Image display system and program

Abstract

To provide a technique for cranial shape correction treatment.SOLUTION: The present invention relates to a computer program, method, and system that acquires the three-dimensional shape of a patient's head and calculates the optimal helmet shape on the basis of the acquired three-dimensional shape. This technique accurately grasps the distance between the patient's head and the helmet and the wearing state, and provides optimal correction treatment.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technical field related to the wearing state of a skull shape correction helmet used for the treatment of deformational plagiocephaly, and in particular to a technology for visualizing the positional deviation of the helmet and the range of the gap caused by the deviation. [Background technology]

[0002] Human infants, especially those over about three months of age, may develop a condition known as plagiocephaly, dolichocephaly, or brachycephaly, which is a distortion of the head shape. For example, plagiocephaly is a condition in which the back of the head is distorted at an angle and asymmetrical when viewed from above. If this condition is left untreated and the distortion progresses as the infant grows, the position of the ears and the face will remain asymmetrical.

[0003] For this reason, a treatment method (hereinafter referred to as "helmet treatment") is sometimes adopted in which a skull shape correction helmet is fitted to the baby's head for a specified period of time up to about 18 months of age depending on the symptoms, and the baby lives daily in that state (Patent Document 1). Helmet treatment makes it possible to gradually return the distorted head shape to normal.

[0004] Furthermore, with the advancement of electronic terminal technology such as smartphones, technology that allows parents and caregivers to easily check the head of a sick child is becoming widespread (Patent Document 2 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6833240 [Patent Document 2] Patent Publication No. 2023-108583 [Non-Patent Document 1] https: / / www.link-j.org / bulletinboard / post-6299.html Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional skull shape correction helmets used to treat deformational plagiocephaly are designed to have a gap in the part of the skull that promotes growth. However, when actually worn, the helmet may shift (the positional relationship between the head and the helmet that the doctor judged to be correct at the beginning may change), and it has been unclear how much this shift affects the treatment effect. In addition, it is difficult for families to judge the appropriate position of the helmet and the acceptable range of shifting, and a solution to this problem is required. By changing the threshold value (th) that exemplifies the thickness of the cushion liner and performing a simulation, it becomes easier to determine the thickness of the cushion liner that has sufficient gaps in the area that promotes growth and has a sufficient contact surface between the cushion liner and the patient's head, making it difficult to shift. Furthermore, the present invention makes it easier to determine the appropriate thickness of the cushion liner for each part / area. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure provides the following inventions.

[0008] That is, one embodiment of the present invention is In cranial shape correction treatment, Using a computer a) acquiring stereoscopic head shape information of the patient and representing the stereoscopic head shape in three dimensions; b) calculating the shape of the helmet that the patient should wear based on the three-dimensional head shape information of the patient, and expressing it three-dimensionally; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to create a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet pose; e) setting a helmet shape that is convertible to the head shape of the patient in the helmet position; A program that executes the above.

[0009] Also, a further embodiment of the present invention is In the above d), the distance information between the head shape of the patient and the helmet shape is A point that satisfies a predetermined condition, an area that satisfies a predetermined condition, or a combination thereof. Any of the above programs.

[0010] Also, a further embodiment of the present invention is calculating the number and area of ​​said points or said regions, or any combination thereof; Any of the above programs.

[0011] Also, a further embodiment of the present invention is The program described in any one of the above, wherein the specified condition is set based on the thickness of a cushion liner attached to the inside of the helmet.

[0012] Also, a further embodiment of the present invention is The program according to any one of the above, further comprising the step of: in e), converting the helmet posture and displaying distance information, or the state of a point satisfying the specified condition, or an area satisfying the specified condition, or a combination thereof.

[0013] Also, a further embodiment of the present invention is Any of the above-mentioned programs, wherein in the step e), the step of convertibly setting the helmet shape to correspond to the head shape of the sick child is set to six degrees of freedom.

[0014] Also, a further embodiment of the present invention is Further, f) the program according to any one of the above, which executes a step of defining an objective function from an evaluation value calculated based on the points or the regions or a combination thereof, with the movements in the x-, y-, and z-directions in the helmet posture and the rotations in the x-, y-, and z-axis directions as variable parameters.

[0015] Also, a further embodiment of the present invention is The objective function is a loss function calculated by adding a penalty when the distance between the head shape and the helmet shape at the point or the region is smaller than a predetermined value. Any of the above programs.

[0016] Also, a further embodiment of the present invention is Furthermore, the variable parameters are varied to find the variable parameters that minimize the calculation result of the loss function. Any of the above programs.

[0017] Another embodiment of the present invention comprises The program described above executes a step of defining an objective function from an evaluation value calculated based on the points or the regions or a combination of these, by setting constraints on the amount of variation in each item (movement in the x-, y-, and z-directions, and rotation along the x-, y-, and z-axes) of the variable range of the variable parameters.

[0018] Also, a further embodiment of the present invention is The method further includes a step of outputting any combination of the distance information, a statistical value of the distance information (an average value calculated for each group after grouping the points into points with small distances and points with large distances, or an average value for each region, etc.), or a numerical value that is a calculation result of the loss function, Any of the above programs.

[0019] Another embodiment of the present invention comprises The program described in any of the above, further comprising a step of determining and outputting a tendency for deviation to occur based on a plurality of helmet postures obtained from any combination of the output distance information, statistical values ​​of the distance information, or numerical values ​​that are the calculation results of the loss function.

[0020] a step of obtaining a plurality of pose groups calculated from the plurality of helmets or the variable parameters in claim 9, or both of them, and for each of them, grouping arbitrarily sampled points or regions or both of them, and obtaining and outputting a statistical value of the distance between the head shape and the helmet shape in each group, a number of sampling points or a region area in each group, or both of them, and a loss function for each of the groups. The program according to claim 10.

[0021] Also, a further embodiment of the present invention is Furthermore, the program may further comprise the step of: g) visualizing a gap three-dimensionally in a state in which the helmet posture and the helmet shape are transformed.

[0022] Also, a further embodiment of the present invention is The program according to any one of the above, wherein the visualization step is performed by changing the transparency and color of the head shape and the helmet shape.

[0023] Also, a further embodiment of the present invention is In the step of calculating the number and area of ​​the points or the regions, or any combination thereof, a step of superimposing and displaying visualized information (assuming x or colored points) according to distance information between the head shape and the helmet shape is included. Any of the above programs.

[0024] Also, a further embodiment of the present invention is The program is capable of setting the predetermined condition as a threshold value (th), varying the threshold value, and outputting any combination of the results of any of the above-described outputs or the above-described superimposed display.

[0025] Also, a further embodiment of the present invention is The program sets the specified condition as a threshold value (th), varies the threshold value, and can output any combination of the results of any of the above-mentioned outputs or the above-mentioned superimposed display.

[0026] Also, a further embodiment of the present invention is The program according to any one of the above, wherein the threshold value is changed depending on a predetermined part of the head shape.

[0027] Another embodiment of the present invention is In cranial shape correction treatment, Using a computer a) acquiring stereoscopic head shape information of the patient and representing the stereoscopic head shape in three dimensions; b) calculating the shape of the helmet that the patient should wear based on the three-dimensional head shape information of the patient, and expressing it three-dimensionally; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to create a helmet posture in which the helmet is worn; d) acquiring distance information between the shape of the patient's head and the shape of the helmet in the helmet pose; e) setting a helmet shape that is convertible to the head shape of the patient in the helmet position; and an image display device that displays the results at each step.

[0028] Another embodiment of the present invention is In cranial shape correction treatment, Using a computer a) acquiring three-dimensional head shape information of a patient and representing the three-dimensional head shape in three dimensions; b) calculating the shape of the helmet to be worn by the patient based on the three-dimensional head shape information of the patient and representing it three-dimensionally; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to create a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet pose; e) setting the helmet shape to be changeable relative to the head shape of the patient in the helmet position; A method for visualizing the state in which a helmet is fitted to a head in cranial orthodontic treatment, comprising:

[0029] Another embodiment of the present invention is In cranial shape correction treatment, A system for checking the space between the head shape of a patient and the helmet shape by using (including) a scanning device, a client terminal, and a computer, The computer, a) acquiring stereoscopic head shape information of the patient and representing the stereoscopic head shape in three dimensions; b) calculating the shape of the helmet that the patient should wear based on the three-dimensional head shape information of the patient, and expressing it three-dimensionally; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to create a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet pose; e) setting a helmet shape that is convertible to the head shape of the patient in the helmet position; Run The client terminal displays the results at each step. Effect of the Invention

[0030] In the corrective treatment of deformational plagiocephaly, parents and caregivers are often concerned about helmet slippage. The present invention provides parents and caregivers with a means to objectively evaluate whether the slippage is acceptable or not.

[0031] Furthermore, the progress and effects of helmet therapy can be shared objectively, making treatment more reassuring and effective.

[0032] Furthermore, according to the present invention, it is possible to perform a simulation taking into account movement constraints for a patient in both a standing and lying position. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a schematic diagram of a system according to the present invention. [Diagram 2] FIG. 2 is a diagram showing the configuration of hardware for executing the program of the present invention. [Diagram 3] FIG. 3 shows a configuration diagram of a server that executes the program of the present invention. [Figure 4] FIG. 4 is a flow diagram of the program of the present invention. [Diagram 5] FIG. 5 is a flow diagram of the program of the present invention. [Figure 6] FIG. 6 is a drawing in which the shape of the patient's head and the shape of a helmet are superimposed in accordance with the present invention, with certain points and areas marked up. [Figure 7] FIG. 7 is a diagram in which the shape of the patient's head and the shape of a helmet are superimposed in accordance with the present invention, with certain points and areas marked up. [Figure 8] FIG. 8 is a diagram illustrating a data set of a patient in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In the present invention, cranial shape correction therapy is a treatment to correct asymmetry and deformation of the baby's head. The baby's skull is soft and can be deformed by long periods of the same posture and external pressure. This deformation can lead to other health problems such as jaw and ear displacement as well as appearance problems. A common correction therapy is to wear a specially designed helmet regularly. This helmet helps the head grow and restores the deformation to a normal shape.

[0035] The computer in the present invention is preferably one having computational and graphics processing capabilities. In order to efficiently acquire, analyze, and visualize 3D shapes, a CPU, a GPU, RAM, and storage are basically required. Such a computer has specific hardware and software optimizations to support the processing of large amounts of data and the rendering of advanced graphics.

[0036] The term "patients" in the present invention refers to infants and young children who are candidates for cranial shape correction treatment. These patients often have asymmetric head shapes and partial or total head deformations. Head deformations can be caused by various external factors, such as pressure at birth and lying in the same position for a long time during infancy. Such deformations can sometimes affect health and growth, and early corrective treatment may be required. Detailed data on the head shape of patients is essential for designing corrective helmets and formulating treatment plans.

[0037] In the present invention, head shape information refers to a digital representation of the three-dimensional shape of the patient's skull. This information is acquired by a scanning device or a three-dimensional measuring device, and can capture the curves, contours, bumps, and irregularities of the head in detail. Head shape information contains precise numerical data of shape, size, and positional relationship, and is therefore extremely important in designing helmets and formulating corrective treatment plans. In particular, accurate acquisition and analysis of this head shape information is essential to ensure that the helmet fits the patient's head appropriately.

[0038] In the present invention, helmet shape refers to the three-dimensional design of a helmet for orthodontic treatment. This shape is adapted to the specific deformations and asymmetries of the patient's head, with the aim of accelerating the growth of the skull by designing the space inside the helmet to suit the areas requiring treatment.

[0039] A program in the present invention is a set of computational instructions for performing a specific task or function to achieve the purpose of the present invention, and is executed on a computer. It is written in a programming language and operates in a manner that gives instructions to a computer. In the present invention, in order to perform the steps recited in the claims, information is processed according to a user's input and expected information is generated.

[0040] In the present invention, distance information is data indicative of the spatial separation between the child's head and the corrective helmet. This information can be processed by the computer or executed on a server that can communicate via the computer. In the present invention, distance information is important in assessing the proper fit of the helmet and the effectiveness of treatment in the child.

[0041] The helmet posture in the present invention refers to a state in which a helmet for corrective treatment is initially attached to the patient's head. The helmet posture may be performed by any method as long as it is a means for superimposing head shape information and helmet information. For example, the head shape and helmet shape may be created three-dimensionally in advance, and then the helmet may be positioned based on this head shape information. In this case, in order to later analyze the deviation between the head shape and the helmet shape, the helmet may be defined as a state in which it is not deviated in any direction with respect to the six degrees of freedom, that is, with respect to the movement along the three axes x, y, and z and the rotation around each axis. By defining the helmet posture, the degree of deviation of this posture can be objectively evaluated, and even if a deviation occurs between the head shape and the helmet shape, it is possible to visualize and share that a space is maintained in the part to be corrected. This allows the monitoring of the treatment period and the accompanying doctor's guidance to be performed appropriately, promoting the growth of the skull evenly, and an optimal correction effect is expected. In addition, by appropriately sharing information with the guardian or caregiver, these people can continue the treatment with peace of mind.

[0042] In the present invention, the patient who wears the helmet is an infant aged from 2 or 3 months to about 6 months. The skull of an infant at this age grows and changes rapidly, so the corrective helmet is designed to reflect the ideal head shape and size. Therefore, at the beginning of treatment, there is a certain amount of space inside the helmet, and ideally, this space is gradually filled as the skull grows. While the large space in the helmet at this early stage can be made stress-free to wear with a cushion liner, it can cause the helmet to slip out of place. In particular, considering the active movements and rapid growth of infants, it is practically impossible to completely prevent the helmet from slipping out of place. Therefore, it is recognized that the helmet slippage in the early stages of treatment is within an acceptable range, but it has been a difficult task for families and caregivers to accurately grasp and judge the acceptable range and the specific degree of the slippage. With the present invention, such judgments can be objectively evaluated by quantifying using an objective function, and the wearing state of the helmet can be visually confirmed by virtual simulation.

[0043] In the present invention, the cushion liner is a member disposed inside the skull shape correction helmet, specifically, inside the shell. This liner is formed of foamed synthetic resin, particularly open-cell foamed synthetic resin, and is preferably disposed on almost the entire inner surface of the shell, except for the peripheral reinforcement portion. Specific materials include foamed polyurethane. The thickness of the liner is 4 to 20 mm, and it is desirable that the liner has a ball resilience of 15% or less. This cushion liner plays a role as a buffer material, and at the same time, has the function of absorbing and dissipating the sweat of the wearer. Therefore, the sweat absorbed by the liner evaporates through a specific part of the helmet, providing a comfortable feeling to the wearer. In addition, the liner is designed to be removable to accommodate contamination and skull growth, and can be easily replaced or adjusted.

[0044] In the present invention, the objective function is a mathematical expression of the goal in a particular optimization problem, in this case, the objective is to find a wearing state that maximizes (or minimizes) the effect of the helmet treatment. The thickness of the cushion liner is considered in this objective function as a factor such as the distance between the helmet and the head and the allowable range of deviation. In other words, if the thickness of the liner changes, the optimal state indicated by the objective function and its evaluation value will also vary. In particular, if the objective function includes a penalty term, if the thickness of the cushion liner is not appropriate compared to a predetermined value, the penalty will increase, and it may become difficult to achieve the optimal wearing state. In the present invention, the thickness of the cushion liner and the objective function are in close relationship to realize the optimal function and performance of the cranial shape correction helmet.

[0045] In one embodiment of the present invention, the objective function may be a loss function. The loss function is defined by calculating the distance from each point of the mesh of the surface of the skull to the inner surface of the helmet. Specifically, if this distance is smaller than a certain threshold, a penalty is applied. The objective of this loss function is used to quantify ensuring that the helmet maintains an appropriate distance from the skull. If the distance is smaller than the threshold, i.e., if the helmet is very close to or touching the skull, a penalty is applied to avoid such a placement.

[0046] In the present invention, the input values ​​are values ​​that indicate the rotational movement of the helmet in six degrees of freedom. These are values ​​that describe how the helmet is positioned and oriented in three-dimensional space. Specifically, there are six values ​​that indicate how much the helmet rotates around the x, y, and z axes, and how much it moves in the x, y, and z directions.

[0047] In one embodiment of the present invention, a genetic algorithm is used to optimize the six degree of freedom inputs. Using a genetic algorithm, it is possible to find the inputs for the rotational movement of the helmet that minimize the loss function. This results in a helmet configuration that minimizes cushion rebound. This method also allows one to see how the helmet may rotate and move, and whether the configuration provides an optimal distance from the skull.

[0048] In the present invention, as the objective function, any calculation method for verifying the difference in shape when overlapping figures can be executed using a computer and can be executed by combining any function and parameter.

[0049] Next, an embodiment of the present invention will be described with reference to the drawings.

[0050] FIG. 1 shows a system configuration diagram of the present invention. The system of the present invention includes a scanning device, a client terminal, and a computer. In the present invention, the client terminal is assumed to be a smartphone or tablet terminal held by the guardian or caregiver of the sick child, but is not limited to these. The medical institution terminal is a computer used by a doctor. The scanning device is a device for acquiring head shape information of the sick child.

[0051] In one embodiment of the present invention, head shape information of a patient is obtained by a scanning device at a medical institution terminal. The head shape information is transmitted from the scanning device to the medical institution terminal, and the medical institution terminal executes the program of the present invention, so that the treatment plan for helmet therapy can be explained to the guardian or caregiver of the patient. In another embodiment of the present invention, data from the scanning device may be transmitted via a communication network or directly to a management server. In such an embodiment, the data from the scanning device may be transmitted to a medical institution terminal and displayed on the medical institution terminal by executing the program of the present invention in a processing unit in the management server. In FIG. 1, the management server may be provided in the medical institution or on a cloud.

[0052] In a further embodiment of the present invention, the execution result of the program of the present invention may be configured to be displayed on the client terminal. Alternatively, the client terminal may acquire head shape information of the patient, and the head shape and helmet shape may be created on the management server or the terminal of the medical institution, and the helmet pose may be created by superimposing them.

[0053] In FIG. 2, the CPU performs arithmetic and logical calculations, and interprets and executes instructions. The GPU, which can be added as an option, is suitable for performing tasks that require parallel processing, such as 3D rendering. In the present invention, the head shape and helmet shape are constructed three-dimensionally, so it is suitable for processing tasks such as overlapping them and evaluating gaps. The CPU and GPU are connected to the RAM, ROM, I / O interface, communication interface, etc. via buses.

[0054] In Figure 2, ROM is a read-only memory device that stores information when the system boots up and fixed program data. RAM is a volatile memory that stores temporary data and currently running programs. They function in conjunction with the CPU through the bus. Input / Output (I / O) manages data exchange with external devices, and I / F (Interface) usually refers to the interface that manages and adjusts connections with external devices and other systems.

[0055] 3 is a diagram for explaining an embodiment of the management server in the system of the present invention. In this management server, an input / output unit exchanges data with external devices and other systems.

[0056] In FIG. 3, the head shape information input unit provides an interface for receiving the head shape information of the patient. It can accept information in various formats, such as scan data and manually input data. The 3D head shape data calculation unit is a part that calculates 3D head shape data based on the data received from the head shape information input unit. This data is used when evaluating the fit of the helmet. Next, the target head shape data calculation unit calculates the optimal head shape (target shape). This calculation result can be used as a standard for how the helmet should fit. Next, the 3D helmet shape data calculation unit calculates 3D helmet shape data based on the user's head shape and the helmet design data. This allows comparison with the actual shape of the helmet. Next, the overlay execution unit overlays the 3D head shape data and the 3D helmet shape data, and uses them to visually evaluate the misalignment and fit.

[0057] Furthermore, in FIG. 3, the head shape information storage unit is a storage unit for head shape information. It can be used for later analysis or reevaluation. Next, the 3D head shape data storage unit is configured to store the calculated 3D head shape data. Next, the target head shape data storage unit stores the calculated target head shape data. Next, the 3D helmet shape data storage unit stores the calculated 3D helmet shape data. Next, the distance calculation result storage unit stores the result of the distance calculation between the helmet and the head. Next, the distance calculation execution unit: calculates the distance between the 3D head shape data and the 3D helmet shape data. This allows a numerical evaluation of how well the helmet fits the head. The display unit visually displays the analysis results such as the overlaid data and the distance calculation results. Also, the patient information storage unit is a unit that stores basic information of the patient and the user. The image storage unit stores image data of the head and the helmet.

[0058] FIG. 4 is a flow diagram for explaining the flow of steps of the program of the present invention. In FIG. 4, patient information synchronization processing (S101) is a process for calling up information from the patient information storage unit in the management server and each storage unit arbitrarily linked thereto. In this process, a new patient may input new patient information, and a patient who is a second or subsequent recipient may call up the previous calculation results and analyzed data and images. Next, head shape information reception (S102) receives head shape information of the patient. The head shape information of the patient may be acquired using the scanning device in FIG. 1 or may be acquired from a client terminal. Next, 3D head shape data creation (S103) generates 3D shape data based on the received head shape information.

[0059] Next, in 3D helmet shape data creation (S105), 3D helmet shape data is generated. Before this step, a step (S104) (not shown) of calculating an optimal head shape (target shape) may be performed, and then the 3D helmet shape data may be created. Next, in overlay data creation (S106), the 3D head shape data (S103) and the 3D helmet shape data (S105) are overlaid (superimposed). After this step, the helmet shape in the overlay image is set to be convertible, so that it is possible to express a case where the helmet is virtually worn with a misalignment (helmet shape conversion process (S107)). In addition, the image and data obtained in S106 may be defined as the initial state as the helmet posture in the present invention.

[0060] Next, after the overlay data creation (S106) or helmet shape conversion process (S107), a distance information acquisition process (S108) is performed. In this process, the distance between the 3D head shape data (S103) and the 3D helmet shape data (S105) is acquired. This information is used in the subsequent distance information markup process (S108) and distance information calculation process (S110).

[0061] In Fig. 4, the distance information calculation process (S109) and the distance information markup process (S110) are processes for calculating the distance between the helmet and the head from the acquired distance information, displaying the numerical calculation result, and marking up selected points and areas. In one embodiment of the present invention, as shown in Fig. 5, the distance between the head shape and the helmet shape at any point or area can be quantified to evaluate the progress of treatment. In another embodiment of the present invention, the distance information markup process (S110) and the distance information calculation process (S109) can be combined to quantify the therapeutic effect of helmet treatment.

[0062] In this embodiment, the patient information synchronization process (S111) is a step of overwriting or adding the processing information from the start to the distance information calculation process (S110) to the management server.

[0063] Next, another aspect of the implementation steps of the program of the present invention will be described with reference to Fig. 5. In helmet therapy, a doctor is usually consulted periodically to determine the progress of cranial formation. In other words, if the steps in Fig. 4 are performed at the first consultation, there is no need to change the 3D helmet shape, and so they can be omitted.

[0064] In the embodiment shown in FIG. 5, if the initially set or actual 3D helmet shape can be obtained in the sensory information synchronization process (S121), this data can be used to execute the overlay data creation step (S126).

[0065] 4 and 5, the head shape information receiving unit (S102 and S122) can use information obtained by simulating the head growth of the patient in addition to the actual scan data. Furthermore, it can simulate changes in facial expression and neck movement to represent deviations that are likely to occur in the helmet shape conversion process (S107 and S127).

[0066] 4 and 5, the distance information acquisition process (S109 and S129) can determine an objective function based on the distance between the head shape and the helmet shape acquired in the distance information acquisition process (S108 and S128). A numerical evaluation can also be given based on the average or total value of the distances at predetermined points and areas sampled arbitrarily or randomly. In this kind of evaluation, the sampling points or areas are fixed, and the fluctuation of the numerical value over time is tracked, so that it is possible to estimate that the numerical value obtained by the objective function becomes smaller as the shape improves, and the expected room for improvement becomes smaller as treatment continues. The smaller the room for improvement, the closer the head shape is to the target shape, and the improvement of the patient's head distortion can be objectively evaluated. EXAMPLES

[0067] An embodiment of the present invention will now be described.

[0068] Using the programming environment Grasshopper in the 3D modeling software Rhinoceros, the original skull shape of the patient and the 3D mesh data of the designed helmet were read. The six degrees of freedom of the helmet's movement and rotation were quantified and input, and the distance from each point on the skull surface mesh to the inner surface of the helmet was obtained at the same time. A loss function was defined by adding a penalty when this distance was smaller than a threshold. A genetic algorithm was used to determine the input value that minimized the loss.

[0069] FIG. 6 shows the state where the head shape and the helmet shape created based on this are superimposed. This is a diagram showing the helmet posture in the present invention. In this example, randomly sampled points are marked up. In this figure, × indicates that the distance between the helmet and the head is 10 mm, and in this simulation, when the helmet liner is set to a thickness of 10 mm, the helmet is held at this part. Also, ◯ indicates the point where the helmet is close to the head, and △ indicates the point where the helmet is far from the head, and it can be seen that there is space in this part, and it is expected that the growth of the skull will be promoted.

[0070] In Fig. 6, calculations were performed assuming a uniform helmet liner of 10 mm, but because the thickness of a helmet liner can be changed partially, it is also possible to perform simulations by changing the thickness of the helmet liner by dividing it into two equal parts front and back, or four equal parts front and back, left and right, etc.

[0071] Next, referring to Fig. 7, a diagram showing the helmet posture converted in the present invention is shown. The marked up symbols are the same. In comparison with Fig. 5, it can be seen by comparing the x marks that the helmet is held at a position that has changed from the right occipital region to the left anterior region. However, since there is no change in the distribution of ◯ and △, it can be explained that this degree of deviation does not pose a problem in terms of treatment.

[0072] In the examples of Figures 6 and 7, when the helmet shape is transformed in each figure, the randomly sampled points are qualitatively evaluated by changing their shape and color. In another embodiment of the present invention, it is also possible to quantitatively evaluate the size of the space between the helmet and the head by performing a step of initially arbitrarily or randomly sampling, fixing the marked up points, and appropriately tallying up the distances between the head shape and the helmet shape at these points.

[0073] Figure 8 shows the results for three patient cases. The input values ​​for rotational movement obtained by the genetic algorithm accurately reproduced the helmet misalignment seen in clinical practice. In other words, in the case of plagiocephaly, rotation along the long axis of the skull was observed, and in the case of brachycephaly, rotation in the anterior-posterior direction was also reproduced. At this time, by visualizing the distance from the skull through the helmet using a color map, it became easier to see that even when the helmet was rotated, a gap was maintained in the flat parts of the skull.

[0074] For the helmet postures obtained from the results of each of the above simulations, it is also possible to group similar posture parameters based on the posture parameters and obtain representative helmet posture groups (hereinafter referred to as "posture groups"). At this time, the average of the calculation results of the loss function corresponding to each helmet posture belonging to the posture group {P_1, ..., P_i, ..., P_n} is taken as the "representative average value", and the probability Pr_i that each posture group P_i occurs (i.e., the helmet displacement represented by P_i occurs) can be obtained from the inverse of the representative average value ω_i using the following formula. Pr_i = ω_i / Σ_i ω_i

[0075] Furthermore, the {(P_i, Pr_i)} obtained above can be converted into natural language based on helmet data P_i with high Pr_i, i.e., helmet data that is likely to occur. Such conversion makes it possible to explain helmet slippage based on objective statistical processing. Specifically, referring to the drawings of this embodiment, when it is determined that positive rotation in the x-axis direction and positive translation in the y-axis direction are likely to occur, a qualitative evaluation of the slippage of the helmet can be made for the patient, such as "the helmet is likely to rotate toward the frontal head and to slip toward the parietal head." In addition, by changing the threshold value (th) that exemplifies the thickness of the cushion liner and performing a simulation, it becomes easier to determine the thickness of the cushion liner that has sufficient voids in the area that promotes growth and has a sufficient contact surface between the cushion liner and the patient's head, making it difficult to slip. Furthermore, the present invention makes it easier to determine the thickness of the cushion liner that is suitable for each part / area.

Claims

1. In cranial shape correction treatment, Using a computer a) acquiring stereoscopic head shape information of a patient and representing the stereoscopic head shape three-dimensionally; b) calculating the shape of a helmet to be worn by the patient based on the three-dimensional head shape information of the patient, and three-dimensionally expressing the shape; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to generate a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet pose; e) setting the helmet shape to be convertible to the head shape of the patient in the helmet position; A program that executes the following.

2. In the above d), the distance information between the head shape of the patient and the helmet shape is A point that satisfies a predetermined condition, an area that satisfies a predetermined condition, or a combination thereof. The program according to claim 1.

3. The program of claim 2 , further comprising the step of calculating the number and area of ​​the points or the regions, or any combination thereof.

4. 3. The computer program product according to claim 2, wherein the predetermined condition is set based on a thickness of a cushion liner attached to the inside of the helmet.

5. 3. The program according to claim 2, further comprising the step of: converting the helmet posture and displaying distance information, or a state of a point satisfying the predetermined condition, or a region satisfying the predetermined condition, or a combination thereof, in e).

6. 2. The program according to claim 1, wherein in the step e), the step of convertibly setting the helmet shape relative to the head shape of the patient is set to six degrees of freedom.

7. The program according to claim 6, further comprising: f) a step of defining an objective function from an evaluation value calculated based on the points or the regions or a combination thereof, with movements in the x-, y-, and z-directions in the helmet posture and rotations in the x-, y-, and z-axis directions as variable parameters.

8. The objective function is a loss function calculated by adding a penalty when the distance between the head shape and the helmet shape at the point or the region is smaller than a predetermined value. The program according to claim 7.

9. Furthermore, the variable parameters are varied to find the variable parameters that minimize the calculation result of the loss function. The program according to claim 8.

10. A step of defining an objective function from an evaluation value calculated based on the points or the regions or a combination of these, by setting restrictions on the amount of variation in each item of the variable parameter variation range (movement in the x-direction, y-direction, and z-direction, and rotation along the x-axis, y-axis, and z-axis); The program according to claim 7.

11. outputting any combination of the distance information, a statistical value of the distance information, or a numerical value that is a calculation result of the loss function; The program according to claim 8 or 9.

12. The method includes a step of determining a tendency for deviation to occur based on a plurality of helmet postures obtained from any combination of the output distance information, the statistical value of the distance information, or the numerical value that is a calculation result of the loss function, and outputting the determined tendency. The program according to claim 10.

13. a step of obtaining a plurality of pose groups calculated from the plurality of helmets or the variable parameters in claim 9, or both of these, and for each of these, grouping arbitrarily sampled points or regions or both of these, and obtaining and outputting a statistical value of the distance between the head shape and the helmet shape in each group, the number of sampling points or the region area in each group, or both of these, and a loss function for each of the groups. The program according to claim 10.

14. The computer-readable medium according to claim 1 , further comprising: g) visualizing a gap in a state in which the helmet posture and the helmet shape are transformed.

15. The program according to claim 10, wherein the visualizing step is performed by changing transparency and color of the head shape and the helmet shape.

16. 11. The program according to claim 10, further comprising a step of superimposing and displaying information visualized according to distance information between the head shape and the helmet shape in the step of calculating the number and area of ​​the points or the area, or any combination thereof.

17. A program for outputting an arbitrary combination of the output in claim 12, the output in claim 13, and the result in claim 16, by setting the predetermined condition to a threshold value (th), and varying the threshold value.

18. The program sets the predetermined condition as a threshold (th), varies the threshold, and outputs all of the output in claim 12, the output in claim 13, and the result in claim 16.

19. The program according to claim 18, wherein the threshold value is changed depending on a predetermined part of the head shape.

20. In cranial shape correction treatment, Using a computer a) acquiring stereoscopic head shape information of a patient and representing the stereoscopic head shape three-dimensionally; b) calculating the shape of a helmet to be worn by the patient based on the three-dimensional head shape information of the patient, and three-dimensionally expressing the shape; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to generate a helmet posture in which the helmet is worn; d) acquiring distance information between the shape of the patient's head and the shape of the helmet in the helmet pose; e) setting the helmet shape to be convertible to the head shape of the patient in the helmet position; An image display device that displays the results at each step.

21. In cranial shape correction treatment, Using a computer a) acquiring stereoscopic head shape information of a patient and representing the stereoscopic head shape three-dimensionally; b) calculating the shape of a helmet to be worn by the patient based on the three-dimensional head shape information of the patient, and three-dimensionally expressing the shape; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to create a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet position; e) setting the helmet shape to be changeable relative to the head shape of the patient in the helmet position; A method for visualizing the fitting state of a head and a helmet in cranial orthodontic treatment, comprising:

22. In cranial shape correction treatment, A system for checking the space between the head shape of a patient and the helmet shape using (including) a scanning device, a client terminal, and a computer, The computer, a) acquiring stereoscopic head shape information of a patient and representing the stereoscopic head shape three-dimensionally; b) calculating the shape of a helmet to be worn by the patient based on the three-dimensional head shape information of the patient, and three-dimensionally expressing the shape; c) virtually superimposing the three-dimensionally represented head shape of the patient on the three-dimensionally represented helmet shape to generate a helmet posture in which the helmet is worn; d) acquiring distance information between the head shape of the patient and the helmet shape in the helmet pose; e) setting the helmet shape to be convertible to the head shape of the patient in the helmet position; Run The system wherein the client terminal displays the results at each of the steps.

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