Determination of the opening degree

Abstract

An oral care system is provided that has an oral care device and a processor. The oral care device has a sensor system configured to measure one or more parameters of the oral care device or the user's oral cavity while the oral care device is being used by the user. The processor is configured to obtain one or more parameters from the sensor system and use the one or more parameters to determine an opening value for the user.

Description

Technical Field

[0001] The present invention relates to the field of oral hygiene. In particular, the present invention relates to the field of detecting trismus and temporomandibular joint disorders.

Background Art

[0002] Trismus (commonly known as lockjaw) and temporomandibular joint (TMJ) disorders (TMJD) cause a reduction in jaw opening or restriction of movement. Trismus and TMJD can interfere with eating, speaking, and maintaining proper oral hygiene. If left untreated or undiagnosed, trismus and TMJD can become chronic and painful, and can affect daily life and health by causing migraines, discomfort in the back, neck, and shoulders, and hearing impairment / loss.

[0003] Examination and treatment of trismus and TMJD typically require access to the oral cavity, which can be limited and in some cases impossible. Trismus can be caused by joint problems, infections, trauma, cancer treatment, or dental procedures. For example, temporomandibular joint disorder can cause trismus. In the United States, approximately 12% (about 35 million people) of the population suffers from TMJD at any given time.

[0004] Another significant cause of trismus is head and neck cancer, and in these cases, the prevalence of trismus is estimated to be as high as 38%. In the case of patients suffering from this type of cancer, management of trismus focuses on preventing the progression of trismus and restoring mandibular function.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Currently, there is no non-invasive mechanism to track the progression of trismus or the restoration of mandibular function to enable medical professionals to see how patients respond to treatment.

[0006] A common method of diagnosing the severity of trismus is to measure the subject's opening via a tool such as a boley gauge or a ruler. A normal oral opening (i.e., without trismus) is expected to exceed 40 mm. Mild trismus is usually classified based on an opening of 30 - 40 mm, moderate trismus is usually classified based on an opening of 15 - 30 mm, and severe trismus is usually classified based on an opening of less than 15 mm.

[0007] Alternatively, a three - finger screening test can be used to estimate the severity of trismus. In the three - finger screening test, the subject tries to open their mouth as wide as possible so that fingers can be accommodated between the upper and lower teeth. The ability to accommodate more than three fingers generally indicates no trismus, two to three fingers indicate mild trismus, one to two fingers indicate moderate trismus, and less than one finger indicates severe trismus.

[0008] Both approaches are considered invasive, require another person for measurement, and do not provide medical professionals with the tools necessary to monitor a patient's progress after procedures such as extraction by a stranger.

[0009] US5097820A discloses the structure of an apparatus that can be used to diagnose and treat opening limitations. However, such an apparatus tends to be invasive and expensive. WO2017015342A1 discloses a trismus rehabilitation apparatus similar to the apparatus disclosed in US5097820A and includes additional sensors that measure the pressure applied to various parts of the jaw to estimate the opening.

[0010] The main limitation of these solutions is that their purpose is typically limited to single-spot measurements performed by dental healthcare providers in a general practice or clinic, and as a result, the frequency with which subjects use these solutions is low. This reduces their usefulness in large-scale monitoring of TMJD or trismus. Furthermore, it is difficult to digitize these measurements in a seamless workflow so as to enable long-term monitoring of disease progression.

[0011] Therefore, there is a need for improved means for detecting the presence of trismus or any opening / closing disorder and continuously tracking its progression, particularly in a home environment.

Means for Solving the Problem

[0012] The present invention is defined by the claims.

[0013] According to an example of one aspect of the present invention, there is provided an oral care system, which includes an oral care device having a sensor system configured to measure one or more parameters of the oral care device or the user's oral cavity during use of the oral care device, and a processor configured to obtain one or more parameters from the sensor system and determine an opening value of the user based on the one or more parameters.

[0014] This oral care device does not treat an opening disorder (such as trismus). For example, the oral care device can be for maintaining oral hygiene or a treatment device for treating a second oral hygiene disorder that is not an opening disorder.

[0015] Trismus is generally called lockjaw and is a condition that restricts jaw movement and can interfere with eating, talking, or maintaining oral hygiene. Current approaches to detecting trismus and determining its severity involve measuring the user's mouth opening using a boley gauge or ruler, or in some cases, the number of fingers that fit within the opening. However, finger measurement is not particularly accurate and has a very limited resolution. On the other hand, more accurate measurements are difficult to perform by oneself.

[0016] Thus, it is understood that when the user is maintaining oral hygiene, the cause of trismus or any other opening restriction can be checked. For example, brushing teeth or using a jet injector is typically done daily. This increases the amount of data obtained related to the detection of trismus without the user having to add additional activities to their daily routine or perform difficult or unpleasant examinations.

[0017] The idea is that when using most oral care devices, the user is forced to open their mouth as wide as possible in some respects. Therefore, a sensor system can be added to the oral care device, which is configured to obtain parameters indicating the oral care device or the user's mouth, thereby providing an indication of how wide the user's mouth can open. The measured parameters may be suitable for determining how wide the user has their mouth open during use of the oral care device.

[0018] The opening value is a value (or set of values) indicating how wide the user is physically opening their mouth. The method can include determining a maximum opening value.

[0019] The maximum opening value is a value (or set of values) indicating how physically wide a user can open their mouth. Generally, the maximum opening value is a measurement of the distance between the upper and lower front teeth. However, any distance at any point in the mouth can indicate the degree of opening. Similarly, the maximum angle formed by the upper and lower jaws when the mouth is open is understood to indicate how physically wide a user can open their mouth. Thus, the maximum opening value can be a distance measurement or an angle measurement with respect to the position of the mouth.

[0020] The minimum opening value can be additionally or alternatively determined. The minimum opening value is a value (or set of values) indicating how physically closed a user can close their mouth. This information can be useful in the ultimate identification of a closing disorder. The minimum opening can also be referred to as the maximum closing.

[0021] The opening value can be determined when the user is performing a specific action. This method can include determining whether the user is performing a specific action and using the corresponding parameters when the user is performing that action. The specific action can vary based on the selected oral care device and the desired opening value. For example, when using a jet spraying device, the mouth can be closed when the user is jet spraying the upper front teeth, which enables determining the minimum opening value. The specific action can include brushing and / or jet spraying of a specific area of the oral cavity.

[0022] The oral care device may be an oral care device for maintaining oral hygiene. Alternatively, the oral care device may be a treatment device.

[0023] At least one of the one or more parameters may be the orientation of the oral care device within the user's oral cavity, and the processor is further configured to detect a change in the orientation of the oral care device using the orientation measurement from the sensor system and determine the user's opening value based on the change in orientation.

[0024] Detecting a change in orientation provides a proxy measurement of the angle at which the mouth can be opened. The maximum angle at which a user can open their mouth has been found to provide a strong indication of potential trismus, or other conditions that limit opening. Thus, the maximum opening can be measured at the maximum angle, instead of a typical distance measurement between the incisors.

[0025] The orientation has at least one angle measurement. The angle measurement can be relative to gravity and / or relative to the teeth. For example, the angle measurement can have a pitch angle measurement, a roll angle measurement, and / or a yaw angle measurement of the oral care device. In some cases, a change in the pitch angle measurement may be sufficient to determine the opening value.

[0026] At least one of the one or more parameters can be the movement of the oral care device in the user's oral cavity, and the processor is further configured to determine the user's opening value based on the movement of the oral care device.

[0027] The movement of the oral care device can also provide a suitable measurement for determining the maximum opening. For example, the movement of the oral care device from the upper teeth to the lower teeth can provide an indication of the maximum opening.

[0028] The processor may be further configured to determine the position of the oral care device in the user's oral cavity.

[0029] At least one of the one or more parameters can be the position of the oral care device in the user's oral cavity. Thus, the processor can determine the position of the oral care device by obtaining the position of the oral care device in the user's oral cavity from the sensor system.

[0030] Alternatively, the processor can process one or more parameters to determine the position of the oral care device in the user's oral cavity. For example, a distance sensor can be used to measure the maximum distance to the back of the mouth and compare the current distance with the maximum distance to the back of the mouth to determine the position.

[0031] The processor can be further configured to determine whether the oral care device is being used on the rearmost teeth of the user's upper jaw, and determining the opening value is based on a measurement from the sensor system corresponding to the oral care device being used on the rearmost teeth of the user's upper jaw.

[0032] When the user uses the oral care device on the innermost tooth (such as the wisdom tooth) of the upper jaw, it has been found that this naturally causes the jaw to drop maximally, which in turn results in the mouth opening maximally. Therefore, the measurements taken at this point are very likely to indicate maximum opening.

[0033] The processor can be configured to determine whether the oral care device is being used on the rearmost teeth of the user's upper jaw by using one or more parameters from the sensor system to determine that the oral care device is positioned in the upper jaw, that the oral care device has moved towards the back of the mouth, and that the oral care device is positioned on the occlusal surface side of the rearmost teeth of the upper jaw.

[0034] At least one of the one or more parameters may be the depth of the oral care device in the user's oral cavity, and determining the opening value is further based on the depth of the oral care device in the user's oral cavity.

[0035] The depth of the oral care device provides context as to where in the user's oral cavity the oral care device is. When the sensor system provides measurements of the operation of the oral care device, the depth within the oral cavity can be used to transform the measured movement at the measured depth into the corresponding movement at depth zero (i.e., the front of the oral cavity where generally maximum opening is measured).

[0036] Furthermore, any measurement value from the sensor system can be compared with previous measurement values corresponding to the same depth in order to track potential conditions that limit the maximum aperture.

[0037] The processor may be further configured to consider the size of the oral care device when determining the aperture value.

[0038] The size of the oral care device may include the thickness, diameter, width, height, and / or length of the oral care device.

[0039] The processor may further be configured to track one or more parameters for the user over time from the sensor system of the oral care device and to track the user's opening progression based on the changes over time in the one or more parameters.

[0040] The processor may be further configured to track one or more parameters from the sensor systems of a plurality of oral care devices used by the user, and tracking the user's opening progression may include combining one or more parameters tracked for the plurality of oral care devices, and during the combining, the one or more parameters are weighted based on the corresponding oral care device.

[0041] The processor may be further configured to determine how much time has elapsed since the determined latest aperture value and to warn the user to use the oral care device if that time is greater than a threshold time period.

[0042] The oral care device can be a toothbrush, a jet injection device, or a toothbrush with a jet injection device.

[0043] The sensor system can have one or more of an acceleration sensor, a rotation sensor, a displacement sensor, a position sensor, a force sensor, a pressure sensor, a torque sensor, an angle sensor, and a distance sensor.

[0044] The sensor system can have an acoustic sensor for measuring sounds within the user's oral cavity, and determining the opening value is based on the sounds in the user's oral cavity.

[0045] At different opening values, the user's oral cavity forms chambers of different volumes. Sounds resonate differently at different volume shapes and sizes. Thus, the characteristics of the sounds resonating in the oral cavity are dependent on the user's opening.

[0046] When the mouth is opened wide (or closed), it is expected that the sound spectrum of the brush will change. However, when the user's head is tilted and the mouth remains closed (or open), the sound spectrum does not change. Thus, the acoustic sensor can also be used when determining whether a change in the parameter corresponds to the user's head being tilted or the mouth being opened.

[0047] When using a powered oral care device, the drive train attenuation when the oral care device is being used is also acoustically measured and can indicate whether the mouth is open.

[0048] The sensor system can have a distance sensor and / or a proximity sensor disposed at a distal portion of the oral care device, where the distal portion of the oral care device is the portion of the oral care device that is inserted into the user's mouth.

[0049] For example, the distal portion may be the brush head of a toothbrush.

[0050] The present invention also provides a method for determining the opening and closing of a user's mouth, the method comprising: obtaining one or more parameters from a sensor system of an oral care device, the parameter being a parameter of the oral care device during use of the oral care device or a parameter of the user's oral cavity; determining an opening value of the user based on the one or more parameters.

[0051] The present invention also provides a computer program product including computer program code which, when executed on a computing device having a processing system, causes the processing system to execute all steps of the aforementioned method.

[0052] These and other aspects of the present invention will become apparent from the embodiments described hereinafter and will be described with reference to the embodiments.

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 9

Modes for Carrying Out the Invention

[0054] For a better understanding of the present invention and to more clearly show the method of its implementation, the accompanying drawings which are merely illustrative are referred to.

[0055] The present invention will be described with reference to the drawings.

[0056] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, system and method, are for illustrative purposes only and are not intended to limit the scope of the present invention. These and other features, aspects and advantages of the apparatus, system and method of the present invention will be more preferably understood from the following description, the appended claims and the accompanying drawings. It should be understood that the figures are merely schematic 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.

[0057] The present invention provides an oral care system having an oral care device and a processor. The oral care device has a sensor system configured to measure one or more parameters of the oral care device or the user's oral cavity while the oral care device is being used by the user. The processor is configured to obtain one or more parameters from the sensor system and use the one or more parameters to determine an opening value of the user.

[0058] A system for obtaining the opening of a user by using an oral care device is proposed. This makes it possible, for example, for a clinician to detect when a user has an opening disorder and to estimate its progression through continuous use of the system.

[0059] This facilitates the continuous remote monitoring of TMJ disorders or trismus and enables medical and dental professionals to evaluate and quantify the results of the treatments provided. An additional advantage is that medical insurance companies and dental insurance companies will have additional data points for verifying benefit claims related to TMJ disorders or trismus by evaluating the date of the treatment billed and the date on which trismus was detected.

[0060] Figure 1 shows an open mouth. As can be seen, the upper teeth 102 do not uniformly separate from the lower teeth 104, and thus the openings (lines 106 and 108) can be different based on the location where the opening measurement is taken. Currently, the opening value / measurement is often taken at the front of the mouth (i.e., line 106). This is because it is the most easily accessible measurement from the outside and thus a clinician or other person can measure the user's degree of opening.

[0061] However, it should be understood that the opening value can be obtained at any position within the oral cavity in a manner that can be interpreted by a clinician. For example, line 108 (near the center of the mouth) can be used in combination with a specific location within the mouth. In contrast, when the position is unknown, the processor can acquire multiple measurements and find the maximum value among those measurements. The maximum measurement is usually interpreted as the opening at line 106 (the front of the mouth). This is because this is usually the position with the maximum opening.

[0062] The maximum degree of opening is currently one of the most important degrees of opening measured. The maximum degree of opening quantifies how much the user can open their mouth. A relatively small maximum degree of opening indicates the possibility of an opening disorder. Similarly, the minimum degree of opening (i.e., the maximum degree of closure) is also a relevant degree of opening. If the user cannot fully close their mouth, this results in a relatively large minimum degree of opening, thereby indicating the possibility of an opening disorder.

[0063] Note that Figure 1 shows a general opening. In reality, the maximum opening (and potentially the minimum opening) is typically more clinically relevant than the general opening. However, if accurate and frequent degrees of opening can be obtained, the full range of degrees of opening can be relevant.

[0064] The inventors have noticed that the use of oral care / hygiene devices (such as toothbrushes, floss devices, jet irrigation devices, etc.) is used entirely within the user's oral cavity and is typically used frequently (e.g., more than once a day). Further, due to the nature of using an oral care device in the user's oral cavity, the user typically keeps their mouth open during use. Thus, it has been proposed to measure the user's opening during the use of an oral care device. This enables the user to do two things simultaneously (i.e., maintain oral hygiene and measure the degree of opening). It also means that opening values can be obtained much more frequently than if the user or typically a clinician had to separately measure the opening.

[0065] The following examples relate to the measurement of maximum mouth opening. However, it should be understood that the systems and methods described in relation to the measurement of maximum mouth opening can also be applied to any general measurement of mouth opening. In specific cases where the system or method is particularly related to maximum opening, alternatives can be provided for minimum opening or general opening.

[0066] Similarly, the following examples use a toothbrush to illustrate the example. However, it should be understood that other oral care devices can also be used.

[0067] In a first embodiment, the sensor is disposed on the head of the toothbrush. FIG. 2 shows a toothbrush head 202 with a sensor system 206 on the head of the toothbrush 202. The sensor system is disposed at the distal end of the toothbrush head 202 near the bristles 204 of the toothbrush head 202. In an alternative embodiment, the sensor system can also be present on the handle of the oral care device.

[0068] The quantitative measure of opening can depend on where the measurement is taken along the patient's jaw. This is because the mouth opens widest at the front and narrowest at the back.

[0069] Figure 3 shows a toothbrush head 202 equipped with a sensor system 206 being used in the oral cavity. In this case, the sensor system can have a proximity sensor and / or a distance sensor and / or an acceleration sensor (inertial measurement) and / or a gyroscope. To estimate the opening level at any position within the oral cavity, the sensor system determines the position of the brush head along a given jaw from distance measurements obtained by the sensor system 206 attached to its longitudinal axis (i.e., along segment AB shown in Figure 3). The opening degree at the current brush head position is determined from distance measurements obtained from a sensor attached on the vertical axis (i.e., along segment BC shown in Figure 3).

[0070] The elevation angle can be calculated at the current position (i.e., angle ∠BAC = ∠BAD). As can be seen, the isosceles triangle BAD can also be used. Point D can be found using simple geometry from points A, B, and C.

[0071] One skilled in the art will understand that the calculation of segment BD is straightforward. Given the measurement of segment BC, an approximate isosceles triangle (ABD) can be created, from which basic trigonometric functions enable the deduction of BD. For this reason, segment AD is calculated by a simple application of the Pythagorean theorem for triangle ABC.

[0072] Although the planes of both the upper and lower jaws are not straight lines, local linearity can be reasonably expected by performing measurements when the brush head is as far back as possible in the occlusal plane. As a result, by calculating the distance represented by line segment BD, the distal opening in the mouth can be approximated.

[0073] Therefore, the opening degree at any other point including the maximum opening degree can be estimated using the elevation angle. If both BD and the angle ∠BAD at its specific given point are known, it is possible to estimate the opening of other points. The non-linear planes of both jaws are expected to limit the accuracy of the proposed approach. However, since the range of opening is large enough (e.g., 15 mm in moderate trismus), the estimated values made using this method are expected to be well within the acceptable range.

[0074] For example, FIG. 4 shows a mouth with an isosceles triangle (AB'D'). As can be seen, despite the irregular nature of the tooth shape, the triangle fits surprisingly well to the shape of the opening. Thus, it can be concluded that the isosceles triangle is a good descriptor of the opening. This leads to the conclusion that the angle ∠B'AD' = ∠BAD can also be used accurately to represent the opening. Thus, the opening value is not limited to the distance measurement between the upper tooth 102 and the lower tooth 104, and the elevation angle can also be used as the opening value.

[0075] The first embodiment can be realized in a sensor system having a two-sensor configuration in which the sensitive axes of both sensors are perpendicular to each other. The directions of the sensors are indicated by segments BA and BC in FIG. 3. Generally, the first example uses triangulation to estimate the opening value.

[0076] In the second embodiment, the opening value is determined using sensor data from a sensor system already present in the current toothbrush. In this embodiment, measurements are taken at a specific brushing position and direction (e.g., behind the upper or lower molar teeth). In particular, the second embodiment enables measurements to be taken during an exact and unique operation that results in the desired opening (e.g., maximum or minimum opening).

[0077] The first embodiment utilizes sensors added to the brush head to facilitate triangulation measurements of the opening, but it has been found that it is also possible to evaluate and track the opening degree using sensors already present in a (powered) oral care device. For example, accelerometers, inertial measurement units, rotational sensors (such as compasses, gyroscopes, etc.), displacement sensors, position sensors, Hall sensors, and / or printed strain gauges may already be present in a powered oral care device.

[0078] Repeatedly, the description and figures show a powered toothbrush used as an example. However, any other toothbrush (e.g., a composite brushing floss device), a water jet spraying device, or a floss device is also conceivable. In particular, a water jet spraying device is very suitable. This is because the head of a device equipped with a jet tube is quite slender, which can reduce measurement problems (e.g., there is no problem that the wide device body of a toothbrush gets in the way of measurement).

[0079] During a specific brushing motion, namely while brushing the back side of the rearmost molar / wisdom tooth, it has been found that the user is forced to open the mouth maximally and rotate the brush at an angle until the brush is strongly pressed against the jaw on the side opposite the teeth being brushed.

[0080] The objective of this embodiment is to measure this brush movement and interpret this measured value as representing the opening degree. Limited movement, or an opening that decreases over time, may be related to an opening disorder (TMJ, trismus, etc.).

[0081] Measurements taken during the cleaning of the upper or lower teeth both, in principle, result in an interpretation of the opening degree, but the inventors have noticed that it may be preferable to use the measurement while brushing the back side of the rearmost molar / wisdom tooth in the upper jaw.

[0082] During upper jaw brushing, the opening results in the jaw dropping, and the brush remains in the same position as its initial flat position against the upper teeth, just as when brushing along the upper surface of the upper teeth. From this fixed reference position, the brush must cross the full opening angle of the mouth before it is pushed against the lower jaw. As a result, the measured movement becomes a direct measure of the opening.

[0083] In contrast, during lower jaw brushing, here too the opening results in the jaw dropping. However, in this case, the jaw dropping, without moving the brush, already separates the brush from the jaw. From this starting position, the brush is only required to cross a part of the opening angle before it is pushed against the upper jaw. As a result, the measured movement may not be a direct measure of the opening. However, it should be noted that this measurement may have some predictive value for vertical measurements.

[0084] Figures 5 and 6 show that the toothbrush 502 is used on the rearmost teeth of the upper jaw 506. To establish the opening during brushing of the upper jaw 506, the following measurements are appropriate means. Measurement of the total movement of the sensor system 504 (including, for example, an accelerometer and / or a position sensor) when the brush rotates from the upper jaw 506 (shown in FIG. 5) to the lower jaw 508 (shown in FIG. 6). Measurement of the rotation angle of the sensor system 504 (including, for example, a compass and / or a gyroscope) when the toothbrush 502 rotates from the upper jaw 506 (shown in FIG. 5) to the lower jaw 508 (shown in FIG. 6). If necessary, by considering the distance of the sensor system 504 from the top of the brush head to the sensor system 504, the rotation angle can be converted into the movement amplitude.

[0085] In many use cases (such as establishing the progression of TMJD), it is sufficient to monitor the measured movement of the brush sensor or the change in the rotation angle.

[0086] However, in some use cases (e.g., confirmation of the severity of TMJD / trismus), it may be preferable to establish an absolute opening degree. To achieve this, at the position on the brush where the brush moves away from the mouth, the magnitude of the distance across which the brush travels can be established. This can be obtained as follows.

[0087] Movement of the brush during opening = Measured movement of the sensor system 504 between point E and point F in FIG. 6 × Ratio of the depth of the mouth (D - opening) to the distance between the sensor system 504 and the brush head (D - sensor). The depth of the mouth (D - opening) is the distance between the frontmost tooth and the rearmost tooth in the mouth.

[0088] When calculating the absolute opening degree, the size (diameter, thickness, etc.) of the brush (brush diameter) at the position on the brush where the brush moves away from the mouth can be considered. For example, opening degree = Distance across which the brush travels at the opening position + Brush diameter.

[0089] It should be noted that in this absolute opening degree measurement, it is advantageous that the part of the toothbrush entering the mouth is relatively narrow and has a constant diameter. For example, a relatively long toothbrush protrudes from the mouth even when placed behind the last tooth. The jet injection device is particularly suitable because it has an essentially elongated tube for injection purposes.

[0090] It is also possible to establish the most likely moment to associate the movement of the brush with the opening. Specifically, when the sensor system 504 has a motion sensor or a position sensor (or the like), the following patterns are likely to represent preferred measurement moments. The brush is at a position where it polishes the upper surface of the upper teeth. The brush moves backward along the teeth. The movement of the brush stops (motion sensor), or the position is at or behind the position of the posterior molar / wisdom tooth (position sensor) and is kept constant. The movement of the brush that potentially represents the opening due to the lowering of the jaw is measured.

[0091] In certain usage examples, it is established that a specific brush head is used, particularly for brushing the back of the molar teeth (i.e., a single tuft brush head). Higher weights can be given to the measurements taken in this specific usage example. This is because it is most likely that the user focuses on cleaning the back of the molar teeth and attempts to fully open the mouth.

[0092] Obviously, the user does not need to perform this operation every time they brush. This is because these jaw-related problems only progress slowly over time. However, if a relatively long period has passed since the measurement became possible, in an alternative approach, the user can be instructed to perform this specific movement by placing the tip of the device as described above, opening the jaw, and moving the device parallel to the jaw opening. In such a manner, good quality reference measurements can always be established. The user can be instructed via an external device (e.g., a smartphone app).

[0093] Existing oral care devices use an algorithm to determine the orientation of the oral device with respect to the gravity vector. This will be used to determine the change in angle when opening the mouth. Directions 602 and 604 are shown in FIG. 6. Orientation 602 is the orientation of the toothbrush as shown in FIG. 5. Point E indicates the arrangement of the sensor system 504 corresponding to the toothbrush orientation 602. Similarly, orientation 604 is the toothbrush orientation as shown in FIG. 6 corresponding to the sensor system 504 being at point F. Thus, the angle Θ between the two directions can be determined.

[0094] In some cases, the conversion from angle measurement to opening distance (requiring "jaw length") may not be necessary here. In fact, the opening angle may be more accurate (because it requires fewer measurements) and may contain more information than the opening distance measurement. The measurement of the opening distance (generally in mm units) is commonly used. This is because it is the most easily evaluated in current practice.

[0095] The robustness against head movement is also a point to note. When detecting a change in orientation, the opening may be confused with the tilt of the head. One approach to address this is to use an algorithm trained to distinguish between "opening the mouth" and "tilting the head". Such an algorithm is currently used to determine the position of the toothbrush in the oral cavity.

[0096] For example, position detection algorithms using sensor signals of inertial measurement units (IMUs) have been used previously. These algorithms estimate the tilt of the head using the average or median direction of the brush over time. Subsequently, the tilt of the head is used to obtain a better estimate of the orientation of the brush with respect to the user's head. In some cases, each time the user changes the operation to another segment of the mouth, the direction of the tilt of the head can be re - estimated (based on the direction of the brush).

[0097] The second approach is to use a pressure sensor to determine when the brush head is pressed against the teeth and when the opening is due to "polishing the back of the molars". The third approach is to add an acoustic sensor to the sensor system. Due to oral cavity resonance, an increase in volume and a change in spectrum occur. These are different based on whether the mouth is open or closed.

[0098] In a third embodiment, an image algorithm with dynamic image rescaling and calibration is used to determine the (maximum) opening degree at a specific brushing position and direction (lingual incisor brushing).

[0099] Figure 7 shows that the toothbrush 702 is used on the lingual side of the upper front teeth 710. The toothbrush has two markers 706 and 707 with a known length 708 between the markers 706. A camera 712 is used to take an image of this operation.

[0100] The third embodiment provides a software-compatible measurement of the opening degree by using a calibrated toothbrush (or a part thereof) and a camera (e.g., on a smartphone) without requiring a sensor on the toothbrush 702. The camera can be part of the handle (distal end) of the toothbrush, while during brushing, the camera faces the bathroom mirror and can capture the opening in such a manner.

[0101] The opening degree is measured at a specific brushing orientation / position that provides a reliable measurement of the opening width. During a specific brushing motion (e.g., brushing the back side of the upper incisors or lower incisors), as shown in FIG. 7, it is understood that the user is forced to rotate the brush at a specific angle until the mouth is opened maximally and the brush is strongly pressed against the lingual side of the upper or lower jaw so that the teeth are being brushed.

[0102] By knowing the distance between (at least) one (reference) marker 706 of the length-calibrated toothbrush shaft and identifying the marker and the opening (e.g., using a feature detection algorithm and / or a feature matching algorithm), for example, accessing a database with known dimensions of the brush head or reference marker, and obtaining an image calibration or image scaling factor, the absolute opening degree can be determined. The marker 706 can be a colored / texture dot added to the toothbrush or a marker specific to the brush head (e.g., an ejector mark from an injection molding process). A single marker 706 (e.g., of a known diameter) can be used.

[0103] A database containing a reference length 708 can be accessed, thereby enabling the image to be dynamically rescaled. The known length enables a reliable determination of the absolute maximum opening value (e.g., when an image is taken in a subsequent week). This is because a person cannot reliably control the distance at which the image is taken (i.e., correction and automatic scaling for different image magnifications are performed).

[0104] The toothbrush 702 may be connected to a database of design data (such as drawings and dimensions) of the brush head including the dimensions (e.g., in mm) of the toothbrush (or a part thereof). A radio frequency identification (RFID) code can be used to recognize the type of toothbrush to be worn.

[0105] An image can be acquired while the toothbrush is in use, enabling determination of the opening degree. FIG. 8 shows an image used to determine the opening degree. The user can brush their teeth and take an image (e.g., via the camera of a smartphone) when the incisors are being brushed. Alternatively, the camera can be part of a bathroom mirror.

[0106] Next, the processor or cloud engine executes the following algorithm steps to determine the absolute maximum opening degree from the acquired image as shown in the processed image of FIG. 8. Decompose the RGB image into RGB channels. Apply feature recognition functions (such as edge detection and boundary detection) to distinguish the features of the brush head and oral features (e.g., lips, teeth). See FIG. 8. Identify markers 706 and 707 and measure the relative distance (measured in pixels) between the two markers. Identify the relative opening degree 804 (measured in pixels). Rescale the uploaded image based on the boundary segmented features, the known distance 708 (e.g., measured in mm) of marker 706 on the brush head, and the relative measurement values. Using the relative distance between the identified markers 706 and 707 in the image and the known distance 708, a calibration coefficient can be determined (e.g., distance / pixel). Apply the length calibration coefficient to the relative opening degree 804 to determine the absolute maximum opening degree.

[0107] As an option, by considering the influence of the brushing angle on the determination of the absolute opening degree, the sensor system 704 already present in the toothbrush 702 can be used to improve the accuracy of the measurement. Note that the lower incisors and the upper incisors are brushed at different pitch angles.

[0108] The camera 712 can also be arranged on the toothbrush 702. This takes advantage of the fact that the user usually brushes their teeth in front of a mirror. Thus, the camera 712 can be arranged on the toothbrush, and as a result, it takes an image of the mirror in front of the user, which reflects the user while brushing their teeth. This eliminates the need to use an external camera during toothbrushing.

[0109] FIG. 9 shows a method for determining the absolute opening degree. The method includes, in step 902, receiving an image of the user while brushing their teeth, and in step 904, measuring the (relative) length (in pixels) between markers (or other parts) on the toothbrush, and in step 906, using the measured length between the markers and a known length between the markers extracted from, for example, a database, to determine a calibration coefficient 906 (e.g., pixels / mm or distance / pixel unit). The (relative) opening degree is also determined or measured (in pixel units) from the image in step 908. Thus, the calibration coefficient can be applied to the (relative) opening degree to determine the absolute opening degree. Note that the opening degree may be the maximum opening degree, the minimum opening degree, or any general opening degree.

[0110] A person skilled in the art would be able to easily develop a processor for executing any of the methods described in this document. Thus, each step of the flowchart may represent different operations executed by the processor and can be executed by individual modules of the processor.

[0111] As described above, this system utilizes a processor for data processing. The processor can be implemented in various ways using software and / or hardware to execute the various required functions. The processor typically uses one or more microprocessors and can be programmed using software (e.g., microcode) to execute the necessary functions. The processor can also be implemented as a combination of dedicated hardware for executing some functions and one or more programmed microprocessors and associated circuitry for executing other functions.

[0112] Examples of circuits that can 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).

[0113] In various implementations, the processor can be associated with one or more storage media such as volatile and non-volatile computer memories such as RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that execute the required functions when executed by one or more processors and / or controllers. The various storage media may be fixed within the processor or controller, or may be transportable such that one or more programs stored therein can be loaded into the processor.

[0114] Modifications to the disclosed embodiments can be understood and implemented by those skilled in the art of practicing the invention claimed in the claims upon review of the figures, disclosure, and 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.

[0115] The functions implemented by the processor can be implemented by a single processor or by a plurality of individual processing units that are considered to constitute the "processor" together. Such processing units may in some cases be separated from each other and can communicate with each other by wire or wirelessly.

[0116] The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used advantageously.

[0117] The computer program can be stored / distributed on a suitable medium such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0118] It should be noted that in the claims or the specification, when the term "adapted to" is used, the term "adapted to" is intended to be equivalent to the term "configured to". It should also be noted that in the claims or the specification, when the term "arrangement" is used, the term "arrangement" is intended to be equivalent to the term "system", and vice versa.

[0119] Any reference signs in the claims shall not be construed as limiting the scope of the invention.

Claims

1. An oral care system, comprising: An oral care device including a sensor system configured to measure one or more parameters of the oral care device or the user's oral cavity during use of the oral care device; A processor configured to obtain one or more parameters from the sensor system and determine an opening value of the user based on the one or more parameters; wherein at least one of the one or more parameters is an orientation of the oral care device in the user's oral cavity, and the processor is further configured to: Use an orientation measurement value from the sensor system to detect a change in the orientation of the oral care device; Determine the opening value of the user based on the change in the orientation; and / or wherein at least one of the one or more parameters is a movement of the oral care device in the user's oral cavity, and the processor is further configured to determine the opening value of the user based on the movement of the oral care device.

2. The system according to claim 1, wherein the processor is further configured to determine a position of the oral care device in the user's oral cavity.

3. The system according to claim 1 or 2, wherein the processor is further configured to determine whether the oral care device is used on the rearmost teeth of the user's upper jaw, and determining the opening value is based on a measurement value from the sensor system corresponding to the oral care device being used on the rearmost teeth of the user's upper jaw.

4. The processor determines whether the oral care device is used on the rearmost teeth of the user's upper jaw by using one or more parameters from the sensor system, Determining that the oral care device is positioned in the upper jaw, Determining that the oral care device has moved towards the back of the mouth, The system according to claim 3, wherein the processor determines that the oral care device is positioned on the occlusal surface side of the rearmost teeth of the upper jaw.

5. The system according to any one of claims 1 to 4, wherein at least one of the one or more parameters is a depth of the oral care device in the user's oral cavity, and determining the opening value is further based on the depth of the oral care device in the user's oral cavity.

6. The system according to any one of claims 1 to 5, wherein the processor further considers a size of the oral care device when determining the opening value.

7. The processor is further configured to: Tracking one or more parameters from the sensor system over time with respect to the user, The system according to any one of claims 1 to 6, tracking the progress of the user's opening based on the change over time of the one or more parameters.

8. The processor further tracks one or more parameters from a sensor system in a plurality of oral care devices used by the user, and tracking the progress of the user's opening comprises combining one or more parameters tracked for the plurality of oral care devices, during which combination, the one or more parameters are weighted based on the corresponding oral care device. The system according to claim 7.

9. The system according to any one of claims 1 to 8, wherein the oral care device is a toothbrush, a jet injection device, or a toothbrush with a jet injection device.

10. The system according to any one of claims 1 to 9, wherein the sensor system has an acoustic sensor for measuring sounds in the user's oral cavity, and determining the opening value is based on the sounds in the user's oral cavity.

11. The system according to any one of claims 1 to 10, wherein the sensor system has a distance sensor and / or a proximity sensor disposed at a distal portion of the oral care device, and the distal portion of the oral care device is the portion of the oral care device inserted into the user's mouth.

12. A computer program including computer program code that, when executed on a computing device having a processing system, causes the processing system to execute a method, the method comprising: Obtaining one or more parameters from a sensor system of an oral care device, wherein the parameters are parameters of the oral care device during use of the oral care device or parameters of the user's oral cavity. Determining an opening value of the user based on the one or more parameters. At least one of the one or more parameters is the orientation of the oral care device in the user's oral cavity, and the processor further Uses an orientation measurement value from the sensor system to detect a change in the orientation of the oral care device. Determines an opening value of the user's mouth based on the change in the orientation, and / or A computer program, wherein at least one of the one or more parameters is the movement of the oral care device in the user's oral cavity, and the processor further determines an opening value of the user based on the movement of the oral care device.

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