A registration method for a navigation-type dental handpiece drill

Abstract

The present invention relates to the field of medical device technology, and in particular to a registration method for a navigation-type dental handpiece drill, comprising the following steps: determining a required drill model, wherein the drill length is L1, and the standard drill length adapted to the registration block is L2; calculating the transformation relationship between the calibration block verification point coordinate system and the drill tip coordinate system; calculating the transformation relationship between the registration block reference array coordinate system and the calibration block verification point coordinate system; calculating the transformation relationship between the dental handpiece reference array coordinate system and the calibration block reference array coordinate system; and calculating the transformation relationship between the dental handpiece reference array coordinate system and the drill tip coordinate system. The registration method of the present invention requires that a standard drill be combined with the registration block. However, the standard drill is not used in actual surgery and is removed after registration is completed. The drill required for the actual surgery is then combined with the dental handpiece. Therefore, the drill that actually contacts the patient does not contact the registration block at all, thereby reducing the possibility of contamination.

Description

Technical Field

[0001] The present invention relates to the field of image navigation technology, and in particular to a registration method for a navigation-type dental mobile phone drill. Background Art

[0002] In image-guided dental surgery, to ensure surgical accuracy, the posture of the surgical instrument model in the virtual image scene needs to be highly consistent with the posture of the actual instrument manipulated by the doctor or robotic arm. When using a navigation dental handpiece:

[0003] 1. A reference array is fixed to the dental handpiece (or to a robotic arm connected thereto). A number of reflective balls (three or more) are fixed to the reference array to form a reference array. The center positions of these balls form a fixed coordinate system F.

[0004] 2. In some manner, the axial direction of the dental handpiece drill and the coordinate values of the drill tip in the dental handpiece reference array coordinate system F can be obtained;

[0005] 3. Using this relationship, the positioning camera can detect the position of the dental handpiece reference array during surgery to determine the coordinates of the drill tip in the world coordinate system (the positioning camera coordinate system) and the drill's real-time orientation in the world coordinate system, thereby helping the dentist (or robotic system) accurately place the drill at the target location.

[0006] In the above process, it is very important to obtain the accurate geometric expression of the drill tip and the drill axis in the dental mobile phone reference array coordinate system, and its accuracy directly affects the accuracy of navigation.

[0007] Disadvantages of existing technology:

[0008] In practical applications, the coordinate values of the drill tip and the direction vector of the drill axis in the dental handpiece reference array coordinate system can be directly calculated from the design drawings. Disadvantage: There is an error between the geometric design value and the actual geometric value due to the limitations of manufacturing accuracy.

[0009] CN108433834A proposes a device and method for aligning dental handpiece drill bits. This method uses an additional alignment device to obtain relatively accurate drill bit geometric parameters. However, analysis of the alignment method reveals that it places high demands on the manufacturing precision of the alignment device itself: the relative positional relationship between the optical positioning patch and the slender cylinder used in conjunction with the dental handpiece must be highly consistent with the design value. Furthermore, because the optical patch and the plate-like component of the alignment device are not integrally formed, precise assembly is challenging. Therefore, we propose a navigation-based alignment method for dental handpiece drill bits. Summary of the Invention

[0010] Based on the technical problems existing in the background technology, the present invention proposes a registration method for a navigation-type dental handpiece drill, which fully considers and solves the problem that the geometric relative relationship between the registration block body and its accompanying reference array deviates from the design value.

[0011] The present invention provides the following technical solution: a registration method for a navigation-type dental handpiece drill, comprising the following steps:

[0012] S1. Determine the required drill bit model, the drill bit length is L1, and the standard drill bit length suitable for the registration block is L2;

[0013] S2, calculating the conversion relationship between the calibration block verification point coordinate system and the drill bit tip coordinate system;

[0014] Establish a three-dimensional orthogonal coordinate system on the standard drill bit. Use engineering drawing software to obtain the coordinates of three verification points on the calibration block corresponding to the required positions in this coordinate system. Use the difference between L1 and L2 to compensate for the coordinates of the verification points.

[0015] The compensated coordinates are used to calculate the unit direction vectors of the three coordinate axes of the coordinate system formed by the verification points of the registration block in the drill tip coordinate system; the three vectors and the compensated coordinates are used to obtain the transformation matrix from the verification point coordinate system to the drill bit coordinate system;

[0016] S3, calculating the conversion relationship between the registration block reference array coordinate system and the calibration block verification point coordinate system;

[0017] S4, calculating the transformation relationship between the dental handpiece reference array coordinate system and the calibration block reference array coordinate system;

[0018] S5. Calculate the transformation relationship between the dental handpiece reference array coordinate system and the drill tip coordinate system.

[0019] Preferably, the specific content of step S3 is as follows:

[0020] S31, collecting and calculating the coordinate values of three verification points on the registration block in the registration block reference array coordinate system;

[0021] S32, calculating the calculated coordinate values as unit direction vectors of the three coordinate axes of the coordinate system formed by the registration block verification points in the registration block reference array coordinate system;

[0022] S33. Use the three vectors of S32 and the coordinate values of S31 to establish a 4X4 matrix, which is the conversion matrix from the registration block reference array coordinate system to the registration block verification point coordinate system.

[0023] Preferably, in step S4, the dental handpiece, the standard drill, and the registration block are combined so that the registration block reference array and the dental handpiece reference array are simultaneously visible under the positioning camera, and the transformation matrix from the dental handpiece reference array coordinate system to the calibration block reference array coordinate system is calculated.

[0024] Preferably, in step S5, according to the iterative principle of coordinate system conversion, a conversion matrix from the dental handpiece reference array coordinate system to the drill tip coordinate system is obtained based on the matrix operations of steps S2-S4.

[0025] Preferably, in step S2, the standard drill bit model and the calibration block three-dimensional model are imported into the engineering drawing software, and the two are combined in a design manner. The tip of the standard drill bit is inserted into the bottom of the through hole of the registration block, and a three-dimensional orthogonal coordinate system is established on the standard drill bit, wherein the origin is located at the tip of the drill bit, the z-axis is the drill bit axis and points in the direction of the drill bit; the direction of the y-axis is arbitrarily specified; and the direction of the x-axis is determined by the cross product of the z-axis direction vector and the y-axis direction vector.

[0026] In the coordinate system set in the previous step, use engineering drawing software to obtain the coordinates of the three verification points on the calibration block corresponding to the required positions, which are recorded as q1, q2, and q3 respectively, where:

[0027]

[0028] The difference between the actual drill bit length and the standard drill bit length on the registration block is used to compensate for the above verification point coordinates to obtain a new set of point coordinates c1, c2, c3 as follows;

[0029]

[0030] Using the coordinate values of the three points above, calculate the following three vectors,

[0031]

[0032]

[0033]

[0034] The values of the three vectors are recorded as follows:

[0035]

[0036] The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the verification points of the registration block in the drill tip coordinate system;

[0037] Use the above three vectors and the coordinates of point c1 to form a 4X4 matrix T drillToCheckPoints as follows:

[0038]

[0039] Matrix T drillTipToCheckPoints This is the transformation matrix from the actual drill bit coordinate system to the verification point coordinate system. By finding its inverse matrix, we can get the transformation matrix T from the verification point coordinate system to the drill bit coordinate system. checkPointsToDrill .

[0040] Preferably, in step S3, the probe tip is placed at the registration block verification point i, i = 1, 2, 3, and the 4X4 transformation matrix from the optical positioning camera coordinate system to the probe coordinate system and the registration block reference array coordinate system is collected, which are T cameraToProbe_i With T cameraToCalibrator_i ;

[0041] Then the homogeneous coordinate value q of the verification point i in the registration block reference array coordinate system can be obtained by the following coordinate system transformation: i ',

[0042]

[0043] Repeat the above steps to obtain the homogeneous coordinate values (4x1 sequence) of all three verification points in the registration block reference array coordinate system, which are q1', q2', q3', and their corresponding three-dimensional coordinate values (3x1 sequence) are c1', c2', c3'.

[0044] Use the coordinate values calculated above to calculate the following three unit vectors:

[0045]

[0046]

[0047]

[0048] The above three vectors are written as follows:

[0049]

[0050] The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the registration block verification points in the registration block reference array coordinate system;

[0051] Use the above three vectors and the coordinate values of c1' [x1', y1', z1'] to create a 4X4 matrix T calibratorToCheckPoints , this matrix is the transformation matrix from the registration block reference array coordinate system to the registration block verification point coordinate system,

[0052]

[0053] Preferably, in step S4, the dental handpiece, the standard drill, and the registration block are combined so that the registration block reference array and the dental handpiece reference array are simultaneously visible under the positioning camera, and the conversion matrices from the positioning camera coordinate system to the dental handpiece reference array coordinate system and the registration block reference array coordinate system are recorded as T and T respectively. cameraToHandPiece With T cameraTocalibrator ;

[0054] Transformation matrix T from the dental handpiece reference array coordinate system to the calibration block reference array coordinate system handPieceToCalibrator The calculation is as follows:

[0055]

[0056] Preferably, in step S5, the conversion matrix T from the dental mobile phone reference array coordinate system to the drill tip coordinate system is handPieceToDri1l The matrix operations through steps S2-S4 are as follows:

[0057] T handPieceToDrill =T handPieceToCalibrator ·T calibratorToCheckPoints ·T checkPointsToDrill .

[0058] This invention provides a registration method for a navigation-based dental handpiece drill. A standard drill bit is required for integration with the registration block. However, the standard drill bit is not used in the actual procedure and is removed after registration is complete. The drill bit required for the actual procedure is then integrated into the dental handpiece. Therefore, the drill bit that actually contacts the patient never comes into contact with the registration block, minimizing the risk of contamination. This method addresses the issue of deviations from the designed geometric relationship between the registration block and its accompanying reference array. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the structure of the navigation-type dental handpiece of the present invention;

[0060] Figure 2 Schematic diagram of the optical tracking probe structure of the present invention;

[0061] Figure 3 This is a schematic structural diagram of the drill bit registration block of the present invention;

[0062] Figure 4 Schematic diagram of establishing a three-dimensional orthogonal coordinate system on a standard drill bit in step S2 of the present invention;

[0063] Figure 5 Schematic diagram of probe collection in step S3 of the present invention;

[0064] Figure 6 This is a schematic diagram of the combination of a dental handpiece, a standard drill bit, and a registration block in step S4 of the present invention. DETAILED DESCRIPTION

[0065] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 efforts are within the scope of protection of the present invention.

[0066] The present invention provides a technical solution: a registration method for a navigation-type dental handpiece drill, which specifically includes the following steps:

[0067] S1. Determine the drill bit model.

[0068] Select the required drill bit model, the drill bit length is L1 (this length needs to be known in advance), and the standard drill bit length suitable for the registration block is L2.

[0069] S2. Calculate the conversion relationship between the registration block verification point coordinate system and the drill tip coordinate system.

[0070] Import the standard drill bit model and the calibration block 3D model into the engineering drawing software and combine them in a design manner. Insert the tip of the standard drill bit into the bottom of the through hole of the registration block, such as Figure 4 A three-dimensional orthogonal coordinate system is established on a standard drill bit, with its origin at the drill tip, the z-axis being the drill axis and pointing in the direction of the drill bit's travel; the y-axis can be arbitrarily oriented; and the x-axis is determined by the cross product of the z-axis direction vector and the y-axis direction vector.

[0071] In the coordinate system set in the previous step, use engineering drawing software to obtain the coordinates of the three verification points on the calibration block corresponding to the required positions, which are recorded as q1, q2, and q3 respectively, where:

[0072]

[0073] The difference between the actual drill bit length and the standard drill bit length on the registration block is used to compensate for the above verification point coordinates to obtain a new set of point coordinates c1, c2, and c3 as follows.

[0074]

[0075] Using the coordinate values of the three points above, calculate the following three vectors,

[0076]

[0077]

[0078]

[0079] The values of the three vectors are recorded as follows:

[0080]

[0081] The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the verification points of the registration block in the drill tip coordinate system.

[0082] Use the above three vectors and the coordinates of point c1 to form a 4X4 matrix T drillToCheckPoints as follows:

[0083]

[0084] Matrix T drillTipToCheckPoints This is the transformation matrix from the actual drill bit coordinate system to the verification point coordinate system. By finding its inverse matrix, we can get the transformation matrix T from the verification point coordinate system to the drill bit coordinate system. checkPointsToDrill .

[0085] S3. Calculate the conversion relationship between the registration block reference array coordinate system and the calibration block verification point coordinate system

[0086] Collect and calculate the coordinate values of the three verification points on the registration block in the registration block reference array coordinate system.

[0087] like Figure 5 As shown, the probe tip is placed at the registration block verification point i (i = 1, 2, 3), and the 4X4 transformation matrix (which can be directly obtained through the positioning system) from the optical positioning camera coordinate system to the probe coordinate system and the registration block reference array coordinate system (set based on its reflective ball) is collected. cameraToProbe_i With T cameraToCalibrator_i .

[0088] Then the homogeneous coordinate value q of the verification point i in the registration block reference array coordinate system can be obtained by the following coordinate system transformation: i '

[0089]

[0090] Repeat the above steps to obtain the homogeneous coordinate values (4X1 series) of all three verification points in the registration block reference array coordinate system, which are q1', q2', q3', and their corresponding three-dimensional space coordinate values (3X1 series) are c1', c2', c3'.

[0091] Use the coordinate values calculated above to calculate the following three unit vectors:

[0092]

[0093]

[0094]

[0095] The above three vectors are written as follows:

[0096]

[0097] The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the registration block verification points in the registration block reference array coordinate system.

[0098] Use the above three vectors and the coordinate values of c1' [x1', y1', z1'] to create a 4X4 matrix T calibratorToCheckPoints , which is the transformation matrix from the registration block reference array coordinate system to the registration block verification point coordinate system

[0099]

[0100] S4. Calculate the transformation relationship between the dental handpiece reference array coordinate system and the calibration block reference array coordinate system.

[0101] like Figure 6 As shown, the dental handpiece, standard drill, and registration block are combined so that the registration block reference array and the dental handpiece reference array are visible at the same time under the positioning camera. The transformation matrices (which can be directly obtained through the positioning system) from the positioning camera coordinate system to the dental handpiece reference array coordinate system and the registration block reference array coordinate system are recorded as T cameraToHandPiece With T cameraTocalibrator .

[0102] Transformation matrix T from the dental handpiece reference array coordinate system to the calibration block reference array coordinate system handPieceToCalibrator The calculation is as follows:

[0103]

[0104] S5. Calculate the transformation relationship between the dental handpiece reference array coordinate system and the drill tip coordinate system

[0105] According to the iterative principle of coordinate system transformation, the transformation matrix T from the dental handpiece reference array coordinate system to the drill tip coordinate system is handPieceToDri1l The matrix obtained above can be obtained by calculation

[0106] T handPieceToDrill =T handPieceToCalibrator ·T calibratorToCheckPoints ·T checkPointsToDrill

[0107] At this point, the dental handpiece drill bit registration is completed, the registration block and the standard drill bit are removed, and the required model drill bit is assembled on the dental handpiece. The obtained transformation matrix T handPieceToDrillThat is, the transformation matrix from the dental reference array coordinate system to the required model drill tip coordinate system.

[0108] The equipment used in the above method includes: a navigation dental handpiece, an optical tracking probe and a drill registration block.

[0109] like Figure 1 As shown, the navigation dental handpiece is fixedly connected to an optical reference array; a coordinate system F is established on the dental handpiece reference array based on the center of the reflective ball attached to it. handpiece ;

[0110] A coordinate system F is established at the dental handpiece drill bit drill The origin of the coordinate system is the tip of the drill bit, the z-axis is parallel to the drill bit axis and faces the direction of the drill bit's movement, and the x-axis and y-axis have no special provisions;

[0111] Solve for F handpiece to F drill The transformation relationship is the core purpose of drill bit registration, and the transformation matrix is recorded as T handPieceToDrill ;

[0112] Using T handPieceToDrill The positioning camera only needs to detect the pose of the dental mobile phone reference array coordinate system in the positioning camera coordinate system, and can further calculate the position of the drill tip and the axial direction of the drill in the positioning camera coordinate system.

[0113] like Figure 2 As shown, an optical tracking probe with three or four reflective spheres forms a tracking array. The probe coordinate system has its origin at the probe tip, and the coordinate axis orientation is not specified. The probe is pre-calibrated by shaking the pen to fit the sphere center, ensuring that the origin of the coordinate system is completely aligned with the tip.

[0114] like Figure 3 As shown, the drill bit alignment block is provided with an optical reference array, which is fixedly connected to the main body of the alignment block; the main body of the alignment block is provided with three optical probe groove points that are not in the same straight line; the main body of the alignment block is provided with a through hole suitable for inserting a standard drill bit; the main body of the alignment block is a one-piece metal molded part, so the error between its physical shape and the design value is negligible; the method of using the alignment block can be found in the subsequent detailed alignment implementation plan.

[0115] In the present invention, step S2 is the only step in the entire registration process that involves the difference between the actual required model drill bit and the standard drill bit, because only the axial direction of the drill bit and the position of the drill tip need to be paid attention to, and the axial direction of the standard drill bit and the actual drill bit are the same, and the difference in the tip position of the two is due to the difference in their lengths. Therefore, the drill bit coordinate system of the standard drill bit and the actual drill bit (constructed in the same way as step S2) only has the origin offset in the z-axis direction, while the coordinate axis direction is the same. In summary, the conversion matrix from the actual drill bit coordinate system to the registration block verification point coordinate system, compared with the conversion matrix from the standard drill bit coordinate system to the registration block verification point coordinate system, only needs to fill in the item L1 in the dotted black box below with the length of the actual drill bit. When the actual required drill bit length changes, it is only necessary to change the value of L1 again to the actual length of the drill bit, without re-collecting the design coordinate value of the registration block verification point and recalculating the entire matrix, thereby reducing the calculation of the conversion matrix T drillTipToCheckPoints complexity.

[0116]

[0117] The dental handpiece drill registration method fully considers and solves the problem that the geometric relative relationship between the registration block body and the accompanying reference array deviates from the design value.

[0118] On the one hand, the main body of the registration block is a metal integral molding. The error between the relative position relationship between the verification point and the standard drill bit inserted into the through hole and the design value is negligible. Therefore, the conversion relationship between the verification point coordinate system and the drill bit tip coordinate system obtained from the engineering design value can be directly applied to the actual object.

[0119] On the other hand, this method uses a probe to obtain the coordinate value of the verification point in the reference array coordinate system of the registration block, thereby establishing a transformation relationship between the verification point coordinate system and the reference array coordinate system. This transformation relationship is captured and calculated by the positioning system, so it is more reliable than the design value.

[0120] In summary, this registration method transfers the design values required for actual calculations to the parts where hardware processing can guarantee accuracy by setting verification points on the registration block. For the parts where hardware processing cannot guarantee accuracy, the geometric relationship is corrected through actual measurement, thereby greatly reducing the possibility of errors caused by relying entirely on hardware processing accuracy.

[0121] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A registration method for a navigation-type dental handpiece drill, characterized by: The steps include: S1. Determine the required drill bit model, the drill bit length is L1, and the standard drill bit length suitable for the registration block is L2; S2, calculating the conversion relationship between the registration block verification point coordinate system and the drill tip coordinate system; Import the standard drill bit model and the registration block 3D model into the engineering drawing software and combine them in a design. Insert the standard drill bit tip into the bottom of the registration block through-hole. Establish a 3D orthogonal coordinate system on the standard drill bit, with its origin at the drill bit tip. The z-axis is the drill bit axis and points in the direction of the drill bit's advance. The direction of the y-axis can be arbitrarily specified. The direction of the x-axis is determined by the cross product of the z-axis direction vector and the y-axis direction vector. In the coordinate system set in the previous step, use engineering drawing software to obtain the coordinates of the three verification points on the registration block corresponding to the required positions, which are recorded as q1, q2, and q3 respectively, where: ， ， ； The difference between the actual drill bit length and the standard drill bit length on the registration block is used to compensate for the above verification point coordinates to obtain a new set of point coordinates c1, c2, c3 as follows; ， ； Using the coordinate values of the three points above, calculate the following three vectors, ； The values of the three vectors are recorded as follows: ， ， ； The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the verification points of the registration block in the drill tip coordinate system; Use the above three vectors and the coordinates of point c1 to form a 4X4 matrix T drillToCheckPoints as follows: ； Matrix T drillTipToCheckPoints This is the transformation matrix from the actual drill tip coordinate system to the verification point coordinate system. By finding its inverse matrix, we can get the transformation matrix T from the verification point coordinate system to the drill tip coordinate system. checkPointsToDrill ; S3, calculating the conversion relationship between the registration block reference array coordinate system and the registration block verification point coordinate system; S4, calculating the transformation relationship between the dental handpiece reference array coordinate system and the registration block reference array coordinate system; S5. Calculate the transformation relationship between the dental handpiece reference array coordinate system and the drill tip coordinate system.

2. A navigation-type dental handpiece drill registration method according to claim 1, characterized in that: The specific content of step S3 is as follows: S31, collecting and calculating the coordinate values of three verification points on the registration block in the registration block reference array coordinate system; S32. Calculate the calculated coordinate values as unit direction vectors of the three coordinate axes of the coordinate system formed by the registration block verification points in the registration block reference array coordinate system; S33. Use the three vectors of S32 and the coordinate values of S31 to establish a 4X4 matrix, which is the transformation matrix from the registration block reference array coordinate system to the registration block verification point coordinate system.

3. The registration method for a navigation-type dental handpiece drill according to claim 1, characterized in that: In step S4, the dental handpiece, the standard drill, and the registration block are combined so that the registration block reference array and the dental handpiece reference array are simultaneously visible under the positioning camera, and the transformation matrix from the dental handpiece reference array coordinate system to the registration block reference array coordinate system is calculated.

4. The registration method for a navigation-type dental handpiece drill according to claim 1, characterized in that: In step S5, according to the iterative principle of coordinate system conversion, a conversion matrix from the dental handpiece reference array coordinate system to the drill tip coordinate system is obtained based on the matrix operations of steps S2-S4.

5. The navigation-type dental handpiece drill registration method according to claim 1, characterized in that: In step S3, the probe tip is placed at the registration block verification point i, i=1, 2, 3, and the 4X4 transformation matrix from the optical positioning camera coordinate system to the probe coordinate system and the registration block reference array coordinate system is collected, which are T cameraToProbe_i With T cameraToCalibrator_i ; Then the homogeneous coordinate value q of the verification point i in the registration block reference array coordinate system can be obtained by the following coordinate system transformation: i ', ; Repeat the above steps to obtain the homogeneous coordinate values of all three verification points in the registration block reference array coordinate system, which are q1', q2', q3', and their corresponding three-dimensional space coordinate values are c1', c2', c3' respectively; Use the coordinate values calculated above to calculate the following three unit vectors: ； The above three vectors are written as follows: ， ， ； The actual meaning of these three vectors is the unit direction vectors of the three coordinate axes of the coordinate system formed by the registration block verification points in the registration block reference array coordinate system; Use the above three vectors and the coordinate values of c1' [x1', y1', z1'] to create a 4X4 matrix T calibratorToCheckPoints , this matrix is the transformation matrix from the registration block reference array coordinate system to the registration block verification point coordinate system, 。 6. The registration method for a navigation-type dental handpiece drill according to claim 5, characterized in that: In step S4, the dental handpiece, the standard drill, and the registration block are combined so that the registration block reference array and the dental handpiece reference array are visible at the same time under the positioning camera, and the conversion matrices from the positioning camera coordinate system to the dental handpiece reference array coordinate system and the registration block reference array coordinate system are recorded as T cameraToHandPiece With T cameraTocalibrator ; Transformation matrix T from the dental handpiece reference array coordinate system to the registration block reference array coordinate system handPieceToCalibrator The calculation is as follows: 。 7. A navigation-type dental handpiece drill registration method according to claim 6, characterized in that: In step S5, the conversion matrix T from the dental handpiece reference array coordinate system to the drill tip coordinate system is handPieceToDrill The matrix operations through steps S2-S4 are as follows: 。

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