Determining degree of opening

Abstract

An oral care system includes 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 an oral cavity of a user when the oral care device is used by the user. The processor is configured to obtain the one or more parameters from the sensor system and determine a mouth opening value of the user using the one or more parameters.

Description

Technical Field

[0001] The present invention relates to the field of oral health. In particular, the present invention relates to the field of detecting trismus and temporomandibular joint dysfunction. Background Art

[0002] Trismus (often called "Lockjaw") and temporomandibular joint (TMJ) dysfunction (TMJD) result in reduced jaw opening or limited movement. Trismus and TMJD interfere with eating, speaking, and maintaining normal oral hygiene. When untreated or undiagnosed, trismus and TMJD can become chronic and painful, and cause migraines, back, neck and shoulder discomfort, and hearing impairment / loss, impacting a person's daily life and health.

[0003] Examination and treatment of trismus and TMJD often requires access to the mouth, which may be limited or, in some cases, not possible. Trismus may be caused by joint problems, infection, trauma, cancer treatment, or post-dental care. For example, temporomandibular joint disease may lead to trismus. In the United States, approximately 12% of the population (approximately 35,000,000 people) are affected by TMJD at any given time.

[0004] Another significant cause of trismus is head and neck cancer, where the prevalence of trismus is estimated to be as high as 38%. For patients with this type of cancer, trismus treatment focuses primarily on preventing the progression of trismus and restoring jaw function. Currently, there is no non-invasive mechanism for tracking the progression of trismus or tracking the restoration of jaw function to allow health professionals to observe how their patients are responding to treatment.

[0005] A common method of diagnosing the severity of trismus is to measure the subject's mouth opening by means of a tool such as a Boley gauge or ruler. Normal mouth opening (i.e., no trismus) is expected to be above 40 mm. Mild trismus is typically classified as a mouth opening between 30 and 40 mm, moderate trismus is typically classified as a mouth opening between 15 and 30 mm, and severe trismus is typically classified as a mouth opening less than 15 mm.

[0006] Alternatively, a three-finger screening test can be used to estimate the severity of trismus. In the three-finger screening test, the subject attempts to open the mouth as wide as possible to place their fingers between the upper and lower teeth. Being able to accommodate three or more fingers generally indicates no trismus, two to three fingers indicates mild trismus, one to two fingers indicates moderate trismus, and less than one finger indicates severe trismus.

[0007] Both methods are considered invasive, require a second person to take the measurements, and do not provide health professionals with the tools they need to monitor a patient's progress after a procedure such as wisdom tooth removal.

[0008] US5097820A discloses a device that can be used to diagnose and treat limited mouth opening. However, such devices are often invasive and very expensive. WO2017015342A1 discloses a trismus rehabilitation device similar to the device disclosed in US5097820A, which has additional sensors to measure the pressure applied at different points on the jaw to estimate the mouth opening.

[0009] The main limitation of these solutions is that their purpose is limited to single-site measurements, usually performed by dental professionals in a practice or clinic, and therefore are not used frequently by subjects. This reduces their usefulness in large-scale monitoring of TMJD or trismus. Additionally, it is difficult to digitize these measurements in a seamless workflow to enable long-term monitoring of disease progression.

[0010] Therefore, there is a need for improved devices to detect the presence of trismus or any oral opening / closing disorder and to continuously track its progression, particularly in a home setting. Summary of the invention

[0011] The invention is defined by the claims.

[0012] According to an example of one aspect of the present invention, there is provided an oral care system, comprising:

[0013] An oral care device comprising a sensor system configured to measure one or more parameters of the oral care device or a user's oral cavity during use of the oral care device; and

[0014] A processor is configured to obtain one or more parameters from the sensor system and determine a mouth opening value of the user based on the one or more parameters.

[0015] Oral care devices are not used to treat mouth opening disorders (such as trismus). For example, oral care devices can be used to maintain oral hygiene or as therapeutic devices for treating other oral health disorders other than mouth opening disorders.

[0016] Trismus, commonly referred to as lockjaw, is a condition in which jaw movement is restricted and may interfere with eating, speaking or maintaining oral hygiene. Current methods for detecting trismus and determining its severity include measuring the user's mouth opening using a Boley gauge, a ruler, or in some cases, using the number of fingers that fit the mouth opening. However, finger measurements are not particularly accurate and have very limited resolution, while more precise measurements are difficult to perform on your own.

[0017] Thus, it has been realized that trismus or any other cause of restricted mouth opening can be detected while the user is maintaining oral hygiene. For example, brushing teeth or using a jet device is typically performed on a daily basis. This increases the amount of data obtained related to trismus detection without requiring the user to add additional activities to their daily life or perform difficult or uncomfortable tests.

[0018] The idea of ​​the present invention is that when using most oral care devices, the user must at some point open their mouth as wide as possible. Therefore, a sensor system can be added to the oral care device and configured to obtain parameters indicative of the oral care device or the user's mouth, thereby providing an indication of how wide the user's mouth can be opened. The measured parameters can be suitable for determining the degree of opening of the user's mouth during use of the oral care device.

[0019] The mouth opening value is a value (or set of values) that indicates how much a user physically opens their mouth. The method may comprise determining a maximum mouth opening value.

[0020] The maximum mouth opening value is a value (or set of values) that indicates the degree to which a user can physically open their mouth. Typically, the maximum mouth opening value is a measure of the distance between the upper and lower front teeth. However, any distance at any point in the mouth also indicates the mouth opening. Similarly, it has been recognized that the maximum angle formed by the upper and lower jaws when the mouth is open also indicates the degree to which a user can physically open their mouth. Therefore, the maximum mouth opening value can be a distance measurement relative to the position of the mouth, or an angle measurement.

[0021] A minimum mouth opening may also be determined similarly or alternatively. The minimum mouth opening is a value (or set of values) indicating the degree to which a user can physically close their mouth. This information helps to ultimately identify oral closure disorders. The minimum mouth opening may also be referred to as the maximum oral closure.

[0022] When a user performs a specific action, a mouth opening value can be determined. The method can include determining whether the user is performing a specific action and using parameters corresponding to when the user performs the action. The specific action can vary depending on the oral care device selected and the mouth opening value required. For example, when using a spraying device, the mouth can be closed when the user sprays the upper front teeth, thereby allowing a minimum mouth opening to be determined. The specific action can include brushing and / or spraying a specific area of ​​the mouth.

[0023] The oral care device may be an oral care device for maintaining oral hygiene. Alternatively, the oral care device may be a therapeutic device.

[0024] At least one of the one or more parameters may be an orientation of the oral care device in the user's mouth, and wherein the processor is further configured to detect a change in orientation of the oral care device using orientation measurements from the sensor system and determine a mouth opening value for the user based on the orientation change.

[0025] Detecting changes in orientation provides an alternative measurement of the angle of mouth opening. It has been found that the maximum angle at which a user's mouth can be opened provides a strong indication of potential trismus or other conditions that restrict mouth opening. Thus, maximum mouth opening can be measured at a maximum angle, rather than the typical distance measurement between the front teeth.

[0026] The orientation may include at least one angle measurement. The angle measurement may be a measurement relative to gravity and / or relative to the teeth. For example, the angle measurement may include 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 mouth opening value.

[0027] At least one parameter of the one or more parameters may be movement of the oral care device in the user's mouth, and wherein the processor is further configured to determine a mouth opening value of the user based on the movement of the oral care device.

[0028] The movement of the oral care device can also provide a suitable measurement to determine the maximum mouth 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 mouth opening.

[0029] The processor may also be configured to determine the position of the oral care device in the user's mouth.

[0030] At least one of the one or more parameters may be a position of the oral care device in the user's mouth. Thus, the processor may determine the position of the oral care device by obtaining the position of the oral care device in the user's mouth from the sensor system.

[0031] Alternatively, the processor can process one or more parameters to determine the position of the oral care device in the user's mouth. For example, a distance sensor can be used to measure the maximum distance to the back of the mouth and determine the position by comparing the current distance to the maximum distance to the back of the mouth.

[0032] The processor may also be configured to determine whether the oral care device is being used on the most posterior teeth of the user's upper jaw, and wherein determining the mouth opening value is based on measurements from the sensor system corresponding to the oral care device being used on the most posterior teeth of the user's upper jaw.

[0033] It has been found that when a user uses an oral care device on the most posterior teeth in the upper jaw (e.g. wisdom teeth), this naturally causes the jaw to drop to its maximum extent, thereby opening the mouth to its maximum extent. Therefore, measurements taken at this point are likely to indicate maximum mouth opening.

[0034] A processor using one or more parameters from a sensor system can be configured to determine whether an oral care device is being used on the most posterior teeth of the user's upper jaw by determining that the oral care device is positioned on the upper jaw, determining that the oral care device has moved toward the back of the mouth, and determining that the oral care device is positioned on the occlusal side of the most posterior teeth of the upper jaw.

[0035] At least one parameter of the one or more parameters may be a depth of the oral care device in the user's mouth, and wherein determining the mouth opening value is further based on the depth of the oral care device in the user's mouth.

[0036] The depth of the oral care device provides context for the position of the oral care device in the user's mouth. Where the sensor system provides motion measurements of the oral care device, the depth in the mouth can be used to convert the motion measured at the measured depth to a corresponding motion at zero depth (i.e., at the front of the mouth where maximum mouth opening measurements are typically performed).

[0037] Additionally, any measurement from the sensor system can be compared to previous measurements corresponding to the same depth to track underlying disease conditions that limit maximum mouth opening.

[0038] The processor may also be configured to take into account the size of the oral care device when determining the mouth opening value.

[0039] The dimensions of an oral care device may include the thickness, diameter, width, height, and / or length of the oral care device.

[0040] The processor may also be configured to track changes in one or more parameters from the sensor system for the user over time, and track the progression of the user's mouth opening based on the changes in the one or more parameters over time.

[0041] The processor may also be configured to track one or more parameters from sensor systems in multiple oral care devices used by the user, wherein tracking the progress of the user's mouth opening includes combining the tracked one or more parameters of the multiple oral care devices, wherein during the combination, the one or more parameters are weighted based on the corresponding oral care devices.

[0042] The processor may also be configured to determine how much time has elapsed since the last time the mouth opening value was determined, and if the time is greater than a threshold time period, prompt the user to use the oral care device.

[0043] The oral care device may be a toothbrush, a spray device, or a toothbrush with a spray device.

[0044] The sensor system may include one or more of an accelerometer, a rotation sensor, a displacement sensor, a position sensor, a force sensor, a pressure sensor, a torque sensor, and an angle sensor, a distance sensor.

[0045] The sensor system may include an acoustic sensor for measuring sounds in the user's mouth, wherein determining the mouth opening value is based on the sounds in the user's mouth.

[0046] At different values ​​of mouth opening, the user's mouth forms a cavity of different volumes. Sound resonates differently in different volume shapes and sizes. Therefore, the resonance characteristics of sound with the mouth depend on the user's mouth opening.

[0047] When the mouth is opened wider (or closed), the sound spectrum of the brush is expected to change. However, when the user's head is tilted and the mouth remains closed (or open), the sound spectrum remains unchanged. Therefore, the acoustic sensor can also be used to determine whether the change in the parameter corresponds to the user's head tilt or mouth opening.

[0048] When using a powered oral care device, the drive train damping of the oral care device while being used can also be acoustically measured to tell if the mouth is open.

[0049] The sensor system may include a distance sensor and / or a proximity sensor positioned at a distal portion of the oral care device, wherein the distal portion of the oral care device is the portion of the oral care device that is inserted into the user's mouth.

[0050] For example, the distal portion may be the head of a toothbrush.

[0051] The present invention also provides a method for determining a user's mouth opening or closing degree, the method comprising:

[0052] Obtaining one or more parameters from a sensor system on the oral care device, the parameters being parameters of the oral care device or parameters of the user's oral cavity during use of the oral care device; and

[0053] A mouth opening value of the user is determined based on one or more parameters.

[0054] The present invention also provides a computer program product comprising computer program code, which, when executed on a computing device having a processing system, causes the processing system to execute all the steps of the aforementioned method.

[0055] 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

[0056] For a better understanding of the present invention, and in order to more clearly show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0057] Figure 1 An open mouth is shown;

[0058] Figure 2 A toothbrush head having a sensor system on the head of the toothbrush is shown;

[0059] Figure 3 A toothbrush head with a sensor system for use in an oral cavity is shown;

[0060] Figure 4 An oral cavity having an isosceles triangle shape is shown;

[0061] Figure 5 and Figure 6 The toothbrush is shown being used on the most lateral teeth in the upper jaw;

[0062] Figure 7 The toothbrush is shown being used on the lingual side of the upper front teeth;

[0063] Figure 8 An image for determining mouth opening is shown; and

[0064] Fig. 9 A method for determining absolute mouth opening is shown. DETAILED DESCRIPTION

[0065] The present invention will be described below with reference to the accompanying drawings.

[0066] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, system, and method, are intended for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the invention may be better understood in conjunction with the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are schematic only and are not drawn to scale. It should also be understood that the same reference numerals represent the same or similar components throughout the drawings.

[0067] The present invention provides an oral care system, comprising an oral care device and a processor. The oral care device has a sensor system, which is configured to measure one or more parameters of the oral care device or the user's oral cavity when the oral care device is used by the user. The processor is configured to obtain the one or more parameters from the sensor system and use the one or more parameters to determine the user's mouth opening value.

[0068] A system for obtaining a user's mouth opening by using an oral care device is proposed. This enables, for example, a clinician to detect a mouth opening dysfunction when the user has the dysfunction and to estimate its progression by continued use of the system.

[0069] This facilitates continuous remote monitoring of TMJ dysfunction or trismus, thereby allowing health and dental professionals to evaluate and quantify the results of the treatment they provide. Another benefit is that by evaluating the requested treatment date with the date trismus was detected, health and dental insurance companies will have an additional data point to validate benefit claims related to TMJ dysfunction or trismus.

[0070] Figure 1 An open mouth is shown. As shown, the upper teeth 102 are not evenly separated from the lower teeth 104, and therefore the degree of mouth opening (lines 106 and 108) may vary depending on where the mouth opening is measured. Currently, mouth opening values / measurements are primarily taken at the front of the mouth (i.e., line 106) because this is the most easily obtained measurement from the outside, and therefore a clinician or other person can measure the user's mouth opening.

[0071] However, it should be understood that the mouth opening value can be obtained at any position in the oral cavity in a manner that can be interpreted by a clinician. For example, line 108 (near the middle of the oral cavity) can be used in conjunction with a specific position in the oral cavity. Conversely, when the position is unknown, the processor can obtain multiple measurements and find the maximum value among these measurements. The maximum measurement is usually interpreted as the mouth opening at line 106 (front of the oral cavity) because this is usually the position with the maximum mouth opening.

[0072] Maximum mouth opening is one of the most relevant mouth openings currently measured. Maximum mouth opening quantifies the maximum extent to which the user's mouth can open. A small maximum mouth opening can indicate the possibility of a mouth opening disorder. Similarly, minimum mouth opening (i.e., maximum mouth closure) is also a relevant mouth opening. If the user cannot completely close their mouth, it will result in a large minimum mouth opening, indicating the possibility of a mouth opening disorder.

[0073] It should be noted that Figure 1 Typical mouth openings are shown. In practice, the maximum mouth opening (and potentially the minimum mouth opening) is often more clinically relevant than the typical mouth opening. However, if accurate and frequent mouth openings can be obtained, the entire range of mouth openings may be relevant.

[0074] The inventors have recognized that the use of oral care / hygiene equipment (such as toothbrushes, dental floss equipment, spray equipment, etc.) all occurs in the user's mouth, and usually occurs frequently (such as once a day or more). In addition, considering the nature of the use of oral care equipment in the user's mouth, the user usually opens his mouth during use. Therefore, it is proposed to measure the user's mouth opening while using the oral care equipment. This enables the user to do two things at the same time (i.e., maintain oral hygiene and measure the mouth opening). Compared with the situation where the user or the usual clinician must perform the mouth opening measurement separately, this also means that the mouth opening value can be obtained more frequently.

[0075] The following examples will relate to measuring maximum mouth opening. However, it should be understood that the systems and methods described with respect to measuring maximum mouth opening can also be applied to the measurement of any general mouth opening. In certain cases where the system or method specifically relates to maximum mouth opening, alternatives to minimum mouth opening or general mouth opening can be provided.

[0076] Similarly, a toothbrush will be used in the following embodiments to illustrate the examples. However, it should be understood that other oral care devices may also be used.

[0077] In a first embodiment, the sensor is placed on the head of the toothbrush. Figure 2 A toothbrush head 202 is shown having a sensor system 206 in the head 202 of the toothbrush. The sensor system is placed at the distal end of the toothbrush head 202, close to the bristles 204 of the toothbrush head 202. In alternative embodiments, the sensor system may also be present in the handle of the oral care device.

[0078] The quantitative measure of mouth opening can depend on where along the patient's jaw the measurement is taken. This is because the mouth opens widest at the front and narrowest at the back.

[0079] Figure 3A toothbrush head 202 with a sensor system 206 is shown for use on the oral cavity. In this case, the sensor system may include proximity sensors and / or distance sensors and / or acceleration sensors (inertial measurement) and / or gyroscopes. In order to estimate the level of oral opening at any location in the oral cavity, a sensor system 206 is provided on the toothbrush head 202 for use on the oral cavity. In this case, the sensor system may include proximity sensors and / or distance sensors and / or acceleration sensors (inertial measurement) and / or gyroscopes. Figure 3 The sensor system determines the brush head position along a given jaw by performing distance measurements from the sensor system 206 attached to the vertical axis (i.e., along the line segment AB shown in FIG. Figure 3 The distance measurement obtained by the sensor on the line segment BC) shown in FIG. 1 determines the mouth opening at the current brush head position.

[0080] The elevation angle of the current position can be calculated (i.e., angle ∠BAC = ∠BAD). As shown in the figure, the isosceles triangle BAD can also be used. Point D can be found using a simple geometric shape consisting of points A, B, and C.

[0081] Those skilled in the art will appreciate that the calculation of segment BD is straightforward. Given the measurements of segment BC, an approximate isosceles triangle (ABD) can be created, from which basic trigonometric functions allow BD to be derived. To this end, segment AD is calculated by simply applying the Pythagorean theorem on triangle ABC.

[0082] Although neither the maxillary nor mandibular planes are linear, local linearity can be reasonably expected by measuring with the brush head as far posterior to the occlusal plane as possible, so that the mouth opening far in the mouth can be approximated by calculating the distance represented by line segment BD.

[0083] Therefore, the elevation angle can be used to estimate the mouth opening at any other point, including the maximum opening. Given the BD and the angle ∠BAD at a particular given point, the mouth opening at other points can be estimated. It is expected that the nonlinear planes of the two jaws may limit the accuracy of the proposed method. However, the mouth opening range is large enough (e.g. 15 mm for moderate trismus) that the estimates made using this method are expected to be within an acceptable range.

[0084] For example, Figure 4 A mouth with an isosceles triangle (AB'D') is shown. As shown, despite the irregularity of the tooth shape, the triangle surprisingly fits the shape of the mouth opening. Thus, it can be concluded that the isosceles triangle is a good descriptor of mouth opening. It follows that the angle ∠B'AD'=∠BAD can also be used to accurately express mouth opening. Thus, the mouth opening value is not limited to the distance measurement between the upper teeth 102 and the lower teeth 104, the elevation angle can also be used as a mouth opening value.

[0085] The first embodiment can be implemented with a sensor system having a dual sensor configuration, wherein the sensitive axes of the two sensors are perpendicular to each other. The orientation of the sensors is determined by Figure 3 The line segments BA and BC in are represented. Generally, the first example uses triangulation to estimate the mouth opening value.

[0086] In a second embodiment, the mouth opening value is determined using sensor data from a sensor system already present in current toothbrushes. In this embodiment, measurements are taken at unique brushing positions and orientations (e.g., behind upper or lower molars). In particular, the second embodiment enables measurements to be taken during precise and unique movements to achieve a desired mouth opening (e.g., maximum or minimum mouth opening).

[0087] While the first embodiment uses sensors added to the brush head to facilitate triangulation of mouth opening, it is recognized that sensors already present in the (electric) oral health device may also be used to assess and track the mouth opening. For example, accelerometers, inertial measurement units, rotation sensors (e.g., compasses, gyroscopes, etc.), displacement sensors, position sensors, Hall sensors, and / or printed strain gauges may already be present in an electric oral health care device.

[0088] As a reminder, the description and the drawings show an electric toothbrush as an example. However, any other toothbrush (e.g. a combined brushing and flossing device) or a water spray device or a flossing device may also be considered. In particular, a water spray device is extremely suitable because the head of the device with a nozzle is relatively long and narrow, which can reduce measurement problems (e.g. there is no problem of the wider device body of the toothbrush interfering with the measurement).

[0089] It has been recognised that during certain brushing movements (ie during brushing behind the rearmost molars / wisdom teeth), the user is forced to open the mouth maximally and rotate the brush through a certain angle until pressing hard against the jaw opposite the tooth being brushed.

[0090] The purpose of this embodiment is to measure this brushing motion and interpret the measurement as representative of mouth opening. Limited motion or reduced opening over time may be associated with mouth opening disorders (e.g., TMJ, trismus, etc.).

[0091] While measurements taken during cleaning of both the upper and lower teeth can in principle form an interpretation of mouth opening, the inventors have realised that using measurements taken while brushing behind the most lateral molars / wisdom teeth in the upper jaw may be preferred.

[0092] When brushing the upper jaw, the opening of the mouth causes the lower jaw to drop, so that the brush is initially in the same position as when brushing along the tops of the upper teeth, flat against the upper teeth. Starting from this fixed reference position, the brush must traverse the entire opening angle of the mouth before pressing against the lower jaw. Therefore, the movement measured is a direct measure of the degree of mouth opening.

[0093] In contrast, when brushing the lower jaw, the opening of the mouth again causes the lower jaw to drop. However, in this case, the jaw drop has already separated the brush from the jaw and there is no need to move the brush. From this starting position, the brush only needs to traverse a portion of the opening angle of the mouth before pressing against the upper jaw. Therefore, the movement measured may not be a direct measure of the degree of mouth opening. However, it must be noted that this measurement may have some predictive value for the longitudinal measurement.

[0094] Figure 5 and Figure 6 The toothbrush 502 is shown being used on the posterior-most teeth of the upper jaw 506. To determine the degree of openness of the mouth during brushing of the upper jaw 506, the following measurements are suitable measures:

[0095] - When brushing from the upper jaw 506 (such as Figure 5 ) to the lower jaw 508 (as shown) Figure 6 As shown), the total movement of the sensor system 504 (e.g., including an accelerometer and / or a position sensor) is measured.

[0096] - When the toothbrush 502 is moved from the upper jaw 506 (eg Figure 5 ) to the lower jaw 508 (as shown in Figure 6 ), the rotation angle of the sensor system 504 (e.g., including a compass and / or a gyroscope) is measured. If necessary, the distance from the top of the brush head to the sensor system 504 can be taken into account to convert the rotation angle into a movement amplitude.

[0097] For many use cases (e.g., such as determining the progression of TMJD), monitoring the measured changes in brush sensor motion or rotation angle may be sufficient.

[0098] However, for some use cases (e.g. determining the severity of TMJD / trismus), it may be preferable to determine the absolute opening of the mouth. To achieve this, the magnitude of the distance traversed by the brush at the location on the brush as it exits the mouth may be determined. This may be derived as follows:

[0099] Brushing motion with open mouth = sensor system 504 Figure 6 The measured motion between point E and point F in the figure is the ratio of the mouth depth (D-mouth opening) to the distance between the sensor system 504 and the brush head (D-sensor). The mouth depth (D-mouth opening) is the distance between the front-most teeth in the mouth and the back-most teeth in the mouth.

[0100] When calculating absolute mouth opening, the dimensions of the brush (e.g., diameter, thickness, etc.) where the brush is on the brush and leaves the mouth (brush diameter) may be considered: for example, mouth opening = distance traversed by the brush at the open mouth position + brush diameter.

[0101] Note that for this absolute mouth opening measurement, it is advantageous for the portion of the toothbrush that enters the mouth to be relatively narrow and of constant diameter. For example, a relatively long toothbrush can extend out of the mouth even when placed behind the last tooth. Spraying devices may be particularly suitable because they have an inherently elongated tube for spraying purposes.

[0102] It is also possible to determine the time when the brushing motion is most likely to be associated with the mouth opening. Specifically, if the sensor system 504 includes a motion or position sensor (or the like), the following pattern may represent a preferred measurement time:

[0103] - the brush is positioned to brush the top surfaces of the upper teeth;

[0104] - Move the brush back along the teeth;

[0105] - The brush stops moving (motion sensor) or the position is at or behind the rear molars / wisdom teeth (position sensor) and remains constant; and

[0106] - The measured brushing movement indicates possible mouth opening due to jaw drop.

[0107] In a particular use case, it may be determined that a particular brush head is being used specifically to brush behind the back teeth (i.e., a single-tuft brush head). The measurements in this particular use case may be given a higher weight because the user is likely focusing on brushing behind the molars and trying to open the mouth fully.

[0108] Obviously, the user does not necessarily have to do this every time they brush, as these jaw-related problems only develop slowly over time. However, if a relatively long time has passed since a measurement could be made, in an alternative method the user can be instructed to perform this specific movement by placing the device tip as described above, opening the jaw and moving the device parallel to the opening of the jaw. In this way, a good quality reference measurement can always be established. The user can be guided via an external device, such as an application on the user's smartphone.

[0109] Existing oral care devices use algorithms to determine the orientation of the oral device relative to the gravity vector. This can be used to determine the angle change when the mouth is open. Figure 6 Orientations 602 and 604 are shown in FIG. Orientation 602 is Figure 5 Point E shows the placement of sensor system 504 corresponding to orientation 602 of the toothbrush. Similarly, orientation 604 is the orientation corresponding to sensor system 504 being located at point F. Figure 6 The orientation of the toothbrush shown. Therefore, the angle θ between the two orientations can be found.

[0110] In some cases, conversion from angle measurements to mouth opening distance (requiring "jaw length") may not be necessary. In fact, angles of mouth opening may be more accurate (because fewer measurements are required) and may contain more information than distance measurements of mouth opening. Use of distance measurements of mouth opening (usually in mm) may be more common as they are easiest to assess according to current practice.

[0111] Robustness to head motion may also be a concern. Mouth opening may be confused with head tilt when orientation changes are detected. One approach to addressing this issue may be to use algorithms trained to differentiate between "mouth opening" and "head tilt". Algorithms such as these are currently used to determine the position of a toothbrush in the mouth.

[0112] For example, position sensing algorithms using inertial measurement unit (IMU) sensor signals have been used previously. These algorithms use the average or median direction of the brush over time to estimate the head tilt. The head tilt is then used to obtain a better estimate of the orientation of the brush relative to the user's head. In some cases, the direction of the head tilt can be re-estimated (based on the brush direction) each time the user changes to an action that acts on another section of the mouth.

[0113] A second approach could be to use pressure sensors to determine when the brush head is against the teeth and when the mouth is open due to "brushing behind the molars". A third approach could be to add an acoustic sensor to the sensor system. Due to the resonance of the mouth, increased sound levels and changes in the sound spectrum occur. These would be different based on whether the mouth is open or closed.

[0114] In a third embodiment, an image algorithm with dynamic image rescaling and calibration is used to determine the (maximum) mouth opening for a unique brushing position and orientation (brushing the lingual incisors).

[0115] Figure 7 A toothbrush 702 is shown being used on the lingual side of the upper front teeth 710. The toothbrush includes two markings 706 and 707 with a known length 708 between the markings 706. A camera 712 is used to capture an image of the action.

[0116] A third embodiment provides software-implemented mouth opening measurement using a calibrated toothbrush (or part thereof) and a camera (e.g., a camera in a smartphone) without the need for a sensor on the toothbrush 702. The camera could also be part of the toothbrush handle (distal end), and during brushing, the camera could be facing the bathroom mirror and in this way image the mouth opening.

[0117] The mouth opening is measured at the unique brushing orientation / position shown, thereby providing a reliable measurement of the width of the mouth opening. It has been recognized that during a particular brushing motion (e.g., brushing behind the maxillary or mandibular front teeth), the user is forced to open the mouth to the maximum and rotate the brush through a unique angle until it is pressed against the lingual maxillary or mandibular side opposite the teeth being brushed, such as Figure 7 shown.

[0118] By knowing the distance to (at least) one (reference) mark 706 of the length calibration toothbrush shaft and identifying the mark and the mouth opening (e.g. using a feature detection algorithm and / or a feature matching algorithm), the absolute mouth opening can be determined by, for example, accessing a database with known brush head or reference mark dimensions, deriving an image calibration or image scaling factor. The mark 706 can be a colored / textured dot added to the toothbrush or a mark inherent to the brush head (e.g. an ejector pin mark from an injection molding process). A single mark 706 (e.g. with a known diameter) can be used.

[0119] A database containing reference lengths 708 may be accessed, allowing images to be rescaled dynamically. Because the distance at which the images are taken cannot be reliably controlled (i.e., to perform compensation and automatic scaling for different image magnification factors), knowing the length enables the absolute maximum mouth opening value to be reliably determined (e.g., if images are taken in subsequent weeks).

[0120] The toothbrush 702 may be connected to a database of brush head design data (eg, diagrams and dimensions) including toothbrush (or portion thereof) dimensions (eg, in mm). A radio frequency identification (RFID) code may be used to identify the type of toothbrush attached.

[0121] Images were acquired while the toothbrush was in use to allow the degree of mouth opening to be determined. Figure 8 An image for determining mouth opening is shown. The user can brush their teeth and take an image (eg, via a smartphone camera) while brushing their front teeth. Alternatively, the camera can be part of a bathroom mirror.

[0122] The processor or cloud engine then performs the following algorithm steps to Figure 8 The absolute maximum mouth opening is determined from the acquired images as shown in the processed images in:

[0123] - Decompose RGB images into RGB channels;

[0124] -Apply feature recognition functions (e.g., boundary and edge detection) to distinguish between brush head features and oral features (e.g., lips, teeth) - see Figure 8 ;

[0125] - Identify markers 706 and 707 and measure the relative distance between the two markers (measured in pixels);

[0126] - Identify the relative mouth opening 804 (measured in pixels);

[0127] - rescaling the uploaded image based on the known distance 708 (e.g. measured in mm) of the boundary segmentation features and the markings 706 on the brush head and the relative measurements;

[0128] - using the relative distances of the markers 706 and 707 identified in the image and the known distance 708, a calibration factor (e.g., distance / pixel) may be determined; and

[0129] - Apply the length calibration factor to the relative mouth opening 804 to determine the absolute maximum mouth opening.

[0130] Optionally, the sensor system 704 already present in the toothbrush 702 can be used to improve the measurement accuracy by taking into account the influence of the brushing angle on the determination of the absolute mouth opening.It should be noted that the mandibular and maxillary incisors are brushed at different pitch angles.

[0131] The camera 712 can also be placed on the toothbrush 702. This takes advantage of the fact that the user usually brushes their teeth in front of a mirror. Therefore, the camera 712 can be placed on the toothbrush so that it captures an image of the user brushing their teeth reflected in the mirror in front of the user. This also eliminates the need to use an external camera while brushing teeth.

[0132] Fig. 9 A method for determining an absolute mouth opening is shown. The method includes receiving an image of a user brushing their teeth in step 902, measuring the (relative) length (in pixels) between marks (or other parts) on the toothbrush in step 904, and determining a calibration factor 906 (e.g., in pixels / mm or distance / pixel) using the measured length between the marks and the known length between the marks (e.g., extracted from a database) in step 906. In step 908, the (relative) mouth opening (in pixels) is also determined or measured based on the image. Therefore, the calibration factor can be applied to the (relative) mouth opening to determine the absolute mouth opening. Note that the mouth opening can be a maximum mouth opening, a minimum mouth opening, or any general mouth opening.

[0133] Those skilled in the art will be able to easily develop a processor for executing any method described herein. Therefore, each step in the flowchart may represent a different action performed by the processor and may be performed by a corresponding module of the processor.

[0134] As described above, the system utilizes a processor to perform data processing. The processor can be implemented in a variety of ways using software and / or hardware to perform various desired functions. The processor typically employs one or more microprocessors that can be programmed with software (such as microcode) to perform the desired functions. The processor can be implemented as a combination of dedicated hardware that performs some functions and one or more programmed microprocessors and their associated circuits that perform other functions.

[0135] Examples of circuits 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).

[0136] In various embodiments, 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 desired functions. The various storage media may be fixed in the processor or controller, or may be transportable so that one or more programs stored therein may be loaded into the processor.

[0137] In the process of implementing the claimed invention, those skilled in the art can understand and implement variations of the disclosed embodiments by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0138] The functions implemented by a processor may be implemented by a single processor or multiple separate processing units, which may be considered to collectively constitute a “processor.” In some cases, these processing units may be remote from each other and communicate with each other in a wired or wireless manner.

[0139] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0140] The computer program may be stored / distributed on an appropriate medium, such as an optical storage medium or solid-state medium provided with the hardware or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

[0141] If the term "suitable for" is used in the claims or the specification, it should be noted that the term "suitable for" is intended to be equivalent to the term "configured to". If the term "device" is used in the claims or the specification, it should be noted that the term "device" is intended to be equivalent to the term "system" and vice versa.

[0142] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An oral care system, comprising: An oral care device (202, 502) comprising a sensor system (206, 504) configured to measure one or more parameters of the oral care device or a user's oral cavity during use of the oral care device; as well as a processor configured to obtain the one or more parameters from the sensor system and determine a mouth opening value (106, 108) of the user based on the one or more parameters; and wherein at least one of the one or more parameters is an orientation of the oral care device in the user's mouth (602, 604), and wherein the processor is further configured to: detecting a change in orientation of the oral care device using orientation measurements from the sensor system; and Determining the mouth opening value of the user based on the orientation change; and / or Wherein at least one parameter of the one or more parameters is movement of the oral care device in the user's mouth, and wherein the processor is further configured to determine a mouth 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 also configured to determine a position of the oral care device in the user's mouth.

3. The system according to any one of claims 1 to 2, wherein: The processor is also configured to determine whether the oral care device is being used on the most posterior teeth of the user's upper jaw (506), and wherein determining the mouth opening value is based on measurements from the sensor system corresponding to the oral care device being used on the most posterior teeth of the user's upper jaw.

4. The system according to claim 3, wherein: Using the one or more parameters from the sensor system, the processor is configured to determine whether the oral care device is being used on the posterior-most tooth of the upper jaw of the user by: determining that the oral care device is positioned on the upper jaw (102); determining that the oral care device has moved toward the back of the oral cavity; as well as The oral care device is determined to be positioned on the occlusal side of the posterior-most tooth of the maxillary jaw.

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

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

7. A system according to any one of claims 1 to 6, wherein: The processor is also configured to: tracking the one or more parameters from the sensor system for the user over time; and The progress of the user's mouth opening is tracked based on changes in the one or more parameters over time.

8. The system according to claim 7, wherein: The processor is also configured to track one or more parameters from sensor systems in multiple oral care devices used by the user, wherein tracking the progress of the user's mouth opening includes combining the tracked one or more parameters of the multiple oral care devices, wherein during the combining, the one or more parameters are weighted based on the corresponding oral care devices.

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

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

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

12. A computer program product comprising computer program code which, when executed on a computing device having a processing system, causes the processing system to perform all of the following steps: obtaining one or more parameters from a sensor system (206, 504) on an oral care device (202, 502), the parameters being parameters of the oral care device or parameters of a user's oral cavity during use of the oral care device; as well as Determining a mouth opening value of the user based on the one or more parameters (106, 108); and wherein at least one of the one or more parameters is an orientation of the oral care device in the user's mouth (602, 604), and wherein the processor is further configured to: detecting a change in orientation of the oral care device using orientation measurements from the sensor system; and Determining a mouth opening value of the user based on the orientation change; and / or Wherein at least one parameter of the one or more parameters is movement of the oral care device in the user's mouth, and wherein the processor is further configured to determine a mouth opening value of the user based on the movement of the oral care device.

Images