Oral care system wear detection

Abstract

Disclosed is a wear assessment for an oral care system 14 (e.g., an oral cleaning device). A sensor unit 16 of the oral care system is configured to provide a sensor signal related to the cleaning effectiveness of a cleaning function of the oral care system. The sensor unit 16 may be or be coupled to an element used during the performance of the oral care function of the device. The element may be, for example, a sensor for detecting intraoral cleaning progress or an element that drives intraoral cleaning or treatment operations. The sensor signal 20 is used to perform a wear assessment by monitoring a characteristic of the signal indicative of the progress of oral cleaning effectiveness (e.g., intraoral cleaning level) during an operation session and monitoring the length of time it takes for the session to reach a certain threshold of effectiveness. If this length of time is equal to or exceeds a certain threshold, this may be an indication that the associated element of the oral care system is worn out.

Description

[Technical Field]

[0001] The present invention relates to detecting wear and tear of components of an oral care system. [Background technology]

[0002] CN106510881A discloses a display method for determining whether a brush head needs to be replaced based on a user's actual tooth brushing usage, which includes the steps of obtaining the user's tooth brushing data, calculating a brush head loss value based on the user's tooth brushing data, and sending a display to the user that the brush head needs to be replaced if the brush head loss value is equal to or greater than a predetermined threshold.

[0003] In the field of oral care devices, it is beneficial to be able to detect wear of the device's associated operating elements, which can cause a decrease in the effectiveness of the oral care function. For example, oral cleaning devices can experience a decrease in cleaning effectiveness over time. This can be caused by physical wear, deformation, or deterioration of cleaning elements, such as bristles in a toothbrush. However, other types of oral care devices include, by way of non-limiting example, powered 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 elements used to provide oral care functions that can wear out over time, such as mechanical cleaning elements, such as bristles, nozzles, applicators, reflectors, or radiation output surfaces.

[0004] Mouthpiece units have been developed as one type of oral care device. These typically have an arc-shaped (e.g., U-shaped) structure with upper and lower tooth-receiving channels and usually contain curved bristles that follow the shape of the tooth-receiving channels. These allow for quick and thorough tooth cleaning while reducing the user's effort. Summary of the Invention [Problem to be solved by the invention]

[0005] As the mouthpiece wears out, performance deteriorates and it would be advantageous to have the ability to automatically advise the user when the entire mouthpiece or a particular element thereof (such as the brushing portion) should be replaced.

[0006] The same problem occurs in the field of toothbrushes and is mainly characterized by bristle spreading.

[0007] There is a general need for developments in the area of ​​wear detection in oral care devices. [Means for solving the problem]

[0008] The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

[0009] According to an embodiment of the present invention, there is provided an oral care system comprising: a sensor unit configured to generate an output signal related to or indicative of the cleaning effectiveness of the oral cleaning function of the system; a processor, the processor comprising: receiving an output signal from the sensor unit; determining one or more predetermined characteristics of said signal; and The system is configured to perform a wear assessment, including determining whether one or more signal characteristics meet one or more predetermined criteria, and generate a wear feedback signal based on the results of the assessment.

[0010] Embodiments of the present invention are based on determining wear and tear by utilizing the output of a sensor unit or module configured to provide a direct or indirect indication of the cleaning effectiveness of the cleaning mechanism of the oral care system, which can be, for example, a cleaning level sensor or a module that detects operational characteristics of the cleaning mechanism of the device (such as drive signal characteristics of a vibratory motion generator).

[0011] The wear feedback signal is a wear indicator signal that indicates that the wear of the cleaning element (eg, bristles) has exceeded a certain threshold.

[0012] The present invention is based on detecting wear through monitoring a characteristic of a signal indicative of the progress of oral cleaning effectiveness (e.g., the level of cleaning in the oral cavity) during an operating session, and monitoring the length of time it takes for effectiveness to reach a certain threshold in a session, which, if the length of time exceeds a second threshold, can be an indirect indication that the relevant element of the oral care device is wearing out.

[0013] The sensor can determine the cleaning level or its (time) derivative, e.g., cleaning rate. When the cleaning level is determined, the time it takes to achieve a first threshold cleaning level is monitored. When the cleaning rate is determined, the time it takes for the cleaning rate to fall below a first threshold level, indicating that no further meaningful improvement in cleaning is possible, is monitored.

[0014] According to an embodiment, the determination of one or more predetermined signal characteristics can be performed during or after a given operating session, said signal characteristics having a duration of time from the start of said operating session during which the output signal of said sensor unit remains below a predetermined first threshold.

[0015] An operating session may refer to when the oral care device is operating in a cleaning mode or a treatment mode, which may correspond to a time during which an operating or functional element is active to perform an oral care (e.g., cleaning) function.

[0016] The one or more predetermined criteria applied in the wear-out assessment may, in some examples, include a second threshold related to the duration measured in one or more operating sessions. This (time) threshold may be applied to the duration measured in one operating session or to the duration recorded over multiple sessions, e.g., an average of multiple sessions.

[0017] As oral care function deteriorates due to wear, it takes longer to reach a certain level of cleaning effectiveness during a session, and detecting when this time exceeds a second threshold therefore provides an indirect indication of the threshold level of wear.

[0018] The second threshold may be fixed, or the second threshold may be dynamically set before each wear-out assessment. For example, it may be set based on duration values ​​determined during one or more past operating sessions. For example, the threshold may be set to detect a certain threshold change in duration between subsequent sessions.

[0019] Exceeding a threshold may mean being above a certain threshold or being below a certain threshold.

[0020] According to one or more embodiments, the sensor unit may be configured to generate electromagnetic (e.g. optical), acoustic or fluid emissions for contact or non-contact physical interaction with surfaces in the user's oral cavity, the output signal depending on the characteristics of the interaction of the emissions with surfaces in the oral cavity, such as teeth, gums or any other (biological) material surfaces.

[0021] In this set of embodiments, the sensor unit may be, by way of example, a sensor for detecting the level of tooth cleaning.

[0022] The output signal can be based on a measurement of one or more detected physical properties of the release after or during physical interaction with the oral cavity surface.

[0023] The signal in this case can be used to give an indication of cleaning level or plaque level.

[0024] In a further series of examples, the sensor unit may include or be electrically coupled to a motion generator that drives vibrational motion of one or more operating elements, e.g., cleaning elements, of an oral care device that is already adapted to perform an oral care function.

[0025] According to one or more embodiments, the sensor unit may include a cleaning level sensor configured for contact or non-contact physical interaction with the oral surface to detect the level of cleaning of the tooth surface, said output signal being indicative of the level of cleaning.

[0026] The output signal in this case may be an output signal generated by a sensor.

[0027] As one set of examples, if the duration it takes for the cleaning level to exceed a predetermined threshold exceeds a second threshold, this provides an indication that the cleaning element of the oral care device has exceeded a predetermined level or threshold of wear.

[0028] In some examples, the cleaning level sensor may be a plaque detection sensor.

[0029] According to one or more embodiments, the cleaning level sensor is a plaque detection sensor configured to generate a fluid flow to be driven onto or across the tooth surface, and the output signal is based on a measurement of the pressure or flow rate of the generated fluid flow.

[0030] The pressure or flow rate of the fluid (such as air) as it is driven in a stream onto or across a tooth surface provides an indication of plaque level, since the fluid flow pressure increases as the level of tooth cleaning increases. Plaque, especially (sticky) plaque, tends to provide some elastic absorption of the applied fluid pressure. The cleaner the tooth surface, the harder it becomes. This means that the measured fluid backpressure increases. Thus, the fluid flow pressure provides an inverse measure of the level of tooth surface cleaning.

[0031] According to one or more embodiments, an oral care system may include a mechanical cleaning element for mechanically engaging a surface in an oral cavity. The oral care system may further include a motion generator configured to drive a vibrational motion of the cleaning element during an operating session. The motion generator may include a motor driven by a drive circuit. The sensor unit in this case may be coupled to the drive circuit. The output signal is indicative of one or more electrical characteristics of the drive circuit.

[0032] Characteristics such as current or voltage of the drive circuit may fluctuate during operation of the teeth cleaning device. However, as the cleaning level increases, these characteristics may stabilize. This stabilization provides an indication of the cleaning level. Thus, the output signal of the sensor unit coupled to the drive circuit is related to or indicative of the cleaning effectiveness.

[0033] According to one or more embodiments, the determination of one or more signal characteristics may occur during or after each operating session, and the wear assessment is based on signal characteristics detected over multiple operating sessions.

[0034] For example, it can be based on an average of one or more signal characteristics over multiple sessions, such as an average of a predetermined number of recent operating sessions, or an average over a predetermined recent period (e.g., an average over a week).

[0035] This determination is performed for each operating session and the results can be stored in local or remote memory. The determination may in some instances be further utilized to provide an end-of-cleaning indicator, indicating that the mouth is sufficiently clean and the cleaning session can end. This can be used to generate a sensory feedback output to the user, or to automatically stop the active cleaning action of the device, for example, deactivating the vibration of the cleaning elements of the device.

[0036] Wear assessments can be done automatically after or during each activity session, or less frequently, such as every week or every two days.

[0037] According to one or more embodiments, an oral care system can include an oral care device having at least a portion for reception within a user's oral cavity, the oral care device including the sensor unit.

[0038] The processor may be included in the oral care device so that the two form a single unit. Alternatively, the processor may be external to the oral care device, for example it may be a processor of a mobile computing device belonging to a user and configured to operatively communicate with the oral care device.

[0039] According to one or more embodiments, the oral care device can include a mouthpiece unit for receipt within a user's oral cavity. The mouthpiece unit can be U-shaped and include upper and lower teeth-receiving channels with mating surfaces disposed between the two channels forming the bases of each of the channels.

[0040] The mouthpiece unit can include a plurality of cleaning elements that protrude into the tooth-receiving channel for mechanically engaging the tooth surfaces during an operating session. The cleaning elements may include cleaning filaments. The cleaning elements may be bristles or bristle tufts, or any other mechanical elements capable of applying force to the oral surface.

[0041] An embodiment according to a further aspect of the present invention provides a method for detecting wear in an oral care device. The method includes receiving an output signal from a sensor unit, the sensor unit configured to be used to generate an output signal related to or indicative of cleaning effectiveness of an oral cleaning function of the system. The method further includes determining one or more predetermined characteristics of the signal. The method further includes performing a wear assessment including determining whether the one or more signal characteristics meet one or more predetermined criteria, and generating a wear feedback signal based on a result of the assessment.

[0042] An embodiment according to a further aspect of the present invention provides a computer program comprising computer program code, the computer program code being executable on a processor, the code being configured to cause the processor to perform a method according to any example or embodiment outlined above or below, or according to any claim of the present application.

[0043] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a diagram outlining elements of an exemplary system including a processor in accordance with one or more embodiments of the present invention. [Figure 2] FIG. 10 illustrates an exemplary graph of the sensor unit output signal over an operating session versus the duration Δt for the signal to reach a predetermined threshold. [Figure 3] FIG. 10 illustrates an exemplary graph of change in duration Δt over multiple operating sessions versus an exemplary second threshold for duration. [Figure 4] FIG. 1 shows an example of a tube used in a fluid-based plaque detector. [Figure 5] FIG. 1 shows an example of a tube used in a fluid-based plaque detector. [Figure 6]FIG. 1 shows an example of a tube used in a fluid-based plaque detector. [Figure 7] FIG. 1 illustrates elements of an exemplary fluid-based plaque detector. [Figure 8] FIG. 1 illustrates an exemplary oral care device having a fluid-based plaque detector that includes multiple fluid outlet pipes. [Figure 9] FIG. 1 illustrates an exemplary oral care device including a light emission-based plaque sensor, where the sensor includes multiple light sensing elements. DETAILED DESCRIPTION OF THE INVENTION

[0045] For a better understanding of the present invention, and in order to show more clearly how it may be carried into effect, reference will now be made to the accompanying drawings, which are given by way of example only, in which:

[0046] The present invention will now be described with reference to the figures.

[0047] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are 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 devices, systems, and methods of the present invention will be better understood from the following description, appended claims, and accompanying drawings. It should be understood that the figures are schematic only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0048] The present invention provides a method and processor for performing a wear assessment of an oral care device (e.g., an oral cleaning device). An output signal is received from a sensor unit of the oral care device, which is adapted, during operation, to provide an output related to the cleaning effectiveness of a cleaning function of the oral care device. The sensor unit may be or be coupled to an element used during the performance of the oral care function of the device, such as a sensor for detecting cleaning progress within the oral cavity or an element that drives a cleaning or treatment action within the oral cavity. This signal is used to perform the wear assessment. As the relevant element used by the device for the oral care function wears out, characteristics of the signal may change in a predictable manner, which can be used to identify that a wear state has been reached.

[0049] In some examples, the output signal of the sensor unit can be based on the characteristics of a functional element included in the oral care device and activated during oral care operation. It is anticipated that the functional element may be an element used as part of the oral care device's normal oral care operation. Most oral care devices include at least one element that physically interacts with teeth or other oral surfaces, either through contact or non-contact. The inventors recognized that the signal characteristics representative of this physical interaction can be usefully utilized for the secondary purpose of determining wear on the device's elements. For example, if the device is an oral cleaning device, wear on the device's cleaning element can be detected. The cleaning element may include, for example, filaments or protrusions designed to scrape against the tooth surface for the cleaning function. However, in other examples, wear may be the wear on other elements. Generally, wear results in a decrease in the effectiveness of the oral care function provided by the device, such as a decrease in cleaning effectiveness resulting from mechanical deformation, spreading, wear, or deterioration of the cleaning element.

[0050] Embodiments of the present invention are applicable to a variety of different oral care devices that can be configured to perform, for example, oral cleaning and / or treatment functions.

[0051] One notable class of oral care devices is the automatic toothbrushing mouthpiece. These devices have a U-shaped cleaning section that includes cleaning elements, such as bristles, and are configured to be received in the oral cavity, with the upper and lower rows of teeth received in upper and lower tooth-receiving channels. The bristles project into the channels to provide a brushing function. This provides faster brushing times and is convenient for the user.

[0052] 1 illustrates generally the basic elements of an exemplary oral care system provided in accordance with one aspect of the present invention. The system includes a processor 12 configured to receive a signal 20 from a sensor unit 16. The sensor unit is included in an oral care device 14.

[0053] A further aspect of the present invention provides a processor 12 alone. The processor may include, for example, a communications module or input / output configured to operatively connect to the sensor unit 16 to receive the signal 20.

[0054] A further aspect of the present invention may provide an oral-care system including an oral-care device 14 (with a sensor unit) and a processor 12 operably coupled to the sensor unit 16 .

[0055] The processor 12 performs a wear-out assessment that includes determining one or more predetermined characteristics of the output signal 20 and determining whether the one or more signal characteristics meet one or more predetermined criteria. The processor is further adapted to generate a wear-out feedback signal 26 based on the results of the assessment. For example, the processor may generate the feedback signal only if the result of the wear-out assessment is positive (i.e., if wear-out is detected).

[0056] The sensor unit 16 can, in some cases, be adapted during operation to engage in contact or non-contact physical interaction 18 with the surfaces of the teeth 22 in the user's oral cavity (e.g., as shown in FIG. 1 ). The sensor unit, in some further examples, is signally coupled to a functional element that performs such contact or non-contact physical interaction 18 with the surfaces of the teeth 22. The output signal 20, in some examples, depends on the characteristics of the physical interaction. These are merely exemplary options, and other configurations are possible.

[0057] An example of a non-contact physical interaction is, for example, the use of acoustic or electromagnetic waves or emissions emitted from a sensor unit, the reflection of which is detected by the sensor unit. An example of a contact physical interaction is, for example, a piezoelectric sensor integrated into the distal end of a cleaning element configured to rub against a tooth surface. The piezoelectric sensor makes direct contact with the tooth. Other examples of contact physical interactions are a drive train mechanism that drives the physical movement of the cleaning element against the tooth surface, or a fluid sensor for detecting plaque. The output signal can be an electrical characteristic of an actuator drive circuit, which can vary based on the characteristics of the interaction between the cleaning element and the tooth surface.

[0058] References to an operating session in this disclosure may correspond to a period of time during which an oral care device is operating in a cleaning mode or a treatment mode. It may correspond to the time during which an operating or functional element is active to perform an oral care function. For example, it may correspond to the time during which a motion generator drives vibration of a cleaning element of an oral care device.

[0059] The feedback signal 26 may be a sensory output signal, such as a control signal for controlling a sensory output device to generate a sensory stimulus to communicate a positive outcome of the wear assessment to the user, which may include, by way of non-limiting example, a visual output, such as illuminating one or more lighting elements, an audio output, such as an alarm sound, or a haptic or tactile output, such as vibrations generated by a vibrator within the oral care device.

[0060] 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 every x number of operating sessions, or at regular time intervals, such as once a week, once a day, or once every two weeks.

[0061] There are many different options for the sensor unit, and in the following several different embodiments are described in more detail to help understand the range of possibilities encompassed by the broad inventive concept described above.

[0062] The present invention is based on detecting wear through monitoring a characteristic of a signal indicative of the progress of oral cleaning effectiveness (e.g., the level of cleaning in the oral cavity) during an operating session, and monitoring the length of time it takes for effectiveness to reach a certain threshold in a session. If the length of time exceeds a second threshold, this can be an indication that the relevant element of the oral care device is wearing out.

[0063] There are a variety of options for the sensor unit and the corresponding output signal.

[0064] Different embodiments are outlined in more detail below.

[0065] According to one set of embodiments, determining one or more predetermined characteristics of the output signal is performed during or after a given operating session of the oral care device. The determined characteristics of the output signal include the duration (Δt) that the signal remains below a first predetermined threshold from the start of the operating session. In other words, it is the length of time it takes for the output signal to reach said first predetermined threshold from the start of the operating session.

[0066] This is shown diagrammatically in FIG. 2, which shows a schematic graph of the output signal 20 (y-axis) as a function of time (x-axis). The output signal relates to real-time cleaning effectiveness. A first threshold is indicated by a horizontal dashed line 32. In the figure, the output signal is shown as increasing in a linear manner; however, in reality, it may follow a more chaotic pattern and generally a non-linear path. FIG. 2 shows the duration Δt between the start of an operating session and the point at which the signal 20 meets or exceeds the first threshold 32.

[0067] Thus, the signal characteristic derived in this group of embodiments is duration Δt. The wear-out assessment includes evaluating one or more predetermined criteria related to this duration Δt. By way of example, the predetermined criteria may be a second threshold related to the duration in one or more operating sessions. The second threshold may be related to the duration in any one operating session or related to the duration across multiple operating sessions, such as an average or other statistical characteristic derived from the duration across multiple sessions, a trend in the duration across multiple sessions, or a relative change in the duration from a number of previous sessions.

[0068] 3 shows schematically where the predetermined criterion used in the wear assessment relates to a second threshold 42 of the duration Δt measured in any one operating session. This is illustrated using a graph showing the duration Δt (y-axis) as a function of date (x-axis) for a series of operating sessions of the oral care device. A vertical line 44 indicates an operating session where the duration Δt exceeds the second threshold 42. When this occurs, the wear assessment applied by the processor 12 results in a positive result, and the processor is therefore configured to generate the feedback signal 26 based on this.

[0069] In connection with this family of embodiments, different options exist regarding the sensor unit 16 used and the nature of the output signal 20.

[0070] According to one advantageous set of embodiments, the sensor unit 16 may be a physical cleaning level sensor configured to detect the cleaning level of tooth surfaces in the mouth. It may be configured to do so continuously or repeatedly throughout an operating session of the oral care device. The duration Δt in this case corresponds to the duration required for the cleaning level or a parameter related thereto to reach a predetermined threshold. Thus, in this set of examples, the oral care device may be a cleaning function, e.g., an oral cleaning device for cleaning tooth surfaces. For example, it may be a toothbrush or a cleaning mouthpiece device (as described above). Thus, an operating session of the device may be an oral cleaning session.

[0071] The length of time it takes from the start of an operating session until a certain threshold level of tooth surface cleaning is reached provides an indication of the cleaning efficiency of the oral care device. This provides an indication of the wear state of the associated components of the oral care device that perform the cleaning function. As these wear out, cleaning efficiency decreases, meaning that a longer time is required to reach a predetermined level of tooth cleaning. In some examples, the device components whose wear is indirectly monitored in this manner may correspond to protruding cleaning elements of a device configured to be rubbed against tooth surfaces to mechanically clean them. The cleaning elements may be cleaning filaments, such as bristles. It is well known that wear of bristles leads to bristles spreading, which reduces cleaning efficiency. Generally, this performance degradation, once initiated, progresses steadily. Another example includes the nozzle of a powered oral flossing device. Wear of the device nozzle corresponds, for example, to the accumulation of limescale within the nozzle, which reduces cleaning efficiency. Similarly, the length of time it takes to reach a predetermined cleaning effectiveness threshold 32 provides an indication of reduced cleaning efficiency and, therefore, wear of the associated cleaning elements.

[0072] In some examples, the processor 12 may be configured to identify and remove outliers in the duration Δt based on one or more outlier detection criteria. For example, there may be certain instances where the duration to reach the cleaning level threshold 32 increases from time to time, such as when there is an abnormally high amount of plaque accumulation due to food or drink intake in the previous period, or when the interval between two consecutive cleaning sessions is longer than usual.

[0073] The processor 12 may identify the first type of outlier based on detecting whether the duration Δt drops to a lower level in activity sessions following an activity session in which a high Δt was measured. In another example, the processor may be configured to calculate a running baseline or trend of the duration Δt after each activity session and use the baseline or trend as the assessed value in the wear-out assessment instead of the raw Δt value.

[0074] Processor 12 may identify a second type of outlier based on keeping a log of the duration of activity sessions, which allows for the detection of activity sessions that occur at longer intervals than normal from previous sessions. This information can be used, for example, to identify and filter out Δt values ​​occurring during such sessions that follow intervals that exceed a certain threshold interval time.

[0075] However, it should be noted that the cleaning level sensor represents just one example that fits this set of embodiments. Another possible example includes a sensor module that measures an electrical characteristic (current, voltage, impedance, etc.) of the drive circuit of the actuator that drives the movement of the cleaning element. As the teeth are gradually cleaned, the electrical characteristic changes, and thus wear of the cleaning element can be related to the duration until a certain characteristic reaches a threshold level.

[0076] In embodiments where the sensor unit is a cleaning level sensor, it may be a plaque detection sensor.

[0077] In some examples, the cleaning level sensor used as sensor unit 16 may be a sensor used during normal cleaning operation of the device to detect when the end of the cleaning session has been reached. For example, the cleaning level sensor may be used to detect when a threshold cleaning level has been reached, meaning that the cleaning session may be terminated, for example, automatically. This may include, for example, stopping a motion generator driving the mechanical vibration of the cleaning element of the device. In some embodiments, a determination of the duration Δt may be made based on this detection of the end of the cleaning session.

[0078] The detected duration Δt of each cleaning session can be recorded or logged in local memory.

[0079] According to one or more embodiments, sensor unit 16 may be configured to generate an electromagnetic (e.g., optical), acoustic, or fluid emission for contact or non-contact physical interaction with a surface in the user's oral cavity, the signal being indicative of a characteristic of the emission's interaction with the surface.

[0080] The sensor unit 16 can be a cleaning level sensor that utilizes such emissions to sense the degree of cleaning of oral surfaces. In other examples, the sensor unit can be signally coupled to an additional functional element that generates emissions to perform a cleaning or treatment function, such as an oral irrigator or powered flosser that generates fluid emissions for a cleaning function, or an RF treatment device that uses RF emissions to treat the gums.

[0081] One exemplary sensor unit in the form of a cleaning level sensor that utilizes fluid release to sense real-time cleaning effectiveness is described below.

[0082] An example of this is shown diagrammatically in FIGS.

[0083] In this example, the sensor unit 16 is a plaque detection sensor configured to generate a fluid stream driven onto or across a tooth surface. The output signal is based on the fluid impinging on the tooth surface and a measurement of the pressure or flow of the generated fluid stream. The fluid may be air (or other gas) in some examples. The presence of plaque on a tooth surface makes the tooth more viscous (greater surface fluid elasticity). This effect results in a higher elastic absorption of fluid pressure by the surface when passing a fluid onto or across the tooth surface compared to a tooth surface without plaque, which results in a measurable decrease in fluid pressure compared to a clean tooth surface. Thus, this sensor can be used to sense the level of plaque on a tooth based on the pressure and / or flow characteristics of the fluid stream passing onto or across the tooth surface. As the tooth becomes increasingly clean (less plaque), the pressure will gradually increase (with a decrease in flow rate).

[0084] The fluid-based plaque sensor may include a tube 56 configured to protrude outward from the surface of the portion of the oral care device that is received in the oral cavity during operation. The distal end of the tube is an opening 58 that allows a stream of fluid 62 to flow from the end of the tube to interact with the tooth surface. The tube is positioned so that the end of the tube engages against the tooth surface during normal operation of the oral care device in the oral cavity. For example, as shown in FIG. 7, it can be integrated into the bristle field 66 of the device. As a result, when bristles are engaged with the tooth surface to clean the teeth, the opening 58 at the end of the tube is automatically engaged with the tooth surface as well.

[0085] The end of the tube 56 can be shaped to facilitate operative engagement of the fluid opening 58 with the tooth surface. For example, FIG. 5 shows an example in which the end of the tube features a recessed channel running diametrically across the distal surface of the tube. The opening 58 is located in a mid-region of the base of the recessed channel. This allows the upper side of the channel to operatively engage the tooth surface, providing an area for fluid engagement with the tooth that is larger and has a different shape (in this case, linear) than the size of the opening itself. FIG. 6 shows a further example in which the end of the tube is chamfered on two opposite sides of the tube opening 58, providing easy engagement of the opening 58 with the tooth surface even when the tube is engaged at an angle.

[0086] 7 , the plaque sensor of this example includes a sensing module 50 fluidly coupled to a tube 56, the tube being positioned to physically protrude from the surface of the oral care device. The sensor module includes a fluid flow generator 52 (preferably a flow generator) configured to provide a pressurized fluid flow through the length of the tube toward a distal end of the tube that includes an opening 58. The sensor module further includes a detector element 54 configured to sense the pressure or flow rate of the fluid flowing through the tube 56. The detector may be configured to sense fluid flow or pressure at a location between the flow generator and the proximal end of the tube 56; for example, it may sense one or both of these properties within a conduit extending between the flow generator and the proximal end of the tube 56.

[0087] The detector 54 can generate an output signal indicative of the sensed pressure or flow rate. Alternatively, it can generate an output signal indicative of the level of plaque on the teeth, which is determined by the detector based on the sensed fluid pressure or flow rate. The output signal from the detector can provide an input signal 20 to the processor for use in assessing wear.

[0088] By way of further illustration, examples of suitable fluid-based plaque detection sensors are described in detail in documents WO2014 / 097240, WO2014 / 097241 and WO2014 / 097031.

[0089] In an advantageous embodiment, the plaque sensor has multiple tubes 56, allowing plaque levels to be sensed at multiple different tooth surface locations. Plaque levels can be sensed at multiple locations simultaneously, or multiple tubes allow plaque levels to be sensed at one or multiple locations.

[0090] An example is shown diagrammatically in FIG. 8. This example depicts an oral care device in the form of a brushing mouthpiece device 72. The figure shows a plan view of the mouthpiece. The mouthpiece device has a U-shaped cleaning portion for reception in the oral cavity. The cleaning portion has upper and lower tooth-receiving channels. In FIG. 8, only the upper 74 tooth-receiving channel is shown. Protruding into the tooth-receiving channel from opposing walls defining the channel are opposing rows of bristles that form a first bristle field 68a and a second bristle field 68b. When a tooth is received in the groove, the bristle fields protrude to contact the tooth surface both buccally and lingually.

[0091] As shown, the mouthpiece includes a plaque sensing arrangement having a sensing module 50 fluidly coupled to a plurality of tubes 56 (based on the description outlined above). A fluid conduit or pipe 51 extends between the sensing module 50 and the tubes 56 to carry a fluid flow for plaque sensing. The tubes are arranged at a series of different spatial locations around the tooth-receiving channel to enable plaque detection in a plurality of different regions of the dentition received in the mouthpiece channel during operation. The plurality of tubes 56 may be fluidly connected in parallel or series to a flow generator 52 (not shown in FIG. 8 ) included in the sensor module 50.

[0092] A tube 56 at multiple locations can be used to sense plaque at multiple locations at once. The output signal 20 received by the processor 12 may be, for example, a signal related to the average plaque level sensed across all locations. Alternatively, the plaque level at just a subset of one or more locations of the tube 56 can be used to provide the signal 20.

[0093] As one advantageous example, the plaque sensor may be configured to utilize plaque sensor readings from the location on the tube 56 where, during one or more previous cleaning sessions, the sensed plaque level decreased most slowly over the course of the cleaning session, or where more plaque was sensed at the end of the cleaning session than at any other location. These locations correspond to areas that tend to accumulate the most plaque or are difficult to clean. This may be based, for example, on previously recorded data from previous cleaning sessions stored in the sensor or processor 12 or in the oral cleaning device's local memory. By using the specific sensing locations where plaque removal was sensed to be slower or less effective, this ensures that when monitoring the signal 20 to detect when the cleaning level has reached the predetermined threshold 32, the cleaning level has reached all parts of the mouth, including the areas sensed to be slowest or most difficult to clean.

[0094] In some instances where the mouthpiece unit is a custom-made mouthpiece, the sensing locations may be configured based on locations known by the dental professional to be spots that may accumulate more plaque or that may be difficult to clean.

[0095] According to one or more further embodiments, the sensor unit 16 can take the form of a cleaning level sensor that detects plaque levels using light (or other electromagnetic) emissions. In particular, the plaque level sensor can include one or more light sources configured to generate a light output that is received at the tooth surface during use of the oral care device. The sensor unit can further include a light (or other EM) sensing element configured to sense reflections of light (or other EM) emissions returning from the tooth. Based on the characteristics of the reflected light signal, the plaque level can be sensed. For example, a plaque-covered tooth surface has different light scattering properties compared to a clean tooth surface, and may also have different fluorescence properties. These different properties detectably affect the optical properties of the reflected light signal relative to a light source signal fixed with respect to these properties. This allows the plaque level on the tooth to be sensed.

[0096] Examples of optical plaque detectors suitable for use in accordance with embodiments of the present invention are described in WO2014 / 097135, WO2014 / 097045 or WO2015 / 056197.

[0097] In an advantageous example, the oral care device includes a plurality of plaque sensing elements 82, each having a light source that generates an optical emission, and an optical sensing element that senses reflection of the emission from the tooth surface. The plaque sensing elements can be operably coupled to an optical sensor module 80 configured to generate a sensor output indicative of an associated optical characteristic of the sensed reflected wave or indicative of plaque level. This output signal can be used to perform wear assessment.

[0098] Figure 9 shows one exemplary oral care device including multiple plaque sensing elements 82 connected to an optical sensing module 80. The device is in the form of a brushing mouthpiece device 72. Other elements of the mouthpiece are the same as those depicted in Figure 8 above.

[0099] The multiple plaque sensing elements 82 are arranged at a series of different spatial locations around the mouthpiece tooth-receiving channel 74, allowing for detection of plaque in multiple different regions of the dentition received in the mouthpiece channel. The multiple plaque sensing elements 82 may be connected in parallel or series to the light-sensing module 80. The sensing elements may be electrically connected. Alternatively, in some examples, the light source included in each sensing element 82 may be optically supplied by a light generator within the sensor module 80. The sensing elements 82 are optically coupled to the light-sensing module 80 via individual optical fibers 84.

[0100] Plaque sensing elements 82 at multiple locations can be used to sense plaque at multiple locations at once. The signal 20 received by processor 12 may be, for example, a signal related to the average plaque level sensed across all locations. Alternatively, the plaque level at just a subset of one or more locations of sensing elements 82 may be used to provide signal 20. In connection with this feature, the same options can be applied as outlined above in connection with FIG. 8. For the sake of brevity, further repetition will be avoided.

[0101] In some examples, similar to the exemplary cleaning level sensors outlined above, the signal from the sensor unit is utilized by the controller of the oral care device to trigger deactivation of an active oral care element (e.g., cleaning element), thereby ending an operating session (e.g., cleaning session), which may include ceasing vibration of the bristles of an oral cleaning device, such as a mouthpiece device.

[0102] In a further example, the sensing unit 16 may only indirectly detect the level of tooth cleaning (e.g., plaque) and may not be configured to use emissions but may utilize another functional element of the oral care device.

[0103] By way of example, the oral care system can include a plurality of mechanical cleaning elements for mechanically engaging surfaces within the oral cavity, and further include a motion generator configured to drive oscillatory motion of the cleaning elements during an operating session, the motion generator having a motor powered by a drive circuit, the sensor unit in this case being signal-communicatively coupled to the drive circuit, and the output signal indicative of one or more electrical characteristics of the drive circuit.

[0104] In particular, characteristics such as the current or voltage of the drive circuit may fluctuate during operation of the teeth cleaning device. For example, the current or voltage may be superimposed by transient cleaning-related signal components. However, as the cleaning level increases, these characteristics may stabilize (due to changes in tooth surface characteristics). This stabilization provides an indication of an increasing cleaning level. Thus, here, the one or more predetermined characteristics of signal 20 determined by processor 12 may be the stability of one or more electrical characteristics of the signal, such as the signal amplitude relative to a baseline, a different measure of signal variability as a function of time (e.g., signal-to-noise ratio), or signal frequency (e.g., obtained from fast Fourier transform FFT analysis). The duration Δt calculated by the processor may represent the time required for a measure of signal variability to fall below a certain threshold or the time required for a measure of signal stability to rise above a certain threshold.

[0105] According to a further example, the oral care device includes one or more cleaning elements extending from a surface of the oral care device configured to be received in the oral cavity during use, the cleaning elements configured to mechanically engage tooth surfaces to perform a cleaning function. The sensor unit may, for example, include one or more piezoelectric elements set within the bristle field of the cleaning device, attached to the one or more cleaning elements, or attached adjacent to the one or more cleaning elements. In this example, changes in the mechanical movement characteristics of the bristles of the oral cleaning device are monitored during an operating session, and the detected changes in the movement characteristics can be used to indirectly detect cleaning progress. As the tooth surface becomes cleaner, the friction characteristics of the tooth surface change (i.e., the teeth become smoother), thereby changing the movement characteristics of the bristles over the tooth surface. In particular, characteristics such as the vibration frequency or amplitude of the bristles can change as the teeth become cleaner. For example, it is expected that the brushing amplitude will increase as plaque is removed. In either case, there will be a stabilization of such characteristics as the mouth becomes cleaner. This stabilization can be used as an indirect measure of the level of cleaning. The signal characteristic calculated by the processor may be a signal indicative of the stability or variability of the signal received from one or more piezoelectric elements over time during an operating session. The duration Δt determined by the processor 12 may correspond to the time it takes for the signal stability to exceed a predetermined threshold or the time it takes for the signal variability to fall below a predetermined threshold.

[0106] According to one or more examples, one or more signal characteristics determined by the processor 12 in the wear assessment may relate to frictional characteristics of the tooth surface. More specifically, the processor may be configured to determine characteristics indicative of stick-slip motion of bristles on the tooth surface. Stick-slip occurs when two surfaces rub against each other when the coefficient of friction between the surfaces is sufficiently high to cause repeated transient sticking between the contact points of the two surfaces moving relative to each other. A high frequency of sticking events is an indication of high static friction between the surfaces. In the case of tooth cleaning, stick-slip is expected to decrease as the cleaning progresses because sticky plaque is removed through the cleaning. Such stick-slip motion can be detected, for example, by monitoring the movement pattern or characteristics of the cleaning elements, such as bristles. This can be detected, for example, using the electrical characteristics of the signal output from the piezoelectric (force) sensor described above, using the electrical characteristics of the drive circuit for the motion generator described above, or from acoustic analysis of the drive signal in the drive circuit for the motion generator.

[0107] According to one or more examples, the oral care device can include one or more triboelectric generating elements configured to harvest kinetic energy from bristle movement to generate an electric charge. The triboelectric elements can be configured, for example, to harvest kinetic energy associated with movement between a cleaning element and a tooth surface or movement between adjacent cleaning elements included in the cleaning device. The electrical signal generated by the triboelectric elements can be used as an output signal 20 provided to the processor 12. The processor can determine signal characteristics of the triboelectric generator signal. In this case, the triboelectric elements can form a sensor unit, or a sensing module electrically coupled to the output of the triboelectric elements can be used as the sensor unit.

[0108] As the tooth surface is cleaned, changes in the triboelectric charge characteristics occur, which are reflected in the electrical characteristics of the signal from the triboelectric element. In particular, characteristics such as triboelectric charge or voltage may change as the tooth is cleaned or as the cleaning element wears out (excessive spreading of fibers reduces the tribopotential due to less fiber-to-fiber contact). In all cases, there is a stabilization of such characteristics as the mouth is cleaned. The stability or variability of the triboelectric generator signal can be used as the signal characteristic calculated by the processor 12 to determine the duration Δt.

[0109] According to any of the above-described embodiments, the processor 12 may be configured to determine the duration Δt during each operating session. If the sensor unit 16 is a cleaning level sensor, such as a plaque detector, this provides a data set indicative of the change in the time required to clean the teeth to a predetermined level. According to one or more embodiments, this data set may be used for the health analysis function.

[0110] For example, it can be used to provide an indication of changes in the oral health or general health of a user. The processor 12 may be configured to perform the oral health assessment at regular intervals or upon receipt of a trigger signal, for example, from a user interface.

[0111] For example, the cleaning time Δt typically depends on the amount or thickness of plaque present on the teeth and the mechanical properties of the plaque. Thus, a long cleaning time can indicate thickening of the plaque. If this persists over an extended period of time, it can be an indication of a change in general health or lifestyle. For example, it can indicate an increase in sugar intake or a decrease in the plaque-inhibiting qualities of saliva (such as increased acidity). This may change the user's health risk profile. The information can be communicated to a dental professional or other medical professional, for example, via a remote data communication channel.

[0112] In a further example, a short cleaning duration can indicate weakened plaque, which may be the result of lifestyle changes (e.g., reduced sugar intake), but may also be the result of low calcium concentrations in saliva resulting from calcium deficiency.

[0113] Trends in the measured duration Δt are detected by processor 12 in a health assessment procedure and can be used to generate feedback for communication to the user and / or health professional regarding changes. For example, if a decline in health status is detected, an alert can be issued to the user.

[0114] To perform a health assessment procedure, it is necessary to separate changes to the cleaning duration Δt caused by health or lifestyle factors from changes due to the progressive wear of the components of the oral care device. Any of these factors can cause changes in the duration Δt over time. One way to do this is to use prior information about the expected rate of change in duration due to wear of the cleaning components. Any changes that occur more quickly and consistently can be assumed to be related to health or lifestyle factors rather than wear of the components.

[0115] For example, it may be known in advance that the cleaning elements of a device slowly deteriorate over a 3-6 month period. Thus, a significant change in cleaning duration within, say, a two-week period may be determined by processor 12 to be associated with a health or lifestyle factor. More generally, any change in duration that follows a different temporal pattern than would be expected due to element wear can be determined by processor 12 to be associated with a health or lifestyle factor.

[0116] The above embodiment is based on detecting the time it takes for a signal characteristic to reach a predetermined threshold 32, and the wear assessment involves determining when the duration meets one or more predetermined criteria.

[0117] By way of example, the sensor unit may be a cleaning level sensor, e.g., a plaque detection sensor, but in other examples it may also be a sensor module electrically coupled to the control circuitry of an emission-based interacting element with a different function, e.g., an element that generates emissions for a cleaning or treatment function, e.g., an RF cleaning emission element.

[0118] The wear-out assessment can include evaluating relevant signal characteristics measured in a single test session, or evaluating relevant signal characteristics measured in multiple test sessions, e.g., test sessions spanning multiple days. For example, a mean value or other statistical characteristic of the relevant signal characteristics can be calculated for values ​​obtained over a predetermined time period, such as a week or a month. Deviation of this mean value or statistical characteristic from a predetermined baseline can be determined to perform the wear-out assessment.

[0119] According to one or more embodiments, the oral care system can include an oral care device having at least a portion adapted to be received within a user's oral cavity, the oral care device including the sensor unit.

[0120] The processor of the oral care system may be included in the oral care device so that the two form a single unit. Alternatively, the processor may be external to the oral care device, for example, it may be a processor of a mobile computing device belonging to a user and configured to operatively communicate with the oral care device.

[0121] According to one or more embodiments, the oral care device can include a mouthpiece unit that is received within the user's oral cavity.

[0122] The mouthpiece unit may be U-shaped and include upper and lower tooth-receiving channels, with a mating surface disposed between the two channels forming the base of each of the channels, or alternatively, it may be a J-shaped partial mouthpiece unit, for example.

[0123] The mouthpiece unit may include a plurality of cleaning elements that rub against the tooth surface during an operating session. The cleaning elements may include cleaning filaments. The cleaning elements may be bristles or bristle tufts.

[0124] The oral care device may include a motion generator for driving the vibratory motion of the bristles on the tooth surface.

[0125] An embodiment according to a further aspect of the present invention provides a method for detecting wear in an oral care device, the method comprising receiving an output signal from a sensor unit, the sensor unit adapted in use to generate an output signal related to cleaning effectiveness of an oral cleaning function of the system, the method further comprising determining one or more predetermined characteristics of the signal, performing a wear assessment comprising determining whether the one or more signal characteristics meet one or more predetermined criteria, and generating a wear feedback signal based on results of the assessment.

[0126] An embodiment according to a further aspect of the present invention provides a computer program comprising computer program code, the computer program code being executable on a processor, the code being configured to cause the processor to perform a method according to any example or embodiment outlined above or below, or according to any claim of the present application.

[0127] The above-described embodiments of the present invention employ a processor. The processor can be implemented in various ways using software and / or hardware to perform the various functions required. A processor typically uses one or more microprocessors, which can be programmed using software (e.g., microcode) to perform the required functions. A processor can also be implemented as a combination of dedicated hardware to perform some functions and one or more programmed microprocessors and associated circuitry to perform other functions.

[0128] Examples of circuitry that may be employed in various embodiments of the present application include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0129] In various implementations, a processor may be associated with one or more storage media, such as volatile and non-volatile computer memory, including RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed by the one or more processors and / or controllers, perform the required functions. The various storage media may be fixed within the processor or controller, or may be transportable such that one or more programs stored thereon can be loaded into the processor.

[0130] 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 figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in a claim. Means recited in mutually different dependent claims may be advantageously combined. A computer program can be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium, provided together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless communication systems. It should be noted that when the term "adapted for" is used in the claims or the description, the term "adapted for" is intended to be equivalent to the term "configured for." Any reference signs in the claims should not be construed as limiting the scope of the invention.

Claims

1. An oral care system comprising: a means for performing oral hygiene on surfaces in the oral cavity; a sensor unit for generating a sensor signal related to the level of cleaning of said surface; a processor that performs a wear assessment on the cleaning element of the oral care system, including monitoring the length of time it takes for the sensor signal to reach a predetermined first threshold, and generates a wear feedback signal based on the results of the wear assessment.

2. 2. The oral care system of claim 1, wherein the sensor unit generates an electromagnetic, acoustic, or fluid emission for contact or non-contact physical interaction with a surface in the user's oral cavity, and the sensor signal depends on characteristics of the interaction of the electromagnetic, acoustic, or fluid emission with the surface in the oral cavity.

3. The oral care system according to claim 1 or 2, wherein the sensor unit includes a plaque detection sensor.

4. the plaque detection sensor generates a fluid flow that is driven onto or across a tooth surface; The oral care system of claim 3 , wherein the sensor signal is based on a measurement of a pressure or a flow rate of the generated fluid flow.

5. the oral care system having a mechanical cleaning element that mechanically engages the intraoral surface; the oral-care system includes a motion generator that drives an oscillatory motion of the cleaning element during an operating session, the motion generator having a motor powered by a drive circuit; The oral-care system of claim 1 , wherein the sensor unit is coupled to the drive circuit, and the sensor signal is based on one or more electrical characteristics of the drive circuit.

6. 6. The oral care system of claim 1, wherein determining one or more signal characteristics of the sensor signal is performed during or after each operating session, and the wear assessment is based on signal characteristics detected over multiple operating sessions.

7. 1. A method for detecting wastage in an oral care system, comprising: receiving a sensor signal from a sensor unit, the sensor signal relating to a level of cleaning of surfaces in the oral cavity cleaned by the oral-care system; performing a wear assessment on a cleaning element of the oral care system, the wear assessment comprising monitoring the length of time it takes for the sensor signal to reach a first predetermined threshold; and generating a wear feedback signal based on the results of the wear assessment.

8. A computer program comprising computer program code, said computer program code being executable on a processor, said computer program code causing the processor to perform the method of claim 7.

Images