Orthodontic robot navigation method and system

Abstract

The present invention relates to the field of orthodontic technology, and specifically to an orthodontic robot navigation method and system, which comprises: setting a first and a second reference mark on an open mouth device; using an optical positioning camera to define a first spatial coordinate system, which is used to define the first coordinates of the first and second reference marks; providing a target model, which defines the relative position between the reference mark and the target point or tooth through the second spatial coordinate system; obtaining the first measurement coordinate of the target point or tooth in the first spatial coordinate system through the first coordinate corresponding conversion; determining the first navigation point according to the first measurement coordinate; when the robot moves to the first navigation point, obtaining the second coordinates of the first and second reference marks in the first spatial coordinate system; when the first difference between the first and second coordinates is less than the set first difference threshold, allowing the robot to continue to move to the first measurement coordinate. The present invention solves the problems that the existing navigation method has high requirements on hardware device performance.

Description

Technical Field

[0001] The present invention relates to an orthodontic robot, and in particular to an orthodontic robot navigation method and system. Background Art

[0002] Defects such as malocclusion of teeth not only affect the appearance, but also have an irresistible impact on chewing, pronunciation, etc., seriously reducing the patient's quality of life.

[0003] Orthodontics is aimed at treating malocclusion of the teeth. It uses braces to apply mechanical correction force and torque to the teeth, adjust the balance and coordination among the facial bones, teeth and maxillofacial muscles, and after a period of correction, it can improve the facial shape, align the teeth and enhance the chewing efficiency.

[0004] Traditional orthodontic clinical operations, especially bracket bonding operations, are mainly completed manually by orthodontists, which requires high experience and precision of manual operations. In addition, human operation errors are large and operation techniques vary greatly, resulting in high technical barriers to orthodontic clinical treatment operations and non-standard treatment. In order to improve the accuracy of bracket bonding, an indirect bonding method is proposed in clinical practice, that is, a bonding guide is designed to assist the transfer of bracket positions. However, under this auxiliary method, extremely high requirements are still placed on the manual operation strength and accuracy of the doctor.

[0005] Patent application CN116737031A discloses a tooth root information visualization system and method based on mixed reality, the system comprising a tracking rigid body 1, a tracking rigid body 2, a probe, an optical tracking device, mixed reality glasses, a checkerboard calibration plate, an orthodontic anchorage nail implantation navigation system, and a visualization system; the method comprises an optical tracking device-mixed reality glasses calibration method and a complete dentition virtual model-patient real space registration method; the optical tracking device-mixed reality glasses calibration method is used to unify the internal coordinate systems of the optical tracking device and the mixed reality glasses; the complete dentition virtual model-patient real space registration method is used to unify the coordinate system of the complete dentition virtual model with the real space where the patient is located.

[0006] Patent application CN112545650A discloses a navigation positioning method and system for dentistry, which comprises the following steps: attaching a developing ball to a dental retainer, placing the dental retainer on the target dentition of the patient, acquiring the data of the target dentition and the hard and soft tissues of the oral and maxillary bones at the target dentition by scanning, and establishing a corresponding target dentition reference space three-dimensional model with developing points in the three-dimensional navigation map in the navigation system; before the operation, the developing ball is clicked by a surgical instrument to match the target dentition with the reference space three-dimensional model to complete the reference positioning of the target dentition; during the operation, a positioning rod arranged in the oral cavity acquires the position and posture of the target dentition in the oral cavity in real time through a first vision system in coordination with a second vision system arranged in the surgical instrument, as well as the position and posture of the surgical instrument; and marking the spatial position in the three-dimensional coordinate system of the reference space three-dimensional model, thereby achieving real-time tracking and positioning of the positional relationship between the surgical instrument and the target dentition during the operation.

[0007] Patent application CN101249001A also discloses a three-dimensional image navigation positioning method and a special device for orthodontic implant support, which uses an infrared camera lens to emit or receive infrared rays, and determines the specific position of the device by tracking the position of the infrared reflective ball on the self-designed orthodontic implant support positioning device, and transmits the signal back to the computer so that the position of the positioning device can be displayed on the patient's preoperative or intraoperative image data. The software is used to compare the three-dimensional spatial orientation of the positioning device determined before the operation, and the connected mechanical arm is used to adjust the orientation of the positioning device to meet the preoperative design requirements. When the designed position is reached, the implant support can be accurately implanted according to the orientation and depth guided by the stereotactic device.

[0008] However, traditional surgical robots have high performance requirements for hardware equipment, which is not conducive to practical application. Summary of the invention

[0009] The object of the present invention is to provide a navigation method for an orthodontic robot, which partially solves or alleviates the above-mentioned deficiencies in the prior art and can reduce the computational pressure of real-time navigation by means of segmented navigation.

[0010] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0011] A first aspect of the present invention is to provide a navigation method for an orthodontic robot, comprising the steps of:

[0012] S100, setting reference marks, the reference marks comprising: a first reference mark set at at least one first target position on the mouth opener, and a second reference mark set at at least one other first target position on the mouth opener, the mouth opener being worn in the oral cavity of the subject to open and fix the oral cavity; wherein the first target position comprises one or more of the following: a position on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, and a midline of a dentition;

[0013] S101, defining a first spatial coordinate system using an optical positioning camera, where the first spatial coordinate system is used to define first coordinates of the first reference mark and the second reference mark;

[0014] S102, providing a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system; the target point is a position where the orthodontic robot is located when installing a bracket on the tooth;

[0015] S103, registering the first spatial coordinate system and the second spatial coordinate system using a coordinate system registration algorithm, and obtaining a first measurement coordinate of the target point or the tooth in the first spatial coordinate system through a corresponding transformation of the first coordinate;

[0016] S104 determines a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold;

[0017] S105: when the orthodontic robot moves to the first navigation point, obtaining the second coordinates of the first reference mark and the second reference mark in the first space coordinates at a second moment;

[0018] S106 calculates at least one first difference between the first coordinate and the second coordinate;

[0019] S107 determines whether the first difference is less than a set first difference threshold, and if so, allows the orthodontic robot to continue moving from the first navigation point to the first measurement coordinate.

[0020] In some embodiments, before step S103, the method further includes:

[0021] Acquire a first image of the oral cavity and the mouth opener at the first shooting angle at the first moment; wherein the first image displays a second target position; the second target position includes one or more of the following: lip bead, lip peak, lip vermilion, incisor, canine, premolar, molar;

[0022] Acquire a second image of the target model at the first shooting angle;

[0023] Calculating a first target interval D1 between the first target position and the second target position in the first image, and calculating a second target interval D2 between the corresponding first target position and the second target position in the second image;

[0024] Calculate a first difference ratio X1 between the first target interval D1 and the second target interval D2; wherein X1=|D1-D2| / D1; or, X1=|D1-D2| / D2;

[0025] Determine whether the first difference ratio X1 is less than a preset second difference threshold;

[0026] If yes, execution of S103 is allowed; if no, a first misalignment prompt signal is sent to the user.

[0027] In some embodiments, before step S102, the method further includes:

[0028] Collecting a plurality of photos of the subject wearing the mouth opener, wherein the photos include: at least one reference mark and at least one tooth, and any two of the plurality of photos have overlapping parts;

[0029] Creating the corresponding target model according to the plurality of photos, wherein the target model is used to describe the positional relationship between the mouth opener and the tooth in the second spatial coordinate system;

[0030] The target model is used to determine the spatial coordinates of the final target point at which the orthodontic robot moves in the second spatial coordinate system.

[0031] In some embodiments, the photograph is a CT scan photograph or a standard orthodontic intraoral photograph.

[0032] In some embodiments, a gripping mechanism is disposed at the end of the orthodontic robot, and the gripping mechanism is used to grip at least one bracket.

[0033] In some embodiments, the orthodontic robot is further provided with a miniature camera adjacent to its end.

[0034] In some embodiments, the step of continuing to move from the first navigation point to the first measurement coordinate includes:

[0035] Determine a second navigation point, where the distance between the second navigation point and the target point is less than a second threshold;

[0036] When the orthodontic robot moves to the second navigation point at a second speed, a third image of the oral cavity at a second shooting angle is acquired by a miniature camera disposed at a position adjacent to the end of the orthodontic robot;

[0037] Acquire a fourth image of the target model at the second shooting angle;

[0038] Calculating a third target interval D3 between the first target position and the second target position in the third image, and calculating a fourth target interval D4 between the corresponding first target position and the second target position in the fourth image;

[0039] Calculating a second difference ratio X2 between the third target interval D3 and the fourth target interval D4;

[0040] Wherein, X2=|D3-D4| / D3; or X2=|D3-D4| / D4;

[0041] Determine whether the second difference ratio X2 is less than a preset third difference threshold;

[0042] If not, a second misalignment prompt signal is sent to the user.

[0043] In some embodiments, before step S105, the method further includes:

[0044] Determining whether there are at least two reference marks that are not blocked;

[0045] If yes, execute step S105;

[0046] If not, perform the following steps:

[0047] Acquire a fifth image of the reference mark and the tooth that is not blocked at a third shooting angle;

[0048] Acquire a sixth image of the target model at the third shooting angle;

[0049] Calculating a fifth target interval D5 between the first target position and the second target position in the fifth image, and calculating a sixth target interval D6 between the corresponding first target position and the second target position in the sixth image;

[0050] Calculating a third difference ratio X3 between the fifth target interval D5 and the sixth target interval D6;

[0051] Wherein, X3=|D5-D6| / D5; or X3=|D5-D6| / D6;

[0052] It is determined whether the third difference ratio X3 is less than a set fourth difference threshold value. If so, the orthodontic robot is allowed to continue moving from the first navigation point to the first measurement coordinate.

[0053] In some embodiments, the reference mark is an optical mark.

[0054] The present invention also provides a navigation system for an orthodontic robot, comprising:

[0055] A first positioning module is used to define a first spatial coordinate system using an optical positioning camera, wherein the first spatial coordinate system is used to define the first coordinates of a current first reference mark and a second reference mark; the first reference mark is set at at least one first target position on the mouth opener, and the second reference mark is set at at least one second target position on the mouth opener; the mouth opener is worn in the mouth of the subject to open and fix the mouth; wherein the first target position includes one or more of the following: positions on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, and a midline of a dentition;

[0056] A second positioning module is used to provide a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system; the target point is the position of the orthodontic robot when installing the bracket on the tooth;

[0057] A third positioning module, configured to register the first spatial coordinate system and the second spatial coordinate system by using a coordinate system registration algorithm, and obtain a first measurement coordinate of the target point or the tooth in the first spatial coordinate system by corresponding transformation of the first coordinate;

[0058] A first navigation point calculation module, used for determining a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold;

[0059] a fourth positioning module, configured to obtain, when the orthodontic robot moves to the first navigation point, second coordinates of the first reference mark and the second reference mark in the first space coordinate at a second moment;

[0060] A first difference calculation module, used for calculating at least one first difference between the first coordinate and the second coordinate;

[0061] The first navigation judgment module is used to judge whether the first difference is less than a set first difference threshold. If so, the orthodontic robot is allowed to continue moving from the first navigation point to the first measurement coordinate.

[0062] Beneficial technical effects:

[0063] The present invention provides a segmented navigation method based on finite optical markers. This segmented navigation method based on finite optical markers can reduce the real-time computing pressure of robot navigation during orthodontic process to a certain extent, thereby reducing the application cost of robot equipment.

[0064] Specifically, the segmented navigation of the present invention can be combined with the doctor's remote operation: through the selection of the first and second navigation points and the segmented navigation, the robot can be quickly positioned and navigated to the operable area (when the robot moves to the operable area, the robot can complete the positioning and installation of the bracket with only a small displacement), and the subsequent precise positioning and installation are completed by the doctor manually controlling the robot coordinates, thereby reducing the doctor's manual operation labor.

[0065] For remote areas with scarce medical resources, it is difficult to afford the economic cost of configuring high-precision medical equipment. The semi-automatic operation robot based on segmented navigation provided by the present invention can effectively reduce the computing pressure of the robot's automatic navigation, thereby reducing the robot's requirements for hardware performance and reducing implementation costs.

[0066] When the robot is connected to a computer system, doctors can use it to perform remote orthodontic operations. For example, when a patient's malocclusion is severe and requires assistance from a doctor from another place, or when the doctor is unable to arrive at the orthodontic site for some reason, the orthodontic operation can be completed by controlling the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without paying creative labor.

[0068] Figure 1 A schematic diagram of a navigation path in an exemplary embodiment of the present invention;

[0069] Figure 2 A schematic diagram of the operating state of a robot in an exemplary embodiment of the present invention;

[0070] Figure 3 is a schematic structural diagram of an equipment station in an exemplary embodiment of the present invention;

[0071] Figure 4 It is a schematic structural diagram of an opener in an exemplary embodiment of the present invention;

[0072] Figure 5 is a schematic structural diagram of a bracket in an exemplary embodiment of the present invention;

[0073] Figure 6 A schematic diagram of the process steps of a robot navigation method in an exemplary embodiment of the present invention;

[0074] Figure 7 The figure is a flow chart of a method for installing brackets in batches in yet another embodiment of the present invention.

[0075] Summary of reference numerals:

[0076] 001 is the equipment table, 002 is the bracket, 003 is the opener, 004 is the robot, 005 is the reference mark, O1 is the initial point, O2 is the first navigation point, and O3 is the target point. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0078] Herein, suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings by themselves. Therefore, "module", "component" or "unit" can be used mixedly.

[0079] In this document, the terms "upper", "lower", "inner", "outer", "front", "back", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0080] In this document, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] Herein "and / or" includes any and all combinations of one or more of the associated listed items.

[0082] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0083] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0084] As used in this specification, the term "about" typically means + / - 5% of the stated value, more typically + / - 4% of the stated value, more typically + / - 3% of the stated value, more typically + / - 2% of the stated value, even more typically + / - 1% of the stated value, and even more typically + / - 0.5% of the stated value.

[0085] In this specification, some embodiments may be disclosed in a format of being in a range. It should be understood that this description of "being in a range" is only for convenience and brevity, and should not be interpreted as a rigid limitation on the disclosed range. Therefore, the description of the range should be considered to have specifically disclosed all possible sub-ranges and independent numerical values ​​within this range. For example, the description of the range 1-6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5 and 6. Regardless of the breadth of the range, the above rules apply.

[0086] Herein, the mouth opener is also called a mouth opener, and the patient can keep the mouth open by wearing the mouth opener. For example, the mouth opener body can be in a "U" shape, and a handle is fixed to each of the two ends of the mouth opener body. The mouth opener body is elastic, and the two side arms of the mouth opener body can be bent toward the inside or outside of the mouth opener body when being pressed by external pressure, and when the external pressure disappears, the two side arms of the mouth opener body return to their original positions.

[0087] In this paper, the "optical positioning camera" can use visible light and computer vision to detect passively marked objects (i.e., reference markers) and track these objects by processing standard video images.

[0088] In this article, "coordinate system registration" refers to the process of converting the coordinates of one spatial reference system into another spatial reference system. For example, in order to improve orthodontic efficiency, before the robot performs the bracket installation task, the oral area of ​​the object (ie, the patient) can be 3D modeled to create a target model, wherein the target model will define the relative position relationship between the mouth opener (especially the reference mark) and the tooth (or the target point to which the robot needs to run) through the second spatial coordinate system. Furthermore, when it is necessary to perform actual orthodontic operations on the object, a first spatial coordinate system can be created based on the current environment, and the coordinates I of at least one reference mark (such as at least three reference marks) in the first spatial coordinate system can be obtained through an optical positioning camera. With the help of the relative position relationship in the second spatial coordinate system, the coordinates II of the tooth (or target point) in the first spatial coordinate system can be indirectly calculated through the coordinates I. This process is also called coordinate system registration.

[0089] In this article, "image positioning" refers to the process of obtaining image data through an image acquisition device (such as a camera), preprocessing the image data, including denoising, enhancement, and segmentation, extracting image feature information such as color, texture, shape, etc., and then using a specific positioning algorithm to match and locate the image features to determine the location of the target. For example, image positioning can be achieved through deep learning technology.

[0090] Embodiment 1

[0091] See also Figure 6 As shown, the present invention provides a navigation method for an orthodontic robot, which comprises the steps of:

[0092] S100, setting reference marks, the reference marks comprising: a first reference mark set at at least one first target position on the mouth opener, and a second reference mark set at at least another first target position on the mouth opener, the mouth opener 003 being worn in the oral cavity of the subject to open and fix the oral cavity;

[0093] For example, in some embodiments, the first target position includes one or more of the following: a position on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, a midline of a dentition (such as a gap between adjacent incisors);

[0094] Preferably, the reference marking is an optical marking.

[0095] Preferably, the optical marker can be a marker ball with an infrared sensitive coating or a visible light marker target.

[0096] Preferably, the optical mark can be set as an indicator graphic such as a triangle or a straight line to assist the user in adjusting the wearing position of the mouth opener.

[0097] S101, using an optical positioning camera to define a first spatial coordinate system W1, where the first spatial coordinate system W1 is used to define first coordinates A1 of the first reference mark and the second reference mark;

[0098] For example, when a patient lies on a dental chair wearing an open mouth, the optical positioning camera can identify the actual coordinates of the reference landmarks.

[0099] S102, providing a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system W2; the target point is a position where the orthodontic robot is located when installing a bracket on the tooth;

[0100] S103, using a coordinate system registration algorithm to register the first spatial coordinate system W1 and the second spatial coordinate system W2, and obtaining a first measurement coordinate B1 of the target point or the tooth in the first spatial coordinate system through a corresponding transformation of the first coordinate A1;

[0101] That is, the position of the target point or tooth in the first spatial coordinate system, i.e., the first measurement coordinate B1, can be indirectly measured by referring to the actual coordinates of the marker;

[0102] In some embodiments, the optical positioning camera can be a binocular vision optical positioning camera.

[0103] For example, in some embodiments, the total number of the first reference markers and the second reference markers in S101 is at least three. Alternatively, in order to improve the registration accuracy, more reference markers may be used.

[0104] S104 determines a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold;

[0105] S105: when the orthodontic robot moves to the first navigation point, obtaining the second coordinates of the first reference mark and the second reference mark in the first space coordinates at a second moment;

[0106] S106 calculates at least one first difference between the first coordinate and the second coordinate;

[0107] S107 determines whether the first difference is less than a set first difference threshold, and if so, allows the orthodontic robot to continue moving from the first navigation point to the first measurement coordinate.

[0108] In this embodiment, the first difference refers to the distance between the positions of the reference mark 005 at the first moment and the second moment.

[0109] For example, in some embodiments, at least one first difference can be calculated based on at least one first reference mark, and at least one first difference can be calculated based on at least one second reference mark, and when multiple first differences are all less than the first difference threshold, it is considered that the position offset of the mouth opener at the first and second moments is within the tolerable range. At this point, the movement from the first navigation point to the next desired position (such as the first measurement coordinate) can continue as planned.

[0110] In this embodiment, it is preferred to set multiple reference marks on the mouth opener to help the doctor determine the wearing position of the mouth opener, so that the position of the mouth opener during the orthodontic process is the same as the position of the mouth opener in the target model (or the deviation is relatively small), thereby enabling the robot to indirectly locate the teeth or target points through the target model during the actual navigation process.

[0111] In some embodiments, the first speed is greater than the second speed.

[0112] This embodiment actually provides a segmented navigation method.

[0113] It is worth noting that during orthodontic treatment, brackets need to be pasted on multiple teeth of the patient. During this long pasting process, the patient's mouth may continue to shift due to head movement. In addition, in order to ensure the orthodontic effect, the brackets need to be accurately installed in specific areas on the teeth. If the position is deviated, the bracket installation will fail. Therefore, this will place higher requirements on the robot's real-time navigation capabilities.

[0114] In this regard, the traditional idea of ​​orthodontic robot navigation is to collect real-time facial skin point cloud data of patients and calculate the navigation path of the robot through real-time facial skin point cloud data collection. However, the applicant found that when this method of real-time collection and calculation of point cloud data is applied to scenes with large target mobility (for example, especially when the patient is a child, it is difficult for him to maintain a relatively fixed posture for a long time), the difficulty of data collection and monitoring will increase significantly.

[0115] On the contrary, for orthodontic operation scenarios where patients have a high degree of freedom (i.e., the head may move at any time), the present invention provides a segmented navigation method based on finite optical markers. This segmented navigation method based on finite optical markers can reduce the real-time computing pressure of robot navigation during the orthodontic process to a certain extent, thereby reducing the application cost of robot equipment.

[0116] For example, see Figure 1-Figure 5 As shown, the workflow of the orthodontic robot is as follows:

[0117] The robot 004 needs to grab the bracket 002 from the equipment table 001, and then move from the initial point O1 to the target point O3 to complete the automatic installation of the bracket;

[0118] Specifically, when the initial point O1 (i.e., the current position of the orthodontic robot) moves to the target point O3 (i.e., the position to which the robot needs to move in order to paste the bracket), a first navigation point O2 can be first created at the first moment T1, and the long-distance path formed by the initial point O1 and the target point O3 can be divided into a first path and a second path by setting the first navigation point O2. Furthermore, in the process of moving to the first navigation point O2 through the first path, a faster speed can be used, and when moving to the first navigation point O2, it can be further determined whether the position of the optical mark at the current moment (i.e., the second moment T2) is significantly deviated from the position at the first moment T1 (i.e., the degree of head activity of the patient at this stage). When the position deviation at the two moments is small, the robot can move to the top of the tooth at a slower speed under camera positioning, thereby completing the installation of the bracket.

[0119] In some embodiments, before step S103, the method further includes:

[0120] Acquire a first image of the oral cavity and the mouth opener at a first shooting angle at the first moment; wherein the first image displays a second target position; the second target position includes one or more of the following: lip bead, lip peak, lip vermilion, incisor, canine, premolar, molar;

[0121] Furthermore, the second target position may be a center point of an incisor, a canine, a premolar, or a molar.

[0122] Acquire a second image of the target model at the first shooting angle;

[0123] Calculating a first target interval D1 between the first target position and the second target position in the first image, and calculating a second target interval D2 between the corresponding first target position and the second target position in the second image;

[0124] Calculate a first difference ratio X1 between the first target interval D1 and the second target interval D2; wherein X1=|D1-D2| / D1; or, X1=|D1-D2| / D2;

[0125] Determine whether the first difference ratio X1 is less than a preset second difference threshold;

[0126] If yes, execution of S103 is allowed; if no, a first misalignment prompt signal is sent to the user.

[0127] For example, when the user receives the first misalignment prompt signal, the doctor can manually adjust the wearing position of the mouth opener of the patient so that the wearing position of the mouth opener is close to the set position in the target model.

[0128] For example, in some embodiments, at least two shooting angles can be selected to obtain at least two first images and at least two second images respectively, and when the ratios of at least two first differences of at least two groups of images are less than the second difference threshold, it is considered that the wearing position of the mouth opener is within the tolerable range, and the coordinate alignment operation is allowed to be performed.

[0129] For example, in some embodiments, the user can set a specific shooting angle, such as the front, side, etc.

[0130] For example, in some embodiments, the shooting angle can be randomly selected by a camera (such as an optical positioning camera, or other shooting devices connected to the robot). At this time, the specific shooting angle can also be calculated based on the position of the camera (specifically, the spatial coordinates and attitude angle of the camera can be obtained) and the position of the optical marker. Correspondingly, according to the shooting angle determined by the camera itself, the image of the target model at the same angle can be output.

[0131] In some embodiments, before step S102, the method further includes:

[0132] Collecting a plurality of photos of the subject wearing the mouth opener, wherein the photos include: at least one reference mark and at least one tooth, and any two of the plurality of photos have overlapping parts;

[0133] Creating the corresponding target model according to the plurality of photos, wherein the target model is used to describe the positional relationship between the mouth opener and the teeth in a second spatial coordinate system;

[0134] The target model is used to determine the spatial coordinates of the final target point at which the orthodontic robot moves in the second spatial coordinate system.

[0135] For example, in some embodiments, after the target model is created, the final target point may be manually set by a doctor.

[0136] In some embodiments, the photograph is a CT scan photograph.

[0137] In some embodiments, the photo is a standard orthodontic intraoral photo, for example, a standard orthodontic intraoral photo includes one or more of the following: a front view, a side view, a 45° side view, a front smiling view, a side smiling view, a 45° side smiling view, an intraoral right side view, an intraoral front view, an intraoral left side view, an upper View from above Face-to-face, covering Covering view.

[0138] In some embodiments, a gripping mechanism is disposed at the end of the orthodontic robot, and the gripping mechanism is used to grip at least one bracket.

[0139] In some embodiments, the orthodontic robot is further provided with a miniature camera near its end, which can be used to capture images of the oral cavity.

[0140] In some embodiments, the step of continuing to move from the first navigation point to the first measurement coordinate (in this embodiment, the first measurement coordinate may refer to the coordinate of the target point O3) includes:

[0141] Determine a second navigation point, where the distance between the second navigation point and the target point is less than a second threshold;

[0142] When the orthodontic robot moves to the second navigation point, a third image of the oral cavity at a second shooting angle is acquired by a miniature camera disposed at a position adjacent to the end of the orthodontic robot;

[0143] Acquire a fourth image of the target model at the second shooting angle;

[0144] Calculating a third target interval D3 between the first target position and the second target position in the third image, and calculating a fourth target interval D4 between the corresponding first target position and the second target position in the fourth image;

[0145] Calculating a first difference ratio X2 between the third target interval D3 and the second target interval D4;

[0146] Wherein, X2=|D3-D4| / D3; or X2=|D3-D4| / D4;

[0147] Determine whether the second difference ratio X2 is less than a preset third difference threshold;

[0148] If not, a second misalignment prompt signal is sent to the user;

[0149] If yes, the robot is allowed to continue moving closer to the target position.

[0150] For example, the process of the robot moving to the first navigation point and the second navigation point can be set as an automatic navigation process, and when the robot moves to the second navigation point, the user (such as a doctor) can manually intervene to fine-tune the end position of the robot.

[0151] For example, in some embodiments, when the robot moves to the second navigation point, the current position of the robot may deviate from the expected position due to the patient's activities and other reasons. At this time, by measuring the deviation between the actual observation image and the expected observation image (i.e., the third and fourth images), if the deviation is within an acceptable range, the robot can continue to move freely. On the contrary, if the deviation is relatively large, the doctor can manually adjust the movement parameters of the robot by manually observing the real-time image (such as obtained by a micro camera), and then fine-tune the end position of the robot.

[0152] For example, in some embodiments, in order to save costs, a combination of automatic navigation and manual navigation can be used. Therefore, the robot can automatically complete the process of actively grabbing the bracket from the equipment table and moving from the equipment table to the first navigation point (reducing the manual operation of the doctor), and when the robot continues to move from the first navigation point to the second navigation point or fine-tunes the position at the second navigation point, manual adjustment can be introduced when the computer determines that the deviation is large. Especially when the doctor and the patient are in different regions, the use of this segmented navigation solution is conducive to the remote operation of orthodontics.

[0153] In the present invention, by selecting the first and second navigation points and performing segmented navigation, the robot can be quickly positioned and navigated to the operable area (when the robot moves to the operable area, the robot can complete the positioning and installation of the bracket with only a small displacement), thereby reducing the doctor's manual operation workload.

[0154] It is worth noting that for remote areas with scarce medical resources, it is difficult to afford the economic cost of configuring high-precision medical equipment. The semi-automatic operation robot based on segmented navigation provided by the present invention can effectively reduce the computing pressure of the robot's automatic navigation, thereby reducing the robot's requirements for hardware performance and reducing implementation costs.

[0155] In other words, this semi-automatic operation robot based on segmented navigation will help promote automated medical applications in remote areas.

[0156] Furthermore, when the robot is connected to a computer system, doctors can also use the robot to perform remote orthodontic operations. For example, when a patient's malocclusion is severe and requires assistance from a doctor from another place, or when the doctor is unable to arrive at the orthodontic site for some reason, the orthodontic operation can be completed by controlling the robot.

[0157] For example, the robot can automatically obtain the bracket from the equipment table and move from the equipment table to the first navigation point. Then, when the robot automatically moves to the operable area, the doctor can manually intervene.

[0158] Of course, in some embodiments, the fine adjustment of the second navigation point can also be automatically completed by image positioning technology. Specifically, the movement process from the first navigation point to the target point can also be completed by real-time image navigation.

[0159] For example, by collecting photos of teeth, the teeth can be positioned with high precision, and then fine-tuned with high precision between the second navigation point and the target point to achieve automatic installation of brackets. And because the early segmented navigation (equivalent to preliminary navigation) can effectively reduce the pressure of high-precision navigation, the overall computing resources consumed by this segmented navigation solution are relatively small, which is conducive to implementation.

[0160] In some embodiments, the optical positioning camera can be set on a robot, such as mounted on a robotic arm of a robot.

[0161] Alternatively, in some other embodiments, the optical positioning camera can be independently provided with the robotic arm, thereby reducing the weight of the robotic arm, thereby helping to improve the positioning accuracy of the robotic arm. In addition, in order to prevent the robotic arm from blocking the light or the oral cavity during movement, in some embodiments, before step S105, the following is further included:

[0162] Determining whether there are at least two reference marks that are not blocked;

[0163] If yes, execute step S105;

[0164] If not, perform the following steps:

[0165] Acquire a fifth image of the reference mark and the target tooth that is not blocked at a third shooting angle;

[0166] Acquire a sixth image of the target model at the third shooting angle;

[0167] Calculating a fifth target interval D5 between the first target position and the second target position in the fifth image, and calculating a sixth target interval D6 between the corresponding first target position and the second target position in the sixth image;

[0168] Calculate a third difference ratio X3 between the fifth target interval D5 and the sixth target interval D6; wherein X3=|D5-D6| / D5; or X3=|D5-D6| / D6;

[0169] It is determined whether the third difference ratio X3 is less than a set fourth difference threshold value. If so, the orthodontic robot is allowed to continue moving from the first navigation point to the first measurement coordinate.

[0170] Otherwise, it is recommended that the user manually intervene to determine whether the robot needs to be fine-tuned.

[0171] In this embodiment, the problem of reference marks being blocked can be solved by using image comparison.

[0172] Embodiment 2

[0173] The present invention also provides a navigation system for an orthodontic robot, comprising:

[0174] A first positioning module is used to define a first spatial coordinate system using an optical positioning camera, wherein the first spatial coordinate system is used to define the first coordinates of a current first reference mark and a second reference mark; the first reference mark is set at at least one first target position on the mouth opener, and the second reference mark is set at at least one second target position on the mouth opener; the mouth opener is worn in the mouth of the subject to open and fix the mouth; wherein the first target position includes one or more of the following: positions on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, and a midline of a dentition;

[0175] A second positioning module is used to provide a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system; the target point is the position of the orthodontic robot when installing the bracket on the tooth;

[0176] A third positioning module, configured to register the first spatial coordinate system and the second spatial coordinate system by using a coordinate system registration algorithm, and obtain a first measurement coordinate of the target point or the tooth in the first spatial coordinate system by corresponding transformation of the first coordinate;

[0177] A first navigation point calculation module, used for determining a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold;

[0178] a fourth positioning module, configured to obtain, when the orthodontic robot moves to the first navigation point, second coordinates of the first reference mark and the second reference mark in the first space coordinate at a second moment;

[0179] A first difference calculation module, used for calculating at least one first difference between the first coordinate and the second coordinate;

[0180] The first navigation judgment module is used to judge whether the first difference is less than a set first difference threshold. If so, the orthodontic robot is allowed to continue moving from the first navigation point to the first measurement coordinate.

[0181] It can be understood that the system in the present invention can implement the method steps described in any of the above embodiments, which will not be repeated here.

[0182] Embodiment 3

[0183] See also Figure 7 As shown, the present invention also provides a robot navigation method capable of synchronously installing brackets on multiple teeth, comprising the steps of:

[0184] S200, setting reference marks, the reference marks comprising: a first reference mark set at at least one first target position on the mouth opener, and a second reference mark set at at least another first target position on the mouth opener, the mouth opener being worn in the oral cavity of the subject to open and fix the oral cavity;

[0185] S201, defining a first spatial coordinate system using an optical positioning camera, where the first spatial coordinate system is used to define first coordinates of the first reference mark and the second reference mark;

[0186] S202, providing a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and the teeth through a second spatial coordinate system; at least two grasping mechanisms are provided at the end of the robot, and the grasping mechanisms are used to grasp and install the brackets; the at least two grasping mechanisms can simultaneously install the brackets on a group of teeth;

[0187] S203, aligning the first spatial coordinate system and the second spatial coordinate system using a coordinate system registration algorithm, and obtaining a first reference coordinate of a first reference point in the first spatial coordinate system by corresponding transformation of one of the first coordinates, and obtaining a second reference coordinate of a second reference point in the first spatial coordinate system by corresponding transformation of another of the first coordinates; the reference point is the tooth;

[0188] S204 calculates a first reference distance and a second reference distance of the first reference point and the second reference point in the first spatial coordinate system and the second spatial coordinate system respectively;

[0189] In this embodiment, the first reference distance is the distance between the first reference point and the second reference point in the first spatial coordinate system, and the second reference distance is the distance between the first reference point and the second reference point in the second spatial coordinate system, and the first and second spatial coordinate systems use the same coordinate scale (in other words, the ratio of the coordinate scale in the first spatial coordinate system to the size in the actual space is the same as the ratio of the coordinate scale in the second spatial coordinate system to the size in the actual space);

[0190] S205 determines whether the difference between the first reference distance and the second reference distance is less than a set reference threshold, and if so, executes S206;

[0191] S206 determines a first navigation point of at least one grasping mechanism according to at least one reference point, wherein a distance between the first navigation point and the reference point is greater than a set first threshold.

[0192] The batch installation scheme proposed in this embodiment can effectively improve the efficiency of bracket installation, and the navigation point (or navigation trajectory) of the orthodontic robot can be verified through the first reference point and the second reference point, thereby improving the accuracy of the navigation scheme based on limited optical markers.

[0193] In some embodiments, the first reference point and the second reference point are respectively located on different teeth in the set of teeth.

[0194] In some embodiments, the first target position includes one or more of the following: a position on the mouth opener corresponding to the lip bead, lip peak, lip vermilion, and midline of the dentition.

[0195] In some embodiments, before step S203, the method further includes:

[0196] Acquire a first image of the oral cavity and the mouth opener at the first shooting angle at the first moment; wherein the first image displays a second target position; the second target position includes one or more of the following: lip bead, lip peak, lip vermilion, incisor, canine, premolar, molar;

[0197] Acquire a second image of the target model at the first shooting angle;

[0198] Calculating a first target interval D1 between the first target position and the second target position in the first image, and calculating a second target interval D2 between the corresponding first target position and the second target position in the second image;

[0199] Calculate a first difference ratio X1 between the first target interval D1 and the second target interval D2; wherein X1=|D1-D2| / D1; or, X1=|D1-D2| / D2;

[0200] Determine whether the first difference ratio X1 is less than a preset second difference threshold;

[0201] If yes, then S203 is allowed to be executed; if no, then a first misalignment prompt signal is sent to the user.

[0202] In some embodiments, the step of creating the target model includes:

[0203] Collecting a plurality of photos of the subject wearing the mouth opener, wherein the photos include: at least one reference mark and at least one tooth, and any two of the plurality of photos have overlapping parts;

[0204] The corresponding target model is created according to the multiple photos, and the target model is used to describe the positional relationship between the mouth opener and the teeth in the second spatial coordinate system.

[0205] In some embodiments, the steps include:

[0206] The target model is used to determine the reference coordinates of the robot moving to the final target point in the second spatial coordinate system.

[0207] In some embodiments, it also includes:

[0208] Obtaining a first measurement coordinate of the target point in the first space coordinate system by converting the reference coordinate of the target point;

[0209] The robot continues to move from the first navigation point to the first measurement coordinate.

[0210] For example, in this embodiment, the first measurement coordinate may refer to the spatial position of the robot end when the robot needs to install the bracket on the corresponding tooth. For example, the first measurement coordinate may be a coordinate pre-set by a user (such as a doctor) with the help of a target model.

[0211] For example, in some embodiments, the robot may first move from a reference point to a first navigation point, and then move from the first navigation point to a first measurement coordinate, thereby reducing the robot's real-time navigation pressure through segmented navigation. For example, the robot may use different moving speeds during movement from far to near to adapt to the navigation characteristics of different navigation stages.

[0212] For another example, in some embodiments, the robot continues to move from the first navigation point to the first measurement coordinates through the intervention of a doctor.

[0213] For example, in some embodiments, the step of continuing to move from the first navigation point to the first measurement coordinate includes:

[0214] Determine a second navigation point, where the distance between the second navigation point and the first measurement coordinate is less than a second threshold;

[0215] When the orthodontic robot moves to the second navigation point at a second speed, a third image of the oral cavity at a second shooting angle is acquired by a micro camera disposed at a position near the end of the robot;

[0216] Acquire a fourth image of the target model at the second shooting angle;

[0217] Calculating a third target interval D3 between the first target position and the second target position in the third image, and calculating a fourth target interval D4 between the corresponding first target position and the second target position in the fourth image;

[0218] Calculating a second difference ratio X2 between the third target interval D3 and the fourth target interval D4;

[0219] Wherein, X2=|D3-D4| / D3; or X2=|D3-D4| / D4;

[0220] Determine whether the second difference ratio X2 is less than a preset third difference threshold;

[0221] If not, a second misalignment prompt signal is sent to the user.

[0222] In some embodiments, the photograph is a CT scan photograph or a standard orthodontic intraoral photograph.

[0223] Embodiment 4

[0224] The present invention also provides a robot navigation system for batch installation of brackets, comprising:

[0225] Reference marks, the reference marks comprising: a first reference mark disposed at at least one first target position on the mouth opener, and a second reference mark disposed at at least one other first target position on the mouth opener, the mouth opener being worn in the oral cavity of a subject to open and fix the oral cavity;

[0226] A first positioning module, used for defining a first spatial coordinate system using an optical positioning camera, wherein the first spatial coordinate system is used for defining first coordinates of the first reference mark and the second reference mark;

[0227] A second positioning module is used to provide a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines the relative position between at least one reference mark and the teeth through a second spatial coordinate system; at least two grasping mechanisms are provided at the end of the robot, and the grasping mechanisms are used to grasp and install the brackets; the at least two grasping mechanisms can simultaneously install the brackets on a group of teeth;

[0228] a third positioning module, configured to align the first spatial coordinate system and the second spatial coordinate system by using a coordinate system alignment algorithm, and obtain a first reference coordinate of a first reference point in the first spatial coordinate system by corresponding transformation of one of the first coordinates, and obtain a second reference coordinate of a second reference point in the first spatial coordinate system by corresponding transformation of another of the first coordinates; the reference point is the tooth;

[0229] A reference distance calculation module, used to calculate a first reference distance and a second reference distance of the first reference point and the second reference point in the first spatial coordinate system and the second spatial coordinate system respectively;

[0230] The first judgment module is used to judge whether the difference between the first reference distance and the second reference distance is less than a set reference threshold. If so, a first navigation point of at least one grasping mechanism is determined based on at least one reference point, and the distance between the first navigation point and the reference point is greater than a set first threshold.

[0231] It can be understood that the system in the present invention can implement the method steps described in any of the above embodiments, which will not be repeated here.

[0232] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0233] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a computer terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0234] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

[0235] References:

[0236] CN202410032572-An intelligent navigation implantation method and system for an oral implantation robot;

[0237] CN202110698441-A dental implant robot navigation and positioning method;

[0238] CN202110867874-An optically navigated dental implant robot system and calibration method thereof;

[0239] CN202310283962-A control method, system and storage medium for a dental surgical robot.

Claims

1. A navigation method for an orthodontic robot, characterized in that: Includes steps: S100, setting reference marks, the reference marks comprising: a first reference mark set at at least one first target position on the mouth opener, and a second reference mark set at at least one other first target position on the mouth opener, the mouth opener being worn in the oral cavity of the subject to open and fix the oral cavity; wherein the first target position comprises one or more of the following: a position on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, and a midline of a dentition; S101, defining a first spatial coordinate system using an optical positioning camera, where the first spatial coordinate system is used to define first coordinates of the first reference mark and the second reference mark; S102, providing a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system; the target point is a position where the orthodontic robot is located when installing a bracket on the tooth; S103, registering the first spatial coordinate system and the second spatial coordinate system using a coordinate system registration algorithm, and obtaining a first measurement coordinate of the target point or the tooth in the first spatial coordinate system through a corresponding transformation of the first coordinate; S104 determines a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold; S105: when the orthodontic robot moves to the first navigation point, obtaining the second coordinates of the first reference mark and the second reference mark in the first space coordinates at a second moment; S106 calculates at least one first difference between the first coordinate and the second coordinate; S107 determines whether the first difference is less than a set first difference threshold, and if so, allows the orthodontic robot to continue moving from the first navigation point to the first measurement coordinate; Before step S103, the method includes: Acquire a first image of the oral cavity and the mouth opener at a first shooting angle at a first moment; wherein the first image displays a second target position; the second target position includes one or more of the following: lip bead, lip peak, lip vermilion, incisor, canine, premolar, molar; Acquire a second image of the target model at the first shooting angle; Calculating a first target interval D1 between the first target position and the second target position in the first image, and calculating a second target interval D2 between the corresponding first target position and the second target position in the second image; Calculate a first difference ratio X1 between the first target interval D1 and the second target interval D2; wherein X1=|D1-D2| / D1; or, X1=|D1-D2| / D2; Determine whether the first difference ratio X1 is less than a preset second difference threshold; If yes, execution of S103 is allowed; if no, a first misalignment prompt signal is sent to the user; Wherein, before step S102, the method includes: Collecting a plurality of photos of the subject wearing the mouth opener, wherein the photos include: at least one reference mark and at least one tooth, and any two of the plurality of photos have overlapping parts; Creating the corresponding target model according to the plurality of photos, wherein the target model is used to describe the positional relationship between the mouth opener and the tooth in the second spatial coordinate system; The step of continuing to move from the first navigation point to the first measurement coordinate includes: Determine a second navigation point, where a distance between the second navigation point and the target point is less than a second threshold; When the orthodontic robot moves to the second navigation point at a second speed, a third image of the oral cavity at a second shooting angle is acquired by a miniature camera disposed at a position adjacent to the end of the orthodontic robot; Acquire a fourth image of the target model at the second shooting angle; Calculating a third target interval D3 between the first target position and the second target position in the third image, and calculating a fourth target interval D4 between the corresponding first target position and the second target position in the fourth image; Calculate a second difference ratio X2 between the third target interval D3 and the fourth target interval D4; wherein X2=|D3-D4| / D3; or X2=|D3-D4| / D4; Determine whether the second difference ratio X2 is less than a preset third difference threshold; If not, a second misalignment prompt signal is sent to the user.

2. The navigation method of an orthodontic robot according to claim 1, characterized in that: The photographs are CT scan photographs or standard orthodontic intraoral photographs.

3. The navigation method of an orthodontic robot according to claim 1, characterized in that: A gripping mechanism is provided at the end of the orthodontic robot, and the gripping mechanism is used to grip at least one bracket.

4. The navigation method of an orthodontic robot according to claim 1, characterized in that: The orthodontic robot is also provided with a miniature camera near its end.

5. The navigation method of an orthodontic robot according to claim 1, characterized in that: Before step S105, the method further includes: Determining whether there are at least two reference marks that are not blocked; If yes, execute step S105; If not, perform the following steps: Acquire a fifth image of the reference mark and the tooth that is not blocked at a third shooting angle; Acquire a sixth image of the target model at the third shooting angle; Calculating a fifth target interval D5 between the first target position and the second target position in the fifth image, and calculating a sixth target interval D6 between the corresponding first target position and the second target position in the sixth image; Calculating a third difference ratio X3 between the fifth target interval D5 and the sixth target interval D6; Where, X3=|D5-D6| / D5; or X3=|D5-D6| / D6; It is determined whether the third difference ratio X3 is less than a set fourth difference threshold value. If so, the orthodontic robot is allowed to continue moving from the first navigation point to the first measurement coordinate.

6. The navigation method of an orthodontic robot according to claim 1, characterized in that: The reference mark is an optical mark.

7. A navigation system for an orthodontic robot, characterized in that: include: A first positioning module is used to define a first spatial coordinate system using an optical positioning camera, wherein the first spatial coordinate system is used to define the first coordinates of a current first reference mark and a second reference mark; the first reference mark is set at at least one first target position on the mouth opener, and the second reference mark is set at at least one second target position on the mouth opener; the mouth opener is worn in the mouth of the subject to open and fix the mouth; wherein the first target position includes one or more of the following: positions on the mouth opener corresponding to a lip bead, a lip peak, a lip vermilion, and a midline of a dentition; A second positioning module is used to provide a preset target model for simulating the oral cavity and the mouth opener, wherein the target model defines a relative position between at least one reference mark and a target point or a tooth through a second spatial coordinate system; the target point is the position of the orthodontic robot when installing the bracket on the tooth; A third positioning module, configured to register the first spatial coordinate system and the second spatial coordinate system by using a coordinate system registration algorithm, and obtain a first measurement coordinate of the target point or the tooth in the first spatial coordinate system by corresponding transformation of the first coordinate; A first navigation point calculation module, used for determining a first navigation point according to the first measurement coordinates, the orthodontic robot moves to the first navigation point at a first speed, and a first distance between the first navigation point and the first measurement coordinates is greater than a set first threshold; a fourth positioning module, configured to obtain, when the orthodontic robot moves to the first navigation point, second coordinates of the first reference mark and the second reference mark in the first space coordinate at a second moment; A first difference calculation module, used for calculating at least one first difference between the first coordinate and the second coordinate; The first navigation judgment module is used to judge whether the first difference is less than a set first difference threshold value, and if so, allow the orthodontic robot to continue moving from the first navigation point to the first measurement coordinate; wherein, before entering the third positioning module, the navigation system is also used to perform the following steps: Acquire a first image of the oral cavity and the mouth opener at a first shooting angle at a first moment; wherein the first image displays a second target position; the second target position includes one or more of the following: lip bead, lip peak, lip vermilion, incisor, canine, premolar, molar; Acquire a second image of the target model at the first shooting angle; Calculating a first target interval D1 between the first target position and the second target position in the first image, and calculating a second target interval D2 between the corresponding first target position and the second target position in the second image; Calculate a first difference ratio X1 between the first target interval D1 and the second target interval D2; wherein X1=|D1-D2| / D1; or, X1=|D1-D2| / D2; Determine whether the first difference ratio X1 is less than a preset second difference threshold; If so, entry into the third positioning module is allowed; if not, a first misalignment prompt signal is issued to the user; Before entering the second positioning module, the navigation system is further configured to perform the following steps: Collecting a plurality of photos of the subject wearing the mouth opener, wherein the photos include: at least one reference mark and at least one tooth, and any two of the plurality of photos have overlapping parts; Creating the corresponding target model according to the plurality of photos, wherein the target model is used to describe the positional relationship between the mouth opener and the tooth in the second spatial coordinate system; The step of continuing to move from the first navigation point to the first measurement coordinate includes: Determine a second navigation point, where a distance between the second navigation point and the target point is less than a second threshold; When the orthodontic robot moves to the second navigation point at a second speed, a third image of the oral cavity at a second shooting angle is acquired by a miniature camera disposed at a position adjacent to the end of the orthodontic robot; Acquire a fourth image of the target model at the second shooting angle; Calculating a third target interval D3 between the first target position and the second target position in the third image, and calculating a fourth target interval D4 between the corresponding first target position and the second target position in the fourth image; Calculate a second difference ratio X2 between the third target interval D3 and the fourth target interval D4; wherein X2=|D3-D4| / D3; or X2=|D3-D4| / D4; Determine whether the second difference ratio X2 is less than a preset third difference threshold; If not, a second misalignment prompt signal is sent to the user.

Images