WO2022206417A1

WO2022206417A1 - Object space calibration positioning method

Info

Publication number: WO2022206417A1
Application number: PCT/CN2022/081521
Authority: WO
Inventors: 孙非; 朱奕; 郭晓杰; 崔芙粒; 单莹
Original assignee: 上海复拓知达医疗科技有限公司
Priority date: 2021-04-01
Filing date: 2022-03-17
Publication date: 2022-10-06
Also published as: CN113509263A

Abstract

An object space calibration positioning method, comprising: capturing a positioning apparatus image in a space, and identifying positioning apparatus identification characteristics in the positioning apparatus image to obtain spatial position information of a positioning apparatus (S1); when an object to be positioned is located at a specific position, capturing image information of the object in the space, and identifying identification characteristics of the object in an image of the object, so as to obtain spatial position information of the object (S2); and correcting the spatial position information of the object according to the spatial position information of the positioning apparatus and the specific position so as to obtain final spatial position information of an apparatus to be positioned (S3). According to the method, for objects in a specific scene, image acquisition and mutual position correction may be carried out on two different objects by means of making the two objects reach a specific angle and position relationship, so that the optical positioning precision of a single party or two parties is improved, and a user may be helped to carry out accurate and complete operations.

Description

A method of object space calibration and positioning

technical field

The invention relates to the technical field of image processing, in particular to a method for calibrating and positioning objects in space.

Background technique

Augmented reality technology usually captures images of real scenes through cameras. It needs to analyze and process the captured images of real scenes, and superimpose and display additional information to users on the basis of real scenes, that is, augmentation of reality. The process of analyzing and processing images of real scenes often includes locating objects in the scene. Under certain specific requirements, the accuracy of object positioning in a scene is extremely high, and the accuracy of object positioning in a scene in the prior art cannot meet the requirements.

For example, when augmented reality technology is applied to surgical navigation scenarios, it is necessary to very accurately determine the positional relationship between medical devices, patients, and scenarios to ensure accurate navigation information is provided to users. For example, puncture navigation based on augmented reality technology can realize fast and accurate surgical navigation with the most simple, convenient, easy-to-learn and easy-to-use equipment. In the whole process, one of the cores of precise navigation: precise spatial positioning of surgical instruments based on visible light patterns, and registration of virtual organs and real human bodies, but before positioning, how to perform rapid positioning matching and correction is very important , In a specific operation, the positioning and calibration of the surgical instrument and the photographing device need to be performed first, in order to ensure the accuracy of the navigation position in the entire navigation process, and then to ensure the accuracy of the enhanced display in the later stage. For the positioning calibration of surgical instruments and photographing devices, it is necessary to rely on accurate spatial positioning of recognizable patterns on the object to be positioned. Due to the limitation of instrument design, the identifiable patterns of different sizes and shapes have different spatial positioning accuracy due to the inherent law of spatial distribution of their own pattern feature points or the characteristics of the production process. Positioning is very inconvenient.

SUMMARY OF THE INVENTION

In view of the above defects or deficiencies, the purpose of the present invention is to provide a method for calibrating and positioning objects in space.

For achieving the above purpose, the technical scheme of the present invention is:

An object space calibration and positioning method, comprising:

capturing an image of the positioning device in the space, and identifying the identification characteristics of the positioning device in the image of the positioning device to obtain spatial position information of the positioning device;

When the object to be positioned is at a specific position, the image information of the object to be positioned in space is captured, and the identification characteristics of the object to be positioned in the image of the object to be positioned are identified to obtain the spatial position information of the object to be positioned; Determine the relative position of the positioning device;

According to the spatial position information of the positioning device and the specific position, the spatial position information of the object to be positioned is corrected to obtain the final spatial position information of the to-be-positioned device.

The identification characteristics of the positioning device include at least the morphological characteristics of the positioning device body and/or the identification characteristics of the positioning device mark; the morphological characteristics of the positioning device body at least include the structure, shape or color of the positioning device body; the identification characteristics of the positioning device mark at least include The pattern, graphic or QR code set on the positioning device.

The identification characteristics of the object to be located include at least the morphological characteristics of the object to be located and/or the identification characteristics of the object to be located; the morphological characteristics of the object to be located include at least the structure, shape or color of the object to be located; The object mark identification features at least include patterns, graphics or two-dimensional codes set on the object to be positioned.

The spatial position information of the positioning device includes at least the spatial coordinates of the positioning device and/or the orientation of the positioning device; the spatial position information of the object to be positioned includes at least the spatial coordinates of the object to be positioned and/or the orientation of the object to be positioned.

The specific position is a position when the object to be positioned has a specific positional relationship with a preset point, line or surface on the positioning device, and the specific positional relationship includes coincidence or partial coincidence of points, lines or surfaces.

The correcting the spatial position information of the object to be positioned according to the spatial position information of the positioning device and the specific position includes:

Calculate the theoretical position information of the object to be positioned according to the spatial position information of the positioning device and the specific position; and correct the spatial position information of the object to be positioned according to the theoretical position information of the object to be positioned.

The calibrating the spatial position information of the object to be positioned includes: calibrating the x and y coordinates of the object to be positioned.

It also includes correcting the spatial position information of the positioning device according to the spatial position information of the object to be positioned and the specific position.

The correcting the spatial position information of the positioning device according to the spatial position information of the object to be positioned and the specific position includes:

Calculate the theoretical position information of the positioning device according to the spatial position information of the object to be positioned and the specific position; and correct the spatial position information of the positioning device according to the theoretical position information of the positioning device.

The calibrating the spatial position information of the positioning device includes: calibrating the z-coordinate of the positioning device.

The object to be positioned is a surgical instrument.

The object to be positioned is a puncture needle.

The positioning device includes: a support part, and a feature part and a limit part arranged on the support part;

Wherein, the feature part comprises a display board, the display board is connected with the support part, and the display board is provided with an optical feature for being photographed and identified;

The limiting portion is configured to limit the object to be positioned.

The feature portion further includes a connection mechanism through which the display panel is connected to the support portion.

The connecting mechanism includes a hinge mechanism, and the display board is rotatably mounted on the support portion through the hinge mechanism.

The optical features include one or any combination of specific graphics, structures, colors for optical identification.

The optical feature is a pattern attached or printed on the display board, and the pattern is a two-dimensional code.

The limiting portion is disposed on one side of the feature portion. When the object to be positioned is moved to a predetermined position, the limiting portion limits the object to be positioned and forms a specific spatial positional relationship with the object to be positioned.

The limiting portion is a detachable structure, and can be installed on one side of the feature portion or replaced.

The position-limiting portion is a columnar structure, a positioning groove is formed on the columnar structure, and a horizontal α angle opening is horizontally formed on the positioning groove.

A through hole or a blind hole for limiting the position of the object to be positioned is provided along the central axis of the cylindrical structure.

The display board is provided with a shielding member for shielding the optical feature.

Compared with the prior art, the beneficial effects of the present invention are:

The invention provides an object space calibration and positioning method, which can make two objects reach a specific angle and position relationship by using the identification characteristics of objects with different error characteristics in the same scene for objects in a specific scene. , and then through the spatial association of the two corresponding objects, the image acquisition and the mutual correction of the positions of the two different objects are performed to achieve the improvement of the optical positioning accuracy of one or both parties. The device and method can be applied in various occasions, such as surgery. The positioning of the medical device operation in the process, the application in the teaching simulation operation, and the use in the game activity process, etc., the accurate positioning and the augmented reality of the position can help the user to carry out the precise and complete operation.

Description of drawings

Fig. 1 is the flow chart of the positioning method of the present invention

Fig. 2 is the embodiment example diagram in the specific embodiment of the present invention;

3 is a schematic diagram 1 of a positioning device in the object space calibration positioning method of the present invention;

4 is a second schematic diagram of a positioning device in the object space calibration positioning method of the present invention;

Fig. 5 is the schematic diagram three of the positioning device of the object space calibration positioning method of the present invention;

FIG. 6 is a schematic diagram of the inter-calibration of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

In the precise operation scene, it is often necessary to obtain and accurately determine the actual position of the object and the position in the image. Under certain specific requirements, the accuracy of the object positioning in the scene is extremely high. For example, in the medical process, it is necessary to Only by very accurately determining the positional relationship between the medical device, the patient, and the scene can we ensure that accurate navigation information is provided to the user. Based on this requirement, the present invention provides an augmented reality method based on correcting the position of an object in space, which can be applied to an operation scene, an operation scene in a simulated teaching process, or a game process. position.

Taking a surgical implementation scenario as an example, the present invention provides the user with the positioning of the surgical instruments in the object. Among them, the user is the observer of the whole in vivo navigation process, and he is also the operator who probes the instrument into the body of the subject. Objects can be people or other animals that the user needs to operate on. The instrument can be any tool that can be penetrated into the body of the subject. The instrument may be, for example, a puncture needle, a biopsy needle, a radiofrequency or microwave ablation needle, an ultrasound probe, a rigid endoscope, an endoscopic oval forceps, an electric knife or a stapler and other medical instruments. Preferably, the positioning device is a fixture in a surgical scene; the object to be positioned is a medical instrument in a surgical scene.

As shown in FIG. 1 , the present invention provides a method for calibrating and positioning objects in space, including:

S1, capturing the positioning device image in the space, and identifying the positioning device identification characteristics in the positioning device image, to obtain the spatial position information of the positioning device;

In order to perform positioning and calibration of the object to be positioned, first obtain the specific spatial position information of a fixed object. The spatial position information at least includes the spatial coordinates of the positioning device and/or the orientation of the positioning device, and the specific spatial position information of the fixed positioning device can be carried out. position.

In this embodiment, the identifying characteristics of the positioning device include at least the morphological characteristics of the positioning device body and/or the identifying characteristics of the marking of the positioning device. The morphological characteristics of the positioning device body at least include the structure, shape or color of the positioning device body, but in the specific implementation process, it is not limited to this, and may also be other identifiable characteristics of the object. Exemplarily, the present invention can fix an object with a fixed shape. Before calibration, the structure and shape of the positioning device are identified. During the identification process, different display modes can be used to prompt the user whether the capture process and the identification process are successful. The positioning device is positioned and identified to obtain accurate spatial position information of the surgical positioning device.

In addition, in the present invention, the marking identification characteristic of the positioning device includes at least a pattern, graphic or two-dimensional code set on the positioning device. The patterns, graphics or two-dimensional codes can be set on the positioning device through the printing process, and the identifiable patterns have different spatial accuracy according to their own pattern rules and production characteristics. Make full use of the combination of recognizable patterns with different characteristics to achieve rapid spatial calibration of navigation instruments.

Exemplarily, in the present invention, a rectangular information board printed with a two-dimensional code can be used, the device for capturing the image of the positioning device is a device capable of image capturing, and the capturing angle is consistent with the user's viewing direction. When the user uses it, he or she can wear the camera on the body, such as the head. Optionally, the photographing device is a head-mounted optical camera. When the user uses it, no matter what posture the user adopts, the acquisition angle of the head-mounted optical camera can be well kept consistent with its viewing direction. The image of the positioning device is obtained by the photographing device, the identification characteristics of the marking of the positioning device are identified, and the morphological characteristics of the positioning device are obtained according to the identification characteristics of the positioning device, and the position of the positioning device in the xyz space coordinate system is obtained, wherein the z coordinate represents the shooting along the camera. The coordinates in the depth direction of , the x and y coordinates are the coordinates in the direction perpendicular to the z coordinate axis, and the current positioning device space coordinates are set to X1, Y1, Z1 for the positioning device.

S2. When the object to be positioned is at a specific position, capture the image information of the object to be positioned in space, and identify the identification characteristics of the object to be positioned in the image of the object to be positioned to obtain spatial position information of the object to be positioned; wherein, the specific position Determine the relative position with the positioning device;

In a specific surgical scenario, instruments need to be used for operation. In the present invention, the object to be positioned is a moving instrument, and the spatial position information of the object to be positioned includes the spatial coordinates of the object to be positioned and/or the orientation of the object to be positioned.

The identification characteristics of the object to be located include at least the morphological characteristics of the object to be located and/or the identification characteristics of the object to be located; the morphological characteristics of the object to be located include at least the structure, shape, or color of the object to be located; The identification feature of the bit object mark at least includes the pattern, figure or two-dimensional code set on the object to be positioned.

A two-dimensional code is a black and white plane figure distributed on a plane, the points on it are very easy to identify, and the positioning of the two-dimensional code can be realized by identifying at least three points among them. Because the two-dimensional code is fixed to the object or device, the positioning of the object or device to which the two-dimensional code is fixed can be realized.

Optionally, the marking recognition characteristic of the object to be located may also be other plane figures such as a checkerboard. Using QR code or checkerboard as an identification makes positioning objects or instruments more accurate and fast. Thereby, fast moving instruments can be navigated more precisely.

Optionally, the logo fixed on the surface of the instrument can also be a three-dimensional figure. For example, during the design and production process of the instrument, the logo can be the handle of the instrument, or a structure fixed on the side of the handle. Although the calculation time required for recognition is longer than that of plane graphics, the spatial positioning accuracy of stationary or slow-moving objects is relatively high.

Exemplarily, the object to be positioned in the present invention is a puncture needle in an operation, the end of the puncture needle is provided with an identification structure, and a two-dimensional code is printed.

When the object to be positioned is at a specific position, capturing an image of the object to be positioned in space of the object to be positioned specifically includes:

The positioning device is fixed in the space, and the object to be positioned is a moving object. When the object to be positioned moves to a specific position, an image of the object to be positioned in the space is captured. In this process, the specific position can be set so that the object to be positioned moves to coincide with the preset position of the positioning device. Or, according to the needs of the actual operation, when a certain position of the object to be positioned reaches a fixed position or completes a prescribed action, the positioning is carried out.

Specifically, the positioning device is fixedly arranged in the space, and the object to be positioned is a moving object. When the object to be positioned moves to a specific position, the object to be positioned is identified according to the identification characteristics of the object to be positioned, and the object to be positioned is obtained. The orientation of the bit object, and the current spatial coordinates of the object to be positioned are set for the object to be positioned, denoted as X2, Y2, and Z2. The relative position of the specific position and the positioning device is determined, and the specific position is the position when the object to be positioned has a specific positional relationship with a preset associated point, line, or surface on the positioning device , the specific positional relationship includes point, line or plane coincidence, and partial coincidence.

Exemplarily, as shown in Figure 2, the information board is used as the positioning device, and the puncture needle is the object to be positioned. positioned and aligned with each other. With reference to Embodiment 1 of the present invention, referring to Figures 3, 4, and 5, when the needle tip or needle body of the puncture needle is below the limit of the limiting portion 3 of the positioning device, that is, the needle tip is located at the positioning groove 31, or When the needle body is placed in the through hole or blind hole of the limiting portion, the positions of the puncture needle and the positioning device are positioned and aligned with each other.

S3. Correct the spatial position information of the object to be positioned according to the spatial position information of the positioning device and the specific position to obtain final spatial position information of the to-be-positioned device.

Preferably, two objects can be relatively corrected according to the actual situation, such as calculating the theoretical position information of the object to be positioned according to the spatial position information of the positioning device and the specific position; according to the theoretical position information of the object to be positioned, the space of the object to be positioned is calculated. position information for correction;

And/or calculate the theoretical position information of the positioning device according to the spatial position information and the specific position of the object to be positioned; correct the spatial position information of the positioning device according to the theoretical position information of the positioning device.

For example, as shown in Figure 2, the position information of the object in the space is calculated according to the image of the positioning device taken. At this time, the coordinates of point A are the characteristics of the positioning device captured by the camera (mainly the pattern features on the panel). ) calculated;

When the doctor holds the object to be positioned (puncture needle) and places point B of the needle tip at point A of the positioning device, at this time, the coordinates of point B of the needle tip of the puncture needle can be calculated according to the easily identifiable features set at the end of the puncture needle;

It is known that the two points A and B are coincident at this time, but the coordinates of the two points A and B obtained through step 1 and step 2 respectively are not necessarily the same. According to the spatial geometric characteristics of the two objects, the accuracy of the x and y coordinates of point A on the positioning device is high but the accuracy of the Z coordinate is relatively low, while the accuracy of the z coordinate of point B on the object to be located (puncture needle) is accurate It is relatively high, so the X2 and Y2 coordinates of the object to be positioned are corrected according to the X1 and Y1 coordinates of the positioning device, and the Z1 coordinate of the positioning device is corrected with the Z2 coordinate of the object to be positioned. Then the corresponding positions of the two structures in the database are adjusted as follows:

X2=X1; Y2=Y1; Z1=Z2;

The specific mutual calibration method consists of the following two parts, and the schematic diagram of mutual calibration is shown in Figure 6:

(1) Determine the coordinates of the needle tip point in the needle identification object coordinate system in advance manually.

(2) Process a hole on the identification plate so that it is parallel to the z-axis and perpendicular to the Oxy plane, and a point at the bottom of the hole is the calibration point. By designing the positioning device phantom, the coordinates p _Q of the calibration point in the positioning device coordinate system should be determined. When calibrating, insert the identification needle into the hole, and ensure that the needle point is located at the calibration point. According to the feature that the coordinates of the calibration point in the camera coordinate system remain unchanged, through the coordinate transformation, the following relationship can be known. At this time, the calibration point has the following two expressions in the needle tip coordinate system: T _C←Q p _Q =T _{C← N} p _N

At this time, the calibration point has the following two expressions in the needle tip coordinate system:

(a) The coordinate system of the object to be positioned, identified by the needle identifier and directly determined by manual point calibration:

(b) The coordinate system of the object to be located identified by the positioning device (recognition board) and obtained by coordinate transformation:

The above two coordinates are the representation of the calibration point in the needle identifier coordinate system. Assuming that the expression (a) is more accurate for the z coordinate component, and the expression (b) is more accurate for the x and y coordinate components, the result after mutual calibration is

Among them, C: camera coordinate system

Q: Positioning device coordinate system

N: puncture needle coordinate system

T _B←A : Represents the coordinate transformation matrix from coordinate system A to coordinate system B

p _A : point p in coordinate system A

v _A : vector v in coordinate system A

In the method of point calibration of the positioning device, the camera recognizes the positioning device and the puncture needle, and then T _C←Q and T _C←N can be obtained. Place the puncture needle tip on a fixed point p on the identification plate. From the processing model of the identification plate, the coordinates of the fixed point in the identification plate coordinate system, that is, p _Q , can be determined. According to the characteristic that the coordinates of this point in the camera coordinate system are unchanged, the following coordinate relationship can be obtained:

T _C←Q p _Q =T _C←N p _N

Therefore, the coordinates of the point in the puncture needle coordinate system are obtained, that is,

In addition, the present invention can also be calibrated by using direction calibration, which specifically includes:

The mutual calibration method consists of the following two parts, and the schematic diagram of the mutual calibration is shown in Figure 6:

(1) The direction vector v _N of the puncture needle in the needle identification object coordinate system is manually determined in advance.

(2) Process a hole on the positioning device so that it is parallel to the z-axis and perpendicular to the Oxy plane. A point at the bottom of the hole is the Calibration Point, and the direction of the hole is called the Calibration Direction. By designing the positioning device model, it is necessary to determine the direction vector v _Q of the hole direction in the positioning device coordinate system. When calibrating, insert the identification needle into the hole, and ensure that the needle point is located at the calibration point. According to the characteristic that the direction of the calibration direction remains unchanged in the camera coordinate system, through the coordinate transformation, the following relationship can be known:

T _C←Q v _Q =T _C←N v _N

At this time, the calibration direction has two expressions in the needle tip coordinate system:

The direction vector of the object to be positioned identified by the needle identifier and directly determined by the manual direction calibration:

(b) The direction vector of the object to be positioned identified by the identification board and obtained by coordinate transformation:

The above two vectors are the representation of the calibration direction in the coordinate system of the needle identifier. Assuming that the expression (a) is more accurate for the w coordinate component, and the expression (b) is more accurate for the u and v coordinate components, the result after mutual calibration is

The orientation calibration method of the positioning device is shown in Figure 7. When the camera recognizes the positioning plate and the puncture needle, T _C←Q and T _C←N can be obtained. Insert the tip of the puncture needle into a fixed hole on the identification plate. From the processing model of the identification plate, the direction vector of the hole in the identification plate coordinate system, ie v _Q , can be determined. Since the direction vector does not change in the camera coordinate system, the following conversion relationship can be obtained

T _C←Q v _Q =T _C←N v _N

Therefore, the representation of the direction vector in the puncture needle coordinate system is obtained, that is,

After the direction calibration, when the camera recognizes the needle identification object in real time, the needle tip direction can be calculated in real time according to the following formula:

v _C =T _C←N v _N

Among them, T _C←N is given by the camera after identifying the needle identification object, and v _N is the calibration result calculated by using mutual calibration or orientation calibration of the positioning device.

In one embodiment, the camera captures the video of the object and the instrument in real time. The user can watch the video, in which not only the surface parts of the object and the instrument captured by the camera are displayed, but also the internal organs of the object, the lesions and the parts of the instrument inside the object that are not actually visible in three dimensions at corresponding positions. In other words, in the video, the actually invisible internal organs, lesions, and parts of the instrument located inside the body are aligned with the human body and the actual instrument, thereby guiding the user in a virtual scene image similar to the real environment and the position of operating the instrument.

In the present invention, the positioning device and the object to be positioned can be identified, and the optical identification objects with different error characteristics can be used in the same scene. For the identification objects with different error characteristics, the correlation of the coordinates of different identification patterns in the same space is determined by matching the geometric structure of the instruments with spatial correlation. By using the known trusted values, the calibration of the spatial recognition positions of different recognition patterns is realized.

Example 2

As shown in FIG. 3 , the present invention further provides a positioning device, comprising: a support portion 1 , a feature portion 2 and a limit portion 3 disposed on the support portion 1 ;

Wherein, the feature part 2 includes a display board 22, the display board 22 is connected with the support part 1, and the display board 22 is provided with an optical feature 221 for being photographed and identified;

The limiting portion 3 is disposed on one side of the feature 2, and is used to limit the position of the object to be positioned.

Preferably, in the present invention, the feature portion 2 further includes a connecting mechanism 21 , and the display board 22 is connected to the supporting portion 1 through the connecting mechanism 21 . The display board 22 can be reversibly installed on the support part 1 through the connecting mechanism 21. The connecting mechanism 21 can be set as a hinge structure, which can be flipped and connected with the support part 1 or can be hingedly connected through a hinge. When the angle of the display board 22 needs to be adjusted At the time of rotation of the connecting mechanism 21, the flip adjustment can be realized to achieve the best angle suitable for shooting.

Further, as shown in FIG. 4 , the display board 22 is provided with a shielding member 222 for shielding the optical features. The shutter 222 can be a baffle that opens and closes up and down and opens and closes left and right, and can be opened when the planar identification object is recognized, and can be blocked when the needle-shaped identification object is identified.

The optical features 221 include one or any combination of specific graphics, structures, colors for being identified. The pattern, figure, structure or two-dimensional code can be set on the positioning device through the printing process, and the identifiable pattern has different spatial accuracy according to its own pattern rules and production characteristics. Take advantage of the combination of different characteristic identifiable patterns for fast spatial calibration. Exemplarily, in the present invention, the optical feature is a pattern attached or printed on the display board 22, and the pattern is a two-dimensional code. The photographing device recognizes the two-dimensional code, and calculates the position space information of the object according to the position information of many feature points on the two-dimensional code pattern. The spatial position information includes one or more of the spatial coordinates of the positioning device and the placement form, and can specifically locate the spatial position of the fixed positioning device.

In the present invention, the limiting portion 3 is a detachable structure, which can be installed on one side of the characteristic portion or replaced. For example, in order to meet different sterilization/disinfection requirements, the limiting portion 3 can be separated from the overall structure. This way the overall structure can be reused and only needs to be sterilized. The limiting portion 3 that will contact the sterile surgical instrument may be a sterilized disposable component. At the site of use, the structure 3 is combined with the overall structure for use, which improves the safety of surgical use. In addition, in the present invention, the limiting portion is provided on one side of the feature portion, and when the object to be positioned moves to a predetermined position, the limiting portion limits the object to be positioned and forms a specific spatial positional relationship with the object to be positioned. For application scenarios during surgery, the photographing device is a head-mounted optical camera. When the user uses it, no matter what posture the user adopts, the acquisition angle of the head-mounted optical camera can be well kept consistent with its viewing direction.

The object to be positioned is a surgical instrument, and the logo fixed on the surface of the instrument can also be a three-dimensional figure. a structure. Using three-dimensional graphics for spatial positioning, although the calculation time required for recognition is longer than that of planar graphics, the spatial positioning accuracy of stationary or slow-moving objects is higher. The instrument may be, for example, a puncture needle, a biopsy needle, a radiofrequency or microwave ablation needle, an ultrasound probe, a rigid endoscope, an endoscopic oval forceps, an electric knife or a stapler and other medical instruments. As shown in Figure 2, taking the puncture needle as an example, the needle tip of the puncture needle moves. When the needle tip of the puncture needle moves to the limit portion, the needle tip and the positioning device form a specific spatial positional relationship to facilitate positioning. The position information of the position is used to correct the position information of the needle tip.

Exemplarily, as shown in FIG. 5 , the limiting portion 3 is a cylindrical structure, and a positioning groove 31 for positioning is provided at the top of the cylindrical structure, and a horizontal α angle opening is horizontally opened on the positioning groove 31 . When the needle body is held, the positioning groove in the needle tip is opened, this structure can ensure that the needle tip will not slip out of the plane when the needle body is moved from the vertical to the horizontal angle of 90 degrees and the horizontal α angle range. In another embodiment, a through hole or a blind hole is provided along the central axis of the cylindrical structure, so that the through hole or blind hole is adapted to accommodate the insertion and placement of the puncture needle, so as to realize the restriction of the straight line where the needle body is located. bit.

For those skilled in the art, it is obvious that the above-mentioned specific examples are only the preferred solutions of the present invention. Therefore, the improvements and changes that those skilled in the art may make to certain parts of the present invention still embody the present invention. However, what is achieved is still the purpose of the present invention, which belongs to the scope of protection of the present invention.

Claims

A method for calibrating and positioning objects in space, comprising:

capturing an image of the positioning device in the space, and identifying the identification characteristics of the positioning device in the image of the positioning device to obtain spatial position information of the positioning device;

When the object to be positioned is at a specific position, the image information of the object to be positioned in space is captured, and the identification characteristics of the object to be positioned in the image of the object to be positioned are identified to obtain the spatial position information of the object to be positioned; Determine the relative position of the positioning device;

According to the spatial position information of the positioning device and the specific position, the spatial position information of the object to be positioned is corrected to obtain the final spatial position information of the to-be-positioned device.
The method for calibrating and positioning objects in space according to claim 1, wherein the identification characteristics of the positioning device include at least the morphological characteristics of the positioning device and/or the identification characteristics of the marking of the positioning device; the morphological characteristics of the positioning device at least include the positioning device The structure, shape or color of the body; the identification characteristics of the positioning device mark at least include patterns, graphics or two-dimensional codes set on the positioning device.
The object space calibration positioning method according to claim 1, wherein the identification characteristics of the object to be located include at least the morphological characteristics of the object to be located and/or the identification characteristics of the mark of the object to be located; the morphological characteristics of the object to be located It includes at least the structure, shape or color of the object body to be located; the mark identification characteristics of the object to be located at least include patterns, graphics or two-dimensional codes set on the object to be located.
The object space calibration positioning method according to claim 1, wherein the spatial position information of the positioning device includes at least the spatial coordinates of the positioning device and/or the orientation of the positioning device; the spatial position information of the object to be positioned includes at least the object to be positioned The spatial coordinates and/or the orientation of the object to be positioned.
The object space calibration positioning method according to claim 1, wherein the specific position is a position when the object to be positioned has a specific positional relationship with a preset point, line or surface on the positioning device, and the The specific positional relationship includes point, line or plane coincidence and partial coincidence.
The object space calibration and positioning method according to claim 1 or 5, wherein the correcting the space position information of the object to be positioned according to the space position information of the positioning device and the specific position comprises:

Calculate the theoretical position information of the object to be positioned according to the spatial position information of the positioning device and the specific position; and correct the spatial position information of the object to be positioned according to the theoretical position information of the object to be positioned.
The method for calibrating and positioning objects in space according to claim 6, wherein the calibrating the spatial position information of the object to be positioned comprises: calibrating the x and y coordinates of the object to be positioned.
The object space calibration and positioning method according to claim 1 or 5, further comprising correcting the space position information of the positioning device according to the space position information of the object to be positioned and the specific position.
The object space calibration and positioning method according to claim 8, wherein the correcting the space position information of the positioning device according to the space position information of the object to be positioned and the specific position comprises:

Calculate the theoretical position information of the positioning device according to the spatial position information of the object to be positioned and the specific position; and correct the spatial position information of the positioning device according to the theoretical position information of the positioning device.
The object space calibration positioning method according to claim 9, wherein the calibrating the spatial position information of the positioning device comprises: calibrating the z-coordinate of the positioning device.
The object space calibration positioning method according to any one of claims 1-10, wherein the object to be positioned is a surgical instrument.
The object space calibration positioning method according to any one of claims 1-10, wherein the object to be positioned is a puncture needle.
The object space calibration positioning method according to any one of claims 1-10, wherein the positioning device comprises: a support part, and a feature part and a limit part provided on the support part; wherein , the feature part includes a display board, the display board is connected with the support part, and the display board is provided with an optical feature for being photographed and recognized; the limiting part is set to limit the object to be positioned bit.