Portable oral scanner and oral scanning system

Abstract

The present invention discloses a portable oral scanner and an oral scanning system. The image acquisition module of the portable oral scanner acquires image information of teeth to be scanned; the image processing module establishes a tooth model to be tested and extracts at least the distance between two adjacent teeth; the tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the tooth model to be tested; and the tooth position display module displays the tooth position of the tooth model to be tested. The present invention identifies and indicates the scanning area, is simple to operate, convenient to carry, and can instantly obtain the user's tooth information.

Description

Technical Field

[0001] The present invention relates to the technical field of oral cavity scanning, and in particular to a portable oral cavity scanner and an oral cavity scanning system. Background Art

[0002] Orthodontics can include repositioning misaligned teeth and changing the bite configuration to improve appearance and / or dental function. During the orthodontic process, it is necessary to obtain the patient's intraoral information. The oral scanner currently used to obtain intraoral information is usually used in conjunction with a computer. Medical staff usually use a handheld oral scanner to optically scan the upper and lower jaw areas of the patient's mouth. The intraoral image information formed during the scanning process will be displayed on the computer screen connected to the scanner to indicate the progress of the scan.

[0003] Since there is no scanning indication function on the current scanners, they need to be used with a computer to complete the scanning. They cannot be used alone and are not convenient to carry. This makes users have many restrictions when using them and cannot truly achieve portable scanning anytime and anywhere. Since oral scanning is an important part of the orthodontic process, with the development of the orthodontic industry, people's requirements for orthodontics are getting higher and higher, and oral scanners will tend to be miniaturized and portable. Summary of the invention

[0004] The main purpose of the present invention is to overcome the defects of the prior art and provide "a portable oral scanner and an oral scanning system", which solves the problem that the existing oral scanners do not have a scanning indication function and need to be used in conjunction with a computer to complete the scanning, thereby truly realizing portable scanning anytime and anywhere.

[0005] The technical solution provided by the present invention is as follows:

[0006] A portable oral scanner includes an image acquisition module, an image processing module, a tooth position determination module and a tooth position display module, wherein:

[0007] The image acquisition module acquires image information of the teeth to be scanned, and sends the image information to the image processing module;

[0008] The image processing module establishes a tooth model to be tested according to the image information, and extracts a feature quantity representing the position of each tooth in the tooth model to be tested and a distance between two adjacent teeth;

[0009] The tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and a characteristic value representing the position of each tooth in the tooth model to be tested and the distance between two adjacent teeth;

[0010] The tooth position display module displays the tooth position of the tooth model to be tested.

[0011] Preferably, the tooth reference model includes a first priori model and a second priori model, the first priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distance between different numbers of missing teeth; the second priori model includes the characteristic quantity representing the position of each tooth in the tooth reference model, and calculates the probability distribution function value for at least the characteristic quantity representing the position of teeth with the same number; the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model.

[0012] Preferably, the tooth reference model also includes a third priori model, which includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

[0013] Preferably, the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model, specifically: based on the tooth reference model, the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously is calculated, and the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value is used as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

[0014] Preferably, the characteristic quantity representing the position of each tooth refers to the abscissa and ordinate of the center point of each tooth on the occlusal plane.

[0015] Preferably, the tooth position display module is a tooth alveolar indicator panel, on which a plurality of indicator lights corresponding to the teeth on the tooth positions are provided, and the tooth position display module changes the state of the corresponding indicator lights on the tooth alveolar indicator panel based on the tooth position of the tooth model to be tested.

[0016] Preferably, it further comprises a communication module, and the communication module sends the tooth position information of the tooth model to be tested to an external data receiving end.

[0017] A portable oral scanner comprises an image acquisition module, an image processing module, a tooth position determination module and a tooth position display module, wherein the image acquisition module acquires image information of teeth to be scanned and sends the image information to the image processing module; the image processing module establishes a tooth model to be tested according to the image information and extracts the distance between two adjacent teeth in the tooth model to be tested; the tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the distance between two adjacent teeth in the tooth model to be tested; and the tooth position display module displays the tooth position of the tooth model to be tested.

[0018] Preferably, the tooth reference model includes a first prior model, which includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distances of different numbers of missing teeth; the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model.

[0019] Preferably, the tooth reference model also includes a third priori model; the third priori model includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

[0020] Preferably, the method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on the tooth reference model, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

[0021] Preferably, the tooth position display module is a tooth alveolar indicator panel, on which a plurality of indicator lights corresponding to the teeth on the tooth positions are provided, and the tooth position display module changes the state of the corresponding indicator lights on the tooth alveolar indicator panel based on the tooth position of the tooth model to be tested.

[0022] Preferably, it further comprises a communication module, and the communication module sends the tooth position information of the tooth model to be tested to an external data receiving end.

[0023] Preferably, the external data receiving end is a mobile terminal with communication function.

[0024] An oral scanning system comprises an image acquisition module, an image processing module, a tooth position determination module, a communication module and a mobile terminal with a communication function, wherein the image acquisition module acquires image information of teeth to be scanned and sends the image information to the image processing module; the image processing module establishes a tooth model to be tested according to the image information, and extracts a characteristic quantity representing the position of each tooth in the tooth model to be tested and the distance between two adjacent teeth; the tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the characteristic quantity representing the position of each tooth in the tooth model to be tested and the distance between two adjacent teeth; the communication module sends the tooth position information of the tooth model to be tested to the mobile terminal; and the mobile terminal displays the tooth position of the tooth model to be tested.

[0025] Preferably, the tooth reference model includes a first priori model and a second priori model, wherein the first priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distance between different numbers of missing teeth; the second priori model includes the characteristic quantity representing the position of each tooth in the tooth reference model, and calculates the probability distribution function value for at least the characteristic quantity representing the position of teeth with the same number; the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model.

[0026] Preferably, the tooth reference model also includes a third priori model, which includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

[0027] Preferably, the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model, specifically: based on the tooth reference model, the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously is calculated, and the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value is used as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

[0028] An oral scanning system comprises an image acquisition module, an image processing module, a tooth position determination module, a communication module and a mobile terminal with a communication function, wherein the image acquisition module acquires image information of teeth to be scanned and sends the image information to the image processing module; the image processing module establishes a tooth model to be tested according to the image information and extracts the distance between two adjacent teeth in the tooth model to be tested; the tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the distance between two adjacent teeth in the tooth model to be tested; the communication module sends the tooth position information of the tooth model to be tested to the mobile terminal; and the mobile terminal displays the tooth position of the tooth model to be tested.

[0029] Preferably, the tooth reference model includes a first prior model, which includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distances of different numbers of missing teeth; the tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model.

[0030] Preferably, the tooth reference model also includes a third priori model; the third priori model includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

[0031] Preferably, the method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on the tooth reference model, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

[0032] The oral scanner and oral scanning system provided by the present invention can bring at least one of the following beneficial effects:

[0033] 1. The oral scanner and oral scanning system of the present invention can identify and indicate the scanning area, so that the user can obtain complete tooth information without an external computer device.

[0034] 2. The oral scanner and the oral scanning system of the present invention determine the tooth position of the tooth model to be tested based on the hidden Markov model, thereby realizing accurate identification and indication of the scanning area.

[0035] 3. The oral scanner and oral scanning system of the present invention are simple to operate, easy to carry, save time, and can quickly and easily obtain image information of teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The preferred implementation scheme will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and their implementation methods.

[0037] Figure 1 It is a schematic diagram of the structure of the oral scanner of the present application;

[0038] Figure 2 is a flow chart of a method for the tooth position determination module of the present application to determine the tooth position of the tooth model to be tested;

[0039] Figure 3 It is a schematic diagram of the upper teeth with tooth numbers;

[0040] Figure 4 is a schematic diagram of the tooth arrangement of the tooth model to be tested in the present application;

[0041] Figure 5 is another schematic diagram of the tooth arrangement of the tooth model to be tested in the present application;

[0042] Figure 6 is another schematic diagram of the tooth arrangement of the tooth model to be tested in the present application;

[0043] Figure 7 is another schematic diagram of the tooth arrangement of the tooth model to be tested in the present application;

[0044] Figure 8 It is a schematic diagram of the setting method of the indicator light of this application;

[0045] Fig. 9 It is another schematic diagram of the setting method of the indicator light of the present application;

[0046] Fig.10 is a schematic diagram of the structure of another oral scanner of the present application;

[0047] Fig.11 is a flow chart of a method for determining the tooth position of a tooth model to be tested by another tooth position determination module of the present application;

[0048] Fig.12 is a flow chart of a method for determining the tooth position of a tooth model to be tested by another tooth position determination module of the present application;

[0049] Fig.13 is a flow chart of a method for determining the tooth position of a tooth model to be tested by another tooth position determination module of the present application;

[0050] Fig.14 It is a structural schematic diagram of another oral scanning system of the present application.

[0051] The reference numerals in the figure are: 10 - image acquisition module, 20 - image processing module, 30 - tooth position determination module, 40 - tooth position display module, 50 - communication module, 60 - mobile terminal, 70 - scanning head, 80 - housing, 401 - indicator light. DETAILED DESCRIPTION

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0053] Embodiment 1

[0054] Please refer to Figure 1 A portable oral scanner includes an image acquisition module 10, an image processing module 20, a tooth position determination module 30 and a tooth position display module 40, wherein:

[0055] The image acquisition module 10 acquires image information of the teeth to be scanned, and sends the image information to the image processing module 20;

[0056] The image processing module 20 establishes a tooth model to be tested according to the image information, and extracts a characteristic value representing the position of each tooth in the tooth model to be tested and a distance between two adjacent teeth;

[0057] Optionally, any one or more of the characteristic quantities representing the area, volume, shape and size of each tooth of the tooth model to be tested is also obtained.

[0058] As a preferred embodiment, the characteristic quantity representing the position of each tooth refers to the horizontal coordinate and the vertical coordinate of the center point of each tooth on the occlusal plane.

[0059] Specifically, the characteristic quantity characterizing the position of each tooth refers to the horizontal and vertical coordinates of the center point of each tooth on the occlusal plane. The characteristic quantity characterizing the area of ​​each tooth refers to the surface area of ​​each tooth. The characteristic quantity characterizing the volume of each tooth refers to the volume of each tooth. The characteristic quantity characterizing the shape and size of each tooth includes the length, width, and height of the smallest cube circumscribed by each tooth; and any one or more of the statistical values ​​of the surface curvature distribution of each tooth.

[0060] The tooth position determination module 30 determines the tooth position of the tooth model to be tested according to the characteristic quantity of the characterizing position of each tooth in the tooth reference model and the tooth model to be tested and the distance between two adjacent teeth; wherein the tooth reference model includes a first a priori model, a second a priori model and a third a priori model, wherein the first a priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distance between different numbers of missing teeth; the second a priori model includes the characteristic quantity of the characterizing position of each tooth in the tooth reference model, and calculates the probability distribution function value for at least the characteristic quantity of the characterizing position of teeth with the same number; the third a priori model includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement;

[0061] The tooth position determination module 30 determines the tooth position of the tooth model to be tested based on the hidden Markov model.

[0062] As a preferred embodiment, the tooth position determination module 30 determines the tooth position of the tooth model to be tested based on the hidden Markov model, specifically: based on the first prior model, the second prior model and the third prior model, the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously is calculated, and the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value is used as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

[0063] Specifically, please refer to Figure 2 The tooth position determination module 30 determines the tooth position of the tooth model to be tested according to the following steps:

[0064] Step S110: establishing a first a priori model, a second a priori model and a third a priori model.

[0065] The first prior model includes collecting the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculating the probability distribution function value for the distance between different numbers of missing teeth. Preferably, the first prior model at least includes calculating the probability distribution function value of the tooth distance under different situations where the number of missing teeth is 0 to 4.

[0066] The second prior model includes collecting feature quantities representing the position of each tooth in the tooth reference model, and calculating the probability distribution function value for at least the feature quantities representing the position of the teeth with the same number. Optionally, the second prior model also includes collecting any one or more feature quantities representing the area, volume, shape and size of each tooth in the existing tooth model, and calculating the probability distribution function values ​​for the feature quantities representing the area, volume, shape and size of the teeth with the same number.

[0067] The third priori model includes collecting the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculating the probability distribution function value of the tooth position arrangement. Preferably, the third priori model at least includes calculating the probability distribution function value of the tooth position arrangement of the two adjacent teeth on the left and right when the number of missing teeth is 0 to 4.

[0068] Preferably, the probability distribution function value is any one of a Gaussian distribution function value or a chi-square distribution function value, wherein Gaussian distribution is also called normal distribution.

[0069] Step S120: Determine the tooth position of the tooth model to be tested based on the hidden Markov model. The hidden Markov model is a classic machine learning model that can be used for prediction (filter), smoothing (smoothing) or decoding (most likely explanation). Decoding refers to finding the state sequence that is most likely to correspond to the observation sequence given a priori model and an observation sequence. In this embodiment, the different tooth position arrangements of the tooth reference model are used as the state sequence, and the tooth model to be tested is used as the observation sequence, and the tooth position of the tooth model to be tested is determined by a machine learning algorithm based on the hidden Markov model.

[0070] Here, the given prior model includes the first prior model, the second prior model and the third prior model, and the tooth state sequence is a vector K, K = [k1, k2, k3, ..., k 2n-1 ], n is the number of teeth in the tooth reference model; the vector K contains 2n-1 elements, the values ​​of odd-numbered elements are tooth numbers, and the values ​​of even-numbered elements are the number of missing teeth between two adjacent teeth. The tooth state sequence K has 16! / [n! ×(16-n)! ] values, where! represents factorial operation, and n is an integer from 0 to 16; each value of the tooth state sequence K corresponds to a tooth position arrangement of the tooth reference model.

[0071] As an example, the teeth are numbered as follows: assuming that there are no missing teeth, the upper right wisdom teeth are numbered 1 to 16 in the direction of the upper left wisdom teeth, and the lower right wisdom teeth are numbered 17 to 32 in the direction of the lower left wisdom teeth. According to this tooth numbering method, Figures 3 to 7 The different tooth position arrangements of the upper tooth model are given. The circles in the figure represent the actual remaining teeth, and the numbers in the circles are the tooth numbers. The boxes in the figure represent the gap between two adjacent remaining teeth, and the numbers in the boxes represent the number of missing teeth between the two adjacent remaining teeth.

[0072] Furthermore, the tooth model to be tested is represented by a tooth observation sequence; the tooth observation sequence is a vector B, B = [X1, b1, X2, b2, ..., b n-1 ,X n ]; where X i represents the characteristic value of the i-th tooth, where i is an integer from 1 to n; b j represents the distance between two adjacent teeth, j is an integer from 1 to n-1; n is the number of teeth contained in the tooth model to be tested.

[0073] Finally, the method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on the first prior model, the second prior model and the third prior model, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested.

[0074] Specifically, first calculate the probability P(B|K) of generating the tooth observation sequence B under each value of the tooth state sequence K, and the state transition probability P(K) of forming the tooth state sequence K, and then calculate the probability P(B|K)P(K) that the tooth observation sequence B and each value of the tooth state sequence K appear at the same time; the tooth position arrangement represented by the value of the tooth state sequence K corresponding to the maximum probability value P(B,K) is used as the tooth position of the tooth model to be tested.

[0075] For example, P(B|K) is calculated using the following formula:

[0076]

[0077] Among them, Π represents the multiplication sign, P(X i |k 2i-1 ) indicates the number is k 2i-1 The tooth appearance characteristic quantity X i The probability, P(b j |k 2j ) indicates the number of missing teeth is k 2j When the distance between two adjacent teeth is b j probability.

[0078] For example, P(K) is calculated using the following formula:

[0079]

[0080] Among them, Π represents the continuous multiplication sign, P(k 2i+1 |k 2i-1 ) represents the tooth number k 2i-1 The tooth number k appears behind the tooth 2i+1 The probability of the tooth position arrangement of the teeth.

[0081] For example, P(B,K) is calculated using the following formula:

[0082]

[0083] Among them, max means taking the maximum value, and Q represents the set of all values ​​of the vector K.

[0084] Finally, the tooth position display module 40 displays the tooth position of the tooth model to be tested.

[0085] As a preferred embodiment, please refer to Figure 8 and Fig. 9 The tooth position display module 40 is a tooth alveolar indicator panel, on which a plurality of indicator lights 401 corresponding to the teeth on the tooth positions are arranged. The tooth position display module 40 changes the state of the corresponding indicator lights 401 on the tooth alveolar indicator panel based on the tooth position of the tooth model to be tested.

[0086] For details, please continue to refer to Figure 8 and Fig. 9 The portable oral scanner includes a housing 80 and a scanning head 70 disposed at one end of the housing 80. A tooth position display module 40 (alveolar indicator panel) is disposed on the housing 80. A tooth model corresponding to the teeth on the tooth position is disposed on the alveolar indicator panel. An indicator light 401 corresponds to the tooth model one by one. The indicator light 401 can be disposed in the following manner: In the first embodiment, the indicator light 401 is disposed on one side of the tooth model. Figure 8 Setting mode 2, the indicator light 401 is set inside the tooth model (not shown in the figure), such as Fig. 9 shown.

[0087] When controlling the indicator light 401, a control circuit can control the change of the indicator light state corresponding to the corresponding tooth on the tooth position according to the determined tooth position of the tooth model to be tested, such as the indicator light 401 state changes from dark to bright or from bright to dark. According to the bright or dark state of the indicator light 401, the scanning status of the corresponding tooth can be known.

[0088] It can be understood that the present embodiment does not limit the specific setting method, shape, brightness and darkness state of the indicator light 401, as long as it can indicate the scanning status of the corresponding teeth.

[0089] As a preferred embodiment, please refer to Fig.10 The portable oral scanner also includes a communication module 50, which sends the tooth position information of the tooth model to be tested to an external data receiving terminal 60.

[0090] As a preferred embodiment, the external data receiving end 60 is a mobile terminal with communication function.

[0091] When using the portable oral scanner of this embodiment, the user turns on the portable oral scanner and starts scanning. The portable oral scanner penetrates into the patient's oral cavity, the image acquisition module 10 scans the patient's tooth image, the image processing module 20 establishes a tooth model to be tested based on the image information, and extracts the characteristic quantity representing the position of each tooth in the tooth model to be tested and the distance between two adjacent teeth; the tooth position determination module 30 determines the tooth position of the tooth model to be tested based on the tooth reference model and the characteristic quantity representing the position of each tooth in the tooth model to be tested and the distance between two adjacent teeth, and the tooth position display module 40 displays the tooth position of the tooth model to be tested.

[0092] Embodiment 2

[0093] The portable oral scanner of this embodiment differs from the portable oral scanner of the first embodiment only in that: the tooth reference model only includes the first prior model;

[0094] Specifically, since the tooth reference model only includes the first prior model, the image processing module 20 only needs to extract the distance between two adjacent teeth in the tooth model to be tested, and does not need to extract the feature quantity representing the position of each tooth. The tooth position determination module 30 determines the tooth position of the tooth model to be tested according to the tooth reference model and the distance between two adjacent teeth of each tooth in the tooth model to be tested.

[0095] Accordingly, the process of the tooth position determination module 30 determining the tooth position of the tooth model to be tested is somewhat different, please refer to Fig.11 , the specific steps are as follows:

[0096] Step S210: Establish a first priori model.

[0097] The first prior model includes collecting the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculating the probability distribution function value for the distances of different numbers of missing teeth.

[0098] Step S220: Determine the tooth position of the tooth model to be tested based on the hidden Markov model.

[0099] The method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on an established prior model or multiple prior models, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested.

[0100] Here, the tooth observation sequence is a vector B, B = [X1, b1, X2, b2, ..., b n-1 ,X n ]; where Xi represents the characteristic value of the i-th tooth, where i is an integer from 1 to n; b j represents the distance between two adjacent teeth, j is an integer from 1 to n-1; n is the number of teeth contained in the tooth model to be tested; due to the lack of the second prior model, X i Use a constant.

[0101] Specifically, in step S220, the probability P(B|K) of generating the tooth observation sequence B under each value of the tooth state sequence K and the state transition probability P(K) of forming the tooth state sequence K are first calculated, and then the probability P(B|K)P(K) of the simultaneous appearance of the tooth observation sequence B and each value of the tooth state sequence K is calculated; the tooth position arrangement represented by the value of the tooth state sequence K corresponding to the maximum probability value P(B, K) is used as the tooth position of the tooth model to be tested.

[0102] For example, P(B|K) is calculated using the following formula:

[0103]

[0104] Among them, Π represents the multiplication sign, P(X i |k 2i-1 ) indicates the number is k 2i-1 The tooth appearance characteristic quantity X i The probability of j |k 2j ) indicates the number of missing teeth is k 2j When the distance between two adjacent teeth is b j Since there is no second prior model, P(X i |k 2i-1 )Use uniform distribution.

[0105] For example, P(K) is calculated using the following formula:

[0106]

[0107] Where Π represents the multiplication sign, P(k 2i+1 |k 2i-1 ) represents the tooth number k 2i-1 The tooth number k appears behind the tooth 2i+1 The probability of the tooth position arrangement of the teeth. Due to the lack of the third prior model, P(k 2i+1 |k 2i-1 )Use uniform distribution.

[0108] For example, P(B,K) is calculated using the following formula:

[0109]

[0110] Among them, max means taking the maximum value, and Q represents the set of all values ​​of the vector K.

[0111] Embodiment 3

[0112] The portable oral scanner of this embodiment is different from the portable oral scanner of the first embodiment only in that: the tooth reference model only includes the first prior model and the second prior model;

[0113] Specifically, since the tooth reference model only includes the first prior model and the second prior model, the process of the tooth position determination module 30 determining the tooth position of the to-be-tested tooth model is correspondingly different. Fig.12 , the specific steps are as follows:

[0114] Step S310: Establish a first priori model and a second priori model.

[0115] The first prior model includes collecting the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculating the probability distribution function value for the distance between different numbers of missing teeth. The second prior model includes collecting the characteristic quantity representing the position of each tooth in the existing tooth model, and calculating the probability distribution function value for at least the characteristic quantity representing the position of teeth with the same number.

[0116] Step S320: Determine the tooth position of the tooth model to be tested based on the hidden Markov model.

[0117] The method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on an established prior model or multiple prior models, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested.

[0118] Here, the tooth observation sequence is a vector B, B = [X1, b1, X2, b2, ..., b n-1 ,X n ]; where X i represents the characteristic value of the i-th tooth, where i is an integer from 1 to n; b j represents the distance between two adjacent teeth, j is an integer from 1 to n-1; n is the number of teeth contained in the tooth model to be tested.

[0119] Specifically, in the step S320, the probability P(B|K) of generating the tooth observation sequence B under each value of the tooth state sequence K and the state transition probability P(K) of forming the tooth state sequence K are first calculated, and then the probability P(B|K)P(K) of the simultaneous appearance of the tooth observation sequence B and each value of the tooth state sequence K is calculated; the tooth position arrangement represented by the value of the tooth state sequence K corresponding to the maximum probability value P(B, K) is used as the tooth position of the tooth model to be tested.

[0120] For example, P(B|K) is calculated using the following formula:

[0121]

[0122] Among them, Π represents the multiplication sign, P(X i |k 2i-1 ) indicates the number is k 2i-1 The tooth appearance characteristic quantity X i The probability of j |k 2j ) indicates the number of missing teeth is k 2j When the distance between two adjacent teeth is b j probability.

[0123] For example, P(K) is calculated using the following formula:

[0124]

[0125] Where Π represents the multiplication sign, P(k 2i+1 |k 2i-1 ) represents the tooth number k 2i-1 The tooth number k appears behind the tooth 2i+1 The probability of the tooth position arrangement of the teeth. Due to the lack of the third prior model, P(k 2i+1 |k 2i-1 )Use uniform distribution.

[0126] For example, P(B,K) is calculated using the following formula:

[0127]

[0128] Among them, max means taking the maximum value, and Q represents the set of all values ​​of the vector K.

[0129] Embodiment 4

[0130] The portable oral scanner of this embodiment differs from the portable oral scanner of the first embodiment only in that: the tooth reference model only includes the first prior model and the third prior model;

[0131] Specifically, since the tooth reference model only includes the first prior model and the third prior model, the image processing module 20 only needs to extract the distance between two adjacent teeth in the tooth model to be tested, and does not need to extract the feature quantity representing the position of each tooth. The tooth position determination module 30 determines the tooth position of the tooth model to be tested according to the tooth reference model and the distance between two adjacent teeth of each tooth in the tooth model to be tested.

[0132] Accordingly, the process of the tooth position determination module 30 determining the tooth position of the tooth model to be tested is somewhat different, please refer to Fig.13 , the specific steps are as follows:

[0133] Step S410: Establish a first a priori model and a third a priori model.

[0134] The first prior model includes collecting the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculating the probability distribution function value for the distances of different numbers of missing teeth.

[0135] The third priori model includes collecting the tooth arrangement of every two adjacent teeth in the existing tooth model when the teeth are not missing or when different numbers of teeth are missing, and calculating the probability distribution function value of the tooth arrangement.

[0136] Step S420: Determine the tooth position of the tooth model to be tested based on the hidden Markov model.

[0137] The method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on an established prior model or multiple prior models, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested.

[0138] Here, the tooth observation sequence is a vector B, B = [X1, b1, X2, b2, ..., b n-1 ,X n ]; where X i represents the characteristic value of the i-th tooth, where i is an integer from 1 to n; b j represents the distance between two adjacent teeth, j is an integer from 1 to n-1; n is the number of teeth contained in the tooth model to be tested; due to the lack of the second prior model, X i Use a constant.

[0139] Specifically, in the step S420, the probability P(B|K) of generating the tooth observation sequence B under each value of the tooth state sequence K and the state transition probability P(K) of forming the tooth state sequence K are first calculated, and then the probability P(B|K)P(K) of the simultaneous appearance of the tooth observation sequence B and each value of the tooth state sequence K is calculated; the tooth position arrangement represented by the value of the tooth state sequence K corresponding to the maximum probability value P(B, K) is used as the tooth position of the tooth model to be tested.

[0140] For example, P(B|K) is calculated using the following formula:

[0141]

[0142] Among them, Π represents the multiplication sign, P(X i |k 2i-1 ) indicates the number is k 2i-1 The tooth appearance characteristic quantity X i The probability of j |k 2j ) indicates the number of missing teeth is k 2j When the distance between two adjacent teeth is b j Since there is no second prior model, P(X i |k 2i-1 )Use uniform distribution.

[0143] For example, P(K) is calculated using the following formula:

[0144]

[0145] Where Π represents the multiplication sign, P(k 2i+1 |k 2i-1 ) represents the tooth number k 2i-1 The tooth number k appears behind the tooth 2i+1 The probability of the tooth position arrangement of the teeth.

[0146] For example, P(B,K) is calculated using the following formula:

[0147]

[0148] Among them, max means taking the maximum value, and Q represents the set of all values ​​of the vector K.

[0149] Embodiment 5

[0150] Based on the oral scanners provided in the above-mentioned embodiments 1 to 4, this embodiment further provides an oral scanning system, please refer to Fig.14, including an image acquisition module 10, an image processing module 20, a tooth position determination module 30, a communication module 50 and a mobile terminal 60 with communication function, wherein the image acquisition module 10, the image processing module 20, and the tooth position determination module 30 implement the functions of the corresponding image acquisition module 10, the image processing module 20, and the tooth position determination module 30 in any of the above-mentioned embodiments 1 to 4.

[0151] Furthermore, the communication module 50 sends the tooth position information of the tooth model to be tested to the mobile terminal 60, and the mobile terminal 60 displays the tooth position of the tooth model to be tested.

[0152] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A portable oral scanner, characterized in that: It includes an image acquisition module, an image processing module, a tooth position determination module and a tooth position display module, wherein: The image acquisition module acquires image information of the teeth to be scanned, and sends the image information to the image processing module; The image processing module establishes a tooth model to be tested according to the image information, and extracts a feature quantity representing the position of each tooth in the tooth model to be tested and a distance between two adjacent teeth; The tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the characteristic quantity of the characterization position of each tooth in the tooth model to be tested and the distance between two adjacent teeth; the tooth reference model includes a first a priori model and a second a priori model, the first a priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distance between different numbers of missing teeth; the second a priori model includes the characteristic quantity of the characterization position of each tooth in the tooth reference model, and calculates the probability distribution function value for at least the characteristic quantity of the characterization position of teeth with the same number; the tooth position determination module determines the tooth position of the tooth model to be tested based on a hidden Markov model; The tooth position display module displays the tooth position of the tooth model to be tested.

2. The portable oral scanner according to claim 1, characterized in that: The tooth reference model also includes a third priori model, which includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

3. The portable oral scanner according to claim 1 or 2, characterized in that: The tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model, specifically: based on the tooth reference model, the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously is calculated, and the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value is used as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

4. The portable oral scanner according to claim 1, characterized in that: The characteristic quantity representing the position of each tooth refers to the horizontal coordinate and the vertical coordinate of the center point of each tooth on the occlusal plane.

5. The portable oral scanner according to claim 1, characterized in that: The tooth position display module is a tooth alveolar indicator panel, on which a plurality of indicator lights corresponding to the teeth on the tooth positions are arranged. The tooth position display module changes the state of the corresponding indicator lights on the tooth alveolar indicator panel based on the tooth position of the tooth model to be tested.

6. The portable oral scanner according to claim 1, characterized in that: It also includes a communication module, which sends the tooth position information of the tooth model to be tested to an external data receiving end.

7. A portable oral scanner, characterized in that: It includes an image acquisition module, an image processing module, a tooth position determination module and a tooth position display module, wherein: The image acquisition module acquires image information of the teeth to be scanned, and sends the image information to the image processing module; The image processing module establishes a tooth model to be tested according to the image information, and extracts the distance between two adjacent teeth in the tooth model to be tested; The tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the distance between two adjacent teeth in the tooth model to be tested; the tooth reference model includes a first priori model, the first priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distances of different numbers of missing teeth; the tooth position determination module determines the tooth position of the tooth model to be tested based on a hidden Markov model; The tooth position display module displays the tooth position of the tooth model to be tested.

8. The portable oral scanner according to claim 7, characterized in that: The tooth reference model also includes a third priori model; the third priori model includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

9. The portable oral scanner according to claim 7 or 8, characterized in that: The method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on the tooth reference model, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

10. The portable oral scanner according to claim 7, characterized in that: The tooth position display module is a tooth alveolar indicator panel, on which a plurality of indicator lights corresponding to the teeth on the tooth positions are arranged. The tooth position display module changes the state of the corresponding indicator lights on the tooth alveolar indicator panel based on the tooth position of the tooth model to be tested.

11. The portable oral scanner according to claim 7, characterized in that: It also includes a communication module, which sends the tooth position information of the tooth model to be tested to an external data receiving end.

12. The portable oral scanner according to claim 11, characterized in that: The external data receiving end is a mobile terminal with communication function.

13. An oral scanning system, characterized in that: It includes an image acquisition module, an image processing module, a tooth position determination module, a communication module and a mobile terminal with communication function, wherein: The image acquisition module acquires image information of the teeth to be scanned, and sends the image information to the image processing module; The image processing module establishes a tooth model to be tested according to the image information, and extracts a feature quantity representing the position of each tooth in the tooth model to be tested and a distance between two adjacent teeth; The tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the characteristic quantity of the characterization position of each tooth in the tooth model to be tested and the distance between two adjacent teeth; the tooth reference model includes a first a priori model and a second a priori model, wherein the first a priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distance between different numbers of missing teeth; the second a priori model includes the characteristic quantity of the characterization position of each tooth in the tooth reference model, and calculates the probability distribution function value for at least the characteristic quantity of the characterization position of teeth with the same number; the tooth position determination module determines the tooth position of the tooth model to be tested based on a hidden Markov model; The communication module sends the tooth position information of the tooth model to be tested to the mobile terminal; The mobile terminal displays the tooth position of the tooth model to be tested.

14. The oral cavity scanning system according to claim 13, characterized in that: The tooth reference model also includes a third priori model, which includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

15. The oral scanning system according to claim 12 or 14, characterized in that: The tooth position determination module determines the tooth position of the tooth model to be tested based on the hidden Markov model, specifically: based on the tooth reference model, the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously is calculated, and the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value is used as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

16. An oral scanning system, characterized in that: It includes an image acquisition module, an image processing module, a tooth position determination module, a communication module and a mobile terminal with communication function, wherein: The image acquisition module acquires image information of the teeth to be scanned, and sends the image information to the image processing module; The image processing module establishes a tooth model to be tested according to the image information, and extracts the distance between two adjacent teeth in the tooth model to be tested; The tooth position determination module determines the tooth position of the tooth model to be tested according to a tooth reference model and the distance between two adjacent teeth in the tooth model to be tested; the tooth reference model includes a first priori model, the first priori model includes the distance between every two adjacent teeth in the tooth reference model and the number of missing teeth corresponding to the distance, and calculates the probability distribution function value for the distances of different numbers of missing teeth; the tooth position determination module determines the tooth position of the tooth model to be tested based on a hidden Markov model; The communication module sends the tooth position information of the tooth model to be tested to the mobile terminal; The mobile terminal displays the tooth position of the tooth model to be tested.

17. The oral cavity scanning system according to claim 16, characterized in that: The tooth reference model also includes a third priori model; the third priori model includes the tooth position arrangement of every two adjacent teeth in the tooth reference model when the teeth are not missing or when different numbers of teeth are missing, and calculates the probability distribution function value of the tooth position arrangement.

18. The oral cavity scanning system according to claim 16 or 17, characterized in that: The method of determining the tooth position of the tooth model to be tested based on the hidden Markov model refers to: calculating the probability value of each value of the tooth state sequence and the tooth observation sequence appearing simultaneously based on the tooth reference model, and taking the tooth position arrangement represented by the value of the tooth state sequence corresponding to the calculated maximum probability value as the tooth position of the tooth model to be tested, wherein the tooth state sequence represents the tooth reference model, and the tooth observation sequence represents the tooth model to be tested.

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