Determining 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 to the field of detecting trismus and temporomandibular joint dysfunction. [Background technology]

[0002] Thrombosis (commonly known as lockjaw) and temporomandibular joint (TMJ) disorder (TMJD) cause reduced jaw opening or restricted movement. Thrombosis and TMJD can interfere with eating, speaking, and maintaining proper oral hygiene. If left untreated or undiagnosed, thrombus and TMJD can affect aspects of daily life and health by becoming chronic and painful, causing migraines, back, neck, and shoulder discomfort, 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 impractical. Trismus can be caused by joint problems, infections, trauma, cancer treatment, or after dental procedures. For example, temporomandibular joint disorder can cause trismus. Approximately 12% of the U.S. population (approximately 35 million people) suffer from TMJD at any given time.

[0004] Another prominent cause of trismus is head and neck cancer, with an estimated prevalence of trismus in these cases of up to 38%. In patients with this type of cancer, management of trismus focuses on preventing progression of trismus and restoring mandibular function. Summary of the Invention [Problem to be solved by the invention]

[0005] Currently, there is no non-invasive mechanism to track the progression of trismus or track the recovery of mandibular function to allow medical professionals to see how the patient responds to treatment.

[0006] A common method of diagnosing the severity of trismus is to measure the subject's mouth opening via an instrument such as a Borley gauge or ruler. A normal oral opening (i.e., no trismus) is expected to be greater than 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 attempts to open their mouth as wide as possible to accommodate a finger between their 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.

[0008] Both approaches are considered invasive, require another person to take the measurements, and do not provide medical professionals with the tools they need to monitor patient progress after procedures such as wisdom tooth extraction.

[0009] US5097820A discloses the construction of a device that can be used to diagnose and treat jaw opening limitations. However, such devices tend to be invasive and expensive. WO2017015342A1 discloses a Trismus rehabilitation device similar to the device disclosed in US5097820A, with additional sensors that measure pressure applied to various points on the jaw to estimate jaw opening.

[0010] The main limitation of these solutions is that they are limited to single-spot measurements, typically performed by dental professionals in a doctor's office or clinic, resulting in infrequent use by subjects. This reduces their usefulness in large-scale monitoring of TMJD or trismus. Furthermore, it is difficult to digitize these measurements in a seamless workflow that would allow for longitudinal monitoring of disease progression.

[0011] Therefore, there is a need for improved means to detect the presence of trismus or any mouth opening / closing disorder and to continuously track its progress, particularly in the home environment. [Means for solving the problem]

[0012] The invention is defined by the claims.

[0013] According to an example according to one aspect of the present invention, there is provided 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 of 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 aperture value for the user based on the one or more parameters.

[0014] The oral care device does not treat trismus (e.g., trismus). For example, the oral care device can be for maintaining oral hygiene or can be a treatment device for treating a second oral hygiene disorder that is not trismus.

[0015] Trismus, commonly referred to as lockjaw, is a condition that restricts jaw movement and can interfere with eating, speaking, or maintaining oral hygiene. Current approaches to detecting trismus and determining its severity involve measuring the user's mouth opening using a Borley gauge or ruler, or in some cases, using the number of fingers that fit into the mouth opening. However, finger measurements are not particularly accurate and have very limited resolution. Meanwhile, more accurate measurements are difficult to perform on one's own.

[0016] It has thus been realized that trismus or any other cause of mouth opening restriction can be checked when the user is maintaining oral hygiene, for example, brushing teeth or using a jet sprayer, which is typically done daily. This increases the amount of data obtained related to the detection of trismus, without requiring the user to add additional activities to their daily routine or to undergo difficult or uncomfortable tests.

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

[0018] The aperture value is a value (or set of values) that indicates how far the user physically opens their mouth. The method can include determining a maximum aperture value.

[0019] The maximum mouth opening value is a value (or set of values) that indicates how far a user can physically open their mouth. Typically, the maximum mouth 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 mouth opening. Similarly, the maximum angle that the upper and lower jaws form when the mouth is opened is understood to indicate how far the user can physically open their mouth. Thus, the maximum mouth opening value can be a distance measurement or an angle measurement relative to the position of the mouth.

[0020] A minimum mouth opening value can additionally or alternatively be determined. The minimum mouth opening value is a value (or set of values) that indicates how well a user can physically close their mouth. This information can be useful in ultimately identifying mouth closing disorders. The minimum mouth opening can also be referred to as the maximum mouth closure.

[0021] The opening value can be determined when the user is performing a specific action. The method can include determining whether the user is performing a specific action and using a corresponding parameter when the user is performing the action. The specific action can vary based on the selected oral care device and the desired opening value. For example, when using a jetting device, the mouth can be closed when the user is jetting the upper front teeth, which allows a minimum opening value to be determined. The specific action can include brushing and / or jetting 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 an orientation of the oral care device in the user's mouth, and the processor is further configured to detect changes in the orientation of the oral care device using orientation measurements from the sensor system and determine the user's mouth opening value based on the changes in orientation.

[0024] Detecting changes in orientation provides a surrogate measure of the angle at which the mouth can be opened. It has been found that the maximum angle at which a user can open their mouth provides a strong indication of potential trismus or other conditions that restrict mouth opening. Thus, maximum mouth opening can be measured in terms of maximum angle instead of the typical distance measurement between the incisors.

[0025] The orientation comprises 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 comprise 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 can be sufficient to determine the aperture value.

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

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

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

[0029] At least one of the one or more parameters can be a 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 may 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 may be used to measure the maximum distance to the back of the mouth and compare the current distance to the maximum distance to the back of the mouth to determine the position.

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

[0032] It has been found that when a user uses the oral care device on the backmost teeth in the upper jaw (such as wisdom teeth), this naturally results in the jaw being pushed down to its maximum, which in turn results in the mouth being opened to its maximum, and therefore measurements taken at this point are most likely to indicate the maximum mouth opening.

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

[0034] At least one of the one or more parameters may be 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.

[0035] The depth of the oral care device provides context for where the oral care device is within the user's oral cavity. If the sensor system provides motion measurements of the oral care device, the depth within the oral cavity can be used to convert measured movement at the measured depth to corresponding movement at a depth of zero (i.e., the front of the oral cavity, where maximum mouth opening is typically measured).

[0036] Additionally, any measurement from the sensor system can be compared to a previous measurement corresponding to the same depth to track potential conditions that limit maximum opening.

[0037] The processor may be further configured to take into account 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 from the sensor system for the user over time, and to track the progress of the user's mouth opening based on changes in the one or more parameters over time.

[0040] The processor may be further configured to track one or more parameters from sensor systems of multiple oral care devices used by the user, and tracking the progress of the user's mouth opening includes combining the one or more parameters tracked for the multiple oral care devices, wherein during the combination, 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 passed since the most recent determined opening value, and to alert the user to use the oral care device if the time is greater than a threshold time period.

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

[0043] The sensor system may include 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 may include an acoustic sensor for measuring sounds in the user's oral cavity, and determining the aperture value is based on the sounds in the user's oral cavity.

[0045] At different opening sizes, the user's mouth forms chambers of different volumes. Sound reverberates differently in different volume shapes and sizes. Thus, the characteristics of the sound resonating in the mouth depend on the user's opening.

[0046] When the mouth is opened wide (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 does not change. Therefore, the acoustic sensor can also be used to determine whether a change in a parameter corresponds to the user's head being tilted or the mouth being opened.

[0047] When using a powered oral care device, drive train damping can also be measured acoustically when the oral care device is in use to indicate whether the mouth is open.

[0048] The sensor system may include a distance sensor and / or a proximity sensor located on a distal portion of the oral care device, the distal portion of the oral care device being 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: acquiring one or more parameters from a sensor system of an oral care device, the parameters being parameters of the oral care device or parameters of a user's oral cavity while the oral care device is in use; and determining an aperture value for the user based on the one or more parameters.

[0051] 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 perform all the steps of the method described above.

[0052] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0053] [Figure 1] FIG. [Figure 2] FIG. 1 shows a toothbrush head with a sensor system in the head of the toothbrush. [Figure 3] FIG. 1 shows a toothbrush head with a sensor system for use in the oral cavity. [Figure 4] FIG. 1 shows an isosceles triangular mouth. [Figure 5] FIG. 1 shows a toothbrush used on the last teeth of the upper jaw. [Figure 6] FIG. 1 shows a toothbrush used on the last teeth of the upper jaw. [Figure 7] FIG. 1 shows a toothbrush used on the lingual side of the upper front teeth. [Figure 8] FIG. 10 shows images used to determine mouth opening. [Figure 9] FIG. 10 illustrates a method for determining absolute opening. DETAILED DESCRIPTION OF THE INVENTION

[0054] For a better understanding of the present invention, and in order to show more clearly how it may be carried into effect, reference will now be made to the accompanying drawings, which are given by way of example only, in which:

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

[0056] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will be better understood from the following description, appended claims, and accompanying drawings. It should be understood that the figures are schematic only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

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

[0058] A system is proposed that acquires a user's mouth opening using an oral care device, which allows, for example, a clinician to detect when a user has trismus and estimate its progression through continued use of the system.

[0059] This facilitates continuous remote monitoring of TMJ disorders or trismus and allows medical and dental professionals to evaluate and quantify the results of the treatments they provide. An added benefit is that medical and dental insurance companies will have an additional data point to validate benefit claims related to TMJ disorders or trismus by evaluating the date of the billed treatment versus the date the trismus was detected.

[0060] 1 shows an open mouth. As can be seen, the upper teeth 102 are not uniformly separated from the lower teeth 104, and therefore the opening (lines 106 and 108) can vary based on where the opening measurement is taken. Currently, opening values / measurements are often taken at the front of the mouth (i.e., line 106) because this is the most readily available measurement from the outside and therefore allows a clinician or other person to measure the user's opening degree.

[0061] However, it should be understood that an aperture value can be obtained at any location in 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 conjunction with a specific location in the mouth. In contrast, when the location is unknown, the processor can take many measurements and find the maximum of those measurements. The maximum measurement is typically interpreted as the aperture at line 106 (the front of the mouth) because this is typically the location with the largest aperture.

[0062] The maximum mouth opening is currently one of the most important mouth openings measured. It quantifies how far the user can open their mouth. A relatively small maximum mouth opening indicates a possible trismus. Similarly, the minimum mouth opening (i.e., maximum mouth closure) is also a relevant mouth opening. If the user cannot completely close their mouth, this will result in a relatively large minimum mouth opening, thereby indicating a possible trismus.

[0063] Note that Figure 1 shows typical openings. In practice, maximum openings (and potentially minimum openings) are typically more clinically relevant than typical openings. However, if accurate and frequent openings can be obtained, the full range of openings can be relevant.

[0064] The inventors have realized that using oral care / hygiene devices (e.g., toothbrushes, flossers, jet sprayers, etc.) are all used in a user's oral cavity and are typically used frequently (e.g., more than once a day). Furthermore, due to the nature of using an oral care device in a user's oral cavity, the user typically opens their mouth during use. Thus, it is proposed to measure the user's mouth opening while using the oral care device. This allows the user to do two things simultaneously (i.e., maintain oral hygiene and measure mouth opening). It also means that mouth opening values ​​are likely to be obtained much more frequently than if the user, or typically a clinician, had to measure the mouth opening separately.

[0065] The following examples relate to measuring maximum opening. However, it should be understood that the systems and methods described with respect to measuring maximum opening can also be applied to measuring any general opening. In specific cases where the system or method specifically relates to maximum opening, alternatives can be given for minimum opening or general opening.

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

[0067] In a first embodiment, the sensor is located in the head of the toothbrush. Figure 2 shows a toothbrush head 202 with a sensor system 206 in the head of the toothbrush 202. The sensor system is located 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 be present in the handle of the oral care device.

[0068] A quantitative measure of mouth opening can depend on where along the patient's jaw the measurement is taken, as the mouth opens widest in the front and narrowest in the back.

[0069] 3 shows a toothbrush head 202 equipped with a sensor system 206 used in the oral cavity. In this case, the sensor system may include proximity sensors and / or distance sensors and / or acceleration sensors (inertial measurements) and / or gyroscopes. To estimate the mouth opening level at any position in 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 FIG. 3). The degree of mouth opening at the current brush head position is determined from distance measurements obtained from a sensor attached to the vertical axis (i.e., along segment BC shown in FIG. 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 from points A, B, and C using simple geometry.

[0071] 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 constructed, from which basic trigonometric functions allow the deduction of BD. Thus, segment AD is calculated by a simple application of the Pythagorean theorem to triangle ABC.

[0072] Although both the maxillary and mandibular planes are not straight, local straightness can be reasonably expected by taking measurements when the brush head is as far posterior to the occlusal plane as possible, so that the far opening in the mouth can be approximated by calculating the distance represented by the line segment BD.

[0073] Therefore, the opening angle at any other point, including the maximum opening angle, can be estimated using the elevation angle. If both BD and the angle ∠BAD at that particular given point are known, it is possible to estimate the opening at other points. It is expected that the nonlinear plane of the jaws will limit the accuracy of the proposed approach. However, since the range of opening is large enough (e.g., 15 mm for moderate trismus), estimates made using this method are expected to be well within acceptable limits.

[0074] For example, Figure 4 shows a mouth with an isosceles triangle (AB'D'). As can be seen, the triangle fits the shape of the aperture surprisingly well, despite the irregular nature of the tooth shape. Thus, it can be concluded that an isosceles triangle is a good descriptor of the aperture. This leads to the conclusion that the angle ∠B'AD' = ∠BAD can also be used accurately to represent the aperture. Thus, the aperture 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 the aperture value.

[0075] The first embodiment can be implemented in a sensor system with a two-sensor configuration, where the sensitive axes of both sensors are perpendicular to each other. The orientation of the sensors is indicated by the segments BA and BC in Figure 3. Generally, the first example uses triangulation to estimate the aperture value.

[0076] In a second embodiment, the opening value is determined using sensor data from a sensor system already present in current toothbrushes. In this embodiment, measurements are taken at specific brushing positions and directions (e.g., behind the upper or lower molars). In particular, the second embodiment allows measurements to be taken during precise, unique movements that result in a desired opening (e.g., maximum or minimum opening).

[0077] While the first embodiment utilizes sensors added to the brush head to facilitate triangulation measurements of mouth opening, it has been found that sensors already present in the (powered) oral care device can also be used to assess and track mouth opening. For example, accelerometers, inertial measurement units, rotational sensors (compasses, gyroscopes, etc.), displacement sensors, position sensors, Hall sensors, and / or printed strain gauges may already be present in the powered oral care device.

[0078] Again, the description and figures show a powered toothbrush used as an example. However, any other toothbrush (e.g., a combined brushing and flossing device), water jet sprayer, or flossing device is also contemplated. In particular, a water jet sprayer is very suitable because the device head with the jet tube is quite elongated, which can reduce measurement problems (e.g., the wide device body of the toothbrush does not interfere with the measurement).

[0079] It has been found that during certain brushing movements, namely brushing behind the last molars / wisdom teeth, the user is forced to open their mouth as wide as possible and rotate the brush at an angle until the brush is pressed firmly against the jaw opposite the tooth being brushed.

[0080] The purpose of this embodiment is to measure this brush movement and interpret this measurement as an indication of mouth opening. Restricted movement, or a decreased mouth opening over time, may be related to trismus (TMJ, trismus, etc.).

[0081] Although measurements taken while cleaning the upper or lower teeth would in principle both provide an interpretation of mouth opening, the inventors have found that it may be preferable to use measurements taken while brushing behind the last molars / wisdom teeth in the maxilla.

[0082] During upper jaw brushing, the jaw opening causes the brush to drop, and the brush remains in the same initial position flat against the upper teeth as when brushing along the top surfaces of the upper teeth. From this fixed reference position, the brush must traverse the full opening angle of the mouth before it is pushed against the lower jaw. As a result, the measured movement is a direct measure of mouth opening.

[0083] In contrast, while brushing the lower jaw, the opening also causes the jaw to drop. However, in this case, the jaw drop already separates the brush from the jaw without the brush moving. From this starting position, the brush is only required to traverse a portion 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 longitudinal measurements.

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

[0085] For many use cases (eg, establishing the progression of TMJD), monitoring changes in measured brush sensor movement or rotation angle is sufficient.

[0086] However, in some use cases (e.g., determining the severity of TMJD / trismus), it may be preferable to establish the absolute mouth opening. To achieve this, the magnitude of the distance traversed by the brush can be established at the point on the brush where it leaves the mouth. This can be obtained as follows:

[0087] Brush movement during mouth opening = measured movement of sensor system 504 between points E and F in Figure 6 x ratio of mouth depth (D-opening) to distance between sensor system 504 and brush head (D-sensor). Mouth depth (D-opening) is the distance between the front and back teeth in the mouth.

[0088] When calculating the absolute opening degree, the size (diameter, thickness, etc.) of the brush at the point on the brush where the brush leaves the mouth (brush diameter) can be taken into account. For example, opening degree = distance traversed by the brush at the opening position + brush diameter.

[0089] It should be noted 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 a constant diameter. For example, a relatively long toothbrush will protrude from the mouth even when placed behind the last tooth. Jet spray devices are particularly suitable because they essentially have an elongated tube for spraying purposes.

[0090] It is also possible to establish the most likely moment to associate the brush movement with the aperture. Specifically, if the sensor system 504 comprises a motion sensor or a position sensor (or the like), the following pattern is likely to represent a preferred measurement moment: The brush is positioned to brush the top surfaces of the upper teeth. The brush moves backward along the teeth. The brush stops moving (motion sensor) or the position is at or behind the rear molars / wisdom teeth (position sensor) and remains constant. Brush movement, potentially representing opening due to jaw dropping, is measured.

[0091] A particular use case establishes that a particular brush head is used specifically for brushing the backs of the molars (i.e., a single-tuft brush head), and measurements made in this particular use case can be given higher weight because it is the case that the user is most likely to be concentrating on cleaning the backs of the molars and attempting to open their mouth fully.

[0092] Obviously, the user does not need to perform this maneuver every time they brush, because these jaw-related problems only develop slowly over time. However, if a relatively long period of time has passed since measurements were possible, an alternative approach would be to instruct the user 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 this manner, a consistently high-quality baseline measurement can be established. The user can be instructed via an external device (e.g., a smartphone app).

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

[0094] In some cases, conversion from angle measurements to aperture distance (requiring "jaw length") may not be required here. In fact, aperture angle may be more accurate (because it requires fewer measurements) and more informative than aperture distance measurements. Aperture distance measurements (typically in mm) are commonly used because they are easiest to assess in current practice.

[0095] Robustness to head movement is also noteworthy. When detecting changes in orientation, mouth opening can be confused with head tilt. One approach to address this is to use an algorithm trained to distinguish between "mouth opening" and "head tilt." Such algorithms are currently used to determine the position of a toothbrush in the oral cavity.

[0096] For example, position detection algorithms that utilize inertial measurement unit (IMU) sensor signals have been used before. These algorithms use the average or median direction of the brush over time to estimate head tilt. The head tilt is then used to obtain a better estimate of the brush orientation relative to the user's head. In some cases, the head tilt direction can be re-estimated (based on the brush direction) each time the user changes motion to a different segment of the mouth.

[0097] The second approach uses pressure sensors to determine when the brush head is pressed against the teeth and when opening is due to "brushing the back of the molars." The third approach is to add an acoustic sensor to the sensor system. Oral resonances cause an increase in volume and a change in spectrum, which 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) mouth opening in a specific brushing position and direction (lingual incisor brushing).

[0099] Figure 7 shows a toothbrush 702 being used on the lingual sides of the upper front teeth 710. The toothbrush has two markers 706 and 707 with a known length 708 between markers 706. A camera 712 is used to capture images of this action.

[0100] A third embodiment provides software-enabled measurement of mouth opening by using a calibrated toothbrush (or part thereof) and a camera (e.g., on a smartphone) without the need for a sensor on the toothbrush 702. The camera can be part of the handle (distal end) of the toothbrush, while facing a bathroom mirror and photographing the mouth opening in that manner during brushing.

[0101] The mouth opening is measured at specific brushing orientations / positions as shown, which provide a reliable measurement of mouth opening width. It has been recognized that during certain brushing movements (e.g., brushing the back of the upper or lower incisors), the user is forced to open their mouth as wide as possible and rotate the brush at a specific angle until the brush is pressed firmly against the lingual side of the upper or lower jaw to brush the teeth, as shown in Figure 7.

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

[0103] A database containing reference lengths 708 can be accessed, allowing the image to be dynamically rescaled. A known length allows the absolute maximum aperture value to be reliably determined (e.g., if images are to be taken in the following week), since one cannot reliably control the distance at which images are taken (i.e., corrections for different image magnifications and automatic scaling are performed).

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

[0105] Images are taken while the toothbrush is in use, allowing the degree of mouth opening to be determined. Figure 8 shows the images used to determine the degree of mouth opening. The user can brush their teeth and take images (e.g., via a smartphone camera) as the incisors are brushed. Alternatively, the camera can be part of a bathroom mirror.

[0106] The processor or cloud engine then performs the following algorithm steps to determine the absolute maximum opening from the acquired image, as shown in the processed image of FIG. 8. Decomposes an RGB image into its RGB channels. Feature recognition functions (e.g., boundary and edge detection) are applied to distinguish between brush head features and oral features (e.g., lips, teeth), see FIG. Markers 706 and 707 are identified and the relative distance between them (measured in pixels) is determined. The relative aperture 804 (measured in pixels) is determined. The uploaded image is rescaled based on the boundary segmented features, the known distance 708 (measured in mm, for example) of the markers 706 on the brush head, and the relative measurements. Using the relative distance of the identified markers 706 and 707 in the image and the known distance 708, a calibration factor can be determined (eg, distance / pixel). A length calibration factor is applied to the relative opening 804 to determine the absolute maximum opening.

[0107] Optionally, the sensor system 704 already present in the toothbrush 702 can be used to improve the accuracy of the measurement by taking into account the effect of brushing angle on the determination of absolute mouth opening. Note that the lower and upper incisors are brushed at different pitch angles.

[0108] The camera 712 can also be placed on the toothbrush 702. This takes advantage of the fact that users typically brush their teeth in front of a mirror. Thus, the camera 712 can be placed on the toothbrush so that it captures an image of the mirror in front of the user that reflects the user brushing their teeth. This eliminates the need to use an external camera when brushing.

[0109] 9 shows a method for determining absolute mouth opening. The method includes receiving an image of a user brushing their teeth in step 902, measuring the (relative) lengths (in pixels) between markers (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 lengths between the markers and known lengths between the markers, e.g., extracted from a database. The (relative) mouth opening is also determined or measured (in pixels) from the image in step 908. Thus, the calibration factor can be applied to the (relative) mouth opening to determine the absolute mouth opening. Note that the mouth opening may be a maximum mouth opening, a minimum mouth opening, or any general mouth opening.

[0110] Those skilled in the art will be able to readily develop a processor to perform any of the methods described herein. Thus, each step of the flowchart may represent a different operation performed by a processor and may be performed by separate modules of the processor.

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

[0112] Examples of circuitry that may be employed in various embodiments of the present application include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

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

[0114] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the figures, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0115] The functions performed by a processor may be performed by a single processor or by multiple individual processing units which together may be considered to constitute a “processor.” Such processing units may be remote from each other and may communicate with each other via wired or wireless communication.

[0116] 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.

[0117] The computer program may 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 may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

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

[0119] Any reference signs in the claims should 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 that measures one or more parameters of the oral care device or of a user's oral cavity during use of the oral care device; a processor that acquires one or more parameters from the sensor system and determines an aperture value for the user based on the one or more parameters; 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 further comprises: detecting a change in the orientation of the oral care device using orientation measurements from the sensor system; determining an aperture value for the user based on the change in orientation; and / or An oral care system, 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 further determines an opening value of the user based on the movement of the oral care device.

2. The system of claim 1 , wherein the processor further determines a position of the oral care device in the user's oral cavity.

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

4. The processor uses one or more parameters from the sensor system to determine whether the oral care device is to be used on the user's upper back teeth; determining that the oral care device is positioned on the upper jaw; determining that the oral care device has moved to the back of the mouth; The system of claim 3 , wherein the determination is made by determining that the oral care appliance is positioned on the occlusal side of the rearmost maxillary tooth.

5. 5. The system of claim 1, 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 of claim 1 , wherein the processor further considers the size of the oral care device when determining the aperture value.

7. The processor further comprises: tracking one or more parameters from the sensor system over time for the user; 5. The system of claim 1, wherein the system tracks the progress of the user's mouth opening based on changes in the one or more parameters over time.

8. 8. The system of claim 7, wherein the processor further tracks one or more parameters from sensor systems in multiple oral care devices used by the user, and tracking the progress of the user's mouth opening includes combining one or more parameters tracked for the multiple oral care devices, wherein during the combination, the one or more parameters are weighted based on the corresponding oral care device.

9. The system of claim 1 , wherein the oral care device is a toothbrush, a jet sprayer, or a jet sprayer toothbrush.

10. 5. The system of claim 1, wherein the sensor system comprises an acoustic sensor that measures sounds in the user's oral cavity, and determining the opening value is based on the sounds in the user's oral cavity.

11. 5. The system of claim 1, wherein the sensor system comprises a distance sensor and / or a proximity sensor positioned in a distal portion of the oral care device, the distal portion of the oral care device being the portion of the oral care device that is inserted into the user's mouth.

12. 1. A computer program comprising computer program code that, when executed on a computing device having a processing system, causes the processing system to perform a method, said method comprising: acquiring one or more parameters from a sensor system of an oral care device, the parameters being parameters of the oral care device or parameters of a user's oral cavity while the oral care device is in use; determining an aperture value for the user based on the one or more parameters; 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 processing system further comprises: detecting a change in the orientation of the oral care device using orientation measurements from the sensor system; determining a mouth opening value for the user based on the change in orientation; and / or The computer program product, 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 processing system further determines an opening value of the user based on the movement of the oral care device.

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