Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
  • B26B19/00—Clippers or shavers operating with a plurality of cutting edges, e.g. hair clippers, dry shavers
  • B26B19/38—Details of, or accessories for, hair clippers, or dry shavers, e.g. housings, casings, grips, guards
  • B26B19/3873—Electric features; Charging; Computing devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
  • B26B19/00—Clippers or shavers operating with a plurality of cutting edges, e.g. hair clippers, dry shavers
  • B26B19/38—Details of, or accessories for, hair clippers, or dry shavers, e.g. housings, casings, grips, guards
  • B26B19/3873—Electric features; Charging; Computing devices
  • B26B19/388—Sensors; Control

Definitions

• This invention relates to the field of personal care devices, and in particular to the field of motorised personal care devices.
• Modern personal care devices often involve motorised or moving components.
• electric toothbrushes contain motor-driven vibrating brush heads, and electric shavers contain rotary driven razor blades.
• wear may occur to the components of the device associated with the motorised element. This may include the brush head of a toothbrush becoming worn down with repeated use, or springs within an actuator mechanism losing their stiffness.
• component wear may result in the operation of the device becoming sub-optimal and the personal care device no longer being able to fulfil its function of providing a personal care treatment to a user. There therefore may be a need for certain components of a personal care device to be replaced or repaired to ensure the device continues to provide a high quality treatment experience to the user.
• a component wear assessment system for a personal care device comprising a double-resonant actuator configured to drive vibration of a vibratory component of the personal care device.
• the component wear assessment system comprises: a data acquisition module configured to obtain motor stroke data of the double-resonant actuator, the motor stroke data describing a stroke value of a motor of the double-resonant actuator during operation of the personal care device; and a data analysis module configured to: determine, from the obtained motor stroke data, a cumulative measure of the stroke value of the motor of the double-resonant actuator over time; and determine an indicator of wear of a component of the personal care device based on the determined cumulative measure of the stroke value of the motor of the double resonant actuator.
• Proposed concepts thus aim to provide schemes, solutions, concepts, designs, methods, and systems pertaining to a component wear assessment system for a personal care device configured to determine an indicator of wear of a component of the personal care device.
• embodiments aim to provide a component wear assessment system suitable for a personal care device comprising a double-resonant actuator configured to drive vibration of a vibratory component of the personal care device.
• the component wear assessment system determines an indicator of wear of a component of the personal care device based on a cumulative measure of the stroke value of a motor of the double-resonant actuator over time.
• the system is configured to use a measure of the cumulative motor stroke of the double-resonant actuator of a personal care device as a surrogate measure for the wear of a given component of the device.
• Double-resonant actuators are a particular type of motor driven actuator that display inherent load stroke stability. Note that the stroke values discussed in this document refer to the maximum peak-to-peak angular displacement of vibration of a particular component.
• a double-resonant actuator may be used within a motorised personal care device to drive vibration of a vibratory component (this may be a treatment component of the device for example) which acts as a load to the motor of the double-resonant actuator.
• a double-resonant actuator is driven at certain frequencies, as the load on the motor of the actuator is increased (e.g., by increasing the force applied to the vibratory component), the stroke of the motor also increases due to the resonant processes within the actuator. This results in the impact of the increased damping caused by the increased load to be negated and therefore the stroke of the vibratory component remains stable even with variable loads.
• the inventors of this application therefore realised that for personal care devices comprising double-resonant actuators the stroke of the motor may be used as a metric of the load applied to the vibratory component. Therefore, by analysing the stroke value of the motor over time, information can be garnered about the level of use of the personal care device which may indicate the level of wear on one or more components of the personal care device.
• the proposed component wear assessment system therefore leverages a cumulative measure of the motor stroke of the double-resonant actuator of a personal care device to determine an indicator of the wear of a given component of the personal care device.
• the proposed component wear assessment system allows for automatic determination of the level of wear (i.e., the condition or repair) of a component of a motorised personal care device that comprises a double-resonant actuator. This is achieved by obtaining measurements of the stroke value of a motor of the double-resonant actuator and using this to determine a cumulative measure of the stroke value over time which may be used to determine an indication of the wear of the component.
• the proposed system is advantageous over previous systems in that it results in a reliable indicator of wear that is specific to a given personal care device.
• the proposed system may provide a device or user specific indication of component wear.
• the determined indicator of wear may be useful for determining whether components of a personal care device are no longer fit for purpose and may need replacing.
• One key application of the proposed system is an automatic brush head replacement trigger for a powered toothbrush.
• an improved component wear assessment system for a personal care device may be supported by the proposed concept(s).
• the indicator of wear of the component of the personal care device may comprise at least one of: an indication of whether the component needs to be replaced; a prediction of a length of time until the component needs to be replaced; and a value describing the condition of the component.
• the proposed method may therefore result in a notification to the user when the component needs to be replaced which allows for continued optimal performance of the personal care device.
• Some components may not be replaceable and hence for these a value describing the condition of the component may be more appropriate whilst still providing information to a user which may be beneficial in optimising the operation of the personal care device.
• determining the indicator of wear of the component of the personal care device may comprise: comparing the cumulative measure of the stroke value of the motor to a predetermined threshold value; and determining the indicator of wear of the component of the personal care device based on this comparison.
• a predetermined threshold allows for known information about the relationship between the stroke value of the motor, the load applied to the vibratory component and the consequent expected wear to the component of the personal care device to be incorporated into the determination of the indicator of wear of the component.
• the motor stroke data may comprise a plurality of time-dependent stroke values of the motor of the double-resonant actuator.
• the motor stroke data may therefore contain information about how the motor stroke of the double-resonant actuator varies over time with continued use of the personal care device. Basing a determination of wear of a component of the personal care device on such data therefore allows for a more reliable and accurate assessment.
• the cumulative measure of the stroke value comprises at least one of: a cumulative sum value; an average stoke value; a maximum stroke value; a minimum stroke value; and a variation in the stroke value.
• various different statistical values describing the stroke value of the motor of the double-resonant actuator over time may be used in the determination of the indicator of wear of a component.
• Each of these different values may have certain benefits in providing different information about the level of use of the device.
• the variation may aid with an understanding of how the stroke value of the motor is likely to vary at future times and the maximum stroke value may be useful as it is indicative of the maximum load applied to the system which may directly relate to the wear.
• determining the indicator of wear of the component of the personal care device may comprise: analysing the motor stroke data with a trend analysis model to determine a trend in the motor stroke data; and determining a prediction of a length of time until the component needs to be replaced based on the determined trend in the motor stroke data and the cumulative measure of the stroke value.
• the motor stroke data contains information about the stroke value of the motor over a period of time, this information may be used to predict future values of the stroke of the motor and thereby predict future wear to the component.
• the present invention allows not only for determination of the current condition of the component but also a prediction as to the condition of the component at a future point in time.
• determining the indicator of wear of the component of the personal care device may comprise: categorising use of the personal care device based on the cumulative measure of the stroke value; and determining the indicator of wear of the component based on the determined use category of the device. Categorisation of the use of a personal care device (or of the user of the device) provides a simple and efficient way of estimating different levels of wear that may have occurred to the component from the motor stroke data.
• the data acquisition module may be further configured to obtain force data of the personal care device, the force data describing a force applied to the vibrating component during operation of the personal care device
• the data analysis module may be further configured to: determine, from the obtained force data, a cumulative measure of the force applied to the vibrating component over time; and determine an indicator of wear of a component of the personal care device based on the determined cumulative measure of the stroke value and the cumulative measure of the force.
• Many motorised personal care devices are equipped with pressure sensors that measure how much force is applied to a treatment component of the device during use and therefore how much load is being applied to the motor. Using this force data in combination with the motor stroke data may improve the accuracy of the determination of the wear of the component.
• the data acquisition module may be further configured to obtain stroke data of the vibratory component, the stroke data of the vibratory component describing a stroke value of the vibratory component during operation of the personal care device.
• the data analysis module may by further configured to determine from the obtained stroke data of the vibratory component, a cumulative measure of the stroke value of the vibratory component over time; and determine an indicator of wear of a component of the personal care device based on the determined cumulative measures of the stroke value of the vibratory component and the stroke value of the motor of the double resonant actuator.
• double-resonant actuators exhibit load stroke stability when the motor is driven at certain frequencies, in some scenarios the relationship between the motor stroke and the load applied to the vibratory component may be more complex. Therefore, it may be beneficial to gather information about both the stroke of the motor and the stroke of the vibratory component the motor is driving to obtain the most accurate indicator of the wear of the component.
• determining the indicator of wear of the component of the personal care device may comprise: comparing the cumulative measure of the stroke value of the motor to a first threshold value; comparing the cumulative measure of the force applied to the vibrating component to a second threshold value; comparing the cumulative measure of the stroke value of the vibratory component to a third threshold value; and determining the indicator of wear of the component based on these comparisons.
• Using the three cumulative measures together in this way may result in a more reliable indicator of the wear of the component as it permits a full picture of the load applied to the double-resonant actuator over time.
• the component of the personal care device may comprise at least one of: a brushing component; a head component; a motor of the double-resonant actuator; a spring of the double-resonant actuator; and the double resonant actuator.
• the proposed system may advantageously permit a determination of the level of wear of any of the components of the personal care device associated with the mechanism of the double-resonant actuator.
• the component of the personal care device may comprise the vibratory component of the personal care device.
• the vibratory component is likely to be the component most easily replaceable and the component most worn down from day-to-day use of the device and it is therefore particularly beneficial to be able to determine the wear of this component.
• a personal care device comprising: a vibratory component; a double-resonant actuator configured to drive the vibratory component to vibrate; and the component wear assessment system of any of the embodiments discussed above.
• the personal care device may be an oral care device; a skin treatment device; or a hair removal device.
• the component wear assessment system may be suitable for any known or novel personal care device.
• the personal care device may further comprise a force sensor configured to measure the force applied to the vibratory component during operation of the personal care device. This allows for force data gathered to be used by the component wear assessment system for a more accurate determination of the wear of the component of the personal care device.
• a component wear assessment system and personal care device comprising the same which is configured to determine an indicator of the wear of a component of the personal care device based on a cumulative measure of the motor stroke of a double-resonant actuator of the personal care device.
• Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to a component wear assessment system for a motorised personal care device, the personal care device comprising a double-resonant actuator.
• a number of possible solutions may be implemented separately or jointly. That is, although these possible solutions may be described below separately, two or more of these possible solutions may be implemented in one combination or another.
• Embodiments of the invention aim to provide a component wear assessment system for a personal care device configured to determine an indicator of wear of a component of the personal care device based on a cumulative measure of the stroke of a motor of the personal care device over time.
• Double-resonant actuators may commonly be used in personal care devices to drive vibration of a vibratory component.
• the vibratory component may be a treatment component and the vibration may be used to provide a personal care treatment to a user.
• the vibratory component acts as a load to the actuating mechanism.
• the load may be increased when a force is applied to the vibratory component to act against the driving mechanism of the actuator.
• double-resonant actuators display stroke stability of the vibratory component. In other words, the stroke of the vibratory component is independent of the load acting on the motor i.e., independent of the damping force applied to the vibratory component.
• the stroke value of its motor may be used as a surrogate measure for the load on the double-resonant actuator of a personal care device. Therefore, by determining a cumulative measure of the stroke of the motor over time, information about the wear of the various components of the personal care device may be determined. This may be a more reliable and accurate way of determining an indicator of wear of the component than the fixed lifetime calculations of traditional systems.
• Proposed concepts thus aim to provide a component wear assessment system configured to obtain motor stroke data of a double resonant actuator within a personal care device, determine a cumulative measure of the motor stroke of the double resonant actuator over time from the motor stroke data, and then use this to determine an indicator of wear of a component of the personal care device.
• Fig. 1 there is depicted a simplified block diagram of a component wear assessment system 100 for a personal care device, the personal care device comprising a double-resonant actuator configured to drive vibration of a vibratory component of the personal care device, according to a proposed embodiment.
• the component wear assessment system 100 comprises a data acquisition module 110 and a data analysis module 120.
• the data acquisition module 110 is configured to obtain motor stroke data 115 of the double-resonant actuator, the motor stroke data describing a stroke value of a motor of the double-resonant actuator during operation of the personal care device.
• the motor stroke data comprises a plurality of time-dependent stroke values of the motor of the double-resonant actuator. Further, in this example, the plurality of time-dependent stroke values describe the stroke value of the motor over the lifetime of a specific component of the personal care device.
• the double-resonant actuator drives vibration of the vibratory component and the stoke (i.e., amplitude) of the vibration of the motor is measured along with a time stamp associated with the measurement.
• the stroke values of the motor may be measured by a stroke sensor configured to sense the movement of the motor, or may be obtained by the motor itself, and then sent to the data acquisition module 110.
• the data acquisition module may itself comprise a stroke sensor, configured in use to measure the stroke of the motor of the double resonant actuator of the personal care device. Suitable motion and or position sensors and mechanisms for sending and receiving data from such sensors are known in the art.
• each stroke value within the motor stroke data has an associated time stamp.
• the time stamp may refer to the absolute time at which the measurement was taken or may describe the total cumulative use time of the personal care device at the time of the measurement.
• the data analysis module 120 is configured to determine from the motor stroke data a cumulative measure of the stroke value of the motor of the double-resonant actuator over time. In this exemplary embodiment, this comprises taking a cumulative sum of the time-dependent stroke values of the motor stroke data describing the cumulative stroke of the motor across the total time period described within the motor stroke data. The data analysis module is then configured to determine an indicator of wear of a component of the personal care device based on the determined cumulative measure of the stroke value.
• the component of the personal care device in this example is the vibratory component of the personal care device, and the indicator of wear is a value describing whether the vibratory component needs to be replaced.
• the component wear assessment system 100 may provide an accurate and reliable way of determining when the driven component of a personal care device (e.g. brush head of a toothbrush, or other treatment component of a personal care device which may experience significant wear during the lifetime of a personal care device) needs to be replaced.
• a personal care device e.g. brush head of a toothbrush, or other treatment component of a personal care device which may experience significant wear during the lifetime of a personal care device
• the data analysis module determines the indicator of wear of the component by comparing the cumulative measure of the stroke value of the motor to a predetermined threshold value and determining the indicator of wear of the component of the personal care device based on this comparison. For example, it may be determined that the component needs replacing if the cumulative sum of the motor stroke values is above a certain predetermined threshold value and determined that that the component does not need replacing if the cumulative sum of the motor stroke values is below this threshold value.
• the predetermined threshold value may be predetermined based on knowledge of the relationship between the wear of the specific component being assessed and the load on the double-resonant actuator. Additionally, information about the link between the stroke value of the motor and the load on the double-resonant actuator for the specific personal care device the component wear assessment system is configured for may be incorporated into the predetermined threshold.
• the indicator of wear comprises an indication of whether a component of the personal care device needs to be replaced, in other embodiments this may not be the case.
• the indicator of wear may instead comprise a prediction of the length of time until the component will need to be replaced and thus the system may be configured to provide greater level of guidance to the user than a binary determination of whether the component needs to be replaced or not.
• the indicator of wear may be a quantitative or qualitative value describing the condition of the component.
• the cumulative measure of the stroke value may not be a cumulative sum of the stroke values of the motor stroke data but may instead describe at least one of: an average stroke value of the motor over time; a maximum stroke value; a minimum stroke value; and a variation in the stroke value.
• various different measures of the stroke value of the motor may be used so long as they capture information about the use of the device over time rather than an instantaneous measure of the motor stroke.
• the system is configured to determine an indicator of wear of the vibratory component this need not be the case in other embodiments.
• the component wear assessment system may be configured to determine the wear of any suitable component within the personal care device that may be worn down over time.
• the component may be at least one of: a brushing component; a head component; a motor of the double-resonant actuator; a spring of the double resonant actuator; and the double resonant actuator.
• the system may be configured to determine wear to the actuating system itself.
• the component wear assessment system 100 is configured to obtain time-dependent stroke values of the motor over the lifetime of the component of the personal care device for which the system 100 is configured to determine an indicator of wear.
• other component wear assessment systems may be configured to obtain different forms of motor stroke data.
• the motor stroke data may comprise a plurality of stroke values of the motor that are not time stamped and determining a cumulative measure of the stroke value of the motor over time may involve simply analysing the distribution of the plurality of stoke values.
• the motor stroke data may not relate to the entire lifetime of the personal care device but may refer only to specific periods of use within the device's lifetime.
• the component wear assessment system may be associated with a memory capable of storing data.
• the data acquisition module may obtain a measurement of the current stroke value of the motor of the double-resonant actuator of the personal care device.
• the data acquisition module is then further configured to obtain a historic cumulative sum stroke value from the memory associated with the component wear assessment system.
• the data acquisition module then passes measured current stroke value of the motor along with the historic cumulative stroke value to the data analysis module.
• the data analysis module is then configured to determine a cumulative measure of the stroke value of the motor by adding the measured current stroke value to the historic cumulative stroke value and determine an indicator of wear of the component based on this cumulative measure.
• the newly determined cumulative measure of the stroke value may replace the historic cumulative sum stroke value within the memory.
• the configuration of the component wear assessment system in this way may be advantageous in that it is not necessary to store extensive motor stroke data describing the full lifetime of the component, but instead involves storing and processing single stroke values at a time.
• An alternative to this configuration may involve storing a counter value alongside the historic cumulative sum stroke value which describes the total number of motor stroke measurements that have been obtained over time. This may enable quantities such as a cumulative average to be determined easily and without the need for storing extensive historic stroke values of the motor.
• the data analysis module and the data acquisition module may be formed of conventional processor components. Although discussed as distinct modules in this document, the data analysis module and the data acquisition module may comprise a single processor.
• the system makes use of processors to perform the data processing.
• the processor can be implemented in numerous ways, with software and/or hardware, to perform the various functions required.
• the processor typically employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform the required functions.
• the processor may 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.
• circuitry examples include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).
• ASICs application specific integrated circuits
• FPGAs field-programmable gate arrays
• 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 media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform the required functions.
• Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor.
• FIG. 2 there is depicted a schematic diagram of a personal care device 200 comprising a double resonant actuator according to a proposed embodiment.
• the personal care device 200 is an electric toothbrush device comprising a brush head element 210 which is driven to vibrate during use of the device by a double-resonant actuator 250.
• This double-resonant actuator comprises a motor 220 which is driven electromagnetically to vibrate at a certain frequency and with a certain stroke value (i.e., amplitude).
• the motor is connected to the brush head element by a configuration of three torsional springs: a front spring 245, a rear spring 240 and a coupling spring 230.
• the coupling spring is connected at one end to the motor 220, and at the other end to the brush head element 210.
• the rear spring connects the motor 220 to a frame structure 260
• the front spring connects the frame structure 260 to the brush head element 210.
• the configuration of the double-resonant actuator 250 may be that described in US patent number US 10813733B2 for example.
• the motor 220 During use of the personal care device 200, the motor 220 generates a torque. Due to the interaction of the springs 230, 240, and 245, this torque results in motion of the brush head element 210.
• a magnet (not shown) is present on the motor 220 and motion of this magnet (due to the motion of the motor itself) results in a back and forth rocking motion of an elastic structure comprising the three springs 230, 240, and 245. This motion (angular vibration) is then transferred to the brush head element.
• This configuration of springs within the double resonant actuator results in the double-resonant actuator displaying an inherent brush head stroke stability.
• resonance effects within the actuator result in the motor naturally increasing its stroke when the load applied to the motor (i.e., the damping force applied to the brush head element) increases.
• This increase in the motor stroke means that in any drop in the amplitude of the vibration of the brush head element that may have occurred due to the increase in load will be minimized. Since the stroke of the motor increases with increasing load in this way, the motor stroke of the double resonant actuator is an effective indicator of the load on the personal care device containing such an actuator and thus a useful indicator of the level of use of the personal care device.
• double-resonant actuator mechanism is shown in Fig. 2 in the context of an electrically driven toothbrush, it will be understood by the skilled person that the same principles apply to any personal care devices in which motion is driven using a double-resonant actuator.
• FIG. 3 there is depicted a simplified flow diagram of a method 300 for determining an indicator of wear of a component of a personal care device.
• a component wear assessment system of the present invention may be configured to carry out the method 300.
• the method commences with a step 310 of obtaining, by a data acquisition module of the component wear assessment system, motor stroke data.
• the motor stroke data describes a stroke value of a motor of a double-resonant actuator of the personal care device.
• the method then proceeds to a step 320 comprising determining, by a data analysis component of the component wear assessment system, from the obtained motor stroke data, a cumulative measure of the stroke value of the motor. This may be any of the suitable cumulative measures of the stroke value of the motor discussed above.
• the data analysis module is configured to determine in a step 330 an indicator of wear of a component.
• the step 330 comprises the sub-steps 332 and 334.
• Step 332 comprises categorising use of the personal care device based on the cumulative measure of the stroke value.
• Step 334 comprises determining the indicator of wear of the component based on the determined use category of the personal care device.
• the cumulative measure of the stroke value may be used to categorise the historic use of the personal care device into use categories such as "heavy use", "average use” and "light use”.
• the different use categories may then lead to different determinations of the indicator of wear.
• the different use categories may correspond to different expected lifetimes of the component and therefore lead to different determinations of the current condition of the component and different timescales for when the component needs to be replaced.
• a component of a personal care device that is categorised as "heavy use” may have a shorter expected lifetime than a component of a personal care device that has been categorised as "light use”. Use categorisation thus provides an efficient way of accounting for the variation in user operation of personal care devices.
• the method 300 may also be advantageous in that it requires fewer motor stroke data to be gathered compared to alternative embodiments.
• Use categorisation may be determined on a cumulative measure of the stroke value of the motor over a single or handful of use sessions of the personal care device for example. In alternative embodiments it may be necessary to obtain a cumulative measure of the stroke value of the motor over the entire lifetime of the device.
• Fig. 4 depicts a simplified flow diagram of another method 400 of determining an indicator of wear of a component of a personal care device comprising a double-resonant actuator according to another proposed embodiment.
• the steps 410 and 420 of the method 400 are similar to the steps 310 and 320 of the method 300 and therefore a discussion of these steps will not be repeated.
• the method 400 differs from the method 300 in that the step 430 of determining the indicator of wear of the component of the personal care device does not comprise the sub-steps 332 and 334 but instead comprises the alternative sub-steps 432 and 434.
• Step 432 comprises analysing the motor stroke data with a trend analysis model to determine a trend in the motor stroke data.
• Step 434 comprises determining a prediction of a length of time until the component needs to be replaced based on the determined trend in the motor stroke data and the cumulative measure of the stroke value.
• historic motor stroke data may be used to predict future wear that is likely to occur to the components of the personal care device.
• Fig. 5 depicts a simplified graph 500 of cumulative motor stroke against time used for trend analysis.
• the data acquisition module of the component wear assessment system of the present invention obtains motor stroke data describing the stroke value of the motor of the double-resonant actuator used to drive vibration of a vibratory component of a personal care device.
• the motor stroke data may comprise a series of stroke values of the motor at various times within the lifetime of a component of the personal care device.
• This motor stroke data may then be processed within the data analysis module of the system to determine a cumulative measure of the stroke value of the motor over time. This may comprise calculating at given points in time, the cumulative sum of the stroke of the motor over the current lifetime of the component.
• the cumulative motor stroke value (in degrees) may be plotted against time (in days) based on the gathered motor stroke data.
• Trend analysis may then be applied to the time-sequenced cumulative sum stroke values to determine a trend within the motor stroke data, this is shown by the solid line 510 on the graph 500.
• linear, polynomial or exponential fitting may be used to fit the discrete cumulative sum stroke values to a continuous trend.
• more advanced or complex trend analysis methods may be used to produce a more accurate analysis of the trend of the cumulative stroke of the motor over time.
• the determined trend may be extrapolated to future times in order to predict future development of the cumulative motor stroke value. This predicted trend is indicated by the dotted line 520 in Fig. 5 .
• a threshold cumulative motor stroke value may be determined with defines when the component has suffered a certain degree of wear such that it is no longer fit for purpose. This predetermined threshold value is indicated by the dashed line 530 on the graph 500.
• the predicted trend in the cumulative motor stroke value based on the trend analysis of the motor stroke value may then be used to determine at what point in time, or how long from the current time, the cumulative motor stroke value is expected to reach this predetermined threshold value and therefore at what point in time the component will need replacing.
• the principle of using trend analysis to predict future wear on the component of the personal care device is not restricted to embodiments of the present invention in which the cumulative measure of the stroke value of the motor comprises a cumulative sum.
• Trend analysis may be applied to any cumulative measures of the stroke value of the motor that contain information about how the stroke value of the motor evolves over time with use of the device.
• FIG. 6 there is depicted a simplified flow diagram of a method 600 for determining an indicator of wear of a component of a personal care device, the personal care device comprising a double-resonant actuator, according to another proposed embodiment. Any of the proposed component wear assessment systems discussed above may be configured to carry out the method 600.
• the method commences with a step 610 of obtaining motor stroke data, the motor stroke data describing the stroke value of a motor of the double resonant actuator. Once the motor stroke data has been obtained the method proceeds to a step 620 comprising determining, based on the motor stroke data a cumulative measure of the stroke value of the motor.
• the method 600 further comprises step 640 of obtaining force data of the personal care device, the force data describing a force applied to the vibratory component during operation of the personal care device.
• This step similar to the step 610 may be carried out by a data analysis module of a proposed component wear assessment system.
• a data acquisition module of a component wear assessment system may be configured to carry out step 650 of the method 600 comprising determining a cumulative measure of the force applied to the vibratory component over time.
• Step 660 of the method 600 comprises obtaining, by the data acquisition module of the component wear assessment system, stroke data of the vibratory component, the stroke data of the vibratory component describing a stroke value of the vibratory component during operation of the personal care device. The method then proceeds to a step 670 of determining, by the data analysis module of the component wear assessment system, a cumulative measure of the stroke value of the vibratory component over time.
• the cumulative measure of the stroke value of the motor, the force applied to the vibratory component, and the stroke value of the vibratory component may comprise at least one of: a cumulative sum value; an average value; a maximum value; a minimum value; and a variation value.
• the three cumulative measures need not be in the same form but may comprise different forms of cumulative measure.
• the method 600 proceeds to a step 630 of determining an indicator of wear of a component of the personal care device based on the determined cumulative measures of the stroke value of the motor, the force applied to the vibratory component, and the stroke value of the vibratory component.
• this step may comprise: comparing the cumulative measure of the stroke value of the motor to a first threshold value; comparing the cumulative measure of the force applied to the vibratory component to a second threshold value; comparing the cumulative measure of the stroke value of the vibratory component to a third threshold value; and determining the indicator of wear of the component based on these comparisons.
• the three different thresholds may be determined based on known information about the relationship between these quantities and the wear experienced by the component.
• double-resonant actuators display load stroke stability, in some devices it may be difficult to drive the actuator at exactly the correct frequency for this effect. Therefore, in these devices there will still be some variation in the stroke value of the driven component (i.e., the vibratory component) as the load on the double-resonant actuator varies.
• Many personal care devices are provided with pressure sensors that measure the force applied to the vibratory component during use of the personal care device. This data may often be used in determining if the personal care device is being operated correctly for example.
• the method 600 uses both the stroke of the motor of the double resonant actuator and the stroke of the vibratory component, in combination with measurements of the force applied to the vibratory component during use to obtain a full picture of the working of the double resonant actuator and the strain it undergoes during use of the personal care device.
• the method 600 may therefore result in a more accurate and reliable determination of the wear on a component of the personal care device compared to a method that relies only on motor stroke data for this determination.
• determining the indicator of wear of the component of the personal care device may comprise: analysing the motor stroke data with a first trend analysis module to determine a trend in the motor stroke data; analysing the force data with a second trend analysis module to determine a trend in the force data; analysing the stroke data of the vibratory component with a third trend analysis module to determine a trend in the stroke data of the vibratory component; and determining a prediction of a length of time until the component needs to be replaced based on: the determined trend in the motor stroke data; the cumulative measure of the stroke value of the motor; the determined trend in the force data; the cumulative measure of the force applied to the vibratory component; the determined trend in the stroke data of the vibratory component; and the cumulative measure of the stroke value of the vibratory component.
• force data and motor stroke data may be used for the determination of the indicator of wear, and in other embodiments on the motor stroke data and the stroke data of the vibratory component may be used depending on the availability of such data.
• FIG. 7 there is depicted a schematic view of a personal care device 700 according to a proposed embodiment.
• the personal care device 700 is an electric shaving device.
• the device comprises a head component 710 which is connected to a body 720 that house functional components of the device.
• the electric shaving device 700 comprises a double resonant actuator 722 (housed within the body 720) which is configured to drive vibratory shaving elements 712 (within the head component 710) to vibrate during use of the device.
• the electric shaving device 700 further comprises a force sensor 714 within the head component 710 configured to measure the force with which a user presses the shaving elements 712 against their skin during use of the device 700.
• the body 720 may also comprise a power unit (not shown) to provide power to the double resonant actuator 722.
• the electric shaving device 700 further comprises the component wear assessment system 100 comprising the data acquisition module 110 and a data analysis module 120 (not shown).
• the data acquisition module of the component wear assessment system 100 is configured to obtain motor stroke data describing the stroke value of a motor of the double resonant actuator 722.
• the data analysis module is configured to determine, based on the obtained motor stroke data, a cumulative measure of the stroke value of the motor of the double-resonant actuator over time and to determine an indicator of wear of a component of the personal care device (in this case the component comprises the shaving elements 712) based on the determined cumulative measure of the stroke value of the motor of the double-resonant actuator.
• the data acquisition module of the component wear assessment system 100 is further configured to obtain force data, the force data describing the force applied to the shaving elements during use of the personal care device 700.
• the data analysis module is then further configured to determine, based on the obtained force data, a cumulative measure of the force applied to the shaving element 712 over time. Determining the indicator of wear of the shaving elements 712 is then based on both the cumulative measure of the force and the cumulative measure of the stroke value of the motor. For example, this may comprise comparing the cumulative measure of the stroke value of the motor to a first threshold value, comparing the cumulative measure of the force to a second threshold value, and determining the indicator of wear of the shaving elements 712 based on these comparisons.
• the component wear assessment system of the proposed invention may be integrated into a wide variety of personal care devices that comprise a double-resonant actuator.
• the personal care device may comprise at least one of: an oral care device; a skin treatment device; and a hair removal device.
• the component wear assessment system of the present invention may exist as a stand alone device, separate from the personal care device.
• each block in the flow diagrams or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s).
• the functions noted in the block may occur out of the order noted in the figures.
• two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
• each block of the block diagram and/or flow diagrams, and combinations of blocks in the block diagram and/or flow diagrams can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention.
• each block in the flow diagrams or block diagram may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s).

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• 2024
  • 2024-04-30 EP EP24173313.8A patent/EP4644070A1/fr active Pending
• 2025
  • 2025-04-22 WO PCT/EP2025/060832 patent/WO2025228718A1/fr active Pending

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