Oral treatment device

Abstract

An oral treatment device for use in treating an oral cavity of a user. The oral treatment device may include a support and at least one deformable cleaning element projecting from the support. The deformable cleaning element may include a piezoelectric element. The oral treatment device may further include a deformation information collection arrangement electrically connected to the piezoelectric element and configured to collect and conduct output electrical energy, representative of deformation of the piezoelectric element, from the piezoelectric element.

Description

[0001] 1 P005412-W001

[0002] ORAL TREATMENT DEVICE

[0003] BACKGROUND

[0004] Oral treatment devices, such as toothbrushes, for use in treating oral cavities of users are known. Some oral treatment devices have a support comprising a head portion, and cleaning elements, such as tufts of bristles, projecting from a front side of the head portion. Some oral treatment devices have a handle integrally formed with the support. Others are configured to be removably attachable to a handle, for instance so that the handle is usable with several different oral treatment devices.

[0005] SUMMARY

[0006] When a user of an oral treatment device uses the oral treatment device inadequately, food debris and a biofilm layer on the user’s teeth may not be removed properly, which can result in plaque accumulation. When the user uses the oral treatment device too vigorously, gum injury may result and / or premature damage to cleaning elements of the oral treatment device may occur.

[0007] A first aspect of the present invention provides an oral treatment system for use in treating an oral cavity of a user, the oral treatment system comprising: a support; at least one first deformable cleaning element projecting from the support, wherein the at least one first deformable cleaning element is configured to conduct electromagnetic energy for emission from the oral treatment system; and an ultrasound generator configured to generate and emit ultrasonic energy from the oral treatment system.

[0008] The emission of both electromagnetic energy and ultrasonic energy from the oral treatment system may enable both types of energy to be directed at the oral cavity and to have a synergistic effect therein. For example, the ultrasonic energy may facilitate improved cleaning of the oral cavity, while the electromagnetic energy may help to avoid or reduce tissue inflammation. Moreover, ultrasound and light-mediated radical generation has been demonstrated to facilitate antimicrobial effects. 2 P005412-W001

[0009] Optionally, the ultrasound generator comprises at least one ultrasound transmitter projecting from the support. Optionally, the ultrasound generator comprises at least one second deformable cleaning element projecting from the support, and the at least one second deformable cleaning element comprises an ultrasound transmitter that is configured to generate and emit the ultrasonic energy from the oral treatment system.

[0010] This may improve an efficacy of the oral treatment system at treating the oral cavity of the user. Ultrasonic waves reduce in intensity the further they travel from their source. By comprising the ultrasound transmitter of the system in the second deformable cleaning element, as opposed to remote from the second deformable cleaning element, ultrasonic waves arising in fluid (such as air, toothpaste and / or saliva) surrounding the second deformable cleaning element in use, as a result of vibration of the ultrasound transmitter, are much less likely to be attenuated and the ultrasonic waves can be delivered closer to the oral cavity, to potentially remove plaque better and thus clean the oral cavity more efficiently. In other words, the ability of the ultrasound transmitter to emit a sufficient stimulus at a desired site in the oral cavity is much improved. Moreover, in a comparative system in which the ultrasound transmitter is remote from the second deformable cleaning element, stronger, lower-frequency ultrasound needs to be employed to ensure wave transmission. However, such lower frequency ultrasound limits the achievable mechanical effects. By providing the ultrasound transmitter in the second deformable cleaning element, higher frequency ultrasound can be employed.

[0011] The ultrasound may beneficially induce inertial cavitation in fluid in the oral cavity, resulting in the creation and subsequent collapse of small bubbles in the fluid. This collapse may generate physical chemical changes around the bubble, including the generation of ultraviolet (UV) light according to a mechanism known as sonoluminescence. If a toothpaste, dentifrice or mouthwash in the oral cavity includes a UV-responsive chemical compound, this sonoluminescence mechanism can be used to indirectly activate that chemical compound in order to generate free radical species. Moreover, the ultrasound may help such a chemical compound to migrate closer to the area of the oral cavity to be cleaned or otherwise treated. 3 P005412-W001

[0012] Moreover, the oral treatment system uses the material of the at least one first deformable cleaning element itself for conducting the electromagnetic energy. That is, the, or each, first deformable cleaning element may act as an optical waveguide. This avoids the need to provide further structure(s) for this purpose.

[0013] A second aspect of the present invention provides an oral treatment device for use in treating an oral cavity of a user, the oral treatment device comprising: a support; at least one first deformable cleaning element projecting from the support, wherein the at least one first deformable cleaning element is configured to conduct electromagnetic energy for emission from the oral treatment device; and at least one second deformable cleaning element projecting from the support, wherein the at least one second deformable cleaning element comprises an ultrasound transmitter configured to generate and emit ultrasonic energy from the oral treatment device.

[0014] As noted elsewhere herein, the emission of both electromagnetic energy and ultrasonic energy from the oral treatment device may enable both types of energy to be directed at the oral cavity and to have a synergistic effect therein. Moreover, as also noted elsewhere herein, comprising the ultrasound transmitter in the second deformable cleaning element may improve an efficacy of the oral treatment device at treating the oral cavity of the user, as compared to locating the ultrasound transmitter remote from the second deformable cleaning element.

[0015] As discussed herein, in some examples the oral treatment device is configured to be removably attachable to a handle. In some other examples, the oral treatment device comprises a handle, such as a handle that is integrally formed with the support. In some examples, the oral treatment device is a brush head or a toothbrush.

[0016] Optionally, in the oral treatment system according to the first aspect of the present invention or the oral treatment device according to the second aspect of the present invention, the at least one second deformable cleaning element is of a different type to that of the at least one first deformable cleaning element. For example, the at least one second deformable cleaning element may not be configured to conduct electromagnetic energy 4 P005412-W001 and / or the at least one first deformable cleaning element may not comprise an ultrasound transmitter.

[0017] Optionally, in the oral treatment system according to the first aspect of the present invention or the oral treatment device according to the second aspect of the present invention, the ultrasound transmitters comprises a piezoelectric element that is optionally made from a piezoelectric polymer or a dielectric polymer. For example, the piezoelectric element may be made from polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0018] Optionally, the at least one second deformable cleaning element comprises at least one electrode on the piezoelectric element. Optionally, the electrode is metallic, such as a metal, e.g., silver. Optionally, the electrode comprises a layer, or coating, of electrically conductive material.

[0019] Optionally, the at least one second deformable cleaning element comprises a non- electrically conductive cover having an interior within which the piezoelectric element is located. This cover may help to preserve the piezoelectric element. Optionally, the electrode(s), when present, is / are located within the interior of the cover. This may help to preserve the electrode(s). Optionally, the at least one second deformable cleaning element comprises at least one electrode on an exterior surface of the piezoelectric element, and the cover contacts the at least one electrode on the exterior surface of the piezoelectric element, so that the at least one electrode on the exterior surface is sandwiched between the piezoelectric element and the cover. This may further help to preserve the electrode on the exterior surface of the piezoelectric element.

[0020] Optionally, the non-electrically conductive cover comprises a layer, or coating, of non- electrically conductive material. Optionally, the non-electrically conductive material is a biocompatible material and / or a polymer, such as Nylon. Optionally, the non-electrically conductive cover comprises polyethylene glycol (PEG), such as a layer of PEG, such as on the layer of non-electrically conductive material. The PEG may change a topography of an external surface of the second deformable cleaning element and reduce a hydrophobicity of 5 P005412-W001 the external surface, thus helping to reduce bacterial adhesion and biofouling of the second deformable cleaning element, in use.

[0021] Optionally, in the oral treatment system according to the first aspect of the present invention or the oral treatment device according to the second aspect of the present invention, the piezoelectric element comprises a piezoelectric fibre. Optionally, the piezoelectric fibre is a hollow piezoelectric fibre. Providing that the piezoelectric fibre is hollow may facilitate connection of electrodes to the piezoelectric fibre in such a way that, when an electrical current is applied to the piezoelectric fibre via the electrodes, the piezoelectric fibre changes shape in a way that improves how the deformable cleaning element is usable to treat the oral cavity of the user. Optionally, the hollow piezoelectric fibre comprises a tubular piezoelectric portion.

[0022] Optionally, the at least one second deformable cleaning element is circular in cross section. Optionally, the at least one second deformable cleaning element has a diameter of about 0.4mm to about 2mm.

[0023] Optionally, the at least one second deformable cleaning element has a tapered end. This may help the second deformable cleaning element reach into small spaces in the oral cavity, in use.

[0024] Optionally, the oral treatment system according to the first aspect of the present invention or the oral treatment device according to the second aspect of the present invention further comprises a deformation information collection arrangement optically coupled to the at least one first deformable cleaning element and configured to collect and conduct output electromagnetic energy, representative of deformation of the at least one first deformable cleaning element, from the at least one first deformable cleaning element.

[0025] By collecting the output electromagnetic energy from the first deformable cleaning element, information about the deformation, such as bending or buckling, of the first deformable cleaning element may be captured. This information may be used to monitor use of the oral treatment device and one or more actions may be taken in consequence. 6 P005412-W001

[0026] Greater accuracy of information may be captured than, for example, monitoring movement of a combination of the whole support and the first deformable cleaning element relative to some point of reference. Accordingly, a better-informed action can be taken. For example, a user of the oral treatment device may be informed about wear of the first deformable cleaning element, about how they are using the oral treatment device, about how they might better use the oral treatment device and / or about when replacement of the oral treatment device is recommended.

[0027] Optionally, the at least one first deformable cleaning element is integrally formed with the deformation information collection arrangement. Such a construction may help to improve collection of the output electromagnetic energy from the first deformable cleaning element, as compared to an arrangement in which the output electromagnetic energy instead needs to navigate a join between the first deformable cleaning element and the deformation information collection arrangement.

[0028] Optionally, the at least one first deformable cleaning element comprises plural first deformable cleaning elements, and wherein the deformation information collection arrangement defines plural paths that are coupled to the respective plural first deformable cleaning elements and configured to collect and conduct output electromagnetic energy, representative of deformation of the respective plural first deformable cleaning elements, from the respective plural first deformable cleaning elements. Such an arrangement may help to keep collected streams of output electromagnetic energy, from the respective first deformable cleaning elements, separate from each other and help to conduct those streams of output electromagnetic energy towards a destination. This may provide the destination with the ability to collect the streams of output electromagnetic energy, and thus assess, monitor or otherwise handle data indicative of the deformation of the respective first deformable cleaning elements separately, i.e., on a per-cleaning-element basis. This may provide the destination with more information about deformation of the first deformable cleaning elements than a comparative system in which output electromagnetic energy from all the first deformable cleaning elements is instead merged together on its way to the destination. 7 P005412-W001

[0029] Optionally, the deformation information collection arrangement comprises plural optical fibres that define the respective plural paths.

[0030] Optionally, the at least one first deformable cleaning element is configured to receive input electromagnetic energy from the deformation information collection arrangement, and reflect the input electromagnetic energy back to the deformation information collection arrangement as the output electromagnetic energy that is collected and conducted by the deformation information collection arrangement. This may enable the oral treatment device to have a fully passive structure for sensing the deformation of the, or each, first deformable cleaning element. For example, the deformation information collection arrangement may transmit input electromagnetic energy to the, or each, first deformable cleaning element, and (e.g., a distal end of) the, or each, first deformable cleaning element may reflect some of that input electromagnetic energy back to the deformation information collection arrangement as the output electromagnetic energy. A remainder of the input electromagnetic energy, which is a difference between the input electromagnetic energy and the output electromagnetic energy, may be lost to the surrounding environment through sides of the, or each, first deformable cleaning element. The percentage of the input electromagnetic energy that is lost in this way may be dependent on the degree of deformation of the, or each, first deformable cleaning element, with a greater degree of deformation resulting in a greater loss of the electromagnetic energy. Accordingly, a magnitude of the output electromagnetic energy, which is collected by and conducted by the deformation information collection arrangement, is therefore indicative of the degree of deformation of the, or each, first deformable cleaning element.

[0031] Optionally, the electromagnetic energy is light. Optionally, the light is white light. Optionally, the light is red light (such as with a wavelength within a range from about 600nm to about 700nm). Optionally, the light is blue light (such as with a wavelength within a range from about 400nm to about 450nm). Optionally, the light is near-infrared light (such as with a wavelength within a range from about 770nm to about 1200nm). Optionally, the source of electromagnetic energy is a combination of lights with wavelengths in different ranges (e.g., combination of red light with blue light). Red light, 8 P005412-W001 blue light and near-infrared light may have photo-biomodulation properties, such as helping to avoid or reduce tissue inflammation.

[0032] Optionally, the electromagnetic energy is visible light, and the output electromagnetic energy collected by the deformation information collection arrangement may be conveniently viewed by a user of the oral treatment device without requiring conversion into a different form of energy. The oral treatment device may therefore be more efficient, simpler, and less costly, since energy conversion can be lossy and would require the oral treatment device to have additional structure(s) to make the conversion.

[0033] In some examples, some of the visible light is lost to the surrounding environment through sides of the, or each, first deformable cleaning element, during the deformation of the, or each, first deformable cleaning element, rather than reflected. This may provide a user of the oral treatment device with a visual indication of how much deformation is being experienced by the, or each, first deformable cleaning element.

[0034] Optionally, the oral treatment system or oral treatment device comprises at least one tuft of plural ones of the first deformable cleaning elements. The, or each, tuft may be circular or non-circular in cross section. Optionally, the oral treatment system or oral treatment device comprises plural such tufts.

[0035] Optionally, respective portions of the first deformable cleaning elements of each tuft are fused together into a block. Further optionally, the deformation information collection arrangement, when provided, is connected to the block and configured to collect and conduct the output electromagnetic energy from the block.

[0036] Optionally, the first deformable cleaning element is circular in cross section. Optionally, the first deformable cleaning element has a diameter of about 0.4mm to about 2mm.

[0037] Optionally, the, or each, first deformable cleaning element is made from a polymer, such as Nylon. 9 P005412-W001

[0038] Optionally, the oral treatment system according to the first aspect of the present invention comprises a source of electromagnetic energy; an electromagnetic energy transmission arrangement configured to transmit input electromagnetic energy from the source of electromagnetic energy to the at least one first deformable cleaning element; a source of electrical energy and an electrical energy transmission arrangement configured to transmit input electrical energy from the source of electrical energy to the at least one second deformable cleaning element.

[0039] Optionally, the support, the at least one first deformable cleaning element and the at least one second deformable cleaning element are comprised in an oral treatment device, and the system further comprises a handle, where the handle comprises the source of electromagnetic energy, the electromagnetic energy transmission arrangement, the source of electrical energy and the electrical energy transmission arrangement. Accordingly, the source of electrical energy and the source of electromagnetic energy may be spaced from the oral treatment device, at least by the electromagnetic energy transmission arrangement and the electrical energy transmission arrangement. This may enable the oral treatment device to be sufficiently compact for comfortable insertion into a user’s mouth. Such a construction may also ensure that a centre of mass of the oral treatment system is close to a user’s hand, which may provide a desirable ergonomic advantage.

[0040] Optionally, the electromagnetic energy is light, so that the source of electromagnetic energy is a light source. Further optionally, the light source comprises one or more light emitting diodes.

[0041] Optionally, the light is white light. Optionally, the light is blue light (such as with a wavelength within a range from about 400nm to about 450nm). Optionally, the source of electromagnetic energy is a source of red light (such as with a wavelength within a range from about 600nm to about 700nm) or near-infrared light (such as with a wavelength within a range from about 770nm to about 1200nm). Optionally, the source of electromagnetic energy is a source of a combination of lights with wavelengths in different ranges (e.g., combination of red light with blue light). The electromagnetic energy may have a therapeutic effect on the user, such as an anti-inflammatory effect. 10 P005412-W001

[0042] Optionally, the source of electrical energy comprises a battery.

[0043] Optionally, the source of electromagnetic energy is configured to output the input electromagnetic energy to the electromagnetic energy transmission arrangement by pulsing or modulating the input electromagnetic energy so that the input electromagnetic energy comprises a series of energy pulses. For example, when the energy source is a light source, the light source may emit the light as a series of flashes. Such pulsed input energy would therefore have a time-varying amplitude. The amplitude of the input electromagnetic energy may be zero or non-zero between the pulses.

[0044] Optionally, the handle is integrally formed with the support of the oral treatment device. This may provide a robust oral treatment system that is convenient to hold and operate.

[0045] Optionally, the handle is configured to be removably attachable to the support of the oral treatment device. Therefore, the oral treatment device may be replaceable by, or interchangeable with, another oral treatment device, so that the source of electromagnetic energy, the source of electrical energy, the electromagnetic energy transmission arrangement and the electrical energy transmission arrangement may be used with several oral treatment devices successively. This may reduce how much of the oral treatment system needs to be disposed of when the oral treatment device is too worn to achieve adequate performance, may enable several users (each having their own respective oral treatment device) to share the handle, and / or may make the oral treatment system more compact for storage or transport.

[0046] Optionally, the oral treatment system comprises an electromagnetic energy receiver and the electromagnetic energy transmission arrangement is further configured to transmit the output electromagnetic energy from the deformation information collection arrangement to the electromagnetic energy receiver.

[0047] In some examples, the electromagnetic energy receiver is an electromagnetic energy detector. 11 P005412-W001

[0048] Optionally, the electromagnetic energy receiver comprises a photodetector. In some other examples, the electromagnetic energy receiver comprises a window through which the electromagnetic output energy can be emitted from the oral treatment system in use, for viewing by a user.

[0049] Optionally, the deformation information collection arrangement is comprised in the oral treatment device, and the electromagnetic energy transmission arrangement is configured to transmit the input electromagnetic energy from the source of electromagnetic energy to the deformation information collection arrangement of the oral treatment device.

[0050] Optionally, the at least one first deformable cleaning element comprises plural first deformable cleaning elements, the deformation information collection arrangement defines plural paths that are coupled to the respective first deformable cleaning elements and configured to collect and conduct respective streams of the output electromagnetic energy, representative of deformation of the respective first deformable cleaning elements, from the respective first deformable cleaning elements, and the electromagnetic energy transmission arrangement defines plural channels that are coupled to the respective plural paths of the deformation information collection arrangement and configured to conduct the respective streams of the output electromagnetic energy from the respective plural paths to the electromagnetic energy receiver.

[0051] Optionally, the electromagnetic energy transmission arrangement comprises plural optical fibres that define the respective plural channels.

[0052] Optionally, the electromagnetic energy receiver comprises an imaging sensor comprising a plurality of pixels, and wherein the plural channels of the electromagnetic energy transmission arrangement are coupled to respective sub-sets of the pixels, each of the subsets comprising one or more of the pixels. The imaging sensor may be a two-dimensional imaging sensor or a linear array imaging sensor, for example. 12 P005412-W001

[0053] Optionally, the electromagnetic energy transmission arrangement comprises an optical component that is configured to: receive the input electromagnetic energy from the source of electromagnetic energy and to direct the input electromagnetic energy to the deformation information collection arrangement; and receive the output electromagnetic energy from the deformation information collection arrangement and to direct the output electromagnetic energy to the electromagnetic energy receiver. Having a single optical component that is configured to perform both of these functions may reduce a space required for the electromagnetic energy transmission arrangement. It may additionally, or alternatively, reduce a number of joints required between components that are to transmit electromagnetic energy. This may be beneficial, as such joints can be locations at which electromagnetic energy may be undesirably lost to the surrounding environment.

[0054] Optionally, the optical component is a V-shaped or Y-shaped component having a first arm that is configured to receive the input electromagnetic energy from the source of electromagnetic energy, a second arm that is configured to direct the output electromagnetic energy to the electromagnetic energy receiver, and a trunk that connects the first and second arms and that is configured to direct the input electromagnetic energy to the deformation information collection arrangement and to receive the output electromagnetic energy from the deformation information collection arrangement. In some examples, the V-shaped or Y-shaped component comprises a bifurcated fibre bundle. The bifurcated fibre bundle may comprise a first sub-bundle of optical fibres that connect the source of electromagnetic energy to a trunk end of the V-shaped or Y-shaped component, and a second sub-bundle of optical fibres that connect the trunk end of the V-shaped or Y- shaped component to the energy receiver. The optical component may therefore define plural parallel channels for directing the output electromagnetic energy to the electromagnetic energy receiver and the input electromagnetic energy towards the deformation information collection arrangement.

[0055] Optionally, the oral treatment system comprises a processor operatively coupled to the electromagnetic energy receiver, wherein the electromagnetic energy receiver is configured to output a signal representative of the output electromagnetic energy to the processor, and wherein the processor is configured to cause performance of an action based on the signal 13 P005412-W001 received from the electromagnetic energy receiver. Accordingly, something may be done in response to the deformation of the first deformable cleaning element. For example, a user of the oral treatment device may be informed about wear of the first deformable cleaning element, about how they are using the oral treatment system, about how they might better use the oral treatment system and / or about when replacement of the oral treatment device is recommended.

[0056] Optionally, the oral treatment system comprises an indicator that is operatively connected to the processor, and the action comprises the indicator providing an indication to a user of the oral treatment system. This may enable the user to be promptly and / or clearly informed of information associated with the deformation of the first deformable cleaning element. For example, the processor may cause the indicator to indicate that the oral treatment device requires replacement, when the processor determines, based on the signal representative of the output electromagnetic energy, that the output electromagnetic energy is below a threshold and thus that the first deformable cleaning element is too worn to be sufficiently effective at cleaning the user’s oral cavity.

[0057] Optionally, the indicator comprises a visual indicator, such as a light or a display screen. Optionally, the indicator comprises an audible indicator, such as a beeper or a buzzer. Optionally, the indicator comprises a haptic indicator, such as a vibrator.

[0058] Optionally, the oral treatment system comprises a memory that is operatively connected to the processor, and the action comprises the memory storing data representative of the output electromagnetic energy. Accordingly, the data may be assessed or handled in the future. In some examples, such data is collected in the memory over multiple uses of the oral treatment system, so that patterns or trends in use of the oral treatment system may be identified over time. This may enable the user to be better informed of information associated with the deformation of the first deformable cleaning element.

[0059] Optionally, the oral treatment system comprises a communication interface that is operatively connected to the processor, and the action comprises the communication interface sending data representative of the output electromagnetic energy from the oral 14 P005412-W001 treatment system to a remote destination. This may enable the data representative of the output electromagnetic energy to be stored in memory, and processed or analysed, at the remote destination, remote from the oral treatment system. This may reduce the processing ability required of the oral treatment system itself.

[0060] In some examples, other information may also be communicated from the oral treatment system to the remote destination. For example, the oral treatment system may comprise an orientation sensor (such as an accelerometer) that is configured to sense an orientation of the oral treatment system relative to the Earth, and to send orientation information (based on the orientation sensed) to the remote destination or to the processor for optional transmission to the remote destination. This orientation information may be combined with the data representative of the output electromagnetic energy to gain further insights. For example, the remote destination may be configured to create a plot of the user’s mouth, to map the orientation information to the data representative of the output electromagnetic energy, and to then indicate on the plot the degree of deformation of the first deformable cleaning element in various regions in the user’s mouth. This may help to inform the user about where in their mouth they are using the first deformable cleaning element to apply forces to their oral cavity that are too great or too small. In other examples, these processes may be performed at the oral treatment system itself rather than, or in addition to, the remote destination.

[0061] Optionally, the action comprises controlling the source of electrical energy to cause a change in a characteristic of the ultrasonic energy emitted from the oral treatment system. Optionally, the characteristic comprises a power of the ultrasonic energy.

[0062] Optionally, the action comprises controlling the source of electrical energy to cause a change in a duty cycle of the input electrical energy transmitted by the electrical energy transmission arrangement from the source of electrical energy, thereby to cause the change in the power of the ultrasonic energy.

[0063] Optionally, the oral treatment system is a toothbrush, such as an electrically powered toothbrush. 15 P005412-W001

[0064] A third aspect of the present invention provides an oral treatment system for use in treating an oral cavity of a user, the oral treatment system comprising: a support, a first deformable cleaning element projecting from the support, a deformation information collection arrangement connected to the first deformable cleaning element and configured to collect and conduct a first type of energy, representative of deformation of the first deformable cleaning element, from the first deformable cleaning element; a generator configured to generate and emit a second type of energy into the oral cavity, wherein the second type of energy is different to the first type of energy; and a processor configured to control the generator to cause a change in a characteristic of the second type of energy based on the first type of energy.

[0065] Optionally, the oral treatment system according to the third aspect of the present invention further comprises an energy receiver and a first energy transmission arrangement configured to transmit the first type of energy from the deformation information collection arrangement to the energy receiver, and the processor is operatively coupled to the energy receiver, wherein the energy receiver is configured to output a signal representative of the first type of energy to the processor, and the processor is configured to control the generator to cause a change in a characteristic of the second type of energy based on the signal received from the energy receiver.

[0066] Using the first type of energy to adjust the second type of energy in this way may provide a relatively simple and effective mechanism for controlling the second type of energy for cleaning the oral cavity. For example, the first type of energy may be effective at giving an indication of a region of the oral cavity that the first deformable cleaning element is in contact with, so that the second type of energy can be adjusted so as to more effectively target or clean that region.

[0067] Optionally, the characteristic of the second type of energy comprises a power of the second type of energy. For example, the processor may be configured to control the generator to cause an increase or a decrease in the power of the second type of energy based on the first type of energy, or optionally, based on the signal received from the energy receiver. For 16 P005412-W001 example, the processor may be configured to control the generator to cause a change in a duty cycle of the second type of energy based on the first type of energy, or optionally, based on the signal received from the energy receiver, thereby to cause the change in the power of the second type of energy.

[0068] Optionally, one of the first type of energy and the second type of energy is a mechanical type of energy and the other of the first type of energy and the second type of energy is a non-mechanical type of energy. Optionally, the first type of energy is a non-mechanical type of energy, and the second type of energy is a mechanical type of energy. A mechanical type of energy may be useful in cleaning the oral cavity, since it could be used to agitate plaque or other detritus or to have an effect on toothpaste, dentifrice or mouthwash in the oral cavity. On the other hand, a non-mechanical type of energy may have an effect that does not mechanically interfere with the mechanical type of energy, such as illuminating the oral cavity or a photo-biomodulation effect on tissue of the oral cavity.

[0069] Optionally, the first type of energy is electromagnetic energy. Optionally, the first deformable cleaning element is configured to conduct electromagnetic energy. Electromagnetic energy may help to avoid or reduce tissue inflammation.

[0070] Optionally, the second type of energy is ultrasonic energy / acoustic energy. Ultrasonic energy may facilitate improved cleaning of the oral cavity.

[0071] Optionally, the generator comprises: a second deformable cleaning element projecting from the support and comprising an ultrasound transmitter configured to generate and emit the ultrasonic energy from the oral treatment system; a source of electrical energy; and an electrical energy transmission arrangement configured to transmit input electrical energy from the source of electrical energy to the second deformable cleaning element. As noted elsewhere herein, comprising the ultrasound transmitter in the second deformable cleaning element may improve an efficacy of the oral treatment device at treating the oral cavity of the user, as compared to locating the ultrasound transmitter, remote from the second 17 P005412-W001 deformable cleaning element. As noted elsewhere herein, ultrasonic energy may beneficially induce inertial cavitation in fluid in the oral cavity.

[0072] Optionally, the ultrasound transmitter may comprise a piezoelectric element that is optionally made from a piezoelectric polymer or a dielectric polymer. For example, the piezoelectric element may be made from polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0073] Optionally, the second deformable cleaning element comprises at least one electrode on the piezoelectric element. Optionally, the electrode is metallic, such as a metal, e.g., silver. Optionally, the electrode comprises a layer, or coating, of electrically conductive material.

[0074] Optionally, the oral treatment system is a toothbrush, such as an electrically powered toothbrush.

[0075] A fourth aspect of the present invention provides a deformable cleaning element for an oral treatment device for use in treating an oral cavity of a user, the deformable cleaning element comprising a hollow piezoelectric fibre.

[0076] Providing that the piezoelectric fibre is hollow may facilitate connection of electrodes to the piezoelectric fibre in such a way that, when an electrical current is applied to the piezoelectric fibre via the electrodes, the piezoelectric fibre changes shape in a way that improves how the deformable cleaning element is usable to treat the oral cavity of the user.

[0077] Optionally, the hollow piezoelectric fibre is made from a piezoelectric polymer or a dielectric polymer, such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0078] Optionally, the hollow piezoelectric fibre comprises a tubular piezoelectric portion. Provision of the tubular piezoelectric portion may increase a flexibility of the hollow piezoelectric fibre as compared to a hollow piezoelectric fibre that does not have a tubular piezoelectric portion as such. 18 P005412-W001

[0079] Optionally, the hollow piezoelectric fibre has an interior surface and an exterior surface, and the deformable cleaning element comprises an electrode on one of the interior surface and the exterior surface. Optionally, the electrode is metallic, such as a metal, e.g., silver. Optionally, the electrode comprises a layer, or coating, of electrically conductive material.

[0080] Optionally, the electrode is tubular. This may help to disperse, through the piezoelectric fibre, electric current flowing to or from the electrode, in use.

[0081] Optionally, the electrode is a first electrode, and the deformable cleaning element comprises a second electrode on the other of the interior surface and the exterior surface, the second electrode being electrically insulated from (non-electrically connected to) the first electrode. Optionally, the second electrode is of a same chemical composition as the first electrode. Optionally, the second electrode is metallic, such as a metal, e.g., silver. Optionally, the second electrode comprises a layer, or coating, of electrically conductive material.

[0082] Optionally, the second electrode is tubular. This may help to further disperse, through the piezoelectric fibre, electric current flowing to or from the second electrode, in use. This effect may be particularly marked when both the first electrode and the second electrode are tubular.

[0083] Optionally, the deformable cleaning element comprises a non-electrically conductive cover having an interior within which the piezoelectric fibre is located. This cover may help to preserve the piezoelectric fibre. Optionally, the electrode(s), when present, is / are located within the interior of the cover. This may help to preserve the electrode(s).

[0084] Optionally, the cover contacts the electrode on the exterior surface of the piezoelectric fibre, when present, so that the electrode on the exterior surface is sandwiched between the piezoelectric fibre and the cover. This may further help to preserve the electrode on the exterior surface of the piezoelectric fibre. 19 P005412-W001

[0085] Optionally, the non-electrically conductive cover comprises a layer, or coating, of non- electrically conductive material. Optionally, the non-electrically conductive material is a biocompatible material and / or a polymer, such as Nylon. Optionally, the non-electrically conductive cover comprises polyethylene glycol (PEG), such as a layer of PEG, such as on the layer of non-electrically conductive material. The PEG may change a topography of an external surface of the deformable cleaning element and reduce a hydrophobicity of the external surface, thus helping to reduce bacterial adhesion and biofouling of the deformable cleaning element, in use.

[0086] Optionally, the deformable cleaning element is circular in cross section. Optionally, the deformable cleaning element has a diameter of about 0.4mm to about 2mm.

[0087] Optionally, the deformable cleaning element has a tapered end. This may help the deformable cleaning element reach into small spaces in the oral cavity, in use.

[0088] A fifth aspect of the present invention provides an oral treatment device for use in treating an oral cavity of a user, the oral treatment device comprising a support and at least one deformable cleaning element projecting from the support, wherein the deformable cleaning element is according to the fourth aspect of the present invention.

[0089] By providing the oral treatment device with the deformable cleaning element comprising a hollow piezoelectric fibre, the oral treatment device may be adapted for generating vibrations at the deformable cleaning element, by way of applying an electrical field to the hollow piezoelectric fibre. This may improve an efficacy of the oral treatment device at treating the oral cavity of the user. Ultrasonic waves reduce in intensity the further they travel from their source. By comprising the piezoelectric element of the device in the deformable cleaning element, as opposed to remote from the deformable cleaning element, ultrasonic waves arising in fluid (such as air, toothpaste and / or saliva) surrounding the deformable cleaning element in use, as a result of vibration of the piezoelectric fibre, are much less likely to be attenuated and the ultrasonic waves can be delivered closer to the oral cavity, to potentially remove plaque better and thus clean the oral cavity more efficiently. In other words, the ability of the piezoelectric element to emit a sufficient 20 P005412-W001 stimulus at a desired site in the oral cavity is much improved. Moreover, in a comparative system in which the piezoelectric element is remote from the second deformable cleaning element, stronger, lower-frequency ultrasound needs to be employed to ensure wave transmission. However, such lower frequency ultrasound limits the achievable mechanical effects. By providing the piezoelectric fibre in the second deformable cleaning element, higher frequency ultrasound can be employed.

[0090] The ultrasound may beneficially induce inertial cavitation in fluid in the oral cavity, resulting in the creation and subsequent collapse of small bubbles in the fluid. This collapse may generate physical chemical changes around the bubble, including the generation of ultraviolet (UV) light according to a mechanism known as sonoluminescence. If a toothpaste, dentifrice or mouthwash in the oral cavity includes a UV-responsive chemical compound, this sonoluminescence mechanism can be used to indirectly activate that chemical compound in order to generate free radical species. Moreover, the ultrasound may help such a chemical compound to migrate closer to the area of the oral cavity to be cleaned or otherwise treated.

[0091] As discussed herein, in some examples the oral treatment device is configured to be removably attachable to a handle. In some other examples, the oral treatment device comprises a handle, such as a handle that is integrally formed with the support. In some examples, the oral treatment device is a brush head or a toothbrush.

[0092] Optionally, the at least one deformable cleaning element comprises plural such deformable cleaning elements. Optionally, the oral treatment device comprises at least one tuft of plural such deformable cleaning elements. The, or each, tuft may be circular or noncircular in cross section. Optionally, the oral treatment device comprises plural such tufts. Optionally, respective portions of the deformable cleaning elements of each tuft are fused together into a block.

[0093] A sixth aspect of the present invention provides a method of manufacturing a deformable cleaning element for an oral treatment device for use in treating an oral cavity of a user, the method comprising providing a hollow piezoelectric fibre for inclusion in the deformable 21 P005412-W001 cleaning element. The hollow piezoelectric fibre may provide the deformable cleaning element with any of the beneficial effects of a hollow piezoelectric fibre discussed herein.

[0094] Optionally, the providing the hollow piezoelectric fibre comprises forming the hollow piezoelectric fibre. Optionally, the forming the hollow piezoelectric fibre comprises electrospinning a material. Electrospinning can beneficially be used to form very thin fibres. Optionally, the material is a piezoelectric polymer or a dielectric polymer, such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0095] Optionally, the providing the hollow piezoelectric fibre comprises providing the hollow piezoelectric fibre with a tubular piezoelectric portion.

[0096] Optionally, the hollow piezoelectric fibre has an interior surface and an exterior surface, and the method comprises providing an electrode on one of the interior surface and the exterior surface. Optionally, the electrode is metallic, such as a metal, e.g., silver. Optionally, the providing an electrode comprises providing a layer, or coating, of electrically conductive material on the one of the interior surface and the exterior surface. Optionally, the electrode is tubular.

[0097] Optionally, the electrode is a first electrode, and the method comprises providing a second electrode on the other of the interior surface and the exterior surface, the second electrode being non-electrically connected to the first electrode. Optionally, the second electrode is of a same chemical composition as the first electrode. Optionally, the second electrode is metallic, such as a metal, e.g., silver. Optionally, the providing the second electrode comprises providing a layer, or coating, of electrically conductive material on the other of the interior surface and the exterior surface. Optionally, the second electrode is tubular.

[0098] Optionally, the method comprises providing, such as forming, a non-electrically conductive cover (directly or indirectly) on the piezoelectric fibre so that the piezoelectric fibre is located within an interior of the cover. This cover may help to preserve the piezoelectric fibre. Optionally, the providing the non-electrically conductive cover comprises providing, such as forming, the cover (directly or indirectly) on the electrode(s), 22 P005412-W001 when present, so that the electrode(s) is / are located within the interior of the cover. This may help to preserve the electrode(s). Optionally, the providing, such as forming, the non- electrically conductive cover comprises applying a layer, or coating, of non-electrically conductive material (directly or indirectly) on the piezoelectric fibre. Optionally, the non- electrically conductive material is a biocompatible material and / or a polymer, such as Nylon.

[0099] Optionally, the providing, such as forming, the non-electrically conductive cover comprises providing a non-electrically conductive cover comprising polyethylene glycol (PEG) (directly or indirectly) on the piezoelectric fibre. The PEG may change a topography of an external surface of the deformable cleaning element and reduce a hydrophobicity of the external surface, thus helping to reduce bacterial adhesion and biofouling of the deformable cleaning element, in use. Optionally, the providing the non- electrically conductive cover comprises applying a layer, or coating, of PEG (directly or indirectly) on the piezoelectric fibre, such as on the layer of non-electrically conductive material, when present.

[0100] Optionally, the method comprises manufacturing the deformable cleaning element so that the deformable cleaning element is circular in cross section. Optionally, the deformable cleaning element has a diameter of about 0.4mm to about 2mm.

[0101] Optionally, the method comprises tapering an end of the deformable cleaning element. This may help the deformable cleaning element reach into small spaces in the oral cavity, in use.

[0102] A seventh aspect of the present invention provides a method of manufacturing an oral treatment device for use in treating an oral cavity of a user, the method comprising providing a support and arranging at least one deformable cleaning element according to the fourth aspect of the present invention so that the at least one deformable cleaning element projects from the support. 23 P005412-W001

[0103] The deformable cleaning element may comprise any of the features described herein as optional features of the fourth aspect of the present invention.

[0104] As discussed herein, in some examples the oral treatment device is configured to be removably attachable to a handle. In some other examples, the oral treatment device comprises a handle, such as a handle that is integrally formed with the support. In some examples, the oral treatment device is a brush head or a toothbrush.

[0105] An eighth aspect of the present invention provides an oral treatment device for use in treating an oral cavity of a user, the oral treatment device comprising: a support; at least one deformable cleaning element projecting from the support, the deformable cleaning element comprising a piezoelectric element; and a deformation information collection arrangement electrically connected to the piezoelectric element and configured to collect and conduct output electrical energy, representative of deformation of the piezoelectric element, from the piezoelectric element.

[0106] By collecting the output electrical energy from the piezoelectric element, information about the deformation, such as bending or buckling, of the piezoelectric element may be captured. This information may be used to monitor use of the oral treatment device and one or more actions may be taken in consequence. Greater accuracy of information may be captured than, for example, monitoring movement of a combination of the whole support and the at least one deformable cleaning element relative to some point of reference. Accordingly, a better-informed action can be taken. For example, a user of the oral treatment device may be informed about wear of the at least one deformable cleaning element, about how they are using the oral treatment device, about how they might better use the oral treatment device and / or about when replacement of the oral treatment device is recommended.

[0107] As discussed herein, in some examples the oral treatment device is configured to be removably attachable to a handle. In some other examples, the oral treatment device comprises a handle, such as a handle that is integrally formed with the support. In some examples, the oral treatment device is a brush head or a toothbrush. 24 P005412-W001

[0108] Optionally, the piezoelectric element is made from a piezoelectric polymer or a dielectric polymer, such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF).

[0109] Optionally, the deformable cleaning element comprises at least one electrode on the piezoelectric element. Optionally, the electrode is metallic, such as a metal, e.g., silver. Optionally, the electrode comprises a layer, or coating, of electrically conductive material.

[0110] Optionally, the deformable cleaning element comprises a non-electrically conductive cover having an interior within which the piezoelectric element is located. This cover may help to preserve the piezoelectric element. Optionally, the electrode(s), when present, is / are located within the interior of the cover. This may help to preserve the electrode(s). Optionally, the deformable cleaning element comprises at least one electrode on an exterior surface of the piezoelectric element, and the cover contacts the at least one electrode on the exterior surface of the piezoelectric element, so that the electrode on the exterior surface is sandwiched between the piezoelectric element and the cover. This may further help to preserve the electrode on the exterior surface of the piezoelectric element.

[0111] Optionally, the non-electrically conductive cover comprises a layer, or coating, of non- electrically conductive material. Optionally, the non-electrically conductive material is a biocompatible material and / or a polymer, such as Nylon. Optionally, the non-electrically conductive cover comprises polyethylene glycol (PEG), such as a layer of PEG, such as on the layer of non-electrically conductive material. The PEG may change a topography of an external surface of the deformable cleaning element and reduce a hydrophobicity of the external surface, thus helping to reduce bacterial adhesion and biofouling of the deformable cleaning element, in use.

[0112] Optionally, the deformable cleaning element is circular in cross section. Optionally, the deformable cleaning element has a diameter of about 0.4mm to about 2mm.

[0113] Optionally, the deformable cleaning element has a tapered end. This may help the deformable cleaning element reach into small spaces in the oral cavity, in use. 25 P005412-W001

[0114] Optionally, the piezoelectric element comprises a piezoelectric fibre. Optionally, the deformable cleaning element is according to the fourth aspect of the present invention, such that the piezoelectric element is a hollow piezoelectric fibre. The deformable cleaning element may comprise any of the features described herein as optional features of the fourth aspect of the present invention.

[0115] Optionally, the at least one deformable cleaning element comprises plural deformable cleaning elements, and the deformation information collection arrangement defines plural electrically conductive paths that are electrically coupled to the piezoelectric fibres of the respective plural deformable cleaning elements and configured to collect and conduct output electrical energy, representative of deformation of the respective piezoelectric fibres, from the respective piezoelectric fibres. Such an arrangement may help to keep collected streams of output electrical energy, from the respective piezoelectric fibres, separate from each other and help to conduct those streams of output electrical energy towards a destination. This may provide the destination with the ability to collect the streams of output electrical energy, and thus assess, monitor or otherwise handle data indicative of the deformation of the respective piezoelectric fibres separately, i.e., on a per- fibre basis. This may provide the destination with more information about deformation of the piezoelectric fibres than a comparative system in which output electrical energy from the piezoelectric fibres of all the deformable cleaning elements is instead merged together on its way to the destination.

[0116] Optionally, the oral treatment device comprises at least one tuft of the plural deformable cleaning elements. The, or each, tuft may be circular or non-circular in cross section. Optionally, the oral treatment device comprises plural such tufts.

[0117] Optionally, respective portions of the deformable cleaning elements of each tuft are fused together into a block. Further optionally, the deformation information collection arrangement is connected to the block and configured to collect and conduct the output electrical energy from the block. 26 P005412-W001

[0118] Optionally, the at least one deformable cleaning element of the oral treatment device according to the eighth aspect of the present invention comprises a passive deformable cleaning element and the oral treatment device further comprises an active deformable cleaning element comprising a piezoelectric element, wherein the deformable information collection arrangement is electrically connected to the piezoelectric element of the passive deformable cleaning element; and the active deformable cleaning element is configured to generate and emit ultrasonic energy from the oral treatment device.

[0119] Optionally, the oral treatment device further comprises at least one deformable electromagnetic energy-conducting cleaning element projecting from the support, wherein the at least one deformable electromagnetic energy-conducting cleaning element is configured to conduct electromagnetic energy for emission from the oral treatment device. Where the active deformable cleaning element is present, the oral treatment device may provide a synergistic effect of emitting electromagnetic energy from the deformable electromagnetic energy-conducting cleaning element and ultrasonic energy from the active deformable cleaning element.

[0120] A ninth aspect of the present invention provides an oral treatment system, comprising: the oral treatment device according to the eighth aspect of the present invention; a source of electrical energy; an electrical energy transmission arrangement configured to transmit input electrical energy from the source of electrical energy to the active deformable cleaning element; and a processor operatively coupled to the deformation information collection arrangement; wherein the processor is configured to control the input electrical energy to the active deformable cleaning element based on the output electrical energy collected and conducted by the deformation information collection arrangement from the piezoelectric element of the passive deformable cleaning element.

[0121] The oral treatment system according to the ninth aspect of the present invention may further include an electrical energy receiver and wherein the electrical energy transmission arrangement is configured to transmit the input electrical energy from the source of electrical energy to the deformation information collection arrangement and to transmit the 27 P005412-W001 output electrical energy from the deformation information collection arrangement to the electrical energy receiver.

[0122] Accordingly, the source of electrical energy and electrical energy receiver may be spaced from the at least one deformable cleaning element, at least by the electrical energy transmission arrangement. This may enable the oral treatment device to be sufficiently compact for comfortable insertion into a user’s mouth.

[0123] Optionally, where the oral treatment device comprises the at least one deformable electromagnetic energy-conducting cleaning element, the oral treatment system may comprise a further deformation information collection arrangement optically coupled to the at least one deformable electromagnetic energy-conducting cleaning element. The further deformation information collection arrangement may be configured to collect and conduct output electromagnetic energy, representative of deformation of the at least one deformable electromagnetic energy-conducting cleaning element, from the at least one deformable electromagnetic energy-conducting cleaning element. The deformation information collection arrangement may be separate from the further deformation information collection arrangement.

[0124] Optionally, the processor is operatively coupled to the further deformation information collection arrangement and may be configured to control the input electrical energy to the active deformable cleaning element based further on the output electromagnetic energy from the at least one deformable electromagnetic energy-conducting cleaning element. The processor may more accurately determine deformation of the bristle tufts based on both the output electromagnetic energy and the output electrical energy.

[0125] Optionally, the source of electrical energy comprises a battery.

[0126] In some examples, the electrical energy receiver is an electrical energy detector. Optionally, the electrical energy detector comprises a device configured to detect or monitor change in an electrical characteristic (such as electrical resistance) of the at least one deformable cleaning element, arising from deformation of the piezoelectric fibre of the 28 P005412-W001 at least one deformable cleaning element, based on the output electrical energy received at the device. In such an arrangement, each of the elements on paths between the source of electrical energy and the, or each, piezoelectric fibre and between the, or each, piezoelectric fibre and the electrical energy detector would be electrically conductive so as to transmit the electrical energy along those paths.

[0127] Optionally, the source of electrical energy is configured to output the input electrical energy to the electrical energy transmission arrangement by pulsing or modulating the input electrical energy so that the input electrical energy comprises a series of energy pulses. Such pulsed input electrical energy would therefore have a time-varying amplitude. The amplitude of the input electrical energy may be zero or non-zero between the pulses.

[0128] Optionally, the at least one deformable cleaning element comprises plural deformable cleaning elements, the deformation information collection arrangement defines plural paths that are coupled to the piezoelectric fibres of the respective plural deformable cleaning elements and configured to collect and conduct respective streams of the output electrical energy, representative of deformation of the respective piezoelectric fibres, from the respective plural deformable cleaning elements, and the electrical energy transmission arrangement defines plural channels that are coupled to the respective plural paths and configured to conduct the respective streams of the output electrical energy from the respective plural paths to the electrical energy receiver.

[0129] Optionally, the oral treatment system comprises a handle, and the handle comprises the source of electrical energy, the electrical energy receiver and the electrical energy transmission arrangement. Such a construction may ensure that these elements are in a part of the oral treatment system that would be away from the support. Accordingly, this may enable the support to be sufficiently compact for comfortable insertion into a user’s mouth and / or may help with ensuring that a centre of mass of the oral treatment system is close to a user’s hand, which may provide a desirable ergonomic advantage. 29 P005412-W001

[0130] Optionally, the handle is integrally formed with the support of the oral treatment device.

[0131] This may provide a robust oral treatment system that is convenient to hold and operate.

[0132] Optionally, the handle is configured to be removably attachable to the support of the oral treatment device. Therefore, the oral treatment device may be replaceable by, or interchangeable with, another oral treatment device, so that the source of electrical energy, the electrical energy receiver, and the electrical energy transmission arrangement may be used with several oral treatment devices successively. This may reduce how much of the oral treatment system needs to be disposed of when the oral treatment device is too worn to achieve adequate performance, may enable several users (each having their own respective oral treatment device) to share the handle, and / or may make the oral treatment system more compact for storage or transport.

[0133] Optionally, the oral treatment system comprises a processor operatively coupled to the electrical energy receiver, the electrical energy receiver is an electrical energy detector that is configured to output a signal representative of the output electrical energy to the processor, and the processor is configured to cause performance of an action based on the signal received from the electrical energy detector. Accordingly, something may be done in response to the deformation of the piezoelectric fibre(s). For example, a user of the oral treatment device may be informed about wear of the at least one deformable cleaning element, about how they are using the oral treatment system, about how they might better use the oral treatment system and / or about when replacement of the oral treatment device is recommended.

[0134] Optionally, the oral treatment system comprises an indicator that is operatively connected to the processor, and the action comprises the indicator providing an indication to a user of the oral treatment system. This may enable the user to be promptly and / or clearly informed of information associated with the deformation of the piezoelectric fibre(s). For example, the processor may cause the indicator to indicate that the oral treatment device requires replacement, when the processor determines, based on the signal representative of the output electrical energy, that the output electrical energy is below a threshold and thus 30 P005412-W001 that the at least one deformable cleaning element is / are too worn to be sufficiently effective at cleaning the user’s oral cavity.

[0135] Optionally, the indicator comprises a visual indicator, such as a light or a display screen. Optionally, the indicator comprises an audible indicator, such as a beeper or a buzzer. Optionally, the indicator comprises a haptic indicator, such as a vibrator.

[0136] Optionally, the oral treatment system comprises a memory that is operatively connected to the processor, and the action comprises the memory storing data representative of the output electrical energy. Accordingly, the data may be assessed or handled in the future. In some examples, such data is collected in the memory over multiple uses of the oral treatment system, so that patterns or trends in use of the oral treatment system may be identified over time. This may enable the user to be better informed of information associated with the deformation of the piezoelectric fibre(s).

[0137] Optionally, the oral treatment system comprises a communication interface that is operatively connected to the processor, and the action comprises the communication interface sending data representative of the output electrical energy from the oral treatment system to a remote destination. This may enable the data representative of the output energy to be stored in memory, and processed or analysed, at the remote destination, remote from the oral treatment system. This may reduce the processing ability required of the oral treatment system itself.

[0138] In some examples, other information may also be communicated from the oral treatment system to the remote destination. For example, the oral treatment system may comprise an orientation sensor (such as an accelerometer) that is configured to sense an orientation of the oral treatment system relative to the Earth, and to send orientation information (based on the orientation sensed) to the remote destination or to the processor for optional transmission to the remote destination. This orientation information may be combined with the data representative of the output energy to gain further insights. For example, the remote destination may be configured to create a plot of the user’s mouth, to map the orientation information to the data representative of the output energy, and to then indicate 31 P005412-W001 on the plot the degree of deformation of the piezoelectric fibre(s) in various regions in the user’s mouth. This may help to inform the user about where in their mouth they are using the at least one deformable cleaning element to apply forces to their oral cavity that are too great or too small. In other examples, these processes may be performed at the oral treatment system itself rather than, or in addition to, the remote destination.

[0139] Optionally, the oral treatment system is a toothbrush, such as an electrically powered toothbrush.

[0140] Optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate.

[0141] BRIEF DESCRIPTION OF THE DRAWINGS

[0142] Figure 1 shows a schematic side view of an example electrically powered toothbrush, in which a brush head of the electrically powered toothbrush is removably attached to a handle, shown in cross-section, of the electrically powered toothbrush;

[0143] Figure 2 shows a schematic cross-sectional side view of the brush head of the electrically powered toothbrush of Figure 1;

[0144] Figure 3 shows a schematic cross-sectional view, taken at A-A in Figure 2, through a neck portion of the brush head of the electrically powered toothbrush of Figure 1;

[0145] Figure 4 shows a schematic cross-sectional view, taken at B-B in Figure 1, through a bristle portion of the brush head of the electrically powered toothbrush of Figure 1;

[0146] Figure 5 shows a schematic cross-sectional view through a bristle portion of an alternative brush head according to an example;

[0147] Figure 6 shows a schematic side cross-sectional view of a deformable piezoelectric bristle of the brush head of Figure 2; 32 P005412-W001

[0148] Figure 7 shows a schematic cross-sectional view, taken at C-C of Figure 6, through the deformable piezoelectric bristle of Figure 6;

[0149] Figure 8 shows a schematic side cross-sectional view of another example electrically powered toothbrush, in which a brush head of the electrically powered toothbrush is removably attached to a handle of the electrically powered toothbrush;

[0150] Figure 9 shows a schematic cross-sectional view, taken at D-D in Figure 8, through a bristle portion of the brush head of the electrically powered toothbrush of Figure 8;

[0151] Figure 10 shows a method of manufacturing a deformable piezoelectric bristle; and

[0152] Figure 11 shows a method of forming an oral treatment device.

[0153] DETAILED DESCRIPTION

[0154] Figures 1 to 7 show an oral treatment system in the form of an electrically powered toothbrush 1. The toothbrush 1 comprises a handle 10 and an oral treatment device, in the form of a brush head 20, that is shaped and sized to be attachable to, and thereafter detachable from, the handle 10. The brush head 20 is for use in brushing an oral cavity of a user of the toothbrush 1. The brush head 20 is replaceable by, or interchangeable with, another brush head (not shown), so that the handle 10 may be used with several brush heads 20 successively.

[0155] The brush head 20 comprises an elongate support 30 having a head portion 40 and a neck portion 50. The neck portion 50 extends from the head portion 40 in a longitudinal direction of the support 30 and is narrower than the head portion 40 in a lateral direction orthogonal to the longitudinal direction. The neck portion 50 has an end distal from the head portion 40 that defines a first interface 21 by which the brush head 20 engages with the handle 10. The first interface 21 comprises a cavity 22 for receipt of a spigot 120 of a second interface 13 of the handle 10, as is described in more detail below. 33 P005412-W001

[0156] The brush head 20 has nineteen bristle tufts 60 that project from a front side 42 of the head portion 40. The front side 42 may therefore be considered a bristle bearing surface. The area of the front side 42 occupied by the bristle tufts 60 and the spaces between the bristle tufts 60 is sometimes known as the bristled area. Each bristle tuft 60 comprises a first type of deformable cleaning element 80 (first deformable cleaning element 80) and a second, different type of deformable cleaning element 82 (second deformable cleaning element 82), as will be described herein after. A rear side 44 of the head portion 40, opposite the front side 42, is devoid of any cleaning elements 80, 82. Each of the bristle tufts 60 is generally circular in cross section and is flexible so as to be bendable during use.

[0157] Each of the bristle tufts 60 comprises a central bundle of the first deformable cleaning element 80, in this example a first bristle 80, or filament, of bendable Nylon or Nylon- coated fibre, and six bundles of the second deformable cleaning element 82, in this example a second bristle 82. The first bristles 80 are of a different type to the second bristles 82, as described hereinafter. The bundles of the second bristles 82 surround the bundle of first bristles 80 as shown in Figure 4. It will be appreciated that, in other examples, each bristle tuft 60 may alternatively comprise any suitable number or arrangement of the first and second bristles 80, 82, such as that shown in Figure 5, which has three bundles of first bristles 80 and nine bundles of second bristles 82.

[0158] Each of the first bristles 80 and the second bristles 82 is circular and has a diameter of about 0.6mm over a majority of a length of the bristle. Ends of the first and second bristles 80, 82 are tapered so as to have a diameter at the tip of between 0.1mm and 0.2mm.

[0159] The head portion 40 includes a head plate 46 having a flat front side that forms most of the front side 42 of the head portion 40. The head plate 46 is made of ABS. The head plate 46 has plural holes 48 extending therethrough from the flat front side of the head plate 46 to an opposite rear side of the head plate 46, which is at an interior of the head portion 40. The holes 48 are spaced apart from each other by respective gaps. Each of the holes 48 corresponds to one of the bristle tufts 60. Each of the bristle tufts 60 has a first portion of the first and second bristles 80, 82 that protrudes through one of the holes 48 and that has a tapered distal end. Each of the bristle tufts 60 has a second portion of the first and second 34 P005412-W001 bristles 80, 82 that protrudes from the head plate 46 on an opposite side to the first portions. The first bristles 80 are fused together into respective blocks 62 at the rear side of the head plate 46, inside the head portion 40. Each of the blocks 62 is wider than the associated hole 48 through the head plate 46, so as to prevent the bundles from being pulled through the holes 48. The second bristles 82 are connected to a printed circuit board (PCB) 83 at a rear side of the head plate 46, inside the head portion 40.

[0160] The brush head 20 also includes a deformation information collection arrangement 70. The deformation information collection arrangement 70 comprises a group of nineteen optical fibres that define respective optical paths. While only five of the optical fibres are shown in Figure 2 for clarity, all nineteen optical fibres are shown in Figure 3. The optical fibres are fused to the respective blocks 62 at respective first ends 71 of the optical fibres, so as to be optically coupled to the first bristles 80 of the respective bristle tufts 60. The optical fibres terminate in the cavity 22 at their respective second ends 72. The second ends 72 of the optical fibres together define a first optical interface, which is for connection to a second optical interface 150 of the handle 10, discussed below.

[0161] The first bristles 80 of the bristle tufts 60 are optical waveguides, in that they are able to conduct electromagnetic energy, in this example light for emission from the toothbrush 1 (in particular, from the brush head 20), and intemally-reflect the electromagnetic energy. More specifically, and as described in more detail below, input light (input electromagnetic energy) received into the bristles 80 from the optical fibres travels inside the first bristles 80 to their tips, and the tips reflect at least some of the light back towards the respective optical fibre. Therefore, in use, each first bristle 80 reflects some of the input light, received from the deformation information collection arrangement 70, back to the deformation information collection arrangement 70 as output light (output electromagnetic energy) that is collected and conducted by the deformation information collection arrangement 70. A remainder of the input light, which is a difference between the input light and the output light, is lost to the surrounding environment by leakage through sides of the first bristles 80. The percentage of the input light that is lost in this way is dependent on the degree of deformation (such as bending, kinking, scoring or roughening) of the first bristles 80, with a greater degree of deformation resulting in a greater loss of the 35 P005412-W001 light. Accordingly, a magnitude of the output light, which is collected by and conducted by the deformation information collection arrangement 70, is indicative of the degree of deformation of the respective first bristle 80.

[0162] The second bristles 82 are arranged to generate and emit ultrasonic energy. More specifically, the second bristles 82 are ultrasound transmitters, in that each second bristle 82 is arranged to expand and contract in response to input electrical energy, as described in more detail below. Figures 6 and 7 show, respectively, a side cross-sectional view and an end-on cross-sectional view of a second bristle 82 according to this example. The second bristle 82 comprises a piezoelectric element in the form of a piezoelectric fibre 84, first and second electrodes 86, 88, and a cover 90 encircling the piezoelectric fibre 84 and the first and second electrodes 86, 88.

[0163] The piezoelectric fibre 84 is made from polyvinylidene fluoride (PVDF), though in other examples may be made from any other suitable material, such as any other suitable piezoelectric polymer or dielectric polymer. The piezoelectric fibre 84 is hollow and tubular, having an interior surface that faces towards a hollow interior 92 of the piezoelectric fibre 84 and an exterior surface that faces towards the cover 90.

[0164] The first electrode 86 is a tubular coating of silver on the interior surface of the piezoelectric fibre 84 and the second electrode 88 is a tubular coating of silver on the exterior surface of the piezoelectric fibre 84. The first and second electrodes 86, 88 directly coat the respective interior or exterior surface of the piezoelectric fibre 84, and do not physically contact one another (hence, are electrically insulated from one another). The first and second electrodes 86, 88 are electrically connected to the first interface 21 via the PCB 83, and arranged to cause electrical energy to be conducted between the interior and exterior surfaces of the piezoelectric fibre 84, as will be described hereinafter.

[0165] The brush head 20 comprises nineteen electrical energy transmitters 98, five of which are shown in dashed lines in Fig. 2 for clarity, but all are shown in Fig. 3. Each electrical energy transmitter 98 is a pair of electrically conductive wires that electrically connect respective electrical contacts of a first electrical interface 160 at the first interface 21 to the 36 P005412-W001

[0166] PCB 83, which connects each energy transmitter 98 to the first and second electrodes 86, 88 of the second bristles 82 of a respective one of the bristle tufts 60.

[0167] The cover 90 is non-electrically conductive, and comprises a coating 94 and an outer layer 96. The coating 94, in this example of Nylon, encircles the surface of the second electrode 88 that faces away from the outer surface of the piezoelectric fibre 84. In this way, the second electrode 88 is sandwiched between the piezoelectric fibre 84 and the coating 94. The outer layer 96, in this example of polyethylene glycol (PEG), defines an external surface of the second bristle 82, encircling the coating 94 and closing an end of the piezoelectric fibre 84 that is distal from the head plate 46. The outer layer 96 serves to protect the piezoelectric fibre 84 and may also include anti-fouling properties to reduce fouling of the second bristles 82.

[0168] Discussion will now turn to the handle 10 of the toothbrush 1. The handle 10 is an elongate structure comprising a grip portion 110 and a spigot 120. The grip portion 110 has a first end 111 that is proximal to the spigot 120 and an opposite second end 112 that is distal from the spigot 120 and that defines a first end 11 of the handle 10. The spigot 120 extends from the first end 111 of the grip portion 110 in a longitudinal direction of the handle 10 and is narrower than the grip portion 110 in a lateral direction orthogonal to the longitudinal direction of the handle 10. The spigot 120 has a first end that is proximal to the grip portion 110 and an opposite second end 122 that is distal from the grip portion 110. The second end 122 of the spigot 120 defines a second end 12 of the handle 10 opposite to the first end 11 of the handle 10, and the spigot 120 forms part of the second interface 13 for engaging with the first interface 21 of the brush head 20. More specifically, the spigot 120 is insertable into the cavity 22 of the first interface 21 of the brush head 20, to engage the spigot 120 with the brush head 20 and thereby releasably connect the brush head 20 to the handle 10. The spigot 120 also comprises the second optical interface 150, mentioned above.

[0169] The grip portion 110 of the handle 10 has an outer housing 113. Mounted on the outer housing 113 is a user interface 130, in the form of a button. Inside the outer housing 113, the handle 10 has a processor 131, a memory 132, nineteen electrical connectors 133, a 37 P005412-W001 source of electrical energy comprising a battery 135, an accelerometer 136, an electromagnetic energy receiver in the form of a photodetector 137, a source of electromagnetic energy in the form of an array 138 of LEDs that output light when powered, and a Y-shaped optical component 139 that extends into the spigot 120 of the handle 10. The user interface 130, the processor 131, the accelerometer 136, the photodetector 137 and the array 138 of LEDs are electrically connected to the battery 135 by electrically conductive wires, as indicated by dashed lines in Figure 1, so as to be electrically powered by the battery 135, which operates at around 12V. Moreover, the processor 131 is operatively connected to the user interface 130, the memory 132, the electrical connectors 133, the accelerometer 136, the photodetector 137, and the array 138 of LEDs.

[0170] The electrical connectors 133 are electrically conductive wires, each arranged to selectively provide electrical energy from the battery 135 to a respective one of the nineteen electrical energy transmitters 98 of the brush head 20 via a second electrical interface 161 at the second interface 13 and the first electrical interface 160. The first and second electrical interfaces 160, 161 each comprises plural electrical contacts that each electrically connect to a corresponding electrical contact on the other of the first and second electrical interfaces 160, 161 when the first and second interfaces 21, 12 interface with each other. Together, the electrical connectors 133 form an electrical energy transmission arrangement to transmit input electrical energy from the battery 135 to the brush head 20.

[0171] The source of electrical energy is configured to output the input electrical energy by pulsing or modulating the input electrical energy, so that the input electrical energy comprises a series of energy pulses. For example, the source of electrical energy may include a waveform generator for pulsing or modulating the input electrical energy from the battery 135. The processor 131 is arranged to control a duty cycle of electrical energy along each electrical connector 133, to control electrical energy transmission from the battery 135 to the respective second bristles 82 of the brush head 20 (via the respective electrical connectors 133, electrical energy transmitters 98 and first and second electrodes 38 P005412-W001

[0172] 86, 88). In turn, this controls characteristics of the ultrasonic energy emitted from the second bristles 82, as described hereinafter.

[0173] Together, the support 30, the first and second bristles 80, 82, the electrical connectors 133, the electrical transmitters 98, the PCB 83 and the battery 135 form an example oral treatment arrangement.

[0174] The Y-shaped optical component 139 is an electromagnetic energy transmission arrangement comprising a bifurcated fibre bundle having a first arm 141, a second arm 142 and a trunk 143. The bifurcated fibre bundle comprises thirty-eight fibres: a first subbundle of nineteen optical fibres within the first arm 141 and the trunk 143, and a second sub-bundle of nineteen optical fibres within the second arm 142 and the trunk 143. The optical fibres of the first sub-bundle of optical fibres optically couple the array 138 of LEDs to the second optical interface 150 at a trunk end of the Y-shaped component 139, and the optical fibres of the second sub-bundle of optical fibres optically couple the second optical interface 150 at the trunk end of the Y-shaped component 139 to the photodetector 137. The second optical interface 150 is for connection to the first optical interface mentioned above so that, when the spigot 120 of the handle 10 is located in the cavity 22 of the brush head 20, to thereby releasably connect the brush head 20 to the handle 10, pairs of the thirty-eight optical fibres of the Y-shaped optical component 139 align, and optically couple with, the nineteen respective optical fibres of the deformation information collection arrangement 70.

[0175] The Y-shaped optical component 139 is shaped and arranged so as to, in use, transmit light from the array 138 of LEDs to the second optical interface 150, and transmit light from the second optical interface 150 to the photodetector 137. The photodetector 137 is a two- dimensional imaging sensor having a plurality of pixels, and the nineteen optical fibres of the second sub-bundle in the second arm 142 are optically coupled to respective ones of the pixels. Accordingly, the pixels are respectively able to detect the light travelling through the nineteen optical fibres in the second arm 142 to the photodetector 137. The photodetector 137 is set up to output a signal to the processor 131, the signal being representative of the light (output electromagnetic energy) received at the pixels of the 39 P005412-W001 photodetector 137. The processor 131 is set up to perform a number of actions, in consequence, as described below.

[0176] The accelerometer 136 is set up to sense an orientation of the toothbrush 1 relative to the Earth, as would be understood by the skilled reader, and to send orientation information, based on this sensed orientation, to the processor 131.

[0177] The memory 132 stores instructions that are executable by the processor 131 to cause the processor 131 to perform the processes described herein. The processor 131 is configured to access the memory 132 to retrieve and execute these instructions. The processor 131 is programmed, by way of these instructions, to cause the array 138 of LEDs to emit light, on the basis of a user command received at the processor 131 from the user interface 130. Moreover, the processor 131 is programmed to store in the memory 132 data that is representative of the light received at the pixels of the photodetector 137, based on the signal received from the photodetector 137, and data that is representative of the orientation of the toothbrush 1 relative to the Earth, based on the orientation information received from the accelerometer 136. Still further, the processor 131 is programmed to generate the plot of the user’s mouth, on the basis of the signal received from the photodetector 137 and the orientation information received from the accelerometer 136. Further still, the processor 131 is programmed to control transmission of electrical energy along each of the electrical connectors 133 and, by extension, the ultrasonic energy generated by and emitted from the piezoelectric fibres 84 of the second bristles 82 of the brush head 20, on the basis of the signal received from the photodetector 137. To do so, the processor 131 controls a duty cycle, comprising electrical pulses transmitted at ultrasonic frequencies to the second bristles 82, for each electrical connector 133. In turn, this controls the power of ultrasonic energy generated by and emitted from the respective second bristles 82.

[0178] Operation of the exemplary toothbrush 1 will now be described, with reference to the Figures. 40 P005412-W001

[0179] During use of the toothbrush 1, the brush head 20 is attached to the handle 10 by way of the user inserting the spigot 120 of the handle 10 into the cavity 22 of the brush head 20. This causes the first and second optical interfaces to align, thereby optically coupling pairs of the thirty-eight optical fibres of the Y-shaped optical component 139 with the nineteen respective optical fibres of the deformation information collection arrangement 70, and the first and second electrical interfaces 160, 161 to align, thereby electrically coupling the electrical connectors 133 to the respective electrical transmitters 98.

[0180] The user then applies dentifrice to the bristle tufts 60 and presses the button of the user interface 130. This pressing of the button causes the user interface 130 to send the user command to the processor 131. The processor 131 receives this user command and, as a consequence, causes the array 138 of LEDs to emit light. The light emitted from the array 138 of LEDs travels along the nineteen optical fibres of the first sub-bundle in the first arm 141 and the trunk 143 of the V-shaped optical component 139, as indicated by arrow A in Figure 1, to the second optical interface 150. The light passes to the first optical interface, then along the nineteen optical fibres of the deformation information collection arrangement 70 to the blocks 62, and then within the first bristles 80 of the bristle tufts 60 to the distal ends, or tips, of the first bristles 80.

[0181] At least some of the light is reflected by the distal ends of the first bristles 80. This reflected light (output electromagnetic energy) travels back along the first bristles 80 to the blocks 62, then along the nineteen optical fibres of the deformation information collection arrangement 70 to the first optical interface, and then to the second optical interface 150. Thereafter, the reflected light travels along the nineteen optical fibres of the second subbundle in the trunk 143 and the second arm 142 of the Y-shaped optical component 139 to the photodetector 137, as indicated by arrow B in Figure 1. The pixels of the photodetector 137 receive the reflected light from the respective optical fibres of the second sub-bundle of the Y-shaped optical component 139. A magnitude of the reflected light, which is collected by and conducted by the deformation information collection arrangement 70, is indicative of the degree of deformation of the first bristles 80 of the bristle tufts 60. This magnitude provides a “baseline” level of reflected light from the first bristles 80 when the toothbrush is stationary and not being used to brush teeth. This may reduce over time due 41 P005412-W001 to use of the brush head 20 causing permanent deformation to the first bristles 80, leading to an increased amount of the input light being lost through the sides of the first bristles 80.

[0182] The signal sent by the photodetector 137 to the processor 131 is representative of the amount of reflected light (output electromagnetic energy) received at each of the pixels of the photodetector 137, and so the processor 131 is informed about the degree of deformation of the bristle tufts 60.

[0183] It is to be noted that, at the meeting point of the first and second optical interfaces, some of the light transmitted from the array 138 of LEDs might reflect directly to the photodetector 137 without first travelling to and from the bristle tufts 60. However, such light would add to the baseline amount of light received at one or more of the pixels and could therefore be accounted for (e.g., factored out) during analysis at the processor 131 or at the remote destination. In one example, the transmission of the light from the array 138 of the LEDs is pulsed, such that the light transmitted from the array 138 of LEDs and the light reflected by the distal ends of the first bristles 80 arrive at different times at the meeting point of the first and second optical interfaces. By sampling the pixel values of the photodetector 137 at appropriate times, the light from the array 138 of LEDs reflected directly to the photodetector 137 can be accounted for.

[0184] The user then brushes their teeth and gums with the bristle tufts 60 and the dentifrice thereon.

[0185] While a user uses the toothbrush 1 to brush their teeth, the first and second bristles 80, 82 of each of the bristle tufts 60 will flex against the teeth. This deflection of the first bristles 80 affects the amount of reflected light that reaches the pixels of the photodetector 137, and thus affects characteristics of the signal that the photodetector 137 sends to the processor 131 during the brushing operation. Using orientation information from the accelerometer 136 and the signal from the photodetector 137, the processor 131 determines that the toothbrush 1 is in motion. In response, the processor 131 causes the electrical connectors 133 to transmit electrical energy in a predefined duty cycle stored in the memory 132. During the predefined duty cycle, electrical energy is transmitted with an 42 P005412-W001 ultrasonic frequency in pulses emitted at predefined intervals and with a first amplitude. The predefined duty cycle may range from 1% to 50%, for example, 10%. In one example, the predefined duty cycle is pulses of electrical energy having a duration of 10ms, transmitted at 100ms intervals. Substantially no electrical energy is transmitted between each pulse. In use of the toothbrush 1 during each pulse, the oral treatment arrangement emits both electromagnetic energy, as leakage of light through walls of the first bristles 80, and ultrasonic energy, due to ultrasound generated by mechanical expansion and contraction of the piezoelectric fibre 84, into the oral cavity of a user. The light may have an anti-inflammatory effect on the user. The ultrasound may induce sonoluminescence in the oral cavity. Further, if the dentifrice or mouthwash in the oral cavity includes a UV- responsive chemical compound, this sonoluminescence can indirectly activate that chemical compound to generate free radical species. Moreover, the ultrasound may help such a chemical compound to migrate closer to the area of the oral cavity to be cleaned or otherwise treated.

[0186] Electrical energy transmitted along the electrical connectors 133 passes across the first and second interfaces 21, 13 to the electrical energy transmitters 98, and then to the first electrode 86 of each second bristle 82 of the brush head 20. At each second bristle 82, the electrical energy passes from the first electrode 86 to the second electrode 88 through the piezoelectric fibre 84. The tubular shape of the piezoelectric fibre 84 is such that, during the presence of electrical energy passing from the first electrode 86 to the second electrode 88, a change in a width of the respective second bristle 82 occurs. During the absence of electrical energy passing through the piezoelectric fibre 84, the second bristle 82 returns to its original, passive width. This causes the piezoelectric fibre 84 to rapidly expand and contract and thus emit ultrasonic energy. As a result, the brush head 20 emits both light and ultrasonic energy from each bristle tuft 60. Initially, each electrical connector 133 is subject to the same predefined duty cycle.

[0187] The processor 131 then determines a difference between the “baseline” level of output light from the first bristles 80 of each bristle tuft 60, and the current level of output light from the first bristles 80 of each bristle tuft 60 to determine whether a change to the 43 P005412-W001 predefined duty cycle is required for any of the electrical connectors 133 and, if so, causes a change from the predefined duty cycle to a different duty cycle.

[0188] For example, as shown in Figure 3, a first group 70a of the optical fibres of the deformation information collection arrangement 70 is shown to be conducting a relatively high amount of light, a second group 70b of the optical fibres of the deformation information collection arrangement 70 is shown to be conducting a relatively low amount of light, and a third group 70c of the optical fibres of the deformation information collection arrangement 70 is shown to be conducting an amount of light somewhere between that conducted by the optical fibres of the first and second groups 70a, 70b. Accordingly, from this, the processor 131 is able to determine that the first bristles 80 of the bristle tufts 60 optically connected to the second group 70b of the optical fibres are being deformed more than the first bristles 80 of the other bristle tufts 60.

[0189] In this instance, the amount of light received from each of the optical fibres in the second group 70b is determined by the processor 131 to be lower than the “baseline” level by more than a first predetermined threshold difference. In this instance, the amount of light received from each of the optical fibres in the third group 70c is determined by the processor 131 to be lower than the “baseline” level by less than the first predetermined threshold difference but more than a second predetermined threshold difference, and the amount of light received from each of the optical fibres in the first group 70a is determined by the processor 131 to be lower than the “baseline” level by less than the second predetermined threshold difference. In response, the processor 131 causes electrical energy to be transmitted along the electrical connectors 133 that are connected to the second bristles 82 of the bristle tufts 60 optically connected to the second group 70b of the optical fibres according to a first new duty cycle, electrical energy to be transmitted along the electrical connectors 133 that are connected to the second bristles 82 of the bristle tufts 60 optically connected to the third group 70c of the optical fibres according to a second new duty cycle, and electrical energy to continue being transmitted along the electrical connectors 133 that are connected to the second bristles 82 of the bristle tufts 60 optically connected to the first group 70a of the optical fibres according to the predetermined duty cycle. During the first and second new duty cycles, the duration of each pulse is changed, 44 P005412-W001 the interval between pulses is changed and / or an amplitude of each pulse is changed compared to the predefined duty cycle. These changes result in a change in power of ultrasonic energy emitted from the second bristles 82. The first and second duty cycles range from 1% to 50%, for example, 20% to 40%.

[0190] Based on the orientation information from the accelerometer 136 and the signal from the photodetector 137 over time, the processor 131 develops a plot of the user’s mouth and determines a position of the brush head 20 within the user’s mouth. When the processor 131 determines that a bristle tuft 60 is cleaning teeth, the processor 131 causes electrical energy to be transmitted along the electrical connector 133 associated with the second bristle 82 of that bristle tuft 60 according to a ‘teeth’ duty cycle. When the processor 131 determines that a bristle tuft 60 is adjacent to a gum, the processor causes electrical energy to be transmitted along the electrical connector 133 associated with the second bristle 82 of that bristle tuft 60 according to a ‘gums’ duty cycle. The ‘teeth’ duty cycle has a different pulse duration, pulse interval and / or pulse amplitude to the ‘gums’ duty cycle. Accordingly, a power of the ultrasonic energy emitted from the second bristle 82 of a bristle tuft 60 is tailored to generate different effects depending on the part of the oral cavity that is in contact, or in close proximity, with the bristle tuft 60. The pulse duration, pulse interval and / or pulse amplitude during the ‘teeth’ duty cycle and the ‘gums’ duty cycle is also dependent on the output light received by the photodetector 70 from the deformation information collection arrangement 70 for the first bristles 80 of that bristle tuft 60.

[0191] Figures 8 and 9 show another oral treatment system in the form of an electrically powered toothbrush 201. The toothbrush 201 is structurally similar to the toothbrush 1 described above with reference to Figures 1 to 7, and like components have the same reference number but increased by 200. The toothbrush comprises a handle 210 and an oral treatment device, in the form of a brush head 220, that is shaped and sized to be attachable to, and thereafter detachable from, the handle 210 in the same way as described previously. The brush head 220 is for use in brushing an oral cavity of a user of the toothbrush 201. 45 P005412-W001

[0192] The brush head 220 comprises an elongate support 230 having a head portion 240 and a neck portion 250 of the same proportions to one another as described previously. The neck portion 250 has an end distal from the head portion 240 that defines a first interface 221 by which the brush head 220 engages with a spigot 320 of the handle 210, in the same way as the brush portion 20 and handle 10 engage in the toothbrush 1 described previously.

[0193] The brush head 220 has nineteen deformable cleaning elements, in the form of bristle tufts 260, that project from a front side 242 of the head portion 240. Each bristle tuft 260 comprises a plurality of deformable piezoelectric bristles 282, in this example nineteen deformable piezoelectric bristles 282. A rear side 244 of the head portion 240, opposite the front side 242, is devoid of any bristles. Each of the bristle tufts 260 is generally circular in cross section and is flexible so as to be bendable during use. Each deformable piezoelectric bristle 282 has the same structure as the second bristles 82 described above and depicted in Figures 6 and 7, and will not be described again here, for brevity. It will be appreciated that a different number or arrangement of bristles may be provided in some or all of the bristle tufts in other examples.

[0194] Each bristle tuft 260 extends through a respective hole 248 in a head plate 246 of the front side 242 of the head portion 240 as described for the previous example. The tapered end of each of the deformable piezoelectric bristles 282 protrudes from, and is distal to, the front side 242 of the head portion 240. An opposing end of each of the deformable piezoelectric bristles 282 to the tapered end is connected, together with the other deformable piezoelectric bristles 282 of the same bristle tuft 260, to a printed circuit board (PCB) 283 at a rear side of the head plate 246, inside the head portion 240.

[0195] The bristle tufts 260 include active bristle tufts 260 (having active bristles 282) configured to generate and emit ultrasonic energy and passive bristle tufts 260 (having passive bristles 282) that do not emit ultrasonic energy. The brush head 220 also includes a deformation information collection arrangement 270. The deformation information collection arrangement 270 comprises a pair of electrical connectors 300 for each bristle tuft 260 in the brush head 220. Only five of the pairs of electrical connectors 300 are shown in Figure 8, for clarity. The pairs of electrical connectors 300 are each electrically coupled at one 46 P005412-W001 end to the PCB 283, and at an opposing end to the first interface 221. Respective first connectors in the pairs of electrical connectors 300 provide electrical connections between respective electrical contacts of a first electrical interface 360 at the first interface 221 and respective first connectors of the PCB 283 that are electrically connected to the respective first electrodes (similar to first electrodes 86) of the deformable piezoelectric bristle 282 in the respective bristle tufts 260. Respective second connectors in the pairs of electrical connectors 300 provide electrical connections between respective second connectors of the PCB 283 that are electrically connected to the respective second electrodes (similar to second electrodes 88) of the deformable piezoelectric bristle 282 in the respective bristle tufts 260 and the first electrical interface 360. At the first electrical interface 360, the electrical contacts are for electrical connection to corresponding electrical contacts of a second electrical interface 361 of the handle 10, as discussed below.

[0196] The deformable piezoelectric bristles 282 of the active bristle tufts 260 are arranged to generate and emit ultrasonic energy in response to a first type of electrical input in a manner similar to that described above with reference to the second bristles 82. A second type of electrical input is provided to the passive bristle tufts 260, and in response, each deformable piezoelectric bristle 282 of the passive bristle tufts 260 generates output electrical energy that has characteristics indicative of deformation of the deformable piezoelectric bristle 282. Accordingly, characteristics of output electrical energy from each passive bristle tuft 260 is indicative of deformation of the deformable piezoelectric bristles 282 in the respective passive bristle tuft 260. In one example, the first type of electrical input is a pulsed input electrical energy with a time-varying amplitude and a predetermined duty cycle; whereas, the second type of electrical input is a fixed direct current.

[0197] Discussion will now turn to the handle 210 of the toothbrush 201. The handle 210 has the same outer housing 313 and spigot 320 arrangement as described previously with respect to the toothbrush 1 shown in Figure 1. Like features will not be described again, for brevity. In this example, the spigot 320 also comprises the second electrical interface 361, mentioned above, rather than the second optical interface described with reference to the first example. 47 P005412-W001

[0198] Mounted on the outer housing 313 is a user interface 330, in the form of a button. Inside the outer housing 313, the handle 210 has a processor 331, a memory 332, an indication unit 340, a wireless communication interface 334, a source of electrical energy comprising a battery 335 which operates at around twelve Volts, nineteen electrical connectors 333 that extend between the battery 335 and the second electrical interface 361 at the spigot 320 of the handle 210, and an accelerometer 316. The user interface 330, the processor 331, the indication unit 340, the wireless communication interface 334 and the accelerometer 316 are electrically connected to the battery 335 by electrically conductive wires, as indicated by dashed lines in Figure 8, so as to be electrically powered by the battery 335. Moreover, the processor 331 is operatively connected to the user interface 330, the memory 332, the electrical connectors 333, the indication unit 340, the wireless communication interface 334 and the accelerometer 316.

[0199] The electrical connectors 333 electrically couple the battery 335 to the second electrical interface 361. The second electrical interface 361 is for electrical connection to the nineteen pairs of electrical connectors 300 mentioned above so that, when the spigot 320 of the handle 210 is located in the cavity 222 of the brush head 220, to thereby releasably connect the brush head 220 to the handle 210, the first and second electrical interfaces 360, 361 align so that the electrical connectors 333 electrically couple with the nineteen pairs of electrical connectors 300 of the deformation information collection arrangement 270.

[0200] The processor 331 is arranged to, in use, selectively cause electrical energy to be transmitted from the battery 335 to the second electrical interface 361. The processor 331 is also arranged to determine electrical resistance of the piezoelectric fibres of the respective passive bristle tufts 260. While not shown in the figures, an electrical energy receiver in the form of an electrical energy detector (e.g., voltage or current detector) is arranged within the handle 313 and connected to the electrical connectors 333, so as to receive an output electrical energy from the passive bristle tufts 260. The electrical energy detector is configured to determine the electrical resistance of the piezoelectric fibres of the passive bristle tufts 260 using the output electrical energy. The processor 331 is set up to perform a number of actions, based on the detected electrical resistance of the piezoelectric fibres of the respective passive bristle tufts 260, as described below. 48 P005412-W001

[0201] The indication unit 340 comprises a display screen, a beeper and a vibrator. The display screen is for displaying a plot of the user’s mouth, as described in more detail below. The indication unit 340 is controlled by the processor 331.

[0202] The accelerometer 316 is set up to sense an orientation of the toothbrush 201 relative to the Earth, as would be understood by the skilled reader, and to send orientation information, based on this sensed orientation, to the processor 331.

[0203] The memory 332 stores instructions that are executable by the processor 331 to cause the processor 331 to perform the processes described herein. The processor 331 is configured to access the memory 332 to retrieve and execute these instructions. The processor 331 is programmed, by way of these instructions, to cause the electrical connectors 333 to transmit electrical energy, on the basis of a user command received at the processor 331 from the user interface 330. Moreover, the processor 331 is programmed to store in the memory 332 data that is representative of the detected electrical resistances of the piezoelectric fibres of the respective passive bristle tufts 260, and data that is representative of the orientation of the toothbrush 201 relative to the Earth, based on the orientation information received from the accelerometer 316. Furthermore, the processor 331 is programmed to cause the wireless communication interface 334 to wirelessly transmit, to a remote destination, such as a smart phone or other mobile electronic device, the data that is representative of the detected electrical resistances, and the data that is representative of the orientation of the toothbrush 201 relative to the Earth, based on the orientation information received from the accelerometer 316. Still further, the processor 331 is programmed to generate the plot of the user’s mouth, on the basis of the detected electrical resistances and the orientation information received from the accelerometer 316, and to cause the display screen of the indication unit 331 to display the plot of the user’s mouth during use of the oral treatment system. The processor 331 is also programmed to cause the beeper of the indication unit 340 to beep, and the light of the indication unit 340 to illuminate, when the processor 331 determines, based on the detected electrical resistances, that the electrical resistance of the piezoelectric fibre of at least one of the deformable piezoelectric bristles 282 has reached a predetermined electrical resistance threshold. 49 P005412-W001

[0204] Operation of the exemplary toothbrush 201 will now be described, with reference to Figures 8 and 9.

[0205] During use of the toothbrush 201, the brush head 220 is attached to the handle 210 by way of the user inserting the spigot 320 of the handle 210 into the cavity 222 of the brush head 220. This causes the contacts of the second electrical interface 361 to align with the contacts of the first electrical interface 360, thereby electrically coupling the electrical connectors 333 in the handle 210 with the respective nineteen pairs of electrical connectors 300 of the deformation information collection arrangement 270.

[0206] The user then applies dentifrice to the bristle tufts 260 and presses the button of the user interface 330. This pressing of the button causes the user interface 330 to send the user command to the processor 331. The processor 331 receives this user command and, as a consequence, causes electrical energy including the above-mentioned first and second types of electrical input to be simultaneously transmitted to the deformable piezoelectric bristles 282 of the active bristle tufts 260 and passive bristle tufts 260 respectively. The first type of electrical input is transmitted in a predefined duty cycle. During the predefined duty cycle, electrical energy is transmitted with an ultrasonic frequency in pulses emitted at predefined intervals and with a first amplitude. In this example, the duty cycle is pulses of electrical energy having a duration of 10ms, transmitted at 100ms intervals. Substantially no electrical energy is transmitted between each pulse. The electrical energy travels along the electrical connectors 333 to the second electrical interface 360. The electrical energy then passes along the first electrical connector of each pair of electrical connectors 300 of the deformation information collection arrangement 270 to the PCB 283, and then to the first electrode 286 of each of the deformable piezoelectric bristles 282. The electrical energy then passes through the piezoelectric fibres 284. For the active bristle tufts 260, the first type of electrical input causes the piezoelectric fibres 284 to expand and contract at an ultrasonic rate, according to the duty cycle of the transmitted electrical energy. This generates ultrasonic energy, which is emitted from the deformable piezoelectric bristle 282 of the active bristle tufts 260. 50 P005412-W001

[0207] The electrical energy then passes to the second electrode of the respective deformable piezoelectric bristle 282, to the PCB 283 and along the second electrical connector of the respective pair of electrical connectors 300. Thereafter, the electrical energy from the active bristle tufts 260 travels back to the battery 335; whereas, the electrical energy from the passive bristle tufts 260 travels to a voltage or current detector. This output electrical energy from the passive bristle tufts 260 is measured by the voltage detector. The electrical resistances of the piezoelectric fibres in the passive bristle tufts 260 are then determined using this output electrical energy.

[0208] The user then brushes their teeth and gums with the bristle tufts 260 and the dentifrice thereon.

[0209] The electrical resistances of the piezoelectric fibres of the deformable piezoelectric bristles 282 (in the passive bristle tufts 260) is influenced by deformation of the respective deformable piezoelectric bristles 282. This information can be monitored in real time. The toothbrush 1 is able to provide a number of insights to the user on the basis of this information.

[0210] First, when the brush head 220 is new, the passive bristle tufts 260 should be in new condition and therefore an electrical resistance of the piezoelectric fibres of the respective deformable piezoelectric bristles 282 is relatively low. However, with increased use during brushing successive operations, the deformable piezoelectric bristles 282 would become increasingly bent, or otherwise permanently deformed, leading to increased electrical resistance of the piezoelectric fibres of the deformable piezoelectric bristles 282. Accordingly, over time, respective “baseline” electrical resistances of the piezoelectric fibres of the deformable piezoelectric bristles 282 will increase when the toothbrush 201 is stationary and not being used to brush teeth. The electrical resistances of the piezoelectric fibres of the deformable piezoelectric bristles 282 detected by the processor 331 inform the processor 331 about the degree of deformation of the deformable piezoelectric bristles 282 of each passive bristle tuft 260, and thus, the wear of the bristle tufts 260. When the processor 331 determines, based on the orientation information from the accelerometer 336 and the detected electrical resistances, that the toothbrush 201 is stationary and at least a 51 P005412-W001 certain number (such as one) of the baseline electrical resistances is above a predetermined baseline electrical resistance threshold, the processor 331 causes the beeper of the indication unit 340 to beep, and the light of the indication unit 340 to illuminate, as an indication to the user that the brush head 220 requires replacement.

[0211] Second, while a user uses the toothbrush 201 to brush their teeth, the bristle tufts 260 will flex against the teeth. This affects the respective electrical resistance of the piezoelectric fibres of the deformable piezoelectric bristles 282 of the passive bristle tufts 260. When the processor 331 determines, based on the orientation information from the accelerometer 316, that the toothbrush 201 is in motion and the electrical resistance of the piezoelectric fibre of at least one of the deformable piezoelectric bristles 282 is above a predetermined deformation threshold, the processor 331 causes the beeper of the indication unit 340 to beep, and the light of the indication unit 340 to illuminate, as an indication to the user that they are currently pressing too hard on their teeth.

[0212] Third, based on the orientation information from the accelerometer 316 and the respective electrical resistances of the piezoelectric fibres of the passive bristle tufts 260 over time, the processor 331 causes the display screen of the indication unit 340 to display a plot of the user’s mouth with indications of the degree of deformation of the passive bristle tufts 260 while the passive bristle tufts 260 are contacting various regions in the user’s mouth. This provides the user with a map showing areas of their mouth where they press one or more of the passive bristle tufts 260 relatively forcibly against their teeth, and areas of their mouth where they press one or more of the passive bristle tufts 260 relatively gently against their teeth. From this plot, the user is able to determine which areas of their mouth are being well cleaned and which they need to clean more thoroughly. The user is also able to determine which areas of their mouth they are applying too much pressure on.

[0213] The processor 331 is also programmed to send the orientation information from the accelerometer 316 and information indicative of the detected electrical resistances of the piezoelectric fibres of the deformable piezoelectric bristles 282 of the passive bristle tufts to the remote destination, via the wireless communication interface 334, so that the remote 52 P005412-W001 destination is able to store the data and perform similar and more advanced analyses than those performed by the onboard processor 331.

[0214] The processor 331 determines for each passive bristle tuft 260, based on the plot of the user’s mouth and the detected electrical resistance, whether that bristle tuft 260 is cleaning teeth or cleaning gums. In response, the processor causes electrical energy to be transmitted to selected active bristle tufts 60 according to a ‘teeth’ duty cycle or a ‘gums’ duty cycle. The selected active bristle tufts 60 may be the active bristle tufts immediately adjacent the passive bristle tuft 260. The ‘teeth’ duty cycle has a different pulse duration and / or interval and / or amplitude to the ‘gums’ duty cycle. Accordingly, the ultrasonic energy emitted from the deformable piezoelectric bristles 282 of an active bristle tuft 60 is tailored to generate different effects depending on the part of the oral cavity that is in contact, or close proximity, with the adjacent passive bristle tuft 260. The ‘teeth’ duty cycle and the ‘gums’ duty cycle is also dependent on the detected resistance of the piezoelectric fibre of the passive bristle tufts 260. For example, the processor causes a change to a pulse interval of the respective ‘teeth’ or ‘gums’ duty cycle, proportional to the detected electrical resistance.

[0215] Fourth, based on the detected electrical resistances of the passive bristle tufts 260, the processor controls the duty cycle of transmission of electrical energy from the battery 335 to the active bristle tufts 260.

[0216] In this example, when the electrical resistance falls within a predefined range stored in the memory 332 for a given passive bristle tuft 260, the processor 331 changes the duty cycle of the electrical energy to selected active bristle tufts 260. These may be active bristle tufts 260 immediately adjacent to the given passive bristle tuft 260. The duty cycle may be changed by increasing a duration of each pulse to 50ms, at the same interval of 100ms, and increasing the amplitude of the pulses to a second amplitude greater than the first amplitude. The predefined range of electrical resistances is indicative of an optimal deformation range of the deformable piezoelectric bristles 282 for oral treatment, during which an increased power of ultrasonic energy generated, compared to the predefined duty cycle, is beneficial for oral treatment. 53 P005412-W001

[0217] When the electrical resistance is above the predefined range for a given passive bristle tuft 260, indicative that the deformable piezoelectric bristles 282 are too deformed for optimal oral treatment, the processor 331 changes the duty cycle of the electrical energy to the selected active bristle tufts 260 (e.g., immediately adjacent active bristle tufts). This may be done by increasing an interval between pulses to around 150ms and decreasing the amplitude of each pulse to a third amplitude less than the second amplitude, to decrease power of the ultrasonic energy generated.

[0218] When the electrical resistance is below the predefined range for a given passive bristle tuft 260, indicative that the deformable piezoelectric bristles 282 are deformed by a less than an optimal amount for oral treatment, the processor 331 causes the predefined duty cycle to be transmitted to the selected active bristle tufts 260 (e.g., immediately adjacent active bristle tufts). The predefined range of electrical resistances in this example is a fixed range, but in other examples is proportional to the baseline electrical resistance, and thus accounts for permanent deformation of the bristle tufts 260. It will be appreciated that suitable alternative changes to the predefined duty cycle may additionally or alternatively be made by the processor 331.

[0219] Figure 10 shows a method 400, according to an example, of manufacturing a deformable piezoelectric bristle, such as the bristle as shown in Figures 6 and 7, and as employed in the example toothbrushes 1, 201 described above as the second bristles 82 and the deformable piezoelectric bristles 282.

[0220] The method 400 comprises providing 410 a hollow piezoelectric fibre, which in this example comprises electrospinning 412 PVDF to form a tubular hollow structure, which is the hollow piezoelectric fibre. In this example, the tubular hollow structure has an outer diameter of around 0.25 mm.

[0221] The method 400 also comprises dip coating 420 the tubular hollow structure with silver so that the silver forms two tubular coatings, respectively on the interior surface and the exterior surface of the tubular hollow structure. 54 P005412-W001

[0222] The method 400 also comprises cutting 426 the tubular hollow structure to a desired length, in this example around 12mm. The cutting 426 is performed in a direction orthogonal to a longitudinal axis of the tubular hollow structure to provide a tubular piezoelectric portion. By performing the cutting 426, first and second electrodes, formed from the respective two tubular coatings of silver, are defined on the respective interior and exterior surfaces of the tubular hollow structure, separated from one another in a radial direction by the PVDF. Each electrode is a coating of silver on the respective interior or exterior surface.

[0223] The method 400 further comprises providing 430 a non-electrically conductive cover on the tubular hollow structure. In this example, the providing 430 comprises coating 432 the second electrode, the layer of silver on the exterior surface of the tubular hollow structure, with a layer of Nylon. Accordingly, the tubular piezoelectric portion and the first and second electrodes are located within an interior of the cover. The coating 432 may be performed before or after the cutting 426. The providing 430 further comprises applying 434 a layer of PEG over the coating of Nylon and tapering 436 an end of the layer of PEG. A tubular portion of the deformable piezoelectric bristle has a diameter of around 0.6mm, and is tapered at the end of the layer of PEG subjected to the tapering 436 to a diameter of around 0.2mm. It will be appreciated that, in other examples, the coating of Nylon extends beyond the piezoelectric portion towards the end that is tapered.

[0224] It will be appreciated that, in other examples, the hollow piezoelectric fibre is provided by any other suitable process. It will also be appreciated that other suitable materials are employed in other examples, for example piezoelectric polymers or dielectric polymers other than PVDT, electrically conductive materials other than silver and non-electrically conductive and biocompatible materials other than Nylon and PEG. It will further be appreciated that other suitable coating processes are employed in other examples, such as spray coating or moulding.

[0225] A deformable piezoelectric bristle manufactured according to the method 400 is arranged to generate and emit ultrasonic energy in response to application of electrical energy to the 55 P005412-W001 electrodes. Such deformable piezoelectric bristles may be employed in oral treatment devices, such as according to the examples described herein, to clean or otherwise treat the oral cavity of a user.

[0226] Figure 11 shows a method 500 of forming an oral treatment device, for example a brush head 220 according to the example described above with reference to Figures 1 and 2.

[0227] The method 500 comprises providing 502 a support, for example a support 30 as described with reference to Figures 1 and 2. The support is sized and shaped to be inserted into the oral cavity of a user.

[0228] The method 500 further comprises providing 504 at least one deformable piezoelectric bristle so as to project from the support. In this example, the deformable piezoelectric bristle comprises a hollow piezoelectric fibre, but in other examples the deformable piezoelectric bristle comprises a piezoelectric element that is not hollow. The at least one deformable piezoelectric bristle is a bristle as shown in Figures 6 and 7 in this example. In examples, the at least one deformable piezoelectric bristle is manufactured using a method according to the disclosure, such as the method 400 shown in Figure 10. In some such examples, the method 500 shown in Figure 11 comprises the method 400 shown in Figure 10.

[0229] Though omitted in other examples, the method 500 in this example further comprises providing 506 at least one deformable electromagnetic energy-conducting bristle so as to project from the support. In this example, the at least one electromagnetic-conducting bristle is a first bristle 80 of the toothbrush 1 described with reference to Figures 1 to 7.

[0230] An oral treatment device manufactured according to the method 500 may be used for treating an oral cavity of a user. In this example, the manufactured oral treatment device comprises an interface for removable attachment to a handle, but in other examples the support is integrally formed with a handle. 56 P005412-W001

[0231] Whilst Figures 1, 2 and 8 show electrically powered toothbrushes 1, 201, it will be appreciated that other oral treatment systems may be otherwise employed, which output ultrasonic energy and electromagnetic energy. The oral treatment system need not include all of the parts shown in the figures. For example, the system need not include both the handle and the brush head. The system may instead simply have a support, first deformable cleaning element(s) projecting from the support to conduct electromagnetic energy for emission from the system and an ultrasound generator configured to generate and emit ultrasonic energy from the system. Further, in some embodiments where the system has both a handle and a brush head, the ultrasound generator may include at least one part (e.g. the ultrasound transmitter) arranged within the brush head and at least one part (e.g., the source of electrical energy and electrical energy transmission arrangement) arranged within the handle. Alternatively, the ultrasound generator may be fully arranged within the handle or fully arranged within the brush head.

[0232] It will be appreciated that in other examples, the toothbrush 201 shown in Figures 8 and 9 also includes at least one deformable electromagnetic energy-conducting bristle protruding from the front side 242 of the brush head 220, an electromagnetic energy transmission arrangement and, optionally, an electromagnetic energy detection system, as described with reference to the toothbrush 1 of Figures 1 to 7. In such examples, the oral treatment device may provide a synergistic effect of emitting electromagnetic energy from the at least one deformable electromagnetic energy-conducting bristle and ultrasonic energy from the deformable piezoelectric bristles 282. Further, the processor may more accurately determine deformation of the bristle tufts based on output electromagnetic energy received from the at least one deformable electromagnetic energy-conducting bristle and output electrical energy from the deformable piezoelectric bristles 282 of the passive bristle tufts 260, and select a duty cycle of electrical energy transmission accordingly. In some examples, the toothbrush may include the deformable electromagnetic energy-conducting bristles and the passive piezoelectric bristle tufts, but exclude the active piezoelectric bristle tufts. In some examples, the toothbrush may include the deformable electromagnetic energy-conducting bristles and the active piezoelectric bristle tufts, but exclude the passive piezoelectric bristle tufts. 57 P005412-W001

[0233] In some examples, instead of sending a fixed direct current to the passive bristle tufts 260, an alternating voltage may be used to determine the wear of the bristle tufts 260 instead. This alternating voltage may have a frequency around (+ / - 5%) the resonant frequency of the piezoelectric fibres of the passive bristle tufts 260. This alternating voltage may be sent to the passive bristle tufts 260 when the toothbrush is stationary and not being used to brush teeth. An electrical impedance readout may be obtained based on the output electrical energy from the passive bristle tufts 260. As an example, the peak impedance value and / or the Q-factor of the peak can be used to monitor the aging and wear on the piezoelectric fibres of the bristle tufts.

[0234] It will be appreciated that various ways of determining electrical resistances of the passive bristle tufts 260 can be used, regardless of whether the input electrical energy to these passive bristles tufts 260 is in the form of a direct fixed current or an alternating voltage.

[0235] It will be appreciated that in other examples, each bristle tuft 260 in the toothbrush 201 shown in Figures 8 and 9 includes both active bristles 282 and passive bristles 282. In these examples, the first type of electrical input is delivered to the active bristles 282 of each bristle tuft 260 and the second type of electrical input is delivered to the passive bristles 282 of each bristle tuft 260. For a given bristle tuft 260, a degree of deformation of the bristle tuft 260 can be determined based on the output electrical energy from the passive bristles 282 of this bristle tuft 260. Based on this determination, the processor 331 may be configured to adjust the first type of electrical input delivered to the active bristles 282 of this bristle tuft 260. This adjustment may be done in a similar manner as described above with reference to the active bristle tufts 260.

[0236] Although not described with reference to the examples above, in other examples, the array of LEDs is arranged to selectively emit light of different wavelengths, for example one or more of white, blue, red or near-infrared light. In some examples, the processor is arranged to change a wavelength of light emitted from the array of LEDs on the basis of the signal received from the photodetector and / or the electrical energy detector, where present. 58 P005412-W001

[0237] Whilst particular examples have been described, it should be understood that these are illustrative examples only and that various modifications may be made without departing from the scope of the invention as defined by the claims.

[0238] For example, in some other examples, the brush head comprises a separate optical fibre connected to each individual first bristle in each bristle tuft, as opposed to an optical fibre connected to all of the first bristles in a bristle tuft. In some embodiments, the first bristles are integrally formed with the deformation information collection arrangement. In some embodiments, the oral treatment device has more, or fewer, than nineteen bristle tufts. In some embodiments, non-visible light is transmitted by the light source to, and reflected by, the first bristles, such as near-infrared light. In some examples, the battery comprises a plurality of electrical sources, for example a first battery to power the array of LEDs and a second battery to power the piezoelectric elements. In some examples, the oral treatment device, such as a toothbrush, comprises a handle, such as a handle that is integrally formed with the support. In some examples, the oral treatment device has only one cleaning element, which may or may not be in the form of a bristle tuft, projecting from the front side of the support. In some embodiments, the processor causes some or all of the LEDs in the array of LEDs to emit light in pulses or flashes, dependent on the signal from the photodetector or electrical energy detector, where present and / or dependent on the position of the bristles within the oral cavity. In some examples, the support of the oral treatment device has a neck portion that extends from a head portion of the support in a first direction and is not narrower than (e.g., is of equal width to) the head portion in a lateral direction orthogonal to a first direction. In some embodiments, the oral treatment system does not include a communication interface, such as the wireless communication interface, for transmitting information to a remote destination. In some embodiments, the photodetector is replaced by an energy receiver in the form of a window that ends of the optical fibres of the transmission arrangement abut, so that the light that has passed through these optical fibres is directly viewable through the window by a user. In some examples, the battery operates at a different voltage, for example a different voltage between 10V and 60V.

Claims

59 P005412-W001CLAIMS1. An oral treatment device for use in treating an oral cavity of a user, the oral treatment device comprising: a support; at least one deformable cleaning element projecting from the support, the deformable cleaning element comprising a piezoelectric element; and a deformation information collection arrangement electrically connected to the piezoelectric element and configured to collect and conduct output electrical energy, representative of deformation of the piezoelectric element, from the piezoelectric element.

2. The oral treatment device according to claim 1, wherein the oral treatment device is configured to be removably attachable to a handle.

3. The oral treatment device according to claim 1 or claim 2, wherein the piezoelectric element is made from a piezoelectric polymer or a dielectric polymer.

4. The oral treatment device according to any one of the preceding claims, wherein the deformable cleaning element comprises at least one electrode on the piezoelectric element.

5. The oral treatment device according to claim 4, wherein the at least one electrode comprises a coating of electrically conductive material.

6. The oral treatment device according to any one of the preceding claims, wherein the deformable cleaning element comprises a non-electrically conductive cover having an interior within which the piezoelectric element is located.

7. The oral treatment device according to claim 6 when dependent on claims 4 - 5, wherein the at least one electrode is located within the interior of the non-electrically conductive cover.60 P005412-W0018. The oral treatment device according to claim 6 or claim 7, wherein the non- electrically conductive cover comprises a layer of non-electrically conductive material and a layer of polyethylene glycol on the layer of non-electrically conductive material.

9. The oral treatment device according to any one of preceding claims, wherein the piezoelectric element comprises a hollow piezoelectric fibre.

10. The oral treatment device according to claim 9, wherein the hollow piezoelectric fibre comprises a tubular piezoelectric portion.

11. The oral treatment device according to claim 9 or claim 10, wherein the hollow piezoelectric fibre has an interior surface and an exterior surface, and the deformable cleaning element comprises an electrode on one of the interior surface and the exterior surface.

12. The oral treatment device according to claim 11, wherein the electrode is a first electrode and the deformable cleaning element comprises a second electrode on the other of the interior surface and the exterior surface, the second electrode being electrically insulated from the first electrode.

13. The oral treatment device according to claim 11, wherein each of the first electrode and the second electrode is tubular.

14. An oral treatment device according to any one of the preceding claims, wherein the at least one deformable cleaning element comprises plural deformable cleaning elements, and the deformation information collection arrangement defines plural electrically conductive paths that are electrically coupled to the piezoelectric fibres of the respective plural deformable cleaning elements and configured to collect and conduct output electrical energy, representative of deformation of the respective piezoelectric fibres, from the respective piezoelectric fibres.61 P005412-W00115. The oral treatment device according to any one of the preceding claims, wherein the at least one deformable cleaning element comprises a passive deformable cleaning element and the oral treatment device further comprises an active deformable cleaning element comprising a piezoelectric element; and wherein the deformable information collection arrangement is electrically connected to the piezoelectric element of the passive deformable cleaning element; and the active deformable cleaning element is configured to generate and emit ultrasonic energy from the oral treatment device.

16. The oral treatment device according to any one of the preceding claims, further comprising at least one deformable electromagnetic energy-conducting cleaning element projecting from the support, wherein the at least one deformable electromagnetic energyconducting cleaning element is configured to conduct electromagnetic energy for emission from the oral treatment device.

17. An oral treatment system comprising the oral treatment device according to claim 15 or claim 16, wherein the oral treatment system further comprises: a source of electrical energy; an electrical energy transmission arrangement configured to transmit input electrical energy from the source of electrical energy to the active deformable cleaning element; and a processor operatively coupled to the deformation information collection arrangement; wherein the processor is configured to control the input electrical energy to the active deformable cleaning element based on the output electrical energy collected and conducted by the deformation information collection arrangement from the piezoelectric element of the passive deformable cleaning element.

18. The oral treatment system according to claim 17 when dependent on claim 16, wherein the oral treatment system further comprises: a further deformation information collection arrangement optically coupled to the at least one deformable electromagnetic energy-conducting cleaning element and configured62 P005412-W001 to collect and conduct output electromagnetic energy, representative of deformation of the at least one deformable electromagnetic energy-conducting cleaning element, from the at least one deformable electromagnetic energy-conducting cleaning element; wherein the deformation information collection arrangement is separate from the further deformation information collection arrangement.

19. The oral treatment system according to claim 18, wherein the processor is operatively coupled to the further deformation information collection arrangement and is configured to control the input electrical energy to the active deformable cleaning element based further on the output electromagnetic energy from the at least one deformable electromagnetic energy-conducting cleaning element.

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