CN116568181A - Wear detection for oral care devices - Google Patents

Abstract

A wear assessment for an oral care system (14) (e.g., an oral cleaning device) is disclosed. The sensor unit (16) of the oral care system is adapted to provide a sensor signal related to a cleaning efficacy of a cleaning function of the oral care system. The sensor unit (16) may be or may be connected to a component used during performance of an oral care function of the device, such as a sensor for detecting the progress of cleaning in the oral cavity, or a component driving a cleaning or treatment action in the oral cavity. According to the invention, a sensor signal (20) generated when the oral care system is outside the oral cavity is used to perform wear assessment. As the associated components used by the oral care system (14) for the oral care function wear, the characteristics of the sensor signal (20) may change in a predictable manner, which may be used to identify when a worn state has been reached.

Description

Wear detection for oral care devices

Technical Field

The invention relates to wear detection of components of an oral care system.

Background

CN 106510881a discloses an indication method for judging whether the brush head needs to be replaced or not according to the actual brushing use condition of the user. The indication method comprises the following steps: the method comprises the steps of obtaining brushing data of a user, calculating a loss value of the brush head according to the brushing data of the user, and sending an indication that the brush head needs to be replaced to the user when the loss value of the brush head is greater than or equal to a predefined threshold.

In the field of oral care devices, it is valuable to be able to detect wear of the relevant operating parts of the device, which wear leads to a reduction in the efficacy of the oral care function. For example, for oral cleaning devices, cleaning efficacy may decrease over time. This may be caused by, for example, physical wear, deformation or degradation of cleaning elements such as bristles in the toothbrush. However, other types of oral care devices include, by way of non-limiting example, motorized flossing devices, oral irrigators, oral treatment devices that use Electromagnetic (EM) energy, such as radio frequency emissions or light, or combinations of these devices. Each of these units also includes components for performing oral care functions and which may wear over time, such as mechanical cleaning elements such as bristles, nozzles, applicators, reflectors, or radiation output surfaces.

One type of development of oral care devices is an interface unit. These generally have an arcuate (e.g., U-shaped) configuration with upper and lower tooth receiving channels and generally include a row of curved bristles that follow the shape of the tooth receiving channels. These allow the user to clean the teeth quickly and thoroughly with reduced effort.

As the interface wears, performance will decrease and it is advantageous to have the ability to automatically notify the user when the entire interface or specific components thereof (e.g., the brushing portion) should be replaced.

The same problem also arises in the field of toothbrushes, which are primarily characterized by bristle splaying.

Developments in the field of wear detection of oral care devices are generally sought.

Disclosure of Invention

The invention is defined by the independent claims. Advantageous embodiments are defined in the dependent claims.

According to an example in accordance with one aspect of the present invention, there is provided an oral care system comprising:

a sensor unit adapted to generate an output signal related to or indicative of the cleaning efficacy of the oral cleaning function of the system; and

a processor arranged to:

receiving an output signal from the sensor unit;

determining one or more predefined characteristics of a signal

Performing the wear assessment includes determining whether one or more signal characteristics meet one or more predefined criteria, and generating a wear feedback signal based on a result of the assessment.

Embodiments of the present invention are based on determining wear using the output of a sensor unit or module arranged to provide a direct or indirect indication of the cleaning efficacy of the cleaning mechanism of the oral care system. This may be, for example, a cleanliness level sensor, or a module that detects an operating characteristic of the cleaning mechanism of the device (e.g., a driving signal characteristic of the oscillating motion generator). The sensor may determine the cleanliness level or a (time) derivative thereof, such as the cleanliness rate.

The wear feedback signal is a wear indicator signal that indicates that the wear of the cleaning elements (e.g., bristles) exceeds a particular threshold.

One set of embodiments is based on the concept of indirectly detecting physical degradation of certain oral care components of the system, which is based on long-term drift of certain characteristics of the sensor unit output signal (i.e., characteristics of the null signal or the calibration signal) measured during times when the device is not being operated for an oral care function.

For example, the wear assessment may include retrieving one or more baseline measures of one or more predefined characteristics of the signal from memory, and detecting a deviation of the determined characteristic of the sensor unit output signal from the baseline measure of the characteristic of the signal.

For example, the one or more predefined criteria applied in the wear assessment may include a threshold or minimum deviation of the defined signal characteristic from a reference or baseline characteristic.

The determination may be made outside of an operating session of the oral care system, i.e., when a component of the oral care system does not physically interact with the oral surface. Thus, the output signal corresponds to, for example, a calibration signal or a null signal.

A baseline characteristic may refer to a particular set of one or more characteristics of the output signal measured at a minimum or zero wear point of a device component. These characteristics are selected to be progressively changing characteristics as the wear of the associated oral care device components (e.g., cleaning elements) increases.

As one example, when bristles of an oral cleaning device, such as an oral cleaning device, begin to splay with wear, they can physically interfere with the operation of the physical sensor. For example, the bristles may be splayed or bent away from the emission path of a cleanliness level sensor using fluid, electromagnetic (e.g., optical), or acoustic emissions. This will change the signal characteristics.

According to one or more embodiments, the sensor unit may be adapted to generate electromagnetic (e.g. optical), acoustic or fluid emissions for contact or non-contact physical interaction with a surface in the oral cavity of the user, and wherein the output signal depends on the nature of the interaction of the emissions with the surface in the oral cavity (e.g. tooth, gum or any other (bio) material surface).

In this set of embodiments, the sensor unit may be a sensor for detecting a tooth cleanliness level, as an example.

The output signal may be based on a measurement of one or more detected physical properties emitted after or during physical interaction with the oral surface.

For example, the output signal may give an indication of the interaction of the emission with the cleaning element en route to the tooth surface.

In another set of examples, the sensor unit may include or be electrically coupled to one or more operating components of the oral care device that have been adapted to perform an oral care function, such as a motion generator that drives an oscillating motion of the cleaning element.

According to one or more embodiments, the sensor unit may comprise a cleanliness level sensor adapted to perform a contact or non-contact physical interaction with the oral surface to detect a cleanliness level of the tooth surface, and wherein the output signal is indicative of the cleanliness level.

In this case, the output signal may be an output signal generated by a sensor.

If certain characteristics of the cleanliness level sensor signal change from a reference value, this may give an indication: the emissions of the cleanliness level sensor have physical interference with the physical elements of the device en route to the tooth surface.

In some examples, the cleanliness level sensor may be a plaque detection sensor.

According to one or more embodiments, the cleanliness level sensor is a plaque detection sensor adapted to generate a fluid flow that is driven onto or over a tooth surface, and wherein the output signal is based on a measurement of the pressure or flow of the generated fluid flow.

When a fluid (e.g., air) is driven onto or over the tooth surface in a stream, the pressure or flow of the fluid (e.g., air) provides an indication of plaque level because the pressure of the fluid stream increases as the level of tooth cleanliness increases. In particular, (viscous) plaque tends to provide some elastic absorption of the applied fluid pressure. As the tooth surface becomes cleaner, it becomes stiffer, meaning that the measured fluid back pressure increases. Thus, the pressure of the fluid flow provides an inverse measure of the level of cleanliness of the tooth surface.

According to one or more embodiments, an oral care system can include a mechanical cleaning element for mechanically engaging a surface in an oral cavity. The oral care system may further comprise a motion generator arranged to drive the oscillating motion of the cleaning element during the operation session. The motion generator may comprise a motor powered by a drive circuit. In this case, the sensor unit may be arranged to be coupled to the drive circuit, and wherein the output signal is indicative of one or more electrical characteristics of the drive circuit.

During operation of the device for cleaning teeth, characteristics of current or voltage, such as a driving circuit, may fluctuate. However, these properties may stabilize as the cleanliness level increases. Thus, this stability gives an indication of the cleanliness level. Thus, the output signal of the sensor unit coupled to the drive circuit is related to or indicative of the cleaning efficacy.

According to one or more embodiments, the determination of the one or more signal characteristics may be made during or after each operating session, and wherein the wear assessment is based on the signal characteristics detected over the plurality of operating sessions.

For example, it may be based on an average of one or more signal characteristics over a plurality of sessions, such as an average over a defined number of most recent operational sessions, or an average over a defined most recent period of time (e.g., an average over a week).

This determination may be performed during each operating session and the results thereof stored in local or remote memory. In some examples, the determination may be further utilized to provide a cleaning end indicator to indicate that the nozzle is sufficiently clean and the cleaning session may end. This may be used to generate a sensory feedback output to the user or may be used to automatically stop an active cleaning operation of the device, such as deactivating oscillation of the cleaning elements of the device.

The wear assessment may be performed automatically after or during each operating session, or may be performed less frequently, such as weekly or bi-daily.

According to one or more embodiments, an oral care system may include an oral care device including at least a portion for being received in an oral cavity of a user, and wherein the oral care device includes a sensor unit.

The processor may be included with the oral care device such that both form a single unit. Alternatively, the processor may be external to the oral care device, for example it may be a processor belonging to a mobile computing device of the user and adapted to be in operative communication with the oral care device.

According to one or more embodiments, an oral care device may include an interface unit for being received in an oral cavity of a user. The interface unit may be U-shaped and may include upper and lower tooth receiving channels with an occlusal surface disposed between the two channels forming a base for each of the channels.

The interface unit may include a plurality of cleaning elements protruding into the tooth receiving channel for mechanical engagement with the tooth surface during an operational session. The cleaning elements may comprise cleaning filaments. The cleaning elements may be bristles or bristle tufts, or any other mechanical element capable of exerting a force on the oral surface.

Embodiments according to another aspect of the present invention provide a method for detecting wear in an oral care device. The method comprises receiving an output signal from a sensor unit adapted in use to generate an output signal related to or indicative of the cleaning efficacy of the oral cleaning function of the system. The method further includes determining one or more predefined characteristics of the signal. The method also includes performing a wear assessment including determining whether the one or more signal characteristics meet one or more predefined criteria, and generating a wear feedback signal based on a result of the assessment.

Examples according to another aspect of the invention provide a computer program product comprising computer program code, the computer program code being executable on a processor and the code being configured to cause the processor to perform a method according to any of the examples or embodiments outlined above or described below or according to any claim of the present application.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

Drawings

For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying schematic drawings in which:

FIG. 1 outlines components of an example system including a processor in accordance with one or more embodiments of the invention;

FIGS. 2-4 illustrate examples of tubes for a fluid-based plaque detector;

FIG. 5 illustrates components of an exemplary fluid-based plaque detector;

FIG. 6 illustrates an example oral care device including a fluid-based plaque detector including a plurality of fluid outlet tubes; and

fig. 7 illustrates an example oral care device including a light emission based plaque sensor including a plurality of optical sensing elements.

Fig. 8-9 illustrate an example wear detection method according to one set of embodiments, wherein interactions between a sensor unit and an operating component of an oral care device are used to detect wear; and

fig. 10 shows an example signal profile of the sensor unit output with low and high wear conditions of the oral care device.

Detailed Description

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

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

The present invention provides a method and processor for performing wear assessment on an oral care device (e.g., an oral cleaning device). An output signal is received from a sensor unit of the oral care device, the sensor unit being adapted in operation to provide an output related to a cleaning efficacy of a cleaning function of the oral care device. The sensor unit may be or may be coupled to a component used during performance of an oral care function of the device, such as a sensor for detecting the progress of cleaning in the oral cavity, or a component that drives a cleaning or treatment action in the oral cavity. This signal is used to perform wear assessment. As the relevant components used by the device for oral care functions wear, the characteristics of the signal may change in a predictable manner, which may be used to identify when a worn state is reached.

In some examples, the output signal of the sensor unit may be based on characteristics of features included in the oral care device and active during an oral care operation session. The intended feature may be a feature that is used as part of the normal oral care operation of the oral care device. Most oral care devices include at least one component that physically interacts with teeth or other oral surfaces, either in contact or non-contact. One insight of the inventors is that the characteristics of the signal indicative of such physical interactions can be usefully employed for a second purpose of determining wear of the components of the device. For example, where the device is an oral cleaning device, wear of the cleaning elements of the device may be detected. The cleaning elements may, for example, comprise filaments or protrusions designed to rub against the tooth surface to perform a cleaning function. However, in other examples, the wear may be wear of other components. Typically, wear results in reduced efficacy of the oral care function provided by the device, such as reduced cleaning efficacy caused by, for example, mechanical deformation, splaying, wear, degradation of the cleaning elements.

Embodiments of the present invention may be applied to a range of different oral care devices that may be adapted to perform, for example, oral cleaning and/or treatment functions.

One emerging type of oral care device is an automatic brushing interface. They include a U-shaped cleaning portion comprising cleaning elements such as bristles and arranged to be received in the oral cavity, with the upper and lower rows of teeth received in the upper and lower teeth receiving channels and the bristles extending into the channels to provide a brushing function. This provides a faster brushing time and easier use for the user.

Fig. 1 schematically depicts the basic components of an example oral care system that may be provided in accordance with an aspect of the present invention. The system comprises a processor 12, the processor 12 being arranged to receive a signal 20 from a sensor unit 16, the sensor unit being comprised by the oral care device 14.

Another aspect of the invention provides only the processor 12. The processor may, for example, comprise a communication module or input/output adapted to be operatively connected to the sensor unit 16 to receive the signal 20.

Another aspect of the invention may provide an oral care system comprising an oral care device 14 (having a sensor unit) and a processor 12 operatively coupled to the sensor unit 16 in operation.

The processor 12 is adapted to determine one or more predefined characteristics of the output signal 20 and perform a wear assessment, including determining whether the one or more signal characteristics meet one or more predefined criteria. The processor is further adapted to generate a wear feedback signal 26 based on the evaluation result. For example, the processor may generate the feedback signal only in case of a positive result of the wear evaluation (i.e. in case wear has been detected).

In some cases, the sensor unit 16 may be adapted to perform a contact or non-contact physical interaction 18 with a surface of a tooth 22 in the user's mouth (e.g., as shown in fig. 1) during an operational session. In some further cases, the sensor unit may be signal coupled to a functional component that performs such contact or non-contact physical interaction 18 with the surface of the tooth 22. In some examples, the output signal 20 may depend on the nature of the physical interaction. These represent only example options and other configurations are possible.

Examples of non-contact physical interactions may be for example using acoustic waves or electromagnetic waves or emissions emitted from the sensor unit, and wherein the sensor unit detects its reflection. An example of a contact physical interaction may be, for example, a piezoelectric sensor integrated at the distal end of a cleaning element arranged to rub against the surface of the tooth, wherein the piezoelectric sensor is in direct contact with the tooth. Another example of a contact physical interaction may be an actuator that drives the physical movement of the cleaning element relative to the tooth surface, or a fluid sensor that detects plaque. The output signal may be an electrical characteristic of the actuator drive circuit that may fluctuate according to the nature of the interaction between the cleaning elements and the tooth surface.

References to an operation session in this disclosure may correspond to a period of time that the oral care device is operating in a cleaning or treatment mode. It may correspond to the time when the operation or feature is active to perform an oral care function. For example, it may correspond to the time at which the motion generator drives the cleaning elements of the oral care device to oscillate.

Feedback signal 26 may be a sensory output signal, such as a control signal for controlling a sensory output device to produce sensory stimuli to convey a positive result of wear assessment to a user. As non-limiting examples, this may include visual outputs, such as illuminating one or more lighting elements, or acoustic outputs, such as warning sounds, or tactile or haptic outputs, such as vibrations generated by a vibrator within the oral care device.

In general, wear assessment may be performed during or after each operating session, or may be performed less regularly. For example, it may be performed after every x operating sessions, may be performed at regular intervals, such as weekly, or once daily, or once every two weeks.

There are various options for the sensor unit. A number of different examples will be described in more detail below to aid in understanding the scope of possibilities encompassed by the above outlined inventive concepts.

In one set of embodiments, wear assessment may be understood to include detecting a deviation of one or more defined characteristics of the output signal from a predefined baseline characteristic. The signal characteristics may be measured outside of the operating session, thus reflecting calibration or null signal characteristics. These may drift from the baseline level over time due to wear of the components.

In this case, the "predefined criteria" may be a threshold or minimum deviation of the defined signal characteristics from a reference or baseline characteristic.

A baseline characteristic may refer to a particular set of one or more characteristics of a signal measured at a minimum or zero wear point of a device component.

There are a number of options regarding the sensor unit and the corresponding output signal.

The different embodiments will now be summarized in more detail.

There are different choices for the characteristics of the sensor unit 16 and the output signal 20 used.

According to one advantageous set of examples, the sensor unit 16 may be a physical cleanliness level sensor adapted to detect the cleanliness level of the tooth surfaces in the oral cavity. It may be adapted to detect this continuously or cyclically during the entire operating session of the oral care device. Thus, in this set of examples, the oral care device may be an oral cleaning device for performing a cleaning function, for example for cleaning a tooth surface. For example, it may be a toothbrush or a cleaning interface device (as described above). Thus, the operating session of the device may be an oral cleaning session.

In some examples, the device components whose wear is monitored indirectly in this way may correspond to protruding cleaning elements of the device that are adapted to rub against tooth surfaces in order to mechanically clean them. The cleaning elements may be cleaning filaments, such as bristles. It is well known that bristles undergo wear, causing the bristles to splay apart, which reduces cleaning efficiency. Typically, once the performance degradation begins, it will steadily increase. Another example may include a nozzle of an oral irrigator motorized flossing device. Wear of the nozzles of the device may correspond to, for example, accumulation of scale in the nozzles, resulting in a decrease in cleaning efficiency.

In embodiments where the sensor unit is a cleanliness level sensor, this may be a plaque detection sensor.

In some examples, the cleanliness level sensor used as sensor unit 16 may be a sensor used during normal cleaning operation of the device for detecting when the end of a cleaning session is reached. For example, a cleanliness level sensor may be used to detect when a threshold cleanliness is reached, meaning that the cleaning session may be terminated (e.g., automatically). This may include, for example, a motion generator disabling mechanical oscillations of the cleaning elements of the drive device.

According to one or more embodiments, the sensor unit 16 may be adapted to generate electromagnetic (e.g. optical), acoustic or fluid emissions for contact or non-contact physical interaction with a surface in the user's mouth, and wherein the signal is indicative of a characteristic of the interaction of said emissions with the surface.

The sensor unit 16 may be a cleanliness level sensor that uses such emissions to perform the sensing of the cleanliness of the oral surface. In other examples, the sensor unit may be signal coupled to another functional component that generates emissions to perform a cleaning or treatment function, such as an oral irrigator or an electric flossing device that generates fluid emissions for cleaning functions, or an RF treatment device that uses RF emissions to treat gums.

An example sensor unit in the form of a cleanliness level sensor that uses fluid emissions to sense real-time cleaning efficacy will now be described.

This example is schematically illustrated in fig. 2-6.

In this example, the sensor unit 16 is a plaque detection sensor adapted to generate a fluid flow that is driven onto or over the tooth surface, and wherein the output signal is based on a measurement of the pressure or flow of the fluid impinging on the tooth surface and the generated fluid flow. In some examples, the fluid may be air (or another gas). When plaque is present on the tooth surface, the tooth is more viscous (the surface is more fluid elastic). The effect is that when fluid is transferred onto or over a tooth surface, the elastic absorption of fluid pressure by the surface is higher relative to a tooth surface without plaque, and this results in a measurable reduction in fluid pressure compared to the state of cleaning of the tooth surface. Thus, the sensor may be used to sense plaque levels on teeth based on pressure and/or flow characteristics of fluid flow delivered onto or over the tooth surface. As the teeth become progressively cleaner (reducing plaque), the pressure increases progressively (as the flow rate decreases).

The fluid-based plaque sensor may include a tube 56, the tube 56 being arranged to protrude outwardly from a surface of a portion of an oral care device that is received in the oral cavity during operation. At the distal end of the tube is an opening 58 that allows fluid flow 62 out of the end of the tube for interaction with the tooth surface. The tube is arranged such that during normal operation of the oral care device in the mouth, the end of the tube is arranged to engage against the tooth surface. For example, as shown in fig. 5, it may be integrated within the bristle field 66 of the device such that when bristles are engaged against the tooth surface to clean the teeth, the opening 58 at the end of the tube is also automatically engaged against the tooth surface.

The end of the tube 56 may be shaped to facilitate the operable engagement of the fluid opening 58 against the tooth surface. For example, fig. 3 shows an example in which the end of the tube has a recessed channel extending diametrically across the distal face of the tube, and in which the opening 58 is positioned in a central region of the base of the recessed channel. This allows the upper side of the channel to operably engage against the tooth surface and provides a region of fluid engagement against the tooth that is larger than the size of the opening itself and has a different shape (i.e., is linear in this case). Fig. 4 shows another example in which the ends of the tube are beveled at two opposite sides of the tube opening 58, which makes it easier for the opening 58 to engage against a tooth surface, even if the tube engages against the surface from a bevel.

Referring to fig. 5, the plaque sensor in this embodiment includes a sensing module 50, the sensing module 50 being in fluid connection with a tube 56 arranged to physically protrude from the surface of the oral care device. The sensor module comprises a fluid flow generator 52 (preferably a flow generator), the fluid flow generator 52 being arranged to provide a flow of pressurized fluid through the length of the tube towards the distal end of the tube comprising the opening 58. The sensor module further comprises a detector element 54 arranged to sense the pressure or flow of fluid flowing through the tube 56. The detector may be arranged to detect fluid flow or pressure at a location between the flow generator and the proximal end of the tube 56, for example it may detect one or both of these properties within a conduit extending between the flow generator and the proximal end of the tube 56.

The detector 54 may generate an output signal indicative of the sensed pressure or flow. Alternatively, it may generate an output signal indicative of the level of plaque on the tooth, as determined by the detector based on the sensed pressure or flow of fluid. The output signal from the detector may provide an input signal 20 to the processor for assessing wear.

As a further illustration, examples of suitable fluid-based plaque detection sensors are described in detail in each of the following documents: WO 2014/097240, WO2014/097241 and WO2014/097031.

In an advantageous example, the plaque sensor may include a plurality of tubes 56 to allow plaque levels to be sensed at a plurality of different tooth surface positions. The plaque level may be sensed at multiple locations simultaneously, or multiple tubes may allow the plaque level to be sensed at any one or more locations.

An example is schematically shown in fig. 6. This example describes an oral care device in the form of a brushing interface device 72. The figure shows a plan view of the interface. The mouthpiece device includes a U-shaped cleaning section for being received in the oral cavity. The U-shaped cleaning portion includes an upper tooth receiving channel and a lower tooth receiving channel. Only the upper tooth receiving channel 74 is shown in fig. 6. Projecting into the tooth receiving channel from the opposed walls defining the channel are opposed bristle rows forming a first bristle field 68a and a second bristle field 68b. When the teeth are received in the channel, the bristle field protrudes to contact the tooth surfaces on both the oral side and lingual side.

As shown, the interface includes a plaque sensing device that includes a sensing module 50, the sensing module 50 being fluidly connected to a plurality of tubes 56 (according to the description outlined above). A fluid conduit or tube 51 extends between the sensing module 50 and the tube 56 to carry a fluid flow for performing plaque sensing. The tubes are arranged at a series of different spatial locations around the tooth receiving channel to allow detection of dental plaque at a plurality of different areas of a row of teeth received in the mouthpiece channel during operation. The plurality of tubes 56 may be fluidly connected in parallel or in series to a flow generator 52 (not shown in fig. 6) included with the sensor module 50.

The tube 56 at multiple locations may be used to sense plaque at multiple locations at a time. The output signal 20 received by the processor 12 may be a signal related to, for example, an average plaque level sensed at all locations. Alternatively, plaque levels at only a subset of one or more tube 56 locations may be used to provide the signal 20.

As one advantageous example, the plaque sensor may be adapted to utilize the following plaque sensor readings from the tube 56 location: during one or more previous cleaning sessions, the sensed plaque level drops slowest during the cleaning session at this tube 56 location, or at this location, a greater amount of plaque is sensed at the end of the cleaning session than at any other location. These locations may correspond to places where there is a tendency to accumulate most plaque, or where cleaning is more inconvenient. This may be based on previously recorded data from a previous cleaning session, for example stored in a local memory of the sensor or processor 12 or the oral cleaning device. By using specific sensing locations where it is sensed that plaque removal has occurred more slowly or less efficiently, this ensures that when the signal 20 is monitored to detect when the cleanliness level has reached the defined threshold 32, the cleanliness level is that of all areas in the mouth that have been reached, including areas that are sensed to be slowest or most difficult to clean.

In some examples, where the interface unit is a custom interface, the sensing location may be configured according to locations known to the dental professional that may accumulate more plaque or that may be difficult to clean.

According to another set of one or more examples, the sensor unit 16 may take the form of a cleanliness level sensor, and wherein the cleanliness level sensor is a plaque sensor that detects plaque levels using optical (or other electromagnetic) emissions. In particular, the plaque level sensor may include one or more light sources arranged to produce a light output that is received on a tooth surface during use of the oral care device. The sensor unit may further comprise an optical (or other EM) sensing element arranged to sense reflection of optical (or other EM) emissions returned from the tooth. Based on the characteristics of the reflected light signal, the level of plaque may be sensed. For example, a tooth surface with a plaque covering has different light scattering properties than a clean tooth surface. It may also have different fluorescent properties. For source optical signals where these properties are fixed, these different properties have a detectable effect on the optical properties of the reflected optical signal. Thus, this allows sensing plaque levels on the teeth.

Examples of optical plaque detectors suitable for use in accordance with embodiments of the invention can be found in: WO 2014/097135, WO 2014/097045 or WO 2015/056197.

In an advantageous embodiment, the oral care device may comprise a plurality of plaque sensing elements 82, each plaque sensing element 82 having a light source generating light emissions and a light sensing element sensing reflection of emissions from the tooth surface. The or each plaque sensing element is operatively coupled to an optical sensor module 80, the optical sensor module 80 being adapted to produce a sensor output indicative of the relevant optical property of the sensed reflected wave or indicative of the plaque level. The output signal may be used to perform wear assessment.

Fig. 7 illustrates one example oral care device including a plurality of plaque sensing elements 82 connected to an optical sensing module 80. The device is in the form of a brushing interface device 72. The components of the interface are otherwise identical to those described above with respect to fig. 6.

The plurality of plaque sensing elements 82 are arranged at a series of different spatial locations around the tooth receiving channel 74 of the mouthpiece to allow detection of plaque at a plurality of different areas of a row of teeth received in the mouthpiece channel. The plurality of plaque sensing elements 82 may be connected to the optical sensing module 80 in parallel or in series. The sensing elements may be electrically connected. Alternatively, in some examples, the light source included by each sensing element 82 may be optically provided by a light generator in the sensor module 80, and wherein the sensing elements 82 are optically coupled to the optical sensing module 80 via respective optical fibers 84.

The plaque detecting elements 82 at multiple locations may be used to detect plaque at multiple locations simultaneously. The signal 20 received by the processor 12 may be a signal related to, for example, an average plaque level sensed at all locations. Alternatively, the signal 20 may be provided using plaque levels at only a subset of the locations of the one or more sensing elements 82. Regarding this feature, the same options as outlined above with respect to fig. 6 may be applied. For brevity, this is not repeated here.

In some examples, as in the example cleanliness level sensor outlined above, the signal from the sensor unit may be utilized by a controller of the oral care device to trigger deactivation of an active oral care component (e.g., cleaning component) to end an operational session (e.g., cleaning session). This may include stopping oscillation of bristles of an oral cleaning device, such as a mouthpiece device.

In further examples, the sensing unit 16 may only indirectly detect the cleanliness level of teeth (e.g., plaque). It may not be suitable for use with a firing, but may utilize another functional component of the oral care device.

For example, the oral care system may comprise a plurality of mechanical cleaning elements for mechanical engagement with surfaces in the oral cavity, and may further comprise a motion generator arranged to drive the oscillating motion of the cleaning elements during an operational session, the motion generator having a motor powered by the drive circuit. In this case, the sensor unit may be signal-coupled to the drive circuit, and wherein the output signal is representative of one or more electrical characteristics of the drive circuit.

As another example, the oral care device may include one or more cleaning elements upstanding from a surface of the oral care device, the one or more cleaning elements being arranged to be received within the oral cavity during use, and the cleaning elements being arranged to mechanically engage a surface of the teeth to perform a cleaning function. The sensor unit may comprise one or more piezoelectric elements mounted on or adjacent to one or more cleaning elements, for example disposed within a bristle field of the cleaning device.

Features will be summarized in terms of a main set of embodiments.

The set of embodiments is based on the concept of indirectly detecting physical degradation of certain components of the device, which results in a change in certain signal characteristics of the sensor unit output signal (i.e. characteristics of the empty signal or the calibration signal) during times when the device is not being used for oral care or cleaning functions and is outside the oral cavity.

In particular, according to one or more embodiments, the wear assessment performed by the processor 12 may include detecting a deviation of one or more defined characteristics of the output signal 20 (from the sensor unit) from a predefined baseline characteristic.

The one or more predefined criteria may include a threshold or minimum deviation of the defined signal characteristic from a reference or baseline characteristic.

The determination may be made outside of an operational session of the oral care device, i.e., when the oral care system is not physically interacting with the tooth surface. Thus, the signal in this case corresponds to a calibration signal or a null signal.

The baseline characteristic may refer to a particular set of one or more characteristics of the output signal measured at a minimum or zero wear point of the equipment component. This may be, for example, a signal characteristic measured in the factory (factory reference). These characteristics are selected to be progressively changing characteristics as the wear of the associated oral care components (e.g., cleaning elements) increases. This provides an indication of increased wear as the signal characteristic or pattern deviates from the baseline characteristic or pattern over time.

In a preferred embodiment, the sensor unit may be a component adapted to produce acoustic, optical or fluid emissions (as described above).

As one example, when bristles of an oral cleaning device, such as an mouthpiece cleaning device, begin to splay with wear, they can physically interfere with the operation of the sensor unit. For example, the bristles may open into or away from the emission path of the sensor unit using fluid, optical or acoustic emissions. This will change the signal characteristics of the emission interaction path and the sensor unit output signal.

For example, the sensor unit may be a cleanliness level sensor, such as a plaque detection sensor. However, in other examples, it may be a sensor module electrically coupled to a control circuit of a radiation-based interaction component having a different function, such as an element that generates radiation for a cleaning or processing function (e.g., RF cleaning radiation).

In this set of examples, the output signal 20 may give an indication of the interaction of the emission with the cleaning element en route to the tooth surface, i.e. an indication of the physical interference between the emission and the cleaning element.

Fig. 8-10 illustrate one example.

Fig. 8 illustrates a portion of an oral cavity cleaning device in which the cleaning elements (e.g., bristles) 66 of the oral cavity cleaning device are in a low or zero wear state (e.g., freshly produced). The sensor unit 16 in this example comprises a fluid emission based plaque sensor comprising a tube 56 (as described in detail above). The sensor unit is arranged such that when the bristles 66 are unworn, the physical interaction between the emissions produced by the sensor unit 16 and the cleaning elements is minimal. The signal characteristics associated with the emission (e.g., electrical characteristics of the light emission, or flow/pressure characteristics of the fluid emission) will have corresponding baseline or reference patterns or values.

As the cleaning elements begin to wear, they may begin to extend into the emission path. This is shown in fig. 9. This thus results in a change in the characteristics of the sensor unit output signal. In different examples, the flow of fluid emitted from tube 56 may be measured by a flow sensor, or the pressure of fluid emitted from tube 56 may be measured by a pressure sensor. In some examples, pressure or flow may be measured at a location along the length of the tube.

Fig. 10 (a) and 10 (b) schematically illustrate example flow 92 and pressure 94 signals of the sensor unit 16 as a function of time during a wear assessment test period. Fig. 10 (a) shows signals of the case when the components of the oral care device are in a low wear state or a new state. Fig. 10 (b) shows the signal when the component is in a high wear state and needs replacement.

When the operation session is no longer in progress, the processor 12 may be adapted to perform a wear assessment after each operation session. Preferably when the oral care device is not received within the user's mouth. The wear assessment may be performed less frequently, e.g. periodic wear analysis may be performed once daily or once weekly or once monthly (automatically or manually triggered by a user).

When performing wear assessment, the sensor unit 16 may be activated for a predetermined test period, and the output signal from the sensor unit is monitored during the test period. Fig. 10 (a) shows the flow 92 and pressure 94 signals during the test period with low wear. As shown, the flow and pressure are maintained at a uniform or relatively constant level throughout the test period. These levels are consistent with baseline or reference levels of these characteristics. Fig. 10 (b) shows the flow 92 and pressure 94 signals for higher wear conditions. As shown, the signal during the test period deviates from the baseline level, resulting in a decrease in flow and an increase in pressure due to the cleaning element striking the flow path from the tube 56. For example, the splayed bristles interfere with or even completely interrupt fluid flow, resulting in fluid back pressure (increased pressure) or reduced fluid flow due to the bristles interfering with the airflow path. In another embodiment or configuration, a change in the characteristics of the fluid emission path may result in a decrease in pressure and an increase in flow rate (e.g., bristles may bend away from the emission path). The deviation in the illustrated example exceeds a predefined deviation threshold 100.

Thus, in this example, the change in the fluid flow/pressure signature pattern (profile) through the bristle field 66 can be used as an indicator of device wear.

The wear assessment may include assessing relevant signal characteristics measured in a single test session or over multiple test sessions (e.g., spanning multiple days). For example, an average or other statistical characteristic of the correlated signal characteristic may be calculated relative to a value obtained over a predetermined period of time (e.g., one week or one month). For wear assessment, deviations of the average or statistical properties from a predefined baseline may be determined.

Thus, in this set of examples, the wear assessment is based on evaluating properties of interaction between oral care components (e.g., cleaning elements) of the device and the sensor unit 16.

Although in the examples shown in fig. 8 and 9, wear is detected based on the interaction between the cleaning element and the sensor unit, this represents just one possible example. For example, in accordance with one or more embodiments, the detected characteristic deviation of the sensor unit signal 20 may be caused, for example, by degradation of the sensor unit itself over time. One example includes, for example, damage to the tip of the tube 56 of the fluid-based plaque sensor. Another example may include damage to the optical output face of the optical sensing element 82. Another example may include mechanical wear of the motion generator (including one) detected based on observable drift of one or more signal characteristics of the drive circuit from a baseline level of the one or more signal characteristics.

As another example, the sensor unit 16 may be a light emission based sensor unit, such as an optical plaque detection sensor. Here, changes in light reflection, absorption, or scattering patterns of a single test session or multiple test sessions may be monitored, and deviations of one or more of these properties from a baseline or reference level may be used to indicate wear. The light reflection, absorption or scattering pattern may change due to degradation of the optical component itself or due to physical interference with the light output path caused by splaying of the bristle field. If the bristles or tufts are splayed, the light path may be interrupted or disturbed, for example. The light reflection, absorption or scattering pattern is measured using the electrical characteristics of the output signal from the optical sensing element.

In another example, the sensor unit 16 may be a sensor module arranged to sense a signal characteristic of a drive circuit of a motion generator of the oral care system (as described above). Here, the splaying of the cleaning elements may cause a change in the moment of inertia of the cleaning unit, which is typically reflected in a change in one or more signal characteristics of the drive circuit. Thus, the sensor unit may be adapted to detect relevant signal characteristics, and wherein wear of the cleaning element is detected based on these deviating from a reference or baseline level by a threshold amount.

According to one or more embodiments, an oral care system may include an oral care device including at least a portion for being received in an oral cavity of a user, wherein the oral care device includes a sensor unit.

The processor of the oral care system may be included by the oral care device such that both form a single unit. Alternatively, the processor may be external to the oral care device, for example it may be a processor belonging to a mobile computing device of the user and adapted to be in operative communication with the oral care device.

According to one or more embodiments, an oral care device may include an interface unit for being received in an oral cavity of a user.

The interface unit may be U-shaped and may include an upper tooth receiving channel and a lower tooth receiving channel with an occlusal surface disposed between the two channels forming a base for each of the channels. In further examples, it may alternatively be a J-section interface unit.

The interface unit may comprise a plurality of cleaning elements for rubbing against the tooth surface during an operational session. The cleaning elements may comprise cleaning filaments. The cleaning elements may be bristles or bristle tufts.

The oral care device may comprise a motion generator for driving the oscillating motion of the bristles over the tooth surfaces.

Embodiments according to another aspect of the present invention provide a method for detecting wear in an oral care device. The method comprises the following steps: an output signal is received from a sensor unit adapted to generate, in use, an output signal related to the cleaning efficacy of the oral cleaning function of the system. The method further includes determining one or more predefined characteristics of the signal. The method also includes performing a wear assessment including determining whether the one or more signal characteristics meet one or more predefined criteria, and generating a wear feedback signal based on a result of the assessment.

Examples according to another aspect of the invention provide a computer program product comprising computer program code, the computer program code being executable on a processor and the code being configured to cause the processor to perform a method according to any of the examples or embodiments outlined above or described below or according to any claim of the present application.

The embodiments of the invention described above employ a processor. The processor may be implemented in software and/or hardware in a variety of ways to perform the various functions required. A processor typically employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform the desired functions. A processor may be implemented as a combination of dedicated hardware for performing certain functions and one or more programmed microprocessors and associated circuits for performing other functions.

Examples of circuitry that may be employed in various embodiments of the present invention include, but are not limited to, conventional microprocessors, application Specific Integrated Circuits (ASICs), and Field Programmable Gate Arrays (FPGAs).

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

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The measures recited in mutually different dependent claims can be advantageously combined. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. If the term "adapted" is used in the claims or specification, it should be noted that the term "adapted" is intended to be equivalent to the term "configured to". Any reference signs in the claims shall not be construed as limiting the scope.

Claims (7)

1. An oral care system (14), comprising:

means (66, 72) for performing oral cleaning;

a sensor unit (16) adapted to generate a sensor signal (20) related to a cleanliness level when the oral cleaning device (66, 72) is in the oral cavity of a user; and is characterized in that

A processor (12) arranged to perform a wear assessment comprising monitoring a sensor signal (20) generated when the oral cleaning device (66, 72) is outside the oral cavity, generating a wear feedback signal (26) in dependence of a result of the wear assessment.

2. The system of claim 1, wherein the wear assessment comprises:

retrieving one or more baseline measurements of one or more predefined characteristics of the sensor signal (20) from a memory when the oral cleaning device (66, 72) is outside the oral cavity;

a deviation of the determined characteristic of the sensor signal (20) from a baseline measurement of the characteristic of the sensor signal (20) is detected.

3. The oral care system (14) according to any one of claims 1-2, wherein the sensor unit (16) is adapted to generate electromagnetic, acoustic or fluid emissions for contact or non-contact physical interaction with a surface in the oral cavity of the user, and wherein the sensor signal (20) depends on properties of the emissions interacting with the surface in the oral cavity.

4. The oral care system (14) according to any one of claims 1-3, wherein the sensor unit (16) comprises a plaque detection sensor.

5. The oral care system (14) according to claim 4, wherein the plaque detection sensor is adapted to generate a fluid flow that is driven onto or over a tooth surface, and wherein the sensor signal (20) is based on a measurement of a pressure or flow of the generated fluid flow.

6. A method for detecting wear in an oral care system (14), the method comprising:

receiving a sensor signal (20) from a sensor unit (16), the sensor signal being related to a level of cleanliness when an oral cleaning device (66, 72) of the oral care system (14) generates the sensor signal while in an oral cavity of a user;

the method is characterized in that:

performing a wear assessment comprising monitoring the sensor signal (20) generated when the oral cleaning device (66, 72) is outside the oral cavity, and

a wear feedback signal (26) is generated based on a result of the wear evaluation.

7. A computer program product comprising computer program code executable on a processor (12) and configured to cause the processor (12) to perform the method according to claim 6.