main magnetic field emitted by the coil, which results in a measurable reduction in the inductance in the coil.

[0162] An example cleaning unit 10 configured for inductive sensing is Figure 6 Schematically shown in FIG. The cleaning unit 10 comprises a conductor arrangement comprising a first (RF transmit) coil 19a and a second (receiver) coil 19b, the second coil being concentrically embedded within the first coil. Each coil in this example comprises a single loop (single winding), however in other examples the coil may comprise multiple loops or windings.

[0163] The AC drive signal is provided by the RF generator ( Figure 6 The current is generated by an electric current (not shown) and supplied to the transmission coil 19a. The electric current generates an alternating magnetic field.

[0164] like Figure 7 As schematically shown, if an electrical conductor 32 is brought close to the coil, eddy currents 42 are induced in the conductor, which generate an opposing (magnetic field) which can be measured using the second (receiver) coil 19b.

[0165] The inductor coils 19a, 19b are integrated in the support structure 12 of the cleaning unit 10 below the support surface 13. For example, they can be embedded in the support structure below the support surface. However, this is not required, and in other examples, the coils can be carried on the surface 13 of the support structure of the cleaning unit.

[0166] As an example, the transmission coil 19a and the receiving coil 19b may be implemented as a single layer of metallization on a foil (eg, polyimide) substrate. This method of manufacturing is low cost and reliable, and is suitable for incorporation into an oral cleaning unit body.

[0167] Figure 6 and Figure 7 The circuit arrangement of the double coil example is Figure 8Schematically shown in FIG. As shown, an RF generator 22 is electrically coupled in parallel across the generator coil 19a. A sensing unit 24 is electrically coupled to the sensing or receiving coil 19b and is adapted to measure changes in electrical characteristics of the receiving coil. For example, the sensing unit 24 may monitor changes in the inductance of the sensing coil based on electrical characteristics of the sensing coil circuit. The sensor unit may, for example, monitor the amplitude and / or frequency of the sensing coil current.

[0168] In further alternative examples, the cleaning unit 10 may include a conductor arrangement including a single inductive coil or loop for both RF field generation and sensing.

[0169] One such example circuit arrangement is in Fig. 9 . The RF generator 22 and the sensing unit 24 are both electrically coupled to the same single inductive coil 19a. In the illustrated example, the sensing unit is connected in parallel across the coil, however in an alternative example it may be connected in series.

[0170] If only one coil 19a is used for both RF field generation and passive inductive sensing, the system can operate in a transmit / receive duty cycle. Here, the system alternates between active RF mode and RF sensing mode. For example, the system can be operated with a pulsed RF field by using a duty cycle drive scheme. Figure 8 The switching is accomplished by the RF generator / oscillator in the RF module.

[0171] Sensing by the sensing unit 24 may be performed in the same manner as the dual coil example described above, based on sensing electrical characteristics such as frequency, amplitude and / or power of the coil current, for example to detect changes in the inductance of the coil 19a.

[0172] Instead of using a duty cycle drive scheme, in other examples, simultaneous sensing and signal generation can also be achieved based on monitoring changes in the impedance of the generator circuit while driving the coil 19a with the drive signal. Simultaneous sensing and field generation can, for example, be based on monitoring changes in the amplitude or frequency of the generator circuit drive signal while driving the coil with the drive signal. The secondary field in the eddy currents interacts with the primary field generated by the coil and causes changes in the electrical characteristics of the coil current during signal generation. This can be measured by the sensing unit 24 while the RF field generation is ongoing.

[0173] The penetration depth of the RF field depends on the frequency. Therefore, by varying the frequency of the generated field, different depth levels within a structure or tissue can be probed. Furthermore, the frequency of the induced eddy currents is also depth dependent, meaning that for a single frequency of the generated RF field, the responses at different depths can be distinguished based on their frequency. The strength of the secondary response signal can be related to its conductivity, allowing an indication of the material type to be determined.

[0174] The relationship between the field frequency f and the penetration depth δ of the foreign material can be expressed as follows:

[0175]

[0176] Where δ is the penetration depth, f is the frequency of the RF field, μ is the magnetic permeability of the material, and σ is the electrical conductivity of the material.

[0177] Therefore, the penetration depth increases as the frequency decreases.

[0178] Increasing the distance between the layers of foreign material of different conductivities and the coil also results in a time delay in the detected eddy currents, which manifests as an increased phase shift at higher frequencies, thereby increasing detectability at greater depths. Different types of foreign matter are at different depths relative to the biting surface of the toothbrush head or mouthpiece.

[0179] An advantage of an inductive sensing embodiment over a capacitive sensing embodiment is that the sensing may be more robust to potential signal artifacts caused, for example, by movement of the electrodes or the presence of fluids such as toothpaste in the RF field.

[0180] The eddy current response sensed at the one or more coils 19a, 19b depends on the conductivity of the material in which the eddy currents are induced, allowing the type of structure or body to be potentially sensed based on the sensed data.

[0181] As described above, the cleaning functions of the device 8 can be adapted by the controller 28 based on the sensing data from the controller 28. For example, the RF field strength or frequency can be adapted based on the sensing information. Additionally or alternatively, other cleaning functions (e.g., mechanical cleaning actions) can be adapted based on the sensing information.

[0182] Fig.10 An example is schematically illustrated in FIG. Fig.10 An example cleaning unit of an example care device 8 is shown. The device in this example includes bristles 44 protruding from the surface of the cleaning head 10. In addition, the device also includes a fluid nozzle 72 or jet port arranged to project a fluid stream for further cleaning functions. This provides a fluid flushing or active fluid cleaning mechanism. The fluid jet can be activated and deactivated, and the force (e.g., flow rate) of the fluid jet can be adjustable.

[0183] Fig.10 A different scene is shown in each of the three drawings of FIG. Each figure shows the cleaning unit 10 of the oral care device located above the crown 64. The gums 62 under each tooth are also shown.

[0184] exist Fig.10In the first case (left), the tooth 64 includes a metal bracket 66 at the natural crown. This protrudes from the tooth surface and enters the bristle area of ​​the cleaning unit / head 10. In the second case (center), there is a stainless steel metal crown at the tooth surface. In the last case (right), the tooth includes a metal screw, pin or dental implant 63.

[0185] In the first and second cases, the metal object at the crown can be detected by the controller 28 processing the sensing data based on, for example, the return signal strength, which is relatively high due to the metal material of the bracket 66 and the crown and their relative proximity to the sensor electrode 18 or (multiple) coils in the device cleaning unit 10. Therefore, it can be determined from the sensing data that there is an exposed metal object in the RF field, but at a different depth relative to the sensor electrode and the nozzle. Based on this, the characteristics of the fluid jet 72 can be adapted, for example to provide higher jet power to clean hard-to-reach areas on and around metal structures.

[0186] In the third case ( Fig.10 ), the controller 28 can detect that there is a metal object based on the sensing data, but it is implanted below the surface. In this case, no specific adaptation of the jet 72 is applied.

[0187] To achieve a high degree of specificity in sensing, in order to distinguish between different objects and their relative positioning, the sensed interaction signal strength and other characteristics (e.g., frequency in the case of inductive sensing) can be used. In some advantageous embodiments, the deflection angle of the bristles 44 and / or the orientation or position of the cleaning unit 10 can also be used to further inform the determination of the type and position of any object detected.

[0188] As described above, in order to detect the depth of the detected object, the strength of the sensed interaction signal received at the electrodes 18a, 18b or the coil(s) 19 may be used to inform this. Fig.11 A typical relationship between the sensed signal strength (y-axis; units: mH for inductive sensing, mF for capacitive sensing) and the distance between the electrode or coil(s) and the object being sensed (x-axis; units in mm) is shown. This relationship can be used to help determine whether metal or foreign matter is exposed or not, and therefore to adjust any response in terms of adaptation of the cleaning mode or characteristics of the device 8.

[0189] The principles of the present invention can be applied to a variety of different types of oral care devices.

[0190] According to one or more embodiments, the oral care device 8 may also include a body portion housing the RF generator 22 and controller 28 (and any sensing unit 24), which may be mechanically and electrically coupled to the cleaning unit 10. For example, the body portion may form a handle of the device.

[0191] In some examples, the cleaning unit 10 can be releasably couplable with the body portion.For example, in some examples, the cleaning unit can be a head for a toothbrush device, a dental floss device, an oral rinse device, or any other oral care device.

[0192] According to one or more embodiments, the cleaning unit 10 may further include a plurality of bristles for cleaning teeth, extending outwardly from the supporting surface 13 of the cleaning unit. The device may be, for example, a toothbrush device, or a partial or full arch toothbrushing mouthpiece unit including bristles.

[0193] According to one or more embodiments, the device 8 may further comprise a mechanical oscillating mechanism arranged to oscillate the supporting surface 13 of the cleaning unit 10 at a first frequency, and wherein oscillation of the first frequency causes the bristles to oscillate.

[0194] As non-limiting examples, an oral care device according to an embodiment of the present invention may be any of the following:

[0195] - Toothbrush devices (e.g. electric toothbrushes);

[0196] - Oral irrigator devices;

[0197] - dental floss equipment;

[0198] - a combined brushing and flossing device; or

[0199] -–Oral devices, such as toothbrushing oral devices.

[0200] According to another aspect of the present invention, a method 90 is provided. The steps of the method are Fig.12 An overview is given in the form of a block diagram.

[0201] Method 90 includes generating 92 and providing an RF drive signal to at least one conductor arrangement of an oral cleaning unit, the cleaning unit being adapted to be received in an oral cavity of a user, the conductor arrangement being adapted to generate an RF field in response to receipt of the RF drive signal, and the RF field being adapted to perform an oral cleaning function when the cleaning unit is received in the oral cavity.

[0202] The method further comprises sensing 94 electrical or electromagnetic signals caused by the interaction of the generated RF field with foreign matter in the oral cavity.The sensing may be accomplished by reusing elements of the RF generating circuit.

[0203] The method also includes receiving and processing 96 the sensed electrical and electromagnetic signals.

[0204] The method may also include an initial step of inserting the oral cleaning unit 10 into the user's oral cavity, and performing the remaining steps of the method while the cleaning unit is received in the user's oral cavity.

[0205] The implementation options and details of each of the above steps can be understood and explained based on the explanations and descriptions provided above for the apparatus aspect (ie, the oral care device aspect) of the present invention.

[0206] Any examples, options or embodiment features or details described above with respect to the apparatus aspect of the invention (regarding cleaning) may be applied or combined or incorporated into the method aspect of the invention.

[0207] According to an example of another aspect of the present invention, there is also provided a computer program product comprising computer program code, which is executable on a processor or a computer, wherein when the processor or the computer is operably coupled to an RF generator of an oral care device, the RF generator is operably coupled to at least one conductor arrangement, the code is configured to cause the processor to perform a method according to any example or embodiment summarized above or described below or according to any claim of the present application.

[0208] The present invention relates to the detection of foreign matter in the oral cavity. The possible uses of this detection capability can be summarized as follows:

[0209] (i) Adjusting oral hygiene routines (e.g., brushing and flossing). For example, if metallic dental material is detected in the oral cavity, the brushing routine can be automatically adjusted to provide concentrated and / or extended brushing time in these areas to help remove occluded bacterial biofilms.

[0210] (ii) Personalized coaching systems that provide education and feedback. For example, advice on different brushing or flossing techniques can be provided. This can be part of a training model.

[0211] (iii) Improved position sensing can be achieved by enabling certain teeth to identify their exact position, down to the level of single tooth accuracy. Intra-oral position sensing can be based on the location of known foreign bodies in the oral cavity.

[0212] (iv) Orthodontic detection. An example is the detection of orthodontic appliances in the oral cavity, which indicates that an orthodontic brushing routine should be performed in the control application, which is significantly different from the normal brushing routine of a normal person (i.e., a non-orthodontic individual). Typically, the brushing routine recommended by dentists is two minutes twice a day, while orthodontic patients are recommended to brush their teeth four times a day for four minutes (at least three minutes), including the regular two minutes and an additional two minutes of brushing from two opposite directions or angles (45 degrees up and down).

[0213] As described above, embodiments utilize controllers. The controller can be implemented in a variety of ways using software and / or hardware to perform the various functions required. A processor is an example of a controller that employs one or more microprocessors, which can be programmed using software (e.g., microcode) to perform the required functions. However, the controller can be implemented with or without a processor, and can also be implemented as a combination of dedicated hardware for performing some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) for performing other functions.

[0214] Examples of controller components that may be used in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0215] In various implementations, a processor or controller may be associated with one or more storage media, such as volatile and non-volatile computer memory, such as RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that perform the desired functions when executed on one or more processors and / or controllers. The various storage media may be fixed within a processor or controller, or may be transportable so that one or more programs stored thereon may be loaded into a processor or controller.

[0216] Those skilled in the art can understand and implement changes to the disclosed embodiments by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0217] A single processor or other unit may fulfill the functions of several items recited in the claims.

[0218] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0219] The computer program may be stored / distributed on a suitable medium, such as optical storage media or solid-state media provided with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0220] If the term "suitable for" is used in the claims or the specification, it should be noted that the term "suitable for" is intended to be equivalent to the term "configured to".

[0221] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An oral care device (8), comprising: A cleaning unit (10) for reception in an oral cavity of a user, the cleaning unit comprising at least one conductor arrangement (18, 19) adapted to generate an RF field in response to receipt of an RF drive signal; an RF generator (22) arranged to provide an RF drive signal to the at least one conductor arrangement to generate an RF field, the RF field being suitable for performing an oral cleaning and / or therapeutic function during use; and A controller (28) is arranged to receive and process sensed electrical or electromagnetic signals (24) caused by the interaction of the generated RF field with foreign matter in the oral cavity, and to adjust the operation of the oral care device based on the received and processed signals, wherein the electrical or electromagnetic signals (24) are sensed using the at least one conductor arrangement used to generate the RF field.

2. The oral care device (8) of claim 1, wherein the controller is adapted to cyclically or continuously adjust the operation of the oral care device based on the received and processed signals.

3. An oral care device (8) according to claim 1 or 2, wherein the at least one conductor arrangement and the RF generator (22) together form an RF generating circuit, and wherein the sensing of the electrical signal or electromagnetic signal (24) is based on detecting changes in one or more electrical characteristics of the RF generating circuit.

4. The oral care device (8) of claim 1 or 2, wherein the controller (28) is adapted to process the sensed electrical or electromagnetic signals (24) to determine or identify objects present in the generated RF field.

5. The oral care device (8) of claim 1 or 2, wherein the controller (28) is adapted to process the sensed electrical or electromagnetic signals (24) to determine or identify entities present in the generated RF field.

6. An oral care device (8) according to claim 1 or 2, wherein the oral care device is capable of operating in multiple mechanical and / or fluid cleaning or treatment modes, and wherein the controller (28) is suitable for configuring or selecting the cleaning or treatment mode based on the sensed electrical signal or electromagnetic signal.

7. An oral care device (8) according to claim 1 or 2, wherein the conductor arrangement comprises at least one pair of electrodes (18a, 18b), the electrodes being spaced apart from each other and adapted to generate an RF field in a region around and between the electrodes in response to receipt of an alternating drive signal applied to the electrodes.

8. The oral care device (8) according to claim 7, wherein the oral cleaning unit (10) comprises a support structure (12) having a support surface (13), and wherein the at least one pair of electrodes (18a, 18b) are arranged to protrude outwardly from the support surface.

9. The oral care device (8) of claim 7, wherein the sensing of the electrical or electromagnetic signal is based on sensing changes in a complex impedance of a circuit comprising the electrodes (18a, 18b).

10. The oral care device (8) of claim 1 or 2, wherein the conductor arrangement comprises at least one induction coil.

11. The oral care device (8) of claim 1 or 2, wherein the conductor arrangement comprises a loop.

12. The oral care device (8) according to claim 10, wherein the sensing of the electrical signal or electromagnetic signal comprises: A change in inductance of a circuit including the at least one coil is sensed.

13. The oral care device (8) of claim 10, wherein the conductor arrangement comprises a single induction coil for both generating the RF field for cleaning or treatment and also for sensing.

14. The oral care device (8) of claim 13, wherein the at least one coil is operated in a transmit / receive duty cycle drive scheme, wherein the coil alternates between a signal generating phase for treatment or cleaning and a signal sensing phase.

15. The oral care device (8) according to claim 13, wherein the cleaning unit (10) comprises a support structure (12) having an outer support surface (13), and wherein the at least one induction coil is integrated in the support structure below the support surface.

16. The oral care device (8) of claim 15, wherein the at least one induction coil is embedded in the support structure beneath the support surface.

17. The oral care device (8) of claim 1 or 2, wherein the controller (28) is adapted to process the sensed electrical or electromagnetic signals to detect the presence of a metal object in the oral cavity.

18. The oral care device of claim 1 or 2, wherein the device further comprises a body portion housing the RF generator (22) and the controller (28), the body portion being mechanically and electrically coupleable to the cleaning unit.

19. A method (90) for an oral care device, comprising: generating (92) an RF drive signal and providing the RF drive signal to at least one conductor arrangement of an oral cleaning unit, the cleaning unit being adapted to be received in an oral cavity of a user, and the conductor arrangement being adapted to generate an RF field in response to receipt of the RF drive signal, and the RF field being adapted to perform oral cleaning during use; sensing (94) electrical or electromagnetic signals caused by interaction of the generated RF field with a foreign object in the oral cavity, wherein the sensing is performed using the at least one conductor arrangement used to generate the RF field; as well as The sensed electrical and electromagnetic signals are received (96) and processed, and operation of the oral care device is adjusted based on the received and processed signals.

20. A computer program product comprising computer program code, the computer program code being executable on a processor or a computer, Wherein when the processor or computer is operably coupled to an RF generator (22) of an oral care device (8), the RF generator being operably coupled to at least one conductor arrangement (18, 19), the code is configured to cause the processor to perform the method according to claim 19.

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