JP7492245B2 - Calculation device, sensor system, and computer program - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act. Disclosure fact 1-1: Published on the website of the abstracts of the 7th Nursing Science and Technology Society Academic Conference (https://nse2019.8href.com/) on May 30, 2019. Disclosure fact 1-2: Presented at the "7th Nursing Science and Technology Society Academic Conference" on June 6, 2019. Disclosure fact 2-1: Published in the Journal of Nursing Science and Technology Society, Vol. 7, 2020, pp. 59-67 (DOI: https://doi.org/10.24462/jnse.7.0_59) on March 31, 2020.

This disclosure relates to a computing device, a sensor system, and a computer program.

Although the brushing position is important in oral care, it is difficult for trainers to convey the appropriate brushing position to trainees during training. In other words, when teaching skills that involve continuous contact, it is difficult to accurately convey the contact position for the object being brushed. Trainees generally check the brushing position and other contact positions by watching the trainer's model actions.

Regarding oral care training, JP 2018-173504 A (hereinafter referred to as Patent Document 1) proposes an oral cavity reproduction model in which pressure sensors are attached to each tooth that makes up the dentition.

JP 2018-173504 A

When using a sensor that detects contact, such as a pressure sensor, as in Patent Document 1, it is necessary to install the sensor at or near the contact position in order to accurately detect the contact position. Also, it is desirable to install many sensors to improve the accuracy of position detection.

However, if pressure sensors are attached to each tooth as in Patent Document 1, the number of communication lines connected to the pressure sensors increases, making wiring and handling cumbersome. Also, depending on the size, it may be difficult to attach a pressure sensor. Also, there may be restrictions on how the sensor can be used, such as applying medicine or rinsing with water.

This disclosure provides a computing device, a sensor system, and a computer program that can detect the exact position of contact with a contacted object without compromising ease of use.

According to one embodiment, the computing device performs processing using force sensing results from a first sensor capable of detecting the line of action of a force applied to a contacted body by contact, and includes an input unit capable of receiving input of the force sensing results, and a processor that executes the processing, and the processing includes calculating candidate points for the point of action of the force on the contacted body using the line of action of the force obtained from the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points.

According to another embodiment, the sensor system includes a sensor that can be attached to a contacted body and can detect the line of action of a force applied to the contacted body by contact, and a computing device that acquires sensing results by communicating with the sensor and performs processing using the sensing results, the processing including calculating candidate points for the point of action of the force on the contacted body using the line of action of the force obtained from the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points.

According to another embodiment, the computer program causes the computer to function as an arithmetic device that performs processing using the sensing results from a first sensor that can detect the line of action of a force applied to a contacted body by contact, and the processing includes calculating candidate points for the point of action of the force on the contacted body using the line of action of the force included in the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points.

Further details are described in the embodiments below.

FIG. 1 is a schematic diagram of a configuration of a sensor system according to an embodiment. FIG. 2 is a top view of a force receiving body of a sensor included in the sensor system, and is a diagram for explaining a positioning mechanism for attaching the sensor to an oral care model. FIG. 3 is a block diagram showing the configuration of a computing device included in the sensor system. FIG. 4 is a diagram for explaining the calculation in the calculation device, and is a diagram for explaining how to represent the gum shape of the oral cavity care model. FIG. 5 is a diagram for explaining the calculation in the calculation device, and is a diagram for explaining candidate points. FIG. 6 is a diagram for explaining the calculations in the calculation device, showing the mathematical expressions used to calculate the coordinates of the candidate points. FIG. 7 is a diagram for explaining the calculations in the calculation device, and shows the angular relationship of the force applied to the point of action. FIG. 8 is a diagram for explaining the calculations in the calculation device, and is a diagram for explaining the conditions used to narrow down the candidate points. FIG. 9 is a diagram for explaining the calculation in the calculation device, and is a diagram for explaining the moving speed of the position of the candidate point. FIG. 10 is a diagram for explaining the calculation in the calculation device, and is a diagram for explaining the determination of the point of action based on the moving speed of the position. FIG. 11 is a flowchart showing the flow of processing in the arithmetic unit. FIG. 12 is a diagram showing an example of a display screen of the sensor system.

＜1. Overview of the computing device, sensor system, and computer program＞

(1) A computing device according to an embodiment of the present invention is a computing device that performs processing using force sensing results from a first sensor that can detect the line of action of a force applied to a contacted body by contact, and includes an input unit that can accept input of the force sensing results, and a processor that executes processing. The processing includes calculating candidate points for the point of action of the force on the contacted body using the line of action of the force obtained from the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points.

The contacted body is an object to be contacted, for example, an oral care model. In this case, contact is, for example, brushing the oral care model with a brush. The first sensor is a sensor capable of detecting the magnitude and direction of coordinate system components of the force applied to the attached contacted body, and the moment acting at the origin, for example, a force sensor. The arithmetic device is, for example, a computer, and the input unit is, for example, an interface to which the first sensor is connected and which accepts input of the sensing results. The shape data of the contacted body is, for example, an equation that expresses the shape of the contacted body in coordinates. The point of action at which the force is applied to the contacted body by contact is determined, thereby obtaining the exact position at which the contacted body is contacted.

(2) Preferably, determining the point of action includes obtaining an index value corresponding to the rate of change of position for each candidate point from the results of sensing a plurality of forces sensed by the first sensor at different timings, and determining the point of action based on the index value. When continuous contact is made with the contacted body, the slope of the line of action changes according to the shape of the surface of the contacted body, and as a result, the rate of change of position differs for each candidate point. Therefore, by utilizing the rate of change of position, the point of action can be determined from among the candidate points.

(3) Preferably, determining the point of action includes determining, from among a plurality of candidate points, the candidate point with the slowest rate of change as the point of action. As the point of action changes, the line of action changes such that the range of the line of action expands as it moves away from the point of action, i.e., the position of contact, as the point of action changes. Therefore, the candidate point with the slowest rate of change can be determined as the point of action.

(4) Preferably, calculating the candidate points includes calculating the intersections between the pre-stored shape data of the contacted body and the line of action. The multiple intersections obtained in this way can be used as candidate points.

(5) Preferably, determining the point of action includes using the force direction included in the force sensing result to eliminate, from among the candidate points, points whose components obtained from the force direction are not within the range of allowable directions corresponding to each candidate point. This makes it possible to reduce the number of candidate points and the amount of calculations.

(6) Preferably, the range of allowable orientations is defined based on the orientations in which contact is possible for the candidate point, since the point of application of the force imparted by the contact is the direction of the force in which contact is possible.

(7) Preferably, the input unit is further capable of accepting input of the sensing result of the shape of the contacted body by the second sensor, and calculating the candidate point includes deforming the shape data of the contacted body based on the shape sensing result and using the deformed shape data. This makes it possible to obtain the point of action even if the contacted body is deformed.

(8) Preferably, the shape data of the contacted body is three-dimensional shape data. This allows the use of shape data that is closer to the actual shape of the contacted body, making it possible to obtain the point of action with high accuracy.

(9) Preferably, the shape data of the contacted object is shape data of an oral care model. This makes it possible to detect the brushing position during oral care.

(10) Preferably, the processing further includes outputting data associating the determined point of action with the magnitude of the force included in the force sensing result. The output of the data is output to the outside of the computing device, for example, by displaying the data on a display described below, transmitting the data to another device, etc. This allows the detection result to be known from the outside.

(11) Preferably, the processing includes outputting data indicating at least one of the total value of the magnitude of the force applied to the application point included in the unit range per unit time for each unit range of the contacted body, and the total value of the time during which the force was applied to the application point included in the unit range. The unit range refers to a range that is set by dividing the shape data of the contacted body into a predetermined size and serves as a unit for output. By outputting for each unit range, it is possible to know the trend of the magnitude of the applied force and the contact time for each unit range.

(12) Preferably, outputting the data includes displaying the data on a display. This allows the data to be understood from the display.

(13) Preferably, displaying on the display includes displaying an image of the contacted object together with the data. This allows the point of action and the contacted object used to be identified from the display.

(14) Preferably, the first sensor is a force sensor. This detects the magnitude and direction of coordinate system components of the force applied to the attached contact object, and the moment acting at the origin.

(15) A sensor system according to an embodiment includes a sensor that can be attached to a contacted body and can detect the line of action of a force applied to the contacted body by contact, and a computing device that acquires sensing results by communicating with the sensor and performs processing using the sensing results, the processing including calculating candidate points for the point of action of the force on the contacted body using the line of action of the force obtained from the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points. By determining the point of action where the force is applied to the contacted body by contact, the exact position of contact with the contacted body can be obtained.

(16) Preferably, the sensor has a positioning mechanism for attaching the sensor to the contacted body in a positional relationship according to the coordinate system of the shape data. This allows the sensor to be attached to the contacted body at a position according to the coordinate system of the stored shape data, preventing a decrease in accuracy due to misalignment.

(17) A computer program according to an embodiment is a computer program that causes a computer to function as a calculation device that performs processing using the sensing results from a first sensor that can detect the line of action of a force applied to a contacted body by contact, and the processing includes calculating candidate points for the point of action of the force on the contacted body using the line of action of the force obtained from the force sensing results and pre-stored shape data of the contacted body, and determining the point of action from among the candidate points. This allows a general-purpose computer to function as the calculation device of (1) to (14), and can be used to build the sensor systems of (15) and (16).

2. Examples of computing devices, sensor systems, and computer programs

The sensor system 100 according to this embodiment is an example of a system that detects the force applied by contact with a contacted object and processes the detection results, and is a system that detects the force applied by contact of a brush or the like with an oral care model.

Referring to FIG. 1, the sensor system 100 includes a computing device 10 and a sensor 20. The sensor 20 can be attached to a contacted object. The contacted object refers to an object to which a force is applied by contact from its periphery, and in this example, is an oral care model 30. The sensor 20 is attached to the oral care model 30 and can detect the line of action of the force applied to the oral care model 30 by contact.

Sensor 20 is a sensor capable of detecting the magnitude and direction of coordinate system components of a force applied to a contacted object to which it is attached, and the moment acting at the origin. Preferably, sensor 20 is capable of sensing in three dimensions along the z-axis, y-axis, and z-axis. One example of sensor 20 is a force sensor.

The sensor 20 has a plate-shaped force receiving body 21, and is attached to the oral care model 30 so that the force receiving body 21 is in contact with the bottom surface of the oral care model 30. In other words, the oral care model 30 is placed on the force receiving body 21 of the sensor 20.

The oral care model 30 has a dentition and is used in oral care training and education to learn proper brushing. The trainee touches a brush to the dentition of the oral care model 30 and performs training such as brushing.

When the force receiving body 21 is the upper surface of the sensor 20, a plate-shaped support body 22 is provided on the lower surface, and a deformable body 23 is disposed between the force receiving body 21 and the support body 22. The sensor 20 electrically detects the deformation state of the deformable body 23, thereby detecting the magnitude, position and direction of the force applied to the contact object placed on the force receiving body 21, i.e., the line of action of the force applied to the oral care model 30.

The sensor 20 has a positioning mechanism for attaching it to the oral care model 30. One example of the positioning mechanism is the guides 211-213 as shown in FIG. 2. Referring to FIG. 2 for more details, the upper surface 21A of the force receiving body 21 of the sensor 20 on which the oral care model 30 is placed is provided with guides 211, 212 for fixing the depth direction of the oral care model 30, and a guide 213 for fixing the center in the lateral direction. The guides 211-213 are, for example, lines or recessed protrusions printed on the upper surface 21A.

By providing guides 211-213 on the upper surface 21A, the oral care model 30 can be placed at a specified position on the upper surface 21A of the force receiving body 21 of the sensor 20. This improves the calculation accuracy in the processing described below.

The sensor 20 and the calculation device 10 are connected by a communication line 40, and the sensing result SG of the sensor 20 is input to the calculation device 10. The sensor 20 and the calculation device 10 may communicate wirelessly. The calculation device 10 is configured as a general computer, and performs processing using the sensing result SG from the sensor 20. The processing using the sensing result SG will be described later.

The calculation device 10 is connected to a display 50, which is an output device, and an input device 60 for performing operation input. In addition, as shown in FIG. 1, a camera 70, which will be described later, may be further connected to the calculation device 10. The camera 70 is not essential to the sensor system 100. When the camera 70 is connected to the calculation device 10, the calculation device 10 may receive input of image data IM of a captured image from the camera 70 and use it in the calculation described later.

The computing device 10 is configured as a computer having a processor 11 and a memory 12. The memory 12 may be a primary storage device or a secondary storage device. The memory 12 stores a computer program 121 that is executed by the processor 11.

The memory 12 further has a shape data storage unit 122 that stores model shape data M1 of the oral care model 30. The model shape data M1 is data representing the shape of the oral care model 30 used in the calculations described below. This allows the data representing the shape of the oral care model 30 to be used in the processing described below.

The shape data storage unit 122 may further store model shape data M2 of different sizes. This allows the processor 11 to set the coordinates of the oral care model 30 used in processing to appropriate model shape data.

The computing device 10 has a sensor I/F (interface) 13 for connecting to the sensor 20. The sensor I/F 13 functions as an input unit capable of accepting input of the sensing result SG from the sensor 20.

The computing device 10 has a camera I/F 14 for connecting to a camera 70 described below. The camera I/F 14 functions as an input unit capable of accepting input of image data IM from the camera 70.

The processor 11 executes the program 121 stored in the memory 12 to perform processing using the sensing result SG from the sensor 20. The processing using the sensing result SG includes a calculation to determine the point of application of the force on the oral care model 30 using the line of action of the force applied to the oral care model 30 obtained from the sensing result SG and the pre-stored model shape data M1.

The calculation to determine the point of action executed by the processor 11 includes a candidate point calculation process 111. The candidate point calculation process 111 is a process to calculate candidate points using the sensing result SG from the sensor 20 and the model shape data M1. A candidate point is a point that is a candidate for the point of action. Calculating the candidate point includes calculating the intersection of the model shape data M1 with the line of action included in the sensing result SG. Details will be described later.

Preferably, the candidate point calculation process 111 includes a correction process 112. The correction process 112 is a process for correcting the model shape data M1 to be used according to the positional relationship between the sensor 20 and the oral care model 30. The method for identifying the positional relationship between the sensor 20 and the oral care model 30 is not limited to a specific method. As an example, when a camera 70 is connected to the calculation device 10, the processor 11 can identify the positional relationship of the oral care model 30 relative to the sensor 20 based on image data IM from the camera 70. Identification may also be performed by other methods. In the correction process 112, the processor 11 corrects the model shape data M1 based on the identified positional relationship. This ensures calculation accuracy even if the positional relationship deviates from the specified relationship.

Preferably, the candidate point calculation process 111 includes a deformation process 113. The deformation process 113 is a process for deforming the model shape data M1 to be used in accordance with the deformation of the oral care model 30. The method for detecting the deformation of the oral care model 30 is not limited to a specific method. As an example, when a camera 70 is connected to the calculation device 10, the processor 11 can detect the deformation of the oral care model 30 based on the image data IM from the camera 70. Detection may also be performed by other methods. In the deformation process 113, the processor 11 deforms the model shape data M1 based on the detected deformation. This ensures calculation accuracy even when the oral care model 30 is deformed.

The calculation to determine the action point executed by the processor 11 includes action point determination processing 114. Action point determination processing 114 is a process to determine the action point from among the candidate points calculated by the candidate point calculation processing 111. In this case, preferably, action point determination processing 114 includes narrowing down processing 115. Narrowing down processing 115 is a process to narrow down the multiple candidate points calculated by the candidate point calculation processing 111, and is a process to remove points that are not candidate points from the candidate points using predefined narrowing down conditions. Details will be described later. This makes it possible to reduce the number of candidate points to be calculated, and the amount of processing.

The action point determination process 114 includes a speed calculation process 116. The speed calculation process 116 is a process for determining an index value corresponding to the speed of change of position for each candidate point from multiple sensing results SG with different sensing timings by the sensor 20. The index value corresponding to the speed of change may be the speed itself. The action point determination process 114 determines the action point based on the speed of change of position for each candidate point. Details will be described later.

By executing the program 121, the processor 11 further executes a display process 117. The display process 117 is a process for outputting data that associates the point of action determined by the point of action determination process 114 with the magnitude of the force included in the sensing result SG, and is, as an example, a process for generating screen data and displaying it on the display 50. As another example, in the case where a communication device (not shown) is included, transmission data may be generated and transmitted to another device.

The principle of the calculation to determine the point of action will be explained using Figures 4 to 10. The model shape data M1 and M2 for the oral care model 30 used are defined in a three-dimensional coordinate system, but here, a two-dimensional model is used to simplify the explanation. In other words, the gum shape of the oral care model 30 is defined on a two-dimensional plane.

First, the candidate point calculation process 111 executed by the processor 11 will be described with reference to FIG. 4 to FIG. 6. Referring to FIG. 4, the outside and inside of the dentition (gums) of the oral care model 30, that is, the outside and inside of the gum shape, are defined by ellipses T1 and T2 shown in formulas (1) and (2), respectively, using the major axis ai, the minor axis bi, and the eccentricity distance ei. In formulas (1) and (2) and the graph of FIG. 4 showing these, the x-axis corresponds to the depth direction of the gum shape, the y-axis corresponds to the width direction of the gum shape, and the direction in which the x-value increases corresponds to the front of the gums. The threshold value xth of the x-value is the x-value corresponding to the innermost position of the gums. The model shape data M1 stored in the shape data storage unit 122 of the memory 12 is, for example, a combination of formulas (1) and (2).

The sensor 20 is attached at a position corresponding to the origin O of the model shape data M1. The sensor 20 detects the x-axis component (x component) Fx of the force F, the y-axis component (y component) Fy, and the moment M about the origin O. The calculation device 10 can obtain these values from the sensing result SG.

The moment M is expressed by equation (3-1) in FIG. 5 using the x-component Fx and the y-component Fy. By transforming equation (3-1), equation (3) for the line of action L1 of the force F is obtained. Therefore, the processor 11 of the calculation device 10 can calculate the line of action L1 using equation (3) using the x-component Fx, y-component Fy, and moment M obtained from the sensing result SG from the sensor 20.

The point of action is the point where the brush or the like comes into contact with the surface of the dentition of the oral care model 30, and therefore exists on the ellipses T1 and T2 expressed by equations (1) and (2). Therefore, the point of action is expressed by the coordinates (xc, yc) on equation (1) or equation (2). The point of action is also on the line of action. Therefore, as shown in FIG. 5, the points of action are obtained at the intersections P11, P12, and P13, P14 of the ellipses T1, T2, respectively, and the line of action L1.

Specifically, in the candidate point calculation process 111, the processor 11 obtains a solution C3 represented by equations (5) and (6) by simultaneous calculation C1 of equations (1) and (3) and simultaneous calculation C2 of equations (2) and (3) as shown in FIG. 6. Solution C3 is obtained at coordinates (xc, yc). Note that constants C and D in equations (5) and (6) are respectively shown in equations (7) and (8) in FIG. 6. From equations (5) and (6), solution C3 is four solutions represented by coordinates (xc, yc). In other words, intersections P11, P12, and P13 and P14 are obtained as candidate points.

Next, the action point determination process 114 executed by the processor 11 will be described with reference to Figures 7 to 9. Figure 7 shows the angular relationship of the force F at the action point A. That is, referring to Figure 7, the angle θ1 of the force F with respect to the horizontal is expressed by equation (9) using the x-component Fx and the y-component Fy. The angle θ2 of the tangent to the horizontal at the action point A of the ellipses T1 and T2 is expressed by equation (10) using the equations (1) and (2) of the ellipses T1 and T2. The angle φ of the force F with respect to the tangent TN at the action point A is expressed by equation (11), which is the difference between θ1 and θ2. The component (tangential force) Fn in the tangent TN direction at the action point A of the force F and the component (normal force) Fv in the normal direction are expressed by equations (13) and (14), respectively, using the angle φ.

In the narrowing down process 115 of the action point determination process 114, the normal force Fv is calculated at each of the candidate intersection points P11 to P14, and points where the normal force Fv does not match the narrowing down conditions stored in advance are removed from the candidate points. The narrowing down conditions are the direction of the normal force, and are set in advance for each candidate point position. In the example of Figure 8, an allowable range R1 to R4 for the direction of the normal force at the candidate point is set for each of the intersection points P11 to P14. In the narrowing down process 115, points where the direction of the normal force Fv is not within the allowable range are removed from the candidate points.

The allowable range of the direction of the normal force is determined based on the direction in which the oral care model 30 can be contacted by a brush or the like. In other words, based on the direction in which the brush can contact the oral care model 30 from the outside, the allowable range is set to a range in which the normal force is directed inward toward the gums. The allowable range may be set in advance, or may be calculated from the coordinate values of points on the ellipses T1 and T2.

In the narrowing down process 115, points whose direction of the normal force Fv is not within the acceptable range are removed from the candidate points. In other words, in the narrowing down process 115, of the multiple calculated candidate points, points whose normal force Fv is oriented away from the gums are removed from the candidate points. In the example of FIG. 8, of the intersection points P11 to P14, the intersection points P12 and P13 are removed from the candidate points.

In the narrowing down process 115, more simply, at least one of the x-component Fx and the y-component Fy of the force F may be used to remove points that are not within the allowable range from the candidate points. This makes it easier to narrow down the candidate points than calculating the normal force Fv for all candidate points. In other words, the narrowing down process 115 can be said to be a process that removes points where the component obtained from the direction of the force F is not within the allowable range corresponding to each candidate point.

Next, in the action point determination process 114, a speed calculation process 116 is executed to calculate the speed of change of the position for each candidate point. The speed of change of the position will be explained with reference to FIG. 9. When a brush is brought into contact with the oral care model 30 to perform a brushing operation, the position where the brush comes into contact, i.e., the point of action of the applied force F, changes continuously. Accordingly, the slope of the action line changes. In particular, since the gums, which are the contactable surface of the oral care model 30, are curved, the time change in the slope of the action line associated with the change in the action point is large. As the action point changes, the action line changes so that the range of the action line expands the further away from the action point, with the action point, i.e., the contact position, at the center.

In this regard, Figure 9 shows a case where a slight brushing action is performed at point Q1 on the gum surface to the extent that it is considered to be the same point. The force applied to point Q1 changes to forces f1 and f2. The action lines AL1 and M2 of forces f1 and f2, respectively, have intersection points Q2 and Q3 at other positions on the gums. Intersection points Q2 and Q3 are the same candidate point, and are detected as being close to each other among the candidate points obtained from two sensing results with different sensing timings by sensor 20.

Since point Q1 is a point on an ellipse and moves on a curved surface, the direction of the action lines AL1 and M2 changes significantly. As a result, the distance between intersections Q2 and Q3 is greater than the distance that intersection Q1 moves. Therefore, the rate of change in the position of the candidate points corresponding to intersections Q2 and Q3 is greater than the rate of change in the position of the candidate point corresponding to intersection Q1.

By utilizing this property, the candidate point with the slowest rate of change to the corresponding position obtained from the sensing results with different sensing timing can be selected as the action point.

The velocity of change vi of the position at the candidate point is expressed by equation (15) in FIG. 9 using the candidate point (xc, yc) and the coordinates of the candidate point after Δt seconds (xciold, yciold). In the velocity calculation process 116, the velocity of change vi is calculated for each calculated candidate point, or for each candidate point calculated and narrowed down by the narrowing down process 115. These are then compared, and the one with the smallest velocity of change vi is determined to be the point of action.

In the example of FIG. 10, the change velocities v1 and v2 of the intersections P11 and P14, which are the candidate points narrowed down by the narrowing down process 115, are calculated. As a result, since v1<v2 as shown in FIG. 10, the intersection P11 is determined to be the point of action.

Note that other index values equivalent to the rate of change vi may be used to determine the point of action. The other index value may be, for example, the distance between points. When the distance between points is used, the candidate point with the smallest distance is set as the point of action.

Figure 11 is a flowchart showing an example of the processing flow in the processor 11 of the computing device 10. The processing in Figure 11 is started, for example, when oral care training begins. At that time, as an example, the operator uses the input device 60 of the computing device 10 to instruct the start of processing and also to instruct the size of the oral care model 30 to be used for training, etc.

The processor 11 reads and executes the program 121 in accordance with the instruction signal from the input device 60, thereby starting the processing. First, the processor 11 reads from the memory 12 the model shape data M1 corresponding to the oral care model 30 specified by the instruction signal from the input device 60 (step S101).

Preferably, the processor 11 corrects the coordinate system of the read model shape data M1 according to the positional deviation of the oral care model 30 (step S103). In step S103, the processor 11, as an example, analyzes image data IM obtained by photographing with the camera 70, and detects the positional deviation of the oral care model 30 from the guides 211-213. The positional deviation may be detected by other methods. In step S103, the coordinates of the model shape data M1 are converted according to the detected positional deviation, and the coordinate system to be applied to the subsequent sensing result SG is also converted. This makes it possible to suppress a decrease in sensing accuracy even if a positional deviation occurs when attaching the sensor 20 to the oral care model 30.

Preferably, the processor 11 corrects the coordinate system of the read model shape data M1 according to the deformation of the oral care model 30 (steps S105, S107). As an example, the processor 11 analyzes the image data IM obtained by photographing with the camera 70 to detect the deformation of the oral care model 30. The deformation is, for example, a change in the angle of the upper jaw relative to the lower jaw. If a deformation is detected (YES in step S105), the processor 11 converts the coordinates of the model shape data M1 according to the deformation and also converts the coordinate system to be applied to the subsequent sensing result SG (step S107). This makes it possible to suppress a decrease in sensing accuracy even if a deformation occurs in the oral care model 30.

The processor 11 reads the sensing result SG from the sensor 20 at a certain time t (step S109). The processor 11 then calculates the intersection points P11 to P14 between the ellipses T1 and T2 representing the gum shape included in the model shape data M1 and the line of action L1 of the force F obtained from the x-component Fx, y-component Fy, and moment M of the force F included in the sensing result SG (step S111), and sets these as candidate points of action.

For each candidate point obtained in step S111, the processor 11 narrows down the candidate points depending on whether the component obtained from the direction of the force F at that point is within the allowable range for the direction corresponding to that candidate point (step S113). That is, in step S113, the processor removes from the candidate points any points that are not within the allowable range, which is the narrowing-down condition, and reduces the number of candidate points. This makes it possible to reduce the amount of subsequent processing. The candidate points narrowed down in step S113 are stored in the memory 12 (step S115).

If the memory 12 does not store candidate points obtained from the sensing results at a timing earlier than timing t (NO in step S117) and the sensing results at the next timing (t+Δt) can be read (YES in step S127), the processor 11 repeats the process from step S105. This causes candidate points to be calculated from the sensing results at the next timing (t+Δt) and stored in the memory 12.

In this case, since the candidate points at the previous timing t are stored in the memory 12 (YES in step S117), the processor 11 calculates the position change velocity vi for the corresponding candidate points obtained at these two timings t and (t+Δt) (step S119), and determines the point with the smallest change velocity vi as the action point (step S121).

When the point of action is determined by the above process, the processor 11 generates display data to be displayed on the display 50 (step S123), passes the data to the display 50, and instructs the display to display the data (step S125). In step S123, display data is generated to display data that associates the point of action determined by the above process with the magnitude of the force F.

The processor 11 repeats the above process. As a result, the display in step S125 continues to be updated until the process ends. In other words, the point of action, i.e., the point where the brush comes into contact and the force F applied to the gums, is displayed on the display 50 in real time in response to the brushing action using the oral care model 30.

As an example, the above process continues while the sensing result is being input from the sensor 20, that is, while the brushing operation is being performed (YES in step S127). In other words, if the sensing result is not being input from the sensor 20 (NO in step S127), the processor 11 ends the process. As another example, the processor 11 may end the process in accordance with an instruction input from the input device 60.

As described above, the model shape data M1 may be shape data in a three-dimensional coordinate system that represents a three-dimensional shape. In that case, equations (1) to (15) can be three-dimensional equations that have a component in the z-axis direction. This allows the model shape data M1 to be closer to the actual oral care model 30, making it easier to understand the point of action, that is, the position where the brush comes into contact and the direction of the force F.

The display 50 displays a screen 51, as shown in FIG. 12 as an example. The screen 51 is a screen when the model shape data M1 is shape data in a three-dimensional coordinate system. For more details, see FIG. 12. The screen 51 includes an area 52 that displays data relating the point of action to the magnitude of the force F.

Data relating the points of action to the magnitude of the force F may be, for example, statistics on the magnitude of the force F applied to each point of action included in the unit range to which the points of action belong, and the total time of contact for each area. The unit range is a range that is set for the model shape data M1 and serves as a unit for display. In the example of FIG. 12, eight ranges are set that divide the gum shape into left and right, front and back for both the lower and upper jaws. By displaying each unit range, it is possible to know the trends in the magnitude of the applied force F and the contact time for each unit range.

The statistical value of the magnitude of the applied force F is, for example, the average value of the magnitude of the force F over a specified time. In addition, the total contact time is, for example, the total time of sensing at which a sensing result indicating a point of action that belongs to that range was obtained.

In the example of FIG. 12, area 252 includes a display 521 showing the average value of the magnitude of force F applied to the point of application included in each unit range and the total time of contact with that range. Preferably, a statistical value of the force F applied for each unit range and/or a threshold value for the total time of contact is set, and the comparison result with the threshold value is also displayed in area 52. In the example of FIG. 12, an image 522 showing the comparison result for each unit range is displayed, and the comparison result is indicated by the color of image 522.

Preferably, the screen 51 includes an area 53 that visually displays the brushing action on the oral care model 30. The area 53 includes a visual display 531 of the oral care model 30 and a display 532 relating to the force F. As an example, the display 532 is a line segment extending from a point on the gum of the oral care model 30, and is positioned with respect to the display 531 such that the point on the gum represents the point of application of the force F, the length or thickness of the line segment represents the magnitude of the force F, and the direction of the line segment represents the direction of the force F.

The display 521 of area 52 allows the user to know the brushing strength and time for each area. For skills that involve continuous contact, such as oral care, it is generally difficult to clarify the position, angle, strength, time, etc. This makes it difficult to judge whether the skill is appropriate or to convey it to people during training, etc. In this regard, when the sensor system 100 is used, the position of contact with the oral care model 30 is identified as the point of application of the applied force F, and is output, such as displayed on the display 50. Additionally, the magnitude, direction, and contact time of the force F can also be known from the screen 51.

For example, when a trainer is modeling brushing movements, the strength and time of brushing for each area can be displayed numerically and as an image. This allows a more accurate understanding of the movements than simply watching the model and imitating it. Also, when a trainee is training with a brush, the trainer can understand the strength and time of brushing for each area by the trainee. This makes it easier to provide appropriate guidance.

Furthermore, the display of image 522 allows one to see at a glance whether the brushing action is appropriate for each area. Also, the display 532 of area 53 allows one to see on the display 50 the brushing action being performed on the oral care model 30, and it can also be compared by being displayed on the same screen as the display content of area 52, which shows the training status. This allows one to check the action even when an instructor is not present.

For example, by using the sensor system 100 when providing tooth brushing instruction, it is possible to present the judgment result of whether the brushing action of the practitioner is appropriate. Therefore, the sensor system 100 can be widely used not only by technicians but also in schools and other places to train and judge brushing actions.

Screen 51 is updated each time the process shown in the flowchart of FIG. 11 is repeated, that is, each time sensing by sensor 20 is repeated during the brushing action. By setting a short sensing interval, the brushing action is displayed in real time in area 53, and the cumulative results of a series of brushing actions can be known by updating the display in area 52.

<3. Notes>
In the above description, the processing of the disclosed computing device 10 is realized by the processor 11 executing the computer program 121, but at least a portion of it may be realized by circuit elements or other hardware.

The program 121 that realizes the processing in the computing device 10 may be provided as a program product recorded on a computer-readable non-transitory recording medium. Alternatively, the program 121 may be provided by downloading via a network.

The program 121 that realizes processing in the computing device 10 has program code for processing in the computing device 10. The program 121 is read and executed by the processor 11 connected to the memory 12 in which the program 121 is stored.

The program 121 that realizes processing in the computing device 10 may be provided as an application program, or part or all of it may be included in the computer's operating system (OS).

The present invention is not limited to the above embodiment, and various modifications are possible.

10: arithmetic unit 11: processor 12: memory 13: sensor I/F
14: Camera I/F
20: sensor 21: force receiving body 21A: upper surface 22: support body 23: deformable body 30: oral cavity care model 40: communication line 50: display 51: screen 52: area 53: area 60: input device 70: camera 100: sensor system 111: candidate point calculation process 112: correction process 113: deformation process 114: point of action determination process 115: narrowing down process 116: velocity calculation process 117: display process 121: computer program 122: shape data storage unit 211: guide 212: guide 213: guide 252: area 521: display 522: image 531: display 532: display A: point of action AL1: line of action C: constant C1: calculation C2: calculation C3: solution D: constant F: force Fv: normal force Fx : x-component Fy : y-component IM : image data L1 : line of action M : moment M1 : model shape data M2 : model shape data O : origin P11 : intersection P12 : intersection P13 : intersection P14 : intersection Q1 : intersection Q2 : intersection Q3 : intersection R1 : allowable range R2 : allowable range R3 : allowable range R4 : allowable range SG : sensing result T1 : ellipse T2 : ellipse TN : tangent ai : major axis bi : minor axis ei : eccentricity f1 : force f2 : force t : timing v1 : rate of change v2 : rate of change vi : rate of change xth : threshold θ1 : angle θ2 : angle φ : angle

Claims (16)

A computing device that performs processing using a force sensing result from a first sensor that can detect a line of action of a force applied to a contacted object by contact, comprising:
an input unit capable of receiving an input of the force sensing result;
A processor for executing the process,
The process comprises:
calculating candidate points for the point of application of the force on the contacted body using a line of action of the force obtained from the force sensing result and shape data of the contacted body that has been stored in advance;
determining the action point from among the candidate points ;
Determining the point of application includes determining an index value corresponding to a rate of change in position for each of the candidate points from a plurality of force sensing results obtained by the first sensor at different timings, and determining the point of application based on the index value.
Calculation device. The arithmetic device according to claim 1 , wherein determining the point of application includes determining, as the point of application, the candidate point having the slowest rate of change among the plurality of candidate points. The computing device according to claim 1 or 2 , wherein calculating the candidate point includes calculating an intersection between pre-stored shape data of the contacted body and the line of action. The computing device according to any one of claims 1 to 3, wherein determining the point of action includes using the force direction included in the force sensing result to eliminate from the candidate points points whose component obtained from the force direction is not within a range of allowable directions corresponding to each of the candidate points. The computing device of claim 4 , wherein the range of allowable orientations is defined based on orientations in which the contact is possible for the candidate point. the input unit is further capable of receiving an input of a sensing result of a shape of the contacted object by a second sensor;
The computing device according to claim 1 , wherein calculating the candidate points includes deforming shape data of the contacted body based on the shape sensing results, and using the deformed shape data of the contacted body. The computing device according to claim 1 , wherein the shape data of the contacted object is three-dimensional shape data. The computing device according to claim 1 , wherein the shape data of the contacted object is shape data of an oral care model. The computing device according to claim 1 , wherein the processing further includes outputting data correlating the determined point of action with the magnitude of the force included in the force sensing result. A computing device that performs processing using a force sensing result from a first sensor that can detect a line of action of a force applied to a contacted object by contact, comprising:
an input unit capable of receiving an input of the force sensing result;
A processor for executing the process,
The process comprises:
calculating candidate points for the point of application of the force on the contacted body using a line of action of the force obtained from the force sensing result and shape data of the contacted body that has been stored in advance;
determining the action point from among the candidate points;
The processing includes outputting, for each unit range of the contacted object, data indicating at least one of a total value of the magnitude of the force applied to the application point included in the unit range per unit time and a total value of the time during which the force is applied to the application point included in the unit range.
Calculation device. The arithmetic device according to claim 9 or 10 , wherein outputting the data includes displaying the data on a display. The computing device according to claim 11 , wherein causing the display to display includes causing an image representing the contacted object to be displayed together with the data. The computing device according to claim 1 , wherein the first sensor is a force sensor. a sensor that can be attached to a contacted body and can detect a line of action of a force applied to the contacted body by contact;
a computing device that acquires a sensing result by communicating with the sensor and performs processing using the force sensing result;
The process comprises:
calculating candidate points for the point of application of the force on the contacted body using a line of action of the force obtained from the force sensing result and shape data of the contacted body that has been stored in advance;
determining the action point from among the candidate points ;
Determining the point of application includes determining an index value corresponding to a rate of change in position for each of the candidate points from a plurality of force sensing results obtained by the sensor at different sensing timings, and determining the point of application based on the index value.
Sensor system. The sensor system according to claim 14 , wherein the sensor has a positioning mechanism for attaching the sensor to the contacted object in a positional relationship according to a coordinate system of the shape data. A computer program that causes a computer to function as an arithmetic device that performs processing using a sensing result from a first sensor that can detect a line of action of a force applied to a contacted object by contact,
The process comprises:
calculating candidate points for the point of application of the force on the contacted body using a line of action of the force obtained from the force sensing result and shape data of the contacted body that has been stored in advance;
determining the action point from among the candidate points ;
Determining the point of application includes determining an index value corresponding to a rate of change in position for each of the candidate points from a plurality of force sensing results obtained by the first sensor at different timings, and determining the point of application based on the index value.
Computer program.

Images