Method and apparatus for positioning devices in the oral cavity

Abstract

The invention relates to a method for controlling cleaning devices of a cleaning apparatus in an oral cavity, wherein a cleaning device is moved over at least one row of teeth of at least one jaw quadrant by means of actuators of the cleaning apparatus, wherein cleaned tooth set geometry data in a head coordinate system in global 3D coordinates X, Y, Z and rotation data described in quaternions are combined together with appliance pose data of the cleaning apparatus, and X, Y, Z values are converted by way of inverse kinematics into an elevation angle, a lateral angle and an extension distance of a cleaning device, wherein the apparatus has at least one bite device which forms at least one zero, defined mechanically in particular, on which a user positions themselves as identically as possible each time in order to keep the differences in pose information between different uses as small as possible and wherein the bite device is arranged on the cleaning apparatus and designed to accommodate at least one tooth of the upper jaw and one tooth of the lower jaw, and the invention also relates to an apparatus for carrying out the method.

Description

[0001] Method and device for positioning devices in the oral cavity

[0002] The invention relates to a method for controlling cleaning devices of a cleaning device in an oral cavity and a cleaning device for carrying out the method.

[0003] Conventional mouth / tooth cleaning is carried out either completely mechanically or partially automatically.

[0004] For example, it is known to design electric toothbrushes with a brush head. Depending on the design, this brush head is formed, for example, with a circular surface from which cleaning bristles protrude in the same direction. Such a head rotates back and forth at a predetermined angle to perform a cleaning motion.

[0005] Other models have a head with an elongated surface similar to a conventional toothbrush, from which the bristles also protrude in one direction. Such brush heads are specifically designed to oscillate around an axis running along the surface, causing the bristles to perform a reversing, oscillating motion, similar to a tilting motion.

[0006] What these prior art designs have in common is that they feature detachable brush heads that can be attached to a handle via a shaft. With these designs, it's common for the user to move the devices over the teeth using the handle. For example, a brushing regimen is specified in which each quadrant of the jaw is to be cleaned, and visual or acoustic signals indicate when the quadrant should be changed and when the brushing process is complete. The cleaning movement is usually also stopped at the end of the brushing process.

[0007] To prevent teeth or gums from being damaged by excessive bristle pressure, it is known to communicate the contact pressure or when the maximum contact pressure is exceeded to the user via an LED light or acoustic signals, or both. However, the movement and angle of the cleaning head is always controlled by the user. This has several problems. For example, right-handed people find it more difficult to clean the right side of their teeth, and some areas of the teeth are generally difficult to reach. In addition, the cleaning time per tooth is not always the same, which can lead to some teeth not being cleaned completely. Furthermore, not all surfaces are cleaned evenly. All of these problems can lead to the formation of tartar or, in the worst case, tooth decay.

[0008] WO 2024 / 073623 A2 discloses a device and method for automated oral care, including cleaning, inspection, imaging, and repair. Translation and rotation of the oral care tool are enabled by motors and actuators. Data regarding the coordinates in the oral cavity are stored and processed, and this data is used to control the movement of the oral care tool relative to a reference point. For example, cameras can be used to create a 3D projection of the oral cavity, which can be used to diagnose abnormalities such as cavities, damaged teeth, diseases, or tumors.

[0009] The object of the invention is to provide a method for controlling cleaning devices of a cleaning device in an oral cavity, with which a cleaning routine can be carried out in a targeted manner.

[0010] The problem is solved by a method having the features of claim 1.

[0011] Advantageous further training is indicated in subclaims.

[0012] A further task is to create a cleaning device with which cleaning equipment can be moved reliably and purposefully.

[0013] The problem is solved with the features of claim 12.

[0014] Advantageous further training is identified in the dependent subclaims.

[0015] The invention particularly relates to a method for the targeted and individual positioning of a cleaning device of a cleaning apparatus in an oral cavity. Based on relative location and movement data obtained with a detection device, a personalized cleaning routine adapted to tooth geometry, biofilm, caries, discoloration, or other oral markers can be implemented.

[0016] Two aspects are necessary for the precise positioning of the two processes in relation to each other and to the user.

[0017] First, the measurement of the oral cavity or the tooth geometry and calculation of an optimal path or a geometric representation of the oral cavity and the tooth geometries.

[0018] Secondly, the detection of the position and rotation or position and orientation of the end effector (the scanning device or the cleaning device) in relation to the base coordinate system, hereinafter referred to as pose as is common in robotics, of the device in relation to the user during the scanning process, but also during routine operations.

[0019] For the detection step, it is therefore possible to subtract the measured device pose from the measured mouth and tooth geometry.

[0020] To ensure a personalized routine, the measured pose of the cleaning device during cleaning is added to the transmitted tooth geometry. The measured positions can thus be precisely controlled via the regulated data path and individually adapted to the user.

[0021] Due to the active splitting of the path and routine into an adapted path and variable pose information, this system operates completely without external infrastructure.

[0022] This allows the user to move freely while the positioning activities are being performed. This allows for uncomplicated and routine measurements of the oral cavity and also allows historical data on oral and dental geometry to be compared at regular intervals.

[0023] Ideally, all of this data is sent to the dentist daily to detect changes and problems as early as possible.

[0024] The detection device has at least one zero point, particularly a mechanically defined zero point, on which the user positions themselves as identically as possible each time in order to minimize differences in pose information between different uses. In the preferred embodiment, this zero point is a bite-stop device that defines the coordinate origin of the device.

[0025] The bite block is arranged on the device and serves to accommodate at least one tooth of the upper jaw and one tooth of the lower jaw. The bite block is preferably shaped so that a user can easily find a predetermined bite or tooth position.

[0026] This can be done, for example, by taking an impression and then shaping the bite piece, which is then individualized to the user.

[0027] During detection, reference is always made to the zero point.

[0028] In order to separate the pose information from the tooth geometry, the device in a preferred embodiment also includes additional sensors so that any possible movements of the device in the user's oral cavity, e.g. up / down movements, movements into the oral cavity as well as rotations around the tooth axis and the body's longitudinal axis, can be recorded.

[0029] In a preferred embodiment, these sensors are 2D mesh sensors in the bitepiece to detect rotations of the bite, cameras that compare translational movements across the position of the interdental space, and time-of-flight sensors inside or outside the oral cavity to measure rotations.

[0030] In addition, additional mechanical reference and support points can be provided, for example by supports on the chin or other parts of the face or body.

[0031] In the preferred embodiment, the first device has at least one detection head, hereinafter also called shuttle.

[0032] In a preferred embodiment, this detection head has, for example, 3 cameras with 4 LEDs each to perfectly illuminate the teeth.

[0033] This shuttle is guided over the teeth by a drive unit.

[0034] Information about the tooth geometry is recorded via angle sensors and encoders in the motor and / or drive shafts. At the end of the measurement, the first device generates a document that defines the tooth geometry using the zero point. Pose information is calculated using the sensor data, symmetry properties of the dentition quadrants, and historical data.

[0035] In particular, the cleaning device is equipped with some or all of the aforementioned sensors and a bite piece identical to the detection device, allowing the same zero point to be defined. It then accesses the pose information and the calculated path referenced to the zero point in real time, correcting it with the currently occurring pose information.

[0036] In one embodiment, the cleaning device has the same sensors and the same zero point so that the pose information can be corrected as easily as possible.

[0037] Since the zero position of the detection device and also of the cleaning device are each defined and since pose information about the movement of the detection device of the detection device and possibly also of the cleaning device of the cleaning device in the user's mouth is available, a special user-adapted routine can be designed that assigns the appropriate profile to each tooth.

[0038] In the preferred embodiment, taking all sensors into account, this allows virtually all user errors to be compensated for and the likelihood of excessive tartar or caries is drastically minimized.

[0039] In addition, it has the advantage that there is no over-cleaning of the tooth by cleaning one or more teeth more thoroughly than necessary.

[0040] This leads to less tooth wear.

[0041] In addition, the cleaning device can be positioned precisely to avoid unnecessary cleaning of the gums.

[0042] This protects the gums and keeps them healthy.

[0043] Several forms of application are possible.

[0044] In one embodiment, the device is used by the user biting down on the bite block of the first device, the device scans the tooth geometry, and calculates a path. The second device receives this data and traverses the same tooth geometry. In a variation, the device is used by the user biting down on the bite block of the first device, all sensors are used while scanning the tooth geometry, and the path is thereby divided into a portion from the origin and into pose information. The second device thus receives cleaned data and traverses the same tooth geometry.

[0045] In another embodiment, the device is used by the user biting down on the bite block of the first device. All sensors are used during scanning of the tooth geometry, thereby dividing the path into a portion from the origin and a portion containing pose information. The second device thus receives cleaned data and traverses the same tooth geometry, while using its own sensors to correct this path for the pose information.

[0046] In yet another variation, the user bites down on the bite block of the first device. All sensors are used while scanning the tooth geometry, thus splitting the path into a portion from the origin and a portion containing pose information. The device itself then traverses the same tooth geometry and also performs the cleaning routine.

[0047] The general procedure for autonomous positioning within a cleaning routine therefore includes first recording data in the detection device during the detection routine and then playing this data back in the cleaning device during the cleaning routine.

[0048] The recorded data consists of tooth set geometry data in the reference system of the detection device. In other words, this data consists of tooth set geometry in a coordinate system of the head and the pose change between the head and the device.

[0049] By using different sensors that record different measurement variables during detection, these two components can be separated. The cleaned tooth geometry is then transferred from the detection device to the cleaning device.

[0050] The cleaning device, in turn, uses its own sensors to measure the pose between the head and the device and combines this data with the obtained tooth geometry.

[0051] The cleaning path, recorded by another device, can thus be individually followed. As is common practice in robotics, the term pose refers to the translation and rotation, or rather, the position and orientation, of the end effector relative to a base coordinate system.

[0052] To perform the positioning according to the invention, a detection routine is first performed to collect the relevant control data. The detection routine thus describes the process of data acquisition and processing to create a clean tooth geometry.

[0053] "Adjusted" describes that the tooth set geometry is specified in the head coordinate system, and the device pose has been calculated away. This involves sensors that measure the entire system in some cases and only the device position / translation in others. This process takes place in real time during the detection process, while parts of it are performed after completion and acquisition of all data.

[0054] The routine begins by recalling previously acquired tooth geometry using the user ID. If available, this geometry is used to trace a specific path during the scan process, thus reducing the duration of the detection routine.

[0055] If no data is available, a special type of detection routine, the auto-calibration, takes care of collecting this initial data.

[0056] The stored data are cleaned tooth set geometry data in the head coordinate system in global 3D coordinates X, Y, Z and rotation data described in quaternions.

[0057] They are converted into an elevation angle, a lateral angle, and an extension distance using inverse kinematics. The device's elevation and lateral adjustment are divided into an active and a passive travel path. When the detection heads extend along the teeth, it is possible to travel a certain reduced distance while simultaneously measuring the correct angles.

[0058] The passive mechanical elements of the detection device also ensure that the measured tooth set geometry is relatively invariant to the device pose. However, this recorded data includes the device pose and is converted into X, Y, and Z data using forward kinematics.

[0059] By regularly measuring camera data and relating it to 3D position data, on the one hand the detection head position data can be optimized, and on the other hand translation data of the teeth to the bite piece is used to determine the device position in relation to the mouth / head.

[0060] This device translation is, in turn, necessary to calculate the device's rotation data using measurements from the Time-Of-Flight (TOF) sensors. Two sensors are used to record the distance and orientation of the measured surface. Taking into account the head shape and limitations of the bite block, constraints can now be established that lead to the missing rotation data of the device. The device pose is composed of translation and rotation and is applied to the recorded data of the tooth set geometry to arrive at a "cleaned" value.

[0061] The tooth set geometry data is then corrected for planar and interplanar symmetry. Consistent temporal deviations of the detection heads indicate a change in the device pose. These values ​​can be compared with TOF sensors and IMU values. Changed pose values, in turn, lead to an optimization of the tooth set geometry. Interplanar optimization defines the utilization of the symmetry of the upper and lower rows of teeth. Large deviations here also indicate changes in the device pose.

[0062] The final optimization step involves using historical data as a reference. The new data must be confirmed with previous data. Major changes indicate device movement.

[0063] Additional optimizations not explicitly listed include curve interpolation, smoothing of the gear set geometry and evaluation of the curve curvature.

[0064] The corrected data is then linked to the previous history and sent to the cleaning device and into the database.

[0065] The cleaning routine according to the invention describes the process of data transformation from tooth set geometry data and device pose data to trace a device-dependent path on the tooth geometry. This involves reacting to and compensating for changes in device position and rotation during the routine.

[0066] The invention thus relates in particular to a method for controlling cleaning devices of a cleaning device in an oral cavity, wherein a cleaning device is moved by actuators of the cleaning device over at least one row of teeth of at least one jaw quadrant, wherein cleaned tooth set geometry data in a coordinate system of a head in global 3D coordinates X, Y, Z and rotation data are combined with device pose data of the cleaning device, and X, Y, Z values ​​are converted via inverse kinematics into an elevation angle, a lateral angle, and an extension distance of a cleaning device, wherein the device has at least one bite device which forms at least one, in particular mechanically defined, zero point on which a user positions themselves as identically as possible each time in order to keep the differences in pose information between different uses as small as possible,wherein the biting device is arranged on the cleaning device and is designed to receive at least one tooth of the upper jaw and one tooth of the lower jaw.,

[0067] A further development provides that the cleaning device measures the pose between the head and the device using its own sensors such as time of flight sensors, mechanical distance sensors, laser sensors, ultrasonic sensors, capacitive sensors, cameras and combines this data with a obtained tooth geometry.

[0068] A further development provides that changes in the cleaning device position and rotation during the routine are recorded and taken into account and subsequently compensated.

[0069] A further development provides that, in order to ensure the necessary cleaning performance on the occlusal surfaces of the teeth, a force sensor-dependent control circuit is implemented, which overlays the calculated elevation angle and indicates a component of a device orientation via a measured position sensor value.

[0070] A further development provides for the calculation of a translation of the cleaning device by evaluating camera data by comparing incisors and a biting device or a pose of the camera.

[0071] A further development provides for the use of camera data in combination with time-of-flight sensors to measure rotation data of the device.

[0072] A further development provides for at least one TOF sensor to be directed at a user's facial surface and measure distances to and orientations of the surface. A further development provides for the cameras, an approximate head shape, and a shape of the bite piece to create constraints that are used to calculate the rotations of the device relative to the head.

[0073] A further development provides that in order to optimize the rotation of the cleaning device, a passive deflection of a self-centering of the cleaning devices is measured, whereby by an oscillating rotation of the cleaning device in a positioning system with planned play, this device aligns itself automatically to a row of teeth, whereby the deviation between the planned cleaning path and the position of the self-centering is calculated as device rotation.

[0074] A further development provides for the use of oscillation around the planned travel path, whereby a motor current measured during the movement of the cleaning device specifies which path offers the smallest resistance, whereby the deviation between the traveled path and the specified path is used to optimize the values ​​of the device rotation.

[0075] A further development provides that after the calculation of the cleaning device pose, the tooth set geometry is modified and approached and the cleaning device pose is calculated again.

[0076] A further aspect relates to a cleaning device, in particular for carrying out the method according to one of the preceding claims, with a cleaning unit, wherein the cleaning device is movable by actuators of the cleaning device over at least one row of teeth of at least one jaw quadrant, wherein the at least one actuator is designed to assume an elevation angle, a lateral angle and an extension distance, wherein the device has at least one biting device which forms at least one, in particular mechanically defined, zero point on which a user positions themselves as identically as possible each time in order to keep the differences in pose information between different uses as small as possible, wherein the biting device is arranged on the cleaning device and is designed to accommodate at least one tooth of the upper jaw and one tooth of the lower jaw.

[0077] A further development provides that the bite block is shaped so that the user can easily find a predefined bite or tooth position, in particular by taking an impression and subsequently shaping the bite block, which is then customized for the user. A further development provides that the cleaning device has sensors for detecting movements of the cleaning device on the user's head and / or of the cleaning device in the user's oral cavity, in particular up / down movements, movements into the oral cavity, and rotations about a tooth axis and a body longitudinal axis.

[0078] A further development provides that this at least one sensor is a 2D mesh sensor in the bite device, cameras that compare translational movements across the position of the interdental space and time-of-flight sensors inside or outside the oral cavity to measure rotations.

[0079] Further training requires the presence of mechanical reference and bearing points, such as supports on the chin or other parts of the face or body.

[0080] The invention is explained by way of example with reference to a drawing, the sole figure of which shows a flow chart of the data collection and processing during autonomous positioning and the cleaning routine.

[0081] The process is initiated by obtaining a cleaned and optimized tooth set geometry via user ID from the database or the detection device. The data is combined with the measured device pose, and X, Y, and Z values ​​are converted into an elevation angle, a azimuth angle, and an extension distance using inverse kinematics.

[0082] To ensure the necessary cleaning performance on the occlusal surfaces of the teeth, a force sensor-dependent control loop was implemented. This overlays the calculated elevation angle and provides a component of the device orientation via the measured position sensor value.

[0083] As with the detection device, the translation of the device is calculated by evaluating camera data based on a comparison of the incisors and the bite piece, or rather the pose of the camera. This data is then used in combination with time-of-flight sensors to measure the device's rotation data. The two TOF sensors are aimed at the user's cheeks and measure distances and orientations of the surfaces. The cameras, the approximate head shape, and the shape of the bite piece can be used to create constraints that make it possible to calculate the rotations of the device in relation to the head. To optimize the rotation of the cleaning device, it is possible to measure the passive deflection of the self-centering of the cleaning heads. The oscillating rotation of the cleaning heads in the positioning system with planned play automatically aligns them to the row of teeth.The deviation between the planned cleaning path and the position of the self-centering can be calculated as device rotation.

[0084] An additional option in the cleaning device is oscillation around the planned path. The motor current measured during this process determines which path offers the least resistance. The deviation between the actual path and the specified path can be used to optimize the device's rotation values.

[0085] Once the device pose has been calculated, the tooth set geometry is modified and approached and the device pose can be calculated again.

[0086] The invention is advantageous in that it enables autonomous positioning of at least one device in the oral cavity, using data from a survey which is available as relative location data, and the device corrects its own position via corresponding sensors in such a way that reference can be made to the relative location data collected.

Claims

Claims 1. A method for controlling cleaning devices of a cleaning device in an oral cavity, wherein a cleaning device is moved by actuators of the cleaning device over at least one row of teeth of at least one jaw quadrant, wherein cleaned tooth set geometry data in a coordinate system of a head in global 3D coordinates X, Y, Z and rotation data are combined with device pose data of the cleaning device, and X, Y, Z values ​​are converted via inverse kinematics into an elevation angle, a lateral angle, and an extension distance of a cleaning device, wherein the device has at least one bite device that forms at least one, in particular mechanically defined, zero point on which a user positions themselves as identically as possible each time in order to keep the differences in pose information between different uses as small as possible,wherein the biting device is arranged on the cleaning device and is designed to receive at least one tooth of the upper jaw and one tooth of the lower jaw., 2. Method according to claim 1, characterized in that the cleaning device measures the pose between the head and the device with its own sensors such as time of flight sensors, mechanical distance sensors, laser sensors, ultrasonic sensors, capacitive sensors, cameras and combines these data with a obtained tooth geometry.

3. Method according to claim 1 or 2, characterized in that changes in the cleaning device position and rotation during the routine are recorded and taken into account and subsequently compensated.

4. Method according to one of the preceding claims, characterized in that, in order to ensure a necessary cleaning performance on occlusal surfaces of the teeth, a force sensor dependent control circuit is implemented, which overlays the calculated elevation angle and indicates a component of a device orientation via a measured position sensor value.

5. Method according to one of the preceding claims, characterized in that a translation of the cleaning device is calculated via an evaluation of camera data by comparing incisors and a biting device or a pose of the camera.

6. Method according to one of the preceding claims, characterized in that the camera data are used in combination with time-of-flight sensors to measure rotation data of the device.

7. Method according to one of the preceding claims, characterized in that the at least one TOF sensor is directed towards a facial surface of a user and measures distances to and orientations of the surface.

8. Method according to one of the preceding claims, characterized in that the cameras, an approximate head shape, and a shape of the bite piece create constraints with which the rotations of the device in relation to the head are calculated.

9. Method according to one of the preceding claims, characterized in that in order to optimize the rotation of the cleaning device, a passive deflection of a self-centering of the cleaning devices is measured, whereby by an oscillating rotation of the cleaning device in a positioning system with planned play, this automatically aligns itself to a row of teeth, whereby the deviation between the planned cleaning path and the position of the self-centering is calculated as device rotation.

10. Method according to one of the preceding claims, characterized in that the oscillation around the planned travel path is used, wherein a motor current measured during the movement of the cleaning device specifies which path offers the smallest resistance, wherein the deviation between the traveled path and the specification is used to optimize the values ​​of the device rotation.

11. Method according to one of the preceding claims, characterized in that after the calculation of the cleaning device pose, the tooth set geometry is modified and approached and the cleaning device pose is recalculated.

12. Cleaning device, in particular for carrying out the method according to one of the preceding claims, with a cleaning device, wherein the cleaning device is movable with actuators of the cleaning device over at least one row of teeth of at least one jaw quadrant, wherein the at least one actuator is designed to be able to assume an elevation angle, a lateral angle and an extension distance, wherein the device has at least one biting device which forms at least one, in particular mechanically defined, zero point on which a user positions themselves as identically as possible each time in order to keep the differences in pose information between different uses as small as possible, wherein the biting device is arranged on the cleaning device and is designed to accommodate at least one tooth of the upper jaw and one tooth of the lower jaw.

13. Cleaning device according to claim 12, characterized in that the bite device is shaped so that a user can easily find a predefined bite or tooth position, in particular by taking an impression and subsequently shaping the bite piece, which is then individualized to the user.

14. Cleaning device according to claim 12 or 13, characterized in that the cleaning device has sensors for detecting movements of the cleaning device on the head of the user and / or of the cleaning device in an oral cavity of the user, in particular up / down movements, movements into the oral cavity and rotations about a tooth axis and a body longitudinal axis.

15. Cleaning device according to claim 14, characterized in that said at least one sensor is a 2D mesh sensor in the biting device, cameras which compare translational movements over the position of the interdental space and time-of-flight sensors inside or outside the oral cavity to measure rotations.

16. Cleaning device according to one of claims 12 to 15, characterized in that mechanical reference and bearing points, such as supports on the chin or other parts of the face or body, are present.

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