System for determining brushing angle of an oral care device

Abstract

The present invention provides a method (300) for determining a brushing angle of an oral care device (10). The method comprises the following steps: generating (310) a drive signal by a controller (30) of the oral care device to move a drive train (24) and produce movement of a bristle zone (18) of the oral care device; measuring (320) a force applied by a user to the bristle zone of the oral care device via a sensor (28); and determining (330) a brushing angle of the bristle zone relative to a surface of the user's oral cavity by the controller of the oral care device at least in part based on the generated drive signal and the measured force on the bristle zone.

Description

Technical Field

[0001] The present disclosure generally relates to methods and systems for determining a brushing angle of an oral care device during a brushing session by a user. Background Art

[0002] In preventive oral care, user technique is a major determinant of effectiveness in removing harmful biofilm from teeth. It is well known to dental professionals that an angle of 45° between the bristle area and the user's gum line is optimal. However, many in the public are still unaware of this optimal brushing angle. Even for users who know this optimal brushing angle, it is difficult for users to self-assess whether they are actually brushing their teeth in this recommended manner.

[0003] Additionally, measuring brushing angles in oral care devices, such as electric toothbrushes, is challenging because such measurements typically require hardware for locating, identifying, and measuring the user's gum line and tooth angles and orientations, e.g., using cameras, proximity sensors, or contact sensors, which are typically bulky and expensive.

[0004] Therefore, there is a need in the art for improved methods and systems for determining the brushing angle of an oral care device. Summary of the invention

[0005] The present disclosure relates to methods and systems for determining the brushing angle of an oral care device relative to a surface in a user's mouth (e.g., the gum line). Various embodiments and specific implementations herein relate to an oral care device (such as an electric toothbrush) driven by a periodic signal (e.g., a sine waveform, a square waveform, a sawtooth waveform). The sensor measures the force applied to the bristle area in the normal direction. The measured force characteristics (e.g., amplitude, frequency, phase) and the drive signal characteristics (e.g., amplitude, frequency, phase) are combined via a transfer function. The transfer function utilizes the change in the characteristic ratio between the load and the drive signal when the brushing angle changes. Uniaxial force measurement achieves resolution of the brushing angle through direct contact with the dental surface, and does not require direct measurement of the orientation of the user's gum line.

[0006] In general, in one aspect, a method for determining a brushing angle of an oral care device is provided. The method includes the steps of: generating a drive signal by a controller of the oral care device to move a drive train and produce movement of a bristle zone of the oral care device; measuring a force applied to the bristle zone of the oral care device by a user via a sensor; and determining, by the controller of the oral care device, a brushing angle of the bristle zone relative to a surface of the user's oral cavity based at least in part on the generated drive signal and the measured force on the bristle zone.

[0007] Specific embodiments may include one or more of the following. The sensor may include a load sensor or a pressure sensor. The determining step may include applying the characteristics of the measured force and the characteristics of the generated drive signal via a transfer function. The transfer function may be based on a change in phase difference or a change in spectral energy density.

[0008] In some implementations, the method may include the step of generating feedback regarding the determined brushing angle of the bristle zone relative to the surface of the user's oral cavity. The method may also include the step of transmitting the generated feedback. The method may also include the step of notifying the user when the determined brushing angle of the oral care device is less than a first predetermined threshold or greater than a second predetermined threshold.

[0009] In another aspect, an oral care device is provided. The device includes a brush head including a bristle field, a drive train responsive to a drive signal and configured to produce movement of the bristle field, a sensor configured to measure a force applied to the bristle field by a user, and a controller configured to: (i) generate a drive signal to move the drive train and produce movement of the bristle field; and (ii) determine a brushing angle of the bristle field relative to a surface of a user's oral cavity based at least in part on the generated drive signal and the measured force on the bristle field.

[0010] Specific embodiments may include one or more of the following. The sensor may include a load sensor or a pressure sensor. The controller may be configured to apply the characteristics of the measured force and the characteristics of the generated drive signal via a transfer function. The transfer function may be based on a change in phase difference or a change in spectral energy density. The controller may be configured to generate feedback about the brushing angle of the determined bristle area relative to the surface of the user's mouth. The controller may be configured to transmit the generated feedback.

[0011] As used herein for the purposes of the present disclosure, the term "controller" is generally used to describe various devices associated with the operation of an oral care device. A controller can be implemented in a variety of ways (e.g., such as by dedicated hardware) to perform the various functions discussed herein. A "processor" is an example of a controller that employs one or more microprocessors that can be programmed using software (e.g., microcode) to perform the various functions discussed herein. A controller can be implemented with or without a processor, and can also be implemented as a combination of dedicated hardware for performing some functions and a processor (e.g., one or more programmed microprocessors and associated circuits) for performing other functions. Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0012] In various implementations, a processor or controller may be associated with one or more storage media (generally referred to herein as "memory", such as volatile and non-volatile computer memory). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. The various storage media may be fixed within the processor or controller, or may be transportable so that one or more programs stored thereon can be loaded into the processor or controller in order to implement the various aspects of the present disclosure discussed herein. As used herein, the term "program" or "computer program" is used in a general sense to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors or controllers.

[0013] As used herein, the term "user interface" refers to an interface between a human user or operator and one or more devices that enables communication between the user and the devices. Examples of user interfaces that may be employed in various implementations of the present disclosure include, but are not limited to, switches, potentiometers, buttons, dials, sliders, trackballs, display screens, various types of graphical user interfaces (GUIs), touch screens, microphones, and other types of sensors that may receive some form of human-generated stimulus and generate signals in response thereto.

[0014] It should be understood that all combinations of the aforementioned concepts and the additional concepts discussed in more detail below (provided that these concepts are not mutually inconsistent) are considered to be part of the inventive subject matter disclosed herein. Specifically, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the inventive subject matter disclosed herein.

[0015] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0017] Figure 1 is a schematic diagram of an oral care device according to the present disclosure.

[0018] Figure 2 is a schematic diagram of a control system of an oral care device according to the present disclosure.

[0019] Figure 3 is a photograph of an oral environment with the brush head oriented at a 45° angle relative to the gum line of the oral cavity.

[0020] Figure 4 is a graph depicting pressure and toothbrush angle for an oral care device having a brush head oriented at a 45° angle in accordance with the present disclosure.

[0021] Figure 5 is a photograph of an oral environment with the brush head oriented at a 0° angle relative to the gum line of the oral cavity.

[0022] Figure 6 is a graph depicting pressure and toothbrush angle for an oral care device according to the present disclosure having a brush head oriented at a 0° angle.

[0023] Figure 7 is a flow chart of a method for determining a brushing angle of an oral care device according to the present disclosure.

[0024] Figure 8 is a flow chart of a method for determining a brushing angle of an oral care device according to the present disclosure. DETAILED DESCRIPTION

[0025] The present disclosure relates to methods and systems for determining the brushing angle of an oral care device relative to a surface (e.g., gum line) in a user's oral cavity. More generally, the applicant has recognized and understood that it is beneficial to provide an oral care device that determines the brushing angle of the device relative to the user's oral surface based at least in part on a generated drive signal and a force applied to a bristle zone of the oral care device. Therefore, the methods and systems described herein or otherwise contemplated provide an oral care device (such as an electric toothbrush) driven by a periodic signal (e.g., a sine waveform, a square waveform, a sawtooth waveform). The sensor measures the force applied to the bristle zone in the normal direction. The measured force characteristics (e.g., amplitude, frequency, phase) and the drive signal characteristics (e.g., amplitude, frequency, phase) are combined via a transfer function. When the brushing angle changes, the transfer function utilizes the change in the characteristic ratio between the load and the drive signal. The uniaxial force measurement achieves the resolution of the brushing angle by direct contact with the dental surface, and does not require direct measurement of the orientation of the user's gum line.

[0026] The embodiments and implementations disclosed herein or otherwise contemplated may be utilized with any oral care device. Examples of suitable oral care devices include toothbrushes, such as the Philips Toothbrush (manufactured by Koninklijke Philips Electronics, NV), or other electric toothbrush. However, the present disclosure is not limited to these listed devices, and thus the present disclosure and embodiments disclosed herein may include any oral care device.

[0027] Reference Figure 1In one embodiment, an oral care device 10 is provided that includes a handle or body portion 12 and a brush head 14. The brush head member 14 includes a brush head 16 at its end distal from the body portion, the brush head including a bristle field 18. The body portion 12 generally includes a housing, at least a portion of which is hollow to accommodate components of the personal care device. According to one embodiment, the brush head 14 is mounted to be able to move relative to the body portion 12. The movement can be any of a variety of different movements, including vibration or rotation, etc.

[0028] The body portion 12 includes a drive train assembly having a motor 22 for generating motion, and a transmission component or drive train 24 for transmitting the generated motion to the brush head 14. For example, the drive train includes a motor or electromagnet 22 that generates motion of the drive train 24, which is then transmitted to the brush head member 14, the brush head 16 and / or the bristle area 18. The drive train may include, among other components, components such as a power source, an oscillator, and one or more electromagnets. In this embodiment, the power source includes one or more rechargeable batteries (not shown), which can be charged, for example, in a charging holder, in which the oral care device 10 is placed when not in use. According to one embodiment, the brush head member 14 is mounted to the drive train 24 so as to be able to vibrate relative to the body portion 12. The brush head member 14 can be fixedly mounted to the drive train 24, or it can be optionally detachably mounted so that the brush head member 14 can be replaced with a different brush head member for different operating characteristics, or when the bristles or another component of the brush head are worn and need to be replaced. The main body 12 is also provided with a user input 26 to activate and deactivate the drive train. The user input 26 allows the user to operate the oral care device 10, such as turning the device on and off. For example, the user input 26 can be a button, a touch screen or a switch.

[0029] The oral care device 10 includes a controller 30 for creating a drive signal to move the drive train 24 and produce movement of the brush head member 14, the brush head 16 and / or the bristle area 18. The drive signal is typically a square wave that rises from a zero level to a positive value in one cycle and falls to a value of opposite polarity after a time determined by the drive frequency, the drive signal cycle continuing for the duration of the operation of the toothbrush for each event. The frequency and amplitude may vary depending on the controller, drive train and other components used.

[0030] The oral care device 10 includes one or more sensors 28. The sensors 28 are Figure 112, but may be located anywhere within the device, including, for example, within the brush head member 14 or the brush head 16. For example, the sensor 28 may include a load sensor or a pressure sensor configured to measure the load or pressure applied to the brush head member 14, the brush head 16, and / or the bristle zone 18. The sensor 28 is configured to generate information indicating the load or pressure (i.e., structural or mechanical force or stress) applied to the brush head member 14, the brush head 16, and / or the bristle zone 18. The load sensor or pressure sensor may be, for example, a switch, a meter, or another component. As an example, the sensor is a Hall effect sensor that responds to a changing magnetic field when the brush head member 14, the brush head 16, and / or the bristle zone 18 moves in response to pressure. The Hall effect sensor determines the lateral displacement of the brush head member 14, the brush head 16, and / or the bristle zone 18 due to the force on the bristles against the teeth. Many different types of load or pressure sensors may be utilized, as described herein or otherwise contemplated.

[0031] The sensor data generated by the sensor 28 is provided to the controller 30. According to one embodiment, the sensor 28 is integrated with the controller 30. The controller 30 may be formed by one or more modules and is configured to operate the personal care device 10 in response to an input (such as an input obtained via the user input 26). For example, the controller 30 may include a processor 32 and a memory 34. The processor 32 may take any suitable form, including but not limited to a microcontroller, a plurality of microcontrollers, a circuit, a single processor, or a plurality of processors. The memory 34 may take any suitable form, including non-volatile memory and / or RAM. The non-volatile memory may include a read-only memory (ROM), a hard disk drive (HDD), or a solid-state drive (SSD). Among other things, the memory may store an operating system. The processor uses RAM for temporary storage of data. According to one embodiment, the operating system may include code that controls the operation of the hardware components of the oral care device 10 when executed by the controller 30. According to an embodiment, the connection module 36 transmits the collected sensor data and may be any module, device, or apparatus capable of transmitting a wired or wireless signal, including but not limited to Wi-Fi, Bluetooth, near field communication, and / or a cellular module.

[0032] According to one embodiment, the oral care device 10 may include a user interface 40 that is configured to provide information to the user before, during and / or after the cleaning process. The user interface 40 may take many different forms, but is configured to provide information to the user. For example, information about the cleaning process may be read, viewed, heard, felt and / or otherwise interpreted. According to one embodiment, the user interface 40 provides feedback to the user, such as a guided cleaning process, which includes information about the brushing angle of the oral care device relative to the user's gum line. Thus, the user interface may be a display that provides information to the user, a tactile mechanism that provides tactile feedback to the user, a speaker that provides sound or text to the user, or any of a variety of other user interface mechanisms. According to one embodiment, the controller 30 of the oral care device 10 receives information from the sensor 28, evaluates and analyzes the information, and provides information that can be displayed to the user via the user interface 40.

[0033] Reference Figure 2 , in one embodiment, a schematic diagram of a control system 100 for an oral care device 10 is provided. The control system 100 for the oral care device 10 includes a controller 30 having a processor 32 and a memory 34, which can store an operating system as well as sensor data. The device also includes a power source 38, which can be an AC power source, or can be battery power from a rechargeable battery. The control system 100 also includes a user interface 40, which is configured to transmit or receive information to a user. The system's sensor 28 (which can be a load sensor or a pressure sensor) generates sensor data indicating the load or pressure applied to the brush head member 14, the brush head 16 and / or the bristle area 18, and transmits the data to the controller 30.

[0034] The connection module 36 of the device can be configured and / or programmed to transmit sensor data to a wireless transceiver (not shown). For example, the connection module 36 can transmit sensor data to a dental professional, a database, or other location via a Wi-Fi connection through the Internet or an intranet. Alternatively, the connection module 36 can transmit sensor or feedback data to a local device (e.g., a separate computing device), a database, or other transceiver via Bluetooth or other wireless connections. For example, the connection module 36 allows a user to transfer sensor data to a separate database so that it is saved for long-term storage, transmit sensor data for further analysis, transmit user feedback to a separate user interface, or share data with a dental professional, among other uses. The connection module 36 can also be a transceiver that can receive user input information, including the standards referenced above (as those of ordinary skill in the art should understand in conjunction with a review of the present disclosure). Other communications and control signals described herein can be implemented via a hardwired (non-wireless) connection or by a combination of wireless and non-wireless connections.

[0035] According to one embodiment, the control system 100 of the oral care device 10 can be programmed and / or configured to determine the brushing angle of the oral care device relative to a surface in the user's mouth (e.g., the gum line). As discussed herein, the information or data analyzed or used by the control system 100 of the oral care device 10 to perform the functions and methods described herein can be generated by one or more sensors 28. For example, the controller 30 can be programmed and / or configured to implement the determination of the brushing angle of the bristle area 18 of the oral care device 10 relative to the user's oral surface based at least in part on the drive signal of the oral care device 10 and the measured force on the bristle area 18.

[0036] The sensor 28 may be any sensor described herein or otherwise contemplated, and may be programmed and / or configured to obtain sensor data regarding one or more aspects of the load or force applied by the user to the brush head member 14, the brush head 16, and / or the bristle field 18 during the brushing process. The controller 30 may receive sensor data from the sensor 28 in real time or periodically. For example, the sensor 28 may send a constant stream of sensor data to the controller 30 for storage and / or analysis, or may temporarily store and aggregate or process the data before sending it to the controller 30. Once received by the controller 30, the sensor data may be processed by the processor 32.

[0037] The methods and systems disclosed herein can advantageously determine the brushing angle of the oral care device 10 based on the uniaxial force measurement using known drive signal properties. In one embodiment, the drive system 24 in the oral care device 10 is driven by a known periodic signal (e.g., a sine waveform, a square waveform, a sawtooth waveform). The sensor 28 measures the force applied to the bristle area 18 in the normal direction. Optimally, the applied load can be sampled at a sufficiently high rate to capture at least the second harmonic of the drive signal above its Nyquist frequency. The controller 30 determines the brushing angle using a transfer function (such as a phase difference or a frequency difference) by applying the characteristics of the drive signal (e.g., amplitude, frequency, phase) and the characteristics of the measured force (e.g., amplitude, frequency, phase). Therefore, when the brushing angle changes, the controller 30 can take advantage of the predictable changes in the characteristic ratio between the load and the drive signal.

[0038] To illustrate the mechanism of the present disclosure, two example scenarios will be discussed: a desired 45° orientation relative to the user's gum line, and a flat orientation at a 0° angle (90° is an equivalent description). In the first example scenario, Figure 3 As shown, the brush head is oriented by the user at the center of rotation (it would be in the same position if the oral care device was turned off). When the oral care device is operated, the pressure applied will contain a periodic component that varies with time due to the number of bristles and tufts in the bristle field that come into contact with the user's teeth and gums varying with position. Figure 3When oriented as shown, the pressure is highest when the brush head is rotated toward the teeth and lowest when the brush head is rotated toward the user's lips and mouth walls. For any short duration, there is effectively a constant DC voltage to which an AC fluctuation containing the angle information is applied.

[0039] Figure 4 is a graph depicting pressure and toothbrush angle (relative to the center of rotation) for an oral care device having a brush head oriented at a 45° angle relative to the user's gum line. As shown at points A and B, the frequency of the drive signal and the frequency of the pressure signal are synchronized. At point A, when the brush head is in most contact with the user's teeth, the pressure is high. At point B, when the brush head is in least contact with the teeth, the pressure is low.

[0040] In the second exemplary scenario, Figure 5 As shown, the brush head is oriented at the center of rotation (the same position it would be if the oral care device was off). When the oral care device is operating for any short duration, there is effectively a constant DC voltage as follows, to which AC fluctuations containing angle information are applied. In this case, the pressure is highest at the center of the brush head position and decreases as the brush head rotates in the opposite direction. In this case, the result is a quarter-cycle offset between the pressure peak and the brush angle peak. In addition, the AC pressure fluctuation frequency is doubled relative to the drive signal.

[0041] Figure 6 is a graph depicting pressure and toothbrush angle (relative to the center of rotation) for an oral care device having a brush head oriented at a 0° angle relative to the user's gum line. As shown at point C, the pressure reaches a peak when the toothbrush is at zero amplitude.

[0042] By utilizing the characteristics of the measured force (e.g., amplitude, frequency, phase) and the characteristics of the drive signal (e.g., amplitude, frequency, phase), the brushing angle of the brush head relative to the user's oral surface can be identified. Figure 7 As shown, drive signal 220 and pressure / load signal 240 are inputs to transfer function 260, which outputs the swiping angle. The transfer function can be based on many characteristics of the input signals, including, for example, changes in phase differences between the input signals, or changes in spectral energy density between the input signals.

[0043] The phase difference between the load and the drive signal is a characteristic that can be used to determine brushing and angle. At a 45° toothbrush orientation (relative to the oral surface), the phase angle difference is zero. When the toothbrush orientation approaches 0°, the phase difference between the load and the drive signal approaches a quarter-cycle difference. The exact form of this relationship depends on the characteristics of the motion transducer and the brush head in the oral care device (e.g., tuft layout or bristle stiffness). To account for this variation, a calibration function can be developed for each relevant system configuration (e.g., motion transducer and brush head pairing) to convert the observed phase difference into a brushing angle.

[0044] The spectral energy density of the load and the drive signal is another characteristic that can be used to determine the brushing angle. In this method, the variation of the AC load frequency can be utilized to identify the brushing angle. To address these situations, the spectral energy density of each signal can be estimated by a method such as the Fast Fourier Transform (FFT), and then quantified by evaluating a specific metric. An exemplary metric for this scenario is the ratio of the energy (A1) of the drive frequency (f1) to the energy (A2) of the first harmonic (f2 = 2f1) in the load signal. When the oral care device is oriented at 45° (relative to the oral surface), the load frequency is concentrated at the same frequency as the drive signal, in which case, A1 > A2. In contrast, when the end effector is oriented at 0° (relative to the oral surface), the time-varying component of the load is concentrated at twice the frequency of the drive frequency, in which case, A1 < A2. The exact form of the relationship depends on the characteristics of the motion transducer and the brush head in the oral care device (e.g., tuft layout or bristle stiffness). To address this variation, a calibration function can be developed for each relevant system configuration (e.g., motion transducer and brush head pairing) to convert the observed spectral energy density ratio (A1:A2) into a brushing angle.

[0045] Reference Figure 8 , in one embodiment, is a flowchart of a method 300 for determining the brushing angle of an oral care device 10. The oral care device can be any device described herein or otherwise envisioned. In step 310, a drive signal is generated by a controller 30 of the oral care device 10 to cause the drive train 24 to move and produce the movement of the bristle region 18 of the oral care device 10. As discussed herein, the drive signal can be a square wave, for example, which rises from a zero level to a positive value within one cycle and then drops to a value of the opposite polarity after a time determined by the drive frequency, and this drive signal cycle continues during the duration of the operation of the toothbrush for each event.

[0046] In step 320, the force applied by the user to the bristle zone 18 of the oral care device 10 is measured by the sensor 28. The sensor 28 can be any sensor described or otherwise contemplated herein (e.g., a load or pressure sensor), and can be programmed and / or configured to obtain sensor data regarding one or more aspects of the load or force applied by the user to the brush head member 14, the brush head 16, and / or the bristle zone 18 during the brushing process.

[0047] In step 330, the controller 30 of the oral care device 10 determines a brushing angle of the bristle zone relative to the user's oral surface based at least in part on the generated drive signal and the measured force on the bristle zone 18. As described herein, the controller 30 can determine the brushing angle by applying characteristics of the drive signal (e.g., amplitude, frequency, phase) and characteristics of the measured force (e.g., amplitude, frequency, phase) using a transfer function (such as a phase difference or a frequency difference).

[0048] In optional step 340, feedback about the determined brushing angle is generated. In optional step 350, the generated feedback is transmitted to the user, the device and / or another individual. The feedback may be real-time feedback, or may be feedback about one or more cleaning processes. According to one embodiment, feedback is provided to the user via a smart phone, a computer program, a base station, a remote software service or via other means. The feedback generated by the oral care device 10, the control system 100 and / or the remote device may be provided to the user in any of a variety of different ways, including via visual, written, auditory, tactile or other types of feedback. According to another embodiment, feedback is provided directly to a healthcare professional such as a dentist or dental hygienist. For example, information about one or more brushing processes may be automatically or upon request stored and transmitted to a healthcare professional. According to one embodiment, the information may be stored on the user's smart phone and then taken to the dentist's office during a visit, where the information is automatically uploaded via a Bluetooth connection. The dentist may then review the feedback and utilize the information during care. In addition to these feedback mechanisms, many other mechanisms are possible. For example, in other types of feedback, the feedback may combine the brushing angle into a display, a report or even a single value.

[0049] In optional step 360, when the determined swiping angle is less than a first predetermined threshold (e.g., 30° or 35°) or greater than a second predetermined threshold (e.g., 55° or 60°), a feedback notification is provided to the user. It should be understood that the lower swiping angle predetermined threshold and the upper swiping angle predetermined threshold can be adjusted to any value.

[0050] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0051] As used herein, the indefinite articles "a" and "an" used in the specification and claims should be understood to mean "at least one", unless explicitly stated to the contrary.

[0052] As used in the specification and claims, the phrase "and / or" should be understood to mean "either or both" of the elements so conjoined, i.e., elements present in some cases in conjunction and in other cases separate. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so conjoined. In addition to the elements specifically identified by the "and / or" clause, other elements may optionally be present, whether related or unrelated to the elements specifically identified.

[0053] As used in the specification and claims, "or" should be understood to have the same meaning as "and / or" defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one of a plurality of elements or a list of elements, but also including more than one element, and optionally including other unlisted items. Only terms that are explicitly indicated to the contrary, such as "only one of them" or "exactly one of them", or when used in the claims, "consisting of...", will refer to the inclusion of exactly one element of a plurality of elements or a list of elements. In general, as used herein, when preceded by an exclusive term such as "any one", "one of them", "only one of them" or "exactly one of them", the term "or" should only be interpreted as indicating an exclusive alternative (i.e., "one or the other, but not both").

[0054] As used in the specification and claims, when referring to a list of one or more elements, the phrase "at least one" should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows that in addition to the elements specifically identified in the list of elements to which the phrase "at least one" refers, elements may optionally be present, whether related or unrelated to the specifically identified elements.

[0055] It should also be understood that in any method claimed herein that includes more than one step or action, the order of the method steps or actions is not necessarily limited to the order in which the method steps or actions are described unless explicitly stated to the contrary.

[0056] In the claims and the above description, all transitional phrases, such as "comprising", "including", "carrying", "having", "including", "involving", "holding", "consisting of", etc., shall be understood as open-ended, i.e., meaning including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively.

[0057] Although several inventive embodiments have been described and illustrated herein, a person of ordinary skill in the art will readily envision various other devices and / or structures for performing functions and / or obtaining results and / or one or more of the advantages described herein, and each of such changes and / or modifications is considered to be within the scope of the inventive embodiments described herein. More generally, a person of ordinary skill in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary, and that actual parameters, dimensions, materials, and / or configurations will depend on one or more specific applications for which the present invention is taught. A person of ordinary skill in the art will recognize or be able to determine many equivalents for the specific inventive embodiments described herein using only routine experiments. Therefore, it should be understood that the above embodiments are presented only as examples, and that, within the scope of the appended claims and their equivalents, in addition to being specifically described and claimed, embodiments of the present invention may be practiced in other ways. The inventive embodiments of the present disclosure relate to and describe each individual feature, system, product, material, kit, and / or method. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods (if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent) is included within the inventive scope of the present disclosure.

Claims

1. A method (300) for determining a brushing angle of an oral care device (10), the method comprising the following steps: generating (310) a drive signal by a controller (30) of the oral care device to move a drive train (24) and produce movement of a bristle zone (18) of the oral care device; measuring (320) via a sensor (28) a force applied by a user to the bristle zone of the oral care device; as well as determining (330), by the controller of the oral care device, a brushing angle of the bristle field relative to a surface of the user's oral cavity based at least in part on the generated drive signal and the measured force on the bristle field, Wherein the determining step comprises applying the measured characteristic of the force and the generated characteristic of the drive signal as inputs to a transfer function to obtain the swiping angle. The method of claim 1 , wherein the transfer function is based on a change in phase difference. The method of claim 1 , wherein the transfer function is based on a change in spectral energy density.

4. The method of claim 1, further comprising the step of generating (340) feedback regarding the determined brushing angle of the bristle field relative to the surface of the user's mouth.

5. The method of claim 4, further comprising the step of transmitting (350) the generated feedback.

6. The method according to claim 1 further includes a step of notifying (360) the user when the determined brushing angle of the oral care device is less than a first predetermined threshold or greater than a second predetermined threshold, wherein the first predetermined threshold is 30° or 35°, and the second predetermined threshold is 55° or 60°. The method of claim 1 , wherein the sensor comprises a load sensor or a pressure sensor.

8. An oral care device (10), comprising: A brush head (16) including a bristle area (18); a drive system (24) responsive to the drive signal and configured to produce movement of the bristle field; a sensor (28) configured to measure a force applied to the bristle field by a user; as well as A controller (30) configured to: (i) generate a drive signal to move the drive train and produce movement of the bristle field; and (ii) determining an angle of brushing of the bristle field relative to a surface of the user's oral cavity based at least in part on the generated drive signal and the measured force on the bristle field, The controller is further configured to apply the measured force characteristic and the generated drive signal characteristic as inputs to a transfer function to obtain the swiping angle.

9. The oral care device of claim 8, wherein the transfer function is based on a change in phase difference.

10. The oral care device of claim 8, wherein the transfer function is based on changes in spectral energy density.

11. The oral care device of claim 8, wherein the controller is further configured to generate feedback regarding the determined brushing angle of the bristle field relative to the surface of the user's mouth.

12. The oral care device of claim 11, wherein the controller is further configured to transmit the generated feedback.

13. The oral care device of claim 8, wherein the sensor comprises a load sensor or a pressure sensor.

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