JP6548971B2 - Electric toothbrush device - Google Patents

Description

  The present invention relates to an electric toothbrush device.

  An electric toothbrush apparatus that detects the posture of the brush using an acceleration sensor or an angular velocity sensor, and estimates the brushed part from among the parts defined by dividing the upper and lower dentition surfaces into a plurality based on the detected posture Are known (see, for example, Patent Document 1).

  And as an electric toothbrush apparatus which presume a brushing part, the electric toothbrush apparatus which evaluates the brushing result for every part based on the brushing time for every part, a brush angle, and a brush pressure and outputs an evaluation result is also known (for example, , Patent Document 2).

JP, 2009-240759, A JP, 2011-139844, A

  Generally, the most back teeth tend to have a large amount of polishing residue. If the most back teeth can be detected as the brushing site, it is possible to present the evaluation result regarding the most back teeth brushing to the user, which contributes to the health improvement of the teeth.

  In the electric toothbrush device described in Patent Document 2, a plurality of electrodes are provided at intervals in the longitudinal direction of the brush handle, and when the estimated brushing portion hits the back side portion of the dentition end, the brush The innermost teeth are detected based on contact patterns between a plurality of electrodes provided on the handle and a living body (cheek or tongue).

  However, although the contact between each of the electrodes and the living body is detected based on the impedance, the detection accuracy of the impedance may be reduced depending on the state of the surface of the electrode or the living body. Moreover, in addition to the sensor for detecting the attitude | position of a brush, the detection part of several electrodes and an impedance is required, and the structure of an electric toothbrush apparatus becomes complexity.

  The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide an electric toothbrush that can accurately estimate a brushing region with a simple configuration.

  The electric toothbrush apparatus according to the present invention uses the locus detection unit that detects the locus of movement of the brush, the posture detection unit that detects the posture of the brush, and at least the locus detected by the locus detection unit. When a part estimation unit that estimates a brushing part at a position and the brushing part estimated by the part estimation unit is the back side part of the dentition end, a change in posture detected by the posture detection unit And the region estimation unit, when the backmost teeth detection unit detects the backmost teeth, the backmost teeth detection unit detects the backmost teeth in the trajectory detected by the trajectory detection unit. And update the brushing site at each position on the trajectory based on the updated most back teeth position.

  ADVANTAGE OF THE INVENTION According to this invention, the electric toothbrush apparatus which can estimate a brushing site | part precisely with a simple structure can be provided.

It is a block diagram showing composition of an example of an electric toothbrush device for describing an embodiment of the present invention. It is a perspective view which shows the external appearance of the electric toothbrush apparatus of FIG. It is sectional drawing which shows the internal structure of the electric toothbrush of FIG. It is a figure which shows an example of division of a brushing site | part. It is a flowchart which shows an example of a brushing evaluation process. It is a figure which shows an example of the estimation method of the brushing site | part based on the attitude | position of a brush. It is a figure which shows an example of the detection method of the innermost tooth based on the attitude | position of a brush. It is a figure which shows the other example of the detection method of the innermost tooth based on the attitude | position of a brush. It is a figure which shows an example of the detection method of the innermost tooth based on the locus | trajectory of a movement of a brush. It is a figure which shows an example of a correction process of a brushing site | part. It is a figure for demonstrating a brush angle. It is a figure which shows an example of the output of the evaluation result of a brushing. It is a figure which shows the structure of the modification of an electric toothbrush apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of an example of an electric toothbrush device to explain the embodiment of the present invention, FIG. 2 shows the appearance of the electric toothbrush device of FIG. 1, and FIG. 3 shows the electric toothbrush device of FIG. Shows the internal configuration of the main unit of

<Configuration of Electric Toothbrush Device>
The electric toothbrush device 1 shown in FIG. 1 and FIG. 2 incorporates a motor 10 as a drive source and has a main body 2 having a brush 5 vibrating with the drive of the motor 10 and a main body 2 mounted thereon to charge the main body 2 And a display 110 for outputting the result of brushing.

  The main body 2 has a substantially cylindrical shape, and also serves as a handle for a user to hold by hand when brushing teeth. The main body 2 is provided with a switch S for switching power on / off and the like. Further, inside the main body 2, a motor 10 as a drive source, a drive circuit 12, a rechargeable battery 13 as a power source, a coil 14 for charging, and the like are provided. When charging the rechargeable battery 13, charging can be performed in a non-contact manner by electromagnetic induction only by mounting the main body 2 on the charger 100. The drive circuit 12 includes a central processing unit (CPU) 120 that executes various calculations and controls, a memory 121 that stores programs and various setting values, a timer 122, a data transmission unit 123, and the like. The data transmission unit 123 performs wireless communication with the data reception unit 112 of the display 110. The display 110 includes a display 111 for outputting data such as the brushing result received by the data receiving unit 112.

  Furthermore, in order to detect the movement trajectory and three-dimensional attitude of the brush 5 inside the main body 2, for example, a multi-axis (here three axes of x, y, z) acceleration sensor 15 and Here, an angular velocity sensor 16 of three axes x, y, z) and a geomagnetic sensor 17 of multiple axes (three axes x, y, z here) are provided.

  The acceleration sensor 15 is installed such that the x-axis is parallel to the brush surface, the y-axis coincides with the longitudinal direction of the main body 2, and the z-axis is perpendicular to the brush surface. That is, when the main body 2 is placed on the charger 100, the gravitational acceleration vector becomes parallel to the y axis, and when the brush surface is directed upward, the gravitational acceleration vector becomes parallel to the z axis, and the main body 2 is The gravity acceleration vector becomes parallel to the x-axis when the brush surface is oriented horizontally with the brush surface oriented horizontally. The output of each axis of the acceleration sensor 15 is input to the CPU 120 and is used to detect the trajectory and attitude of the movement of the brush 5. As the acceleration sensor 15, a piezoresistive type, capacitance type, or heat detection type MEMS sensor can be preferably used. This is because the MEMS sensor is so compact that it can be easily incorporated into the main body 2. However, the form of the acceleration sensor 15 is not limited to this, and an electrodynamic sensor, a strain gauge sensor, a piezoelectric sensor, or the like may be used.

  The angular velocity sensor 16 is installed to be able to detect an angular velocity around the x axis, an angular velocity around the y axis, and an angular velocity around the z axis. The output of each axis of the angular velocity sensor 16 is input to the CPU 120 and is used to detect the locus and posture of movement of the brush 5. As the angular velocity sensor 16, any type such as vibration type, optical type, mechanical type can be used, but a MEMS sensor can be suitably used because it is small and easy to be incorporated into the main body 2. .

  The geomagnetic sensor 17 is installed to be able to detect geomagnetism in the x-axis direction, geomagnetism in the y-axis direction, and geomagnetism in the z-axis direction. The output of each axis of the geomagnetic sensor 17 is input to the CPU 120 and is used to detect the movement trajectory and posture of the brush 5. As the geomagnetic sensor 17, MEMS sensors of MR (Magneto-Resistive) element type, MI (Magneto-Impedance) element type, Hall element type can be preferably used.

  Further, a load sensor 18 for detecting a brush pressure (load acting on the brush) is provided in the inside of the main body 2. As the load sensor 18, any type of strain gauge, load cell, pressure sensor, etc. can be used, but a MEMS sensor can be suitably used because it is small and easy to be incorporated into the main body 2. .

  The brush 5 includes a stem portion 20 fixed to the main body 2 side, and a brush component 21 mounted on the stem portion 20. The bristles 210 are implanted at the tip of the brush part 21. Since the brush part 21 is a consumable part, the brush part 21 is configured to be detachable from the stem portion 20 so that it can be replaced with a new one.

  The stem portion 20 is made of a resin material, and is attached to the main body 2 via an elastic member 202 made of an elastomer. The stem portion 20 is a tubular member whose tip (end on the brush side) is closed, and has a bearing 203 at the tip inside the barrel. The tip of the eccentric shaft 30 connected to the rotation shaft 11 of the motor 10 is inserted into the bearing 203 of the stem portion 20. The eccentric shaft 30 has a weight 300 near the bearing 203, and the center of gravity of the eccentric shaft 30 is offset from its center of rotation. A minute clearance is provided between the tip of the eccentric shaft 30 and the bearing 203.

<Drive principle of brush>
The CPU 120 supplies a drive signal to the motor 10 to rotate the rotating shaft 11 of the motor 10. The eccentric shaft 30 also rotates with the rotation of the rotating shaft 11, but the eccentric shaft 30 performs a motion to pivot around the rotation center because the center of gravity is shifted. Therefore, the tip of the eccentric shaft 30 repeatedly collides against the inner wall of the bearing 203, and the stem portion 20 and the brush component 21 mounted thereon are vibrated (moved) at high speed. That is, the motor 10 plays a role of a drive unit that vibrates (moves) the brush 5, and the eccentric shaft 30 converts the output (rotation) of the motor 10 into the vibration of the brush 5 It plays a role.

  The user can brush the body 2 by holding the body 2 by hand and applying the brush hairs 210 vibrating at high speed to the teeth. The CPU 120 monitors the continuous operation time using the timer 122, and automatically stops the vibration of the brush 5 when a predetermined time (for example, 2 minutes) elapses.

<About operation of electric toothbrush device>
Each site has different food residue and plaque formation, and thus there is a difference in the effective brushing operation for each site. Therefore, it is desirable to perform site-by-site assessment of proper brushing. Therefore, the electric toothbrush device 1 estimates the brushing region based on the movement locus and posture of the brush 5 detected using the acceleration sensor 15, the angular velocity sensor 16 and the geomagnetic sensor 17, thereby evaluating brushing for each region. To realize. There are various evaluation items, but in this case, three items, brushing time, brush angle and brush pressure, are evaluated.

  As shown in FIG. 4, the upper and lower dentition surfaces are "maxillary anterior buccal surface", "maxillary anterior lingual surface", "maxillary left buccal surface", "maxillary left lingual surface", "maxillary left bite" 'Mapping right buccal surface', 'maxillary right tongue surface', 'maxillary right meshing surface', 'mandibular anterior buccal surface', 'mandibular anterior tongue surface', 'mandibular left buccal surface , "Mandibular left tongue surface", "Mandibular left meshing surface", "Mandibular right buccal surface", "Mandibular right tongue surface", "Mandibular right meshing surface" divided into 16 sections. However, the division of the dentition surface is not limited to this, and may be a rough division or a finer division.

  The flow of the brushing evaluation will be specifically described with reference to FIG. The process described below is a process executed by the CPU 120 according to a program stored in the memory 121 unless otherwise noted.

  When the power supply of the main body 2 is turned on, the CPU 120 detects the movement locus and posture of the brush 5 based on the outputs of the acceleration sensor 15, the angular velocity sensor 16 and the geomagnetic sensor 17 (step S10). Next, the CPU 120 estimates a brushing region using at least the trajectory detected in step S10 (step S20). Next, the CPU 120 detects the innermost tooth when the brushing portion estimated in step S20 is the back side portion of the dentition end (step S30). Next, the CPU 120 corrects the brushing portion at each position in the movement trajectory of the brush 5 based on the position of the innermost tooth detected in step S30 (step S40). Next, the CPU 120 estimates a brush angle and detects a brush pressure (step S50). Information on the brushing portion, the brush angle, and the brush pressure is recorded in the memory 121 in association with each position in the trajectory of the brush 5.

  The processing of steps S10 to S50 is repeatedly performed, and when the power is turned off or the continuous operation time reaches a predetermined time (for example, 2 minutes), the CPU 120 performs brushing information (brushing portion, brush angle, etc.) recorded in the memory 121. Based on the brush pressure, the brushing result for each part is evaluated, and the evaluation result is output to the display 110 (step S60).

  The processes of steps S10 to S60 will be described in detail below.

(Detection of trajectory and attitude)
The CPU 120 obtains the outputs Ax, Ay, Az of the x axis, y axis, z axis from the acceleration sensor 15, and obtains the outputs Bx, By, Bz of the x axis, y axis, z axis from the angular velocity sensor 16. The outputs Cx, Cy, Cz of the x-axis, y-axis, and z-axis are obtained from the geomagnetic sensor 17, respectively. Ax represents an acceleration component in the x-axis direction, Ay represents an acceleration component in the y-axis direction, and Az represents an acceleration component in the z-axis direction. Bx represents an angular velocity component around the x axis, By represents an angular velocity component around the y axis, and Bz represents an angular velocity component around the z axis. Cx represents a magnetic component in the x-axis direction, Cy represents a magnetic component in the y-axis direction, and Cz represents a magnetic component in the z-axis direction.

  If the magnitude of the combined vector A (Ax, Ay, Az) is smaller than the predetermined threshold equivalent to the gravitational acceleration, the CPU 120 determines that the main body 2 is stationary, and the outputs Ax, Ay of the acceleration sensor 15 , Az as posture vectors D (Dx, Dy, Dz) representing the three-dimensional posture of the brush 5.

  When the magnitude of the combined vector A (Ax, Ay, Az) is larger than the above threshold, the CPU 120 determines that the main body 2 is moving, and based on the outputs Bx, By, Bz of the angular velocity sensor 16, The angle change amount of the main body 2 around each of the x-axis, y-axis, and z-axis from when it is determined that the main body 2 is at rest is calculated. The composite vector A (Ax, Ay, Az) at the time of determination is rotated by the determined angle change amount, and the posture vector D (Dx, Dy, Dz) is determined.

  The posture vector D (Dx, Dy, Dz) determined as described above corresponds to gravitational acceleration. Since the angular velocity sensor 16 generally causes a drift, and errors are accumulated in the calculation of the amount of change in angle, the CPU 120 performs the zero point calibration of the angular velocity sensor 16 using the outputs of the acceleration sensor 15 and the geomagnetic sensor 17 as needed.

  Further, the CPU 120 obtains the displacement amount of the main body 2 in each of the x-axis, y-axis, and z-axis directions based on the dynamic acceleration component obtained by removing the gravitational acceleration component from the outputs Ax, Ay, Az of the acceleration sensor 15. The gravity acceleration component included in the outputs Ax, Ay, Az can use the posture vector D (Dx, Dy, Dz). Then, the CPU 120 obtains the locus of movement of the brush 5 in consideration of the position of the brush 5 in the main body 2 determined from the three-dimensional attitude of the brush 5.

(Estimate of brushing site)
The CPU 120 estimates the brushing region at each position on the movement locus of the brush 5 by matching the movement locus of the brush 5 with the dentition surface. As the locus is accumulated, the estimation accuracy of the brushing region increases, but if the user is notified of the brushing start region, it is possible to estimate the brushing region with high accuracy from a relatively early stage.

  In addition, it is possible to estimate a brushing part with higher precision by considering the posture of the brush 5 together. For example, based on the z-axis direction component Dz of the posture vector D, it is possible to determine whether it is the upper jaw or the lower jaw. As shown in FIG. 6, attention is paid to the fact that when brushing the upper dentition, the brush surface is slightly upward, and when brushing the lower dentition, the brush surface is not downward. When Dz> 0, it can be determined that the upper jaw is present, and when Dz ≦ 0, it is determined that the lower jaw is present.

(Detection of innermost teeth)
The estimated brushing site is the back side of the end of the dentition, that is, the upper jaw left buccal surface, the upper jaw left lingual surface, the upper jaw left meshing surface, and the upper jaw right among the 16 regions described above. Buccal surface, "maxillary right lingual surface", "maxillary right meshing surface", "mandibular left buccal surface", "mandibular left tongue surface", "mandibular left meshing surface", "mandibular right cheek surface The CPU 120 detects the innermost tooth when it is the surface, the “mandible right tongue surface”, and the “mandible right meshing surface”.

  FIG. 7 shows an example of a method of detecting the innermost teeth when the estimated brushing site is the “mandible left buccal surface” and the “mandibular left tongue surface”, and FIG. 8 shows the estimated brushing site “ An example of a method of detecting the innermost teeth in the case of the lower jaw left meshing surface will be shown.

  When brushing the side surface S0 of the maxillary left most back tooth, typically, the brush 5 is moved to the back side along the dentition surface of the lower mandible to reach the side surface S0 of the most back tooth.

  When the brush 5 is moved, for example, along the "mandible left buccal surface", as shown in FIG. 7, the brush 5 rotates rapidly around the x axis in the process from the buccal surface S1 to the side S0 of the innermost teeth. Be done. Therefore, when the estimated brushing site is the “mandible left buccal surface”, the posture of the brush 5 around the x axis with reference to the posture that the brush 5 follows the dentition surface of the “mandible left buccal surface”. When the change amount θa is larger than a predetermined threshold value, the innermost teeth can be detected. The posture in which the brush 5 follows the dentition surface of the lower mandibular left buccal surface, which serves as a reference, is, for example, an average of the postures of the brush 5 at each position estimated to be "mandible left buccal surface" in the trajectory of the brush 5 Can.

  Even when the brush 5 is moved along the "mandibular left lingual surface", the brush 5 is rapidly rotated about the x axis in the process from the lingual surface S2 of the innermost tooth to the side surface S0. Therefore, when the estimated brushing site is the "mandible left tongue side surface", the brush 5 is used based on the posture along which the brush 5 follows the dentition surface of the "mandible left tongue side surface". When the amount of change in posture θb around the x axis of 5 is larger than a predetermined threshold value, the innermost teeth can be detected.

  In addition, when the brush 5 is moved along the "mandible left biting surface", as shown in FIG. 8, the brush 5 moves around the x axis in the process from the biting surface S3 of the innermost tooth to the side surface S0. It is rapidly rotated. Therefore, when the estimated brushing portion is the “mandible left meshing surface”, the posture of the brush 5 around the x axis with reference to the posture that the brush 5 follows the dentition surface of the “mandible left meshed surface”. When the change amount θc is larger than a predetermined threshold value, the innermost teeth can be detected.

  The estimated brushing site is "mandibular right buccal surface", "mandibular right lingual surface", "maxillary left buccal surface", "maxillary left lingual surface", "maxillary right buccal surface", "maxillary right tongue" In the case of the side surface, in the same manner as in the detection method shown in FIG. 7, the estimated brushing site is the “mandible right biting surface”, the “upper mandible biting surface”, and the “upper mandible biting surface”. In the case of “1”, the innermost tooth can be detected based on the change of the posture of the brush 5 in the same manner as the detection method shown in FIG.

  The above-described method for detecting the innermost teeth focuses on the three-dimensional posture of the brush 5 specific to brushing the innermost teeth, while the method for detecting the innermost teeth shown in FIG. 9 is the brush 5 specific to brushing the innermost teeth. Focusing on the movement of the

  In general, it is difficult to move the brush 5 along the dentition surface more deeply than the innermost teeth due to the interference with the living tissue in the oral cavity. In addition, after the brush 5 is moved to the back side along the dentition surface and reaches the innermost tooth, the brush 5 is moved to the front side again. Therefore, as shown in FIG. 9, of the movement locus of the brush 5, in the locus part of the back side part of the dentition end, among the turning points RP1, RP2 and RP3 of the movement of the brush 5, it is at the backmost side. The turning point RP3 of the movement of the brush 5 can be detected as the innermost tooth. Although FIG. 9 shows a locus portion of “mandible left cheek side surface”, similarly for the locus portions of other back side parts, the folding point of the movement of the brush 5 at the backmost side is the most similar. It can be detected as a back tooth.

  The CPU 120 may be configured to detect the innermost teeth independently by performing detection of the innermost teeth based on the change in the posture of the brush 5 and detection of the innermost teeth based on the trajectory of movement of the brush 5 independently. Preferably, the innermost teeth are detected based on the change in the posture of the brush 5 at the turning point on the backmost side of the movement of the brush 5. Thereby, the detection accuracy of the innermost teeth can be further enhanced.

(Correction of brushing site)
FIG. 10 shows an example of correction processing of the brushing portion at each position on the movement locus of the brush 5.

  For each position P1 to P11 on the movement locus of the brush 5, the brushing site at the brush position P1 to P4 is estimated to be "mandible right buccal surface", and the brushing site at P5 to P7 is "mandible anterior buccal surface" It is estimated that the brushing site of P8 to P11 is assumed to be "mandibular left buccal surface". Then, with regard to the position P12 of the brush 5 detected in the next step S10, it is assumed that the brushing portion is estimated to be “mandible left buccal surface” and the innermost tooth is detected at the position P12.

  When the innermost tooth is detected at the position P12, the CPU 120 updates the position of the lowermost innermost tooth in the movement trajectory of the brush 5 to the position P12. Then, the CPU 120 corrects the brushing portion of each of the positions P1 to P11 estimated by the matching of the movement locus of the brush 5 and the dentition surface based on the updated position of the innermost tooth. In the illustrated example, P1 to P3 are corrected to "mandible right buccal surface", P4 to P8 to "mandibular anterior buccal surface", and P9 to P11 to "mandibular left buccal surface" by correction. There is.

  Thus, when the innermost teeth are detected, the positions of the innermost teeth in the trajectory of movement of the brush 5 accumulated so far are updated, and based on the updated positions of the innermost teeth at each position in the trajectory By correcting the brushing portion, it is possible to further improve the estimation accuracy of the brushing portion by the matching between the subsequent locus and the dentition surface.

(Estimate of brush angle, detection of brush pressure)
The CPU 120 estimates the brush angle based on the posture of the brush 5 detected in step S10. The brush angle is the contact angle of the brush with respect to the tooth axis (axis along the head and root of the tooth). The upper part of FIG. 11 shows the state of the brush angle = 15 degrees, the middle part shows the state of the brush angle = 45 degrees, and the lower part shows the state of the brush angle = 90 degrees. In order to effectively scrape food residue and plaque from periodontal pockets and between teeth, it is recommended to move the brush so that the tips of the brushes enter periodontal pockets and between teeth. Therefore, the brush angle is preferably in the range of 35 degrees to 55 degrees.

  The brush angle can be estimated, for example, from the z-axis direction component Dz of the posture vector D. When the brush angle is about 90 degrees, Dz indicates almost 0, and the smaller the brush angle, the larger the absolute value of Dz. The reason is that the value of Dz changes significantly depending on the brush angle. The brush angle may be calculated as a continuous amount, or may be roughly estimated as “less than 35 degrees”, “35 degrees to 55 degrees”, “55 degrees or more”.

  The CPU 120 also calculates the brush pressure based on the output of the load sensor 18. If the brush pressure is too small, the plaque removing power decreases, and if it is too high, problems such as a decrease in brush life and an increase in burden on the gum may occur. The brush pressure of the electric toothbrush may be smaller than that of a normal toothbrush, and it is said that most people who start using the electric toothbrush tend to be over-brushed. The optimal value of the brush pressure is about 100 g.

(Evaluation / output of brushing result)
The CPU 120 evaluates the brushing result for each part based on the brushing information (brushing part, brush angle, brush pressure) of each position in the movement locus of the brush 5 recorded in the memory 121, and displays the evaluation result 110 (display 111). Here, the brushing time, brush angle and brush pressure are evaluated.

  The brushing time for each part is counted up by counting the brushing part at each position in the movement locus of the brush 5 for each part. For example, if the processing of the above steps S10 to S50 is executed once in 0.1 seconds, then the brushing time of the site is counted up by +0.1 second each time the brushing site is counted up. .

  The brush angle for each part is calculated, for example, as an average value by aggregating the brush angle at each position for each part based on the brushing part at each position in the movement locus of the brush 5. Similarly, the brush pressure for each part is calculated, for example, as an average value by aggregating the brush angle at each position for each part based on the brushing part at each position in the movement locus of the brush 5.

  The evaluation of brushing time, brush angle and brush pressure for each part is not particularly limited. For the brushing time, for example, less than 7 seconds can be evaluated in three stages as "insufficient", 7 to 15 seconds as "good", and more than 15 seconds as "excess". Further, with regard to the brush angle, for example, "less than 35 degrees" can be evaluated in three stages of "insufficient", "35 to 55 degrees" as "good", and "55 degrees or more" as "excessive". Moreover, about brush pressure, less than 80 g can be evaluated in three steps as "insufficient", 80 g-150 g as "good", and more than 150 g as "excessive". The evaluation results are sent to the display 110.

  The output of the evaluation result in the display 110 is also not particularly limited. For example, as shown in FIG. 12, the upper and lower dentitions are displayed, and each part is colored in accordance with the evaluation result of that part (“insufficient” is white, “good” is yellow, “excess” is red, etc.) It can be displayed. By looking at such a display, the user can intuitively grasp which part of the dentition the brushing is insufficient or excessive.

  And since the position of the innermost tooth is detected in the locus of movement of the brush 5, it is possible to evaluate the result of brushing the innermost tooth as a detailed part in the inner side part of the end of the dentition. The CPU 120 determines whether or not the innermost tooth is brushed based on the detection of the innermost tooth, and further, based on the brush position at which the innermost tooth is detected and the brushing information in the vicinity thereof, the brushing time for the innermost tooth, the brush Evaluate the angle and brush pressure. In general, tooth health can be promoted by detecting the innermost teeth tending to have a large amount of unpolished teeth and presenting the evaluation result regarding brushing of the innermost teeth to the user.

  As described above, according to the electric toothbrush device 1, the backmost teeth can be detected by the acceleration sensor 15 or the like for detecting the movement locus and posture of the brush 5, so the configuration of the electric toothbrush device 1 is simplified. It can be Then, when the innermost teeth are detected, the positions of the innermost teeth in the trajectory of movement of the brush 5 accumulated so far are updated, and the brushing portion at each position in the trajectory is updated based on the updated positions of the innermost teeth. Since the correction is performed, the brushing site can be accurately estimated.

  FIG. 13 shows the configuration of a modification of the electric toothbrush device 1.

  In the example shown in FIG. 13, the camera 19 is provided at the tip of the brush 5 in the y-axis direction. Any camera such as a visible light camera or an infrared camera may be used as the camera 19 as long as image information in the oral cavity can be acquired. An infrared camera monitors radiation heat (also referred to as thermography). An infrared camera may be preferable to a visible light camera because the oral cavity during brushing may be dark. The resolution of the camera may not be very high, as it is sufficient to know the contour of the uvula as described below.

  In step S10 (FIG. 5), the CPU 120 acquires an image from the camera 19 in addition to the outputs of the acceleration sensor 15, the angular velocity sensor 16 and the geomagnetic sensor 17, and detects the uvula from the image. Known image analysis techniques can be used to detect the uvula. For example, edge detection, contour detection of the uvula by Hough transformation, or detection of the uvula by pattern matching may be considered.

  When the brush 5 is on the tongue side, the tip of the brush 5 is directed to the throat, so the probability that the uvula is shown in the image is high. On the other hand, when the brush 5 is on the cheek side, the uvula is not shown in the image. Therefore, the CPU 120 determines that it is the "tongue side" when the uvula can be detected, and determines that it is the "cheek side" when the uvula can not be detected.

  Although the uvula was used as a detection target, the position and posture of the brush may be determined by recognizing other regions in the oral cavity (for example, tongue, throat, teeth, gums, etc.). For example, if the image shows a tongue or throat, it can be determined that the brush is on the tongue side.

  Thus, in addition to the trajectory of movement of the brush 5 detected based on the outputs of the acceleration sensor 15, the angular velocity sensor 16, and the geomagnetic sensor 17, the image of the camera 19 is complementarily used for brushing region estimation. The estimation accuracy of the brushing site can be further enhanced.

  In addition, it is also preferable to provide an optical sensor in a brush part instead of a camera. The light is detected on the tongue side while the cheek side is completely dark, so it is possible to distinguish between the two by analyzing the output of the light sensor.

  The embodiments described above are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown by the claim, and it is intended that the meaning of a claim and equality and all the changes within the range are included.

  As described above, the following matters are disclosed in the present specification.

  The disclosed electric toothbrush device uses a locus detection unit that detects a locus of movement of a brush, an attitude detection unit that detects an attitude of the brush, and at least the locus detected by the locus detection unit. When a part estimation unit that estimates a brushing part at a position and the brushing part estimated by the part estimation unit is the back side part of the dentition end, a change in posture detected by the posture detection unit And the region estimation unit, when the backmost teeth detection unit detects the backmost teeth, the backmost teeth detection unit detects the backmost teeth in the trajectory detected by the trajectory detection unit. And update the brushing site at each position on the trajectory based on the updated most back teeth position.

  Further, in the disclosed electric toothbrush device, the difference between the posture detected by the posture detection unit and the reference with respect to the posture that the backmost teeth detection unit follows the brush arrangement on the dentition surface of the back side portion Detect the innermost teeth based on

  Further, in the disclosed electric toothbrush device, the brushing part estimated by the part estimation unit in the locus detected by the locus detection unit is the innermost part of the dentition end part of the locus detected by the locus detection part. In the locus portion, the turning point on the back of the movement of the brush is detected as the innermost tooth.

  Further, in the disclosed electric toothbrush device, the part estimation unit further estimates the brushing part at each position on the trajectory detected by the trajectory detection unit, further using the posture detected by the posture detection unit.

  In addition, the disclosed electric toothbrush device further includes an evaluation output unit that evaluates and outputs a brushing result for each part.

DESCRIPTION OF SYMBOLS 1 electric toothbrush apparatus 2 main body 5 brush 15 acceleration sensor 16 angular velocity sensor 17 geomagnetic sensor 18 load sensor 19 camera 110 indicator 111 display

Claims (5)

A locus detection unit that detects a locus of movement of the brush;
A posture detection unit that detects the posture of the brush;
A part estimation unit that estimates a brushing part at each position on the locus using at least the locus detected by the locus detection unit;
If the brushing portion estimated by the portion estimation unit is the far side portion of the dentition end, a deepest tooth detection unit that detects the innermost tooth based on the change in posture detected by the posture detection unit;
Equipped with
The part estimation unit updates the position of the innermost tooth in the locus detected by the locus detection unit when the innermost tooth is detected by the innermost tooth detection unit, and based on the updated position of the innermost tooth. The electric toothbrush apparatus which correct | amends the brushing site | part in each position on the said locus | trajectory. The electric toothbrush apparatus according to claim 1, wherein
The innermost tooth detection unit is an electric toothbrush that detects the innermost tooth based on the difference between the posture detected by the posture detection unit and the reference with respect to the posture along which the brush follows the dentition surface of the rear side portion. apparatus. The electric toothbrush device according to claim 1 or 2, wherein
The innermost teeth detection unit is the most movable portion of the movement of the brush in a locus portion where the brushing portion estimated by the portion estimation unit is the back side portion of the dentition end in the locus detected by the locus detection unit. An electric toothbrush that detects the turning point on the back side as the innermost tooth. The electric toothbrush device according to any one of claims 1 to 3, wherein
The said part estimation part is an electric toothbrush apparatus which estimates the brushing part in each position on the locus | trajectory detected by the said locus | trajectory detection part further using the attitude | position detected by the said attitude | position detection part. The electric toothbrush apparatus according to any one of claims 1 to 4, wherein
The electric toothbrush apparatus further provided with the evaluation output part which evaluates and outputs the brushing result for every site | part.

Images