CN202982047U - Optical calibration device of ultrasonic probe - Google Patents

Abstract

The utility model discloses an ultrasonic probe calibration device which is provided with the following components: optical positioning equipment which senses position of an ultrasonic probe and is provided with a camera I, a camera II and a horizontal mount, wherein the horizontal mount is provided with a slideway, the camera I and the camera II are movably connected with the horizontal mount through bolts which are matched with the slideway; and a stereo calibration template which is equipped in front of the optical positioning equipment and comprises a rectangular frame I and a rectangular frame II that are equipped relatively, wherein the rectangular frame I and the rectangular frame II are completely same. A plurality of calibration straight lines are connected with the top points of the two rectangular frames. The calibration template can be expanded from two dimensions to three dimensions, thus reinforcing restriction conditions in the calibration calculation process and obtaining a more accurate calibration effect. The optical positioning equipment is adopted for acquiring gesture of the ultrasonic probe, and the effect by a power supply line can be omitted, and therefore a wider calibration range is obtained.

Description

The optical calibrating device of ultrasound probe

Technical field

This utility model relates to a kind of optical calibrating device, relates in particular to a kind of optical calibrating device of ultrasound probe.

Background technology

Existing Manual three-dimensional ultrasonoscopy scaling method based on magnetic locator: fix an electromagnetic receiver on ultrasonic probe, utilize the electromagnetic location device to obtain this receptor with respect to the spatial information of emitter, set up ultrasonoscopy coordinate system I, receptor coordinate system R, transmitter coordinate system T, four coordinate systems of template coordinate system C, calibration formula be P (C)= ^CT _T ^TTR ^RT _IP (I), wherein ^TT _RRepresent electromagnetic receiver to the transformation matrix of emitter, the template coordinate P (C) of the ultrasonoscopy coordinate P (I) of known spatial point, correspondence and each measurement ^TT _R, utilize method of least square to obtain spatial mappings relation between receptor and ultrasonoscopy ^CT _TWith ^RT _I

There is problem in Manual three-dimensional ultrasonoscopy scaling method based on magnetic locator:

(1) the N shape calibrating template of design is the calibrating template of two dimension in the space, and the calibrating template coordinate that obtains lacks the spatial information of the third dimension;

(2) calibration formula P (C)= ^CT _T* ^TT _R* ^RT _I* the unknown quantity in P (I) has ^CT _TWith ^RT _ITwo, calculate comparatively complexity, need to gather several uncalibrated images;

(3) acquiescence replaces the ultrasonic probe coordinate system with the receptor coordinate system, may have mapping fault;

(4) need to be on ultrasonic probe the Motionless electromagnetic receptor, active receiving restriction, and need to be equipped with the electromagnetic location device of different size for the ultrasonic probe of different model makes equipment complicated, adaptability is not high;

(5) there is electromagnetic compatibility problem in electromagnetic location equipment in surgical navigational is used.

The utility model content

This utility model is for the proposition of above problem, and a kind of ultrasound probe caliberating device of development has:

The optical positioning device of perception ultrasound probe position: this optical positioning device has camera I, camera II and horizontal fixed mount, described horizontal fixed mount has slideway, and described camera I and camera II are flexibly connected by bolt and the horizontal fixed mount that matches with described slideway;

Stereo calibration template: be arranged on the place ahead of described optical positioning device, comprise: two rectangular frame I that are oppositely arranged and rectangular frame II, described two rectangular frame I and rectangular frame II are in full accord; Demarcate the summit that straight line connects described two rectangular shaped rim for many; And, ultrasound probe to be calibrated, the top of this ultrasound probe is provided with at least 3 identification points.Camera I and camera II are identical.

Owing to having adopted technique scheme, the optical calibrating method of the ultrasound probe that this utility model provides, have can be with the calibrating template coordinate by two-dimensional expansion to three-dimensional, can strengthen like this constraints in the calibrated and calculated process, make calibration result more accurate; Adopt optical positioning device to obtain the ultrasonic probe attitude, need not to consider the impact of power line, make to demarcate wider; There is not the problem of electromagnetic compatibility in optical positioning device in the surgical navigational environment.

Description of drawings

Technical scheme for clearer explanation embodiment of the present utility model or prior art, the below will do one to the accompanying drawing of required use in embodiment or description of the Prior Art and introduce simply, apparently, accompanying drawing in the following describes is only embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is the setting schematic diagram of stereo calibration template of the present utility model and coordinate system thereof;

Fig. 2 is signature identification point and the Coordinate Setting thereof on ultrasonic probe of the present utility model;

Fig. 3 is volume template work schematic diagram of the present utility model;

Fig. 4 is the coordinate Calculation schematic diagram of spatial point E of the present utility model in stereo calibration template coordinate system;

Fig. 5 is schematic diagram of the present utility model.

In figure: 1. optical positioning device, 101. camera I, 102. camera II, 103. horizontal fixed mounts, 201. rectangular frame I, 202. rectangular frame II, 203. demarcate straight line.

The specific embodiment

For the purpose, technical scheme and the advantage that make embodiment of the present utility model clearer, below in conjunction with the accompanying drawing in this utility model embodiment, technical scheme in this utility model embodiment is known complete description, obviously, described embodiment is a part of embodiment of the present utility model, rather than whole embodiment.Based on the embodiment in this utility model, those of ordinary skills belong to protection domain of the present utility model not making all other embodiment that obtain under the creative work prerequisite.

As shown in Fig. 1-5: a kind of ultrasound probe caliberating device has:

The optical positioning device 1 of perception ultrasound probe position: this optical positioning device has two identical camera I101, camera II102 and horizontal fixed mount 103, described horizontal fixed mount 103 have a slideway, described camera I101 and camera II102 are flexibly connected by bolt and the horizontal fixed mount 103 that matches with described slideway;

Stereo calibration template 2: be arranged on the place ahead of described optical positioning device 1, comprise: two rectangular frame I201 that are oppositely arranged and rectangular frame II202, described two rectangular frame I201 and rectangular frame II202 are in full accord; Demarcate the summit that straight line 203 connects described two rectangular shaped rim for many;

Described camera I101 and camera II102 are identical.

Can adopt in use following mode that ultrasound probe is demarcated, as Figure 1-Figure 4:

Choose two pieces of identical cameras that optical axis is parallel to each other, as optical positioning device.Two pieces of identical cameras, the camera lens of outfit same model, preferred, be fixed on horizontally disposed fixed mount.The photocentre distance of two pieces of cameras is the parallax range scalable.With left camera, camera I101 photocentre is the axle center, and the base direction of camera I101 and camera II102 is the X-axis line, sets up rectangular coordinate system, as optical positioning device coordinate system C.

stereo calibration template and Coordinate Setting thereof: select two on all four rectangular frames or rectangular panel, preferably, select two on all four rectangular frames of size in the present embodiment, to connect framework is vertically and is oppositely arranged, making wherein, the orthographic projection of rectangular frame A on another rectangular frame B overlaps fully with rectangular frame B, also can be expressed as two relative faces in space virtual cuboid of described two rectangular frame Special compositions, demarcate straight line for selected many, the summit that connects described two rectangular panel, preferably, method of attachment such as Fig. 1 show: with the O point as zero, set up rectangular coordinate system in space, as stereo calibration template coordinate system M.It is a kind of that the feature identification point of arranging on ultrasonic probe is not limited to that Fig. 1 shows, can provide spatial point information to get final product, and can be Visible Light Characteristics point and infrared LED characteristic point etc.Characteristic point quantity is at least 3, and the arrangement of characteristic point is not limited to illustrate a kind of, can set up rectangular coordinate system and get final product.

Signature identification point on ultrasonic probe and Coordinate Setting thereof show as Fig. 2, choose the ultrasound probe of a 2D, choose at least three characteristic points on this ultrasound probe, set up rectangular coordinate system in space, as ultrasound probe coordinate system T.

Use ultrasound probe scanning calibrating template: in the time of work, described calibrating template is put into the approximately water of 50 ℃ of water temperature, hand-held 2D ultrasonic probe scans this template, and the plane of scanning motion and calibration line intersect at D, E, F, G, H, M, seven spatial point of N.

Simultaneously, set ultrasonoscopy coordinate system I, utilize the ultrasonoscopy treatment technology to obtain the coordinate of described each spatial point in ultrasonography, note is P (I)=(u _i, v _i, 0,1) ^T

The D that obtains, E, F, G, H, M, seven spatial point of N, the coordinate of each point in volume template coordinate system M is made as P (M)=(x _i, y _i, z _i, 1) ^T, as shown in Figure 4, EFC is similar to triangle as example take coplanar 3 of D, E, F, the E point is arranged at stereo calibration according to the principle of similar triangles

Coordinate in template is (x _E, y _E, z _E, 1) ^T,

Wherein $x_E=\mathrm{OC}\·\frac{\mathrm{DE}}{\mathrm{DF}},$ $y_E=\mathrm{OA}\·\frac{\mathrm{DE}}{\mathrm{DF}},$ z _E＝0，

The geometry information of known stereo calibration template OA, OB, OC, DE, DF can measure in ultrasonoscopy, so just can obtain an E in stereo calibration template coordinate system coordinate, every width uncalibrated image can obtain the coordinate as 3 of E, G, M.

If the corresponding point image coordinate of spatial point in ultrasonoscopy is P (I)=(u _i, v _i, 0,1) ^T, the technology that this image coordinate can utilize ultrasonoscopy to process is obtained.

Because the stereo calibration template is static with respect to optical positioning device in calibration process, so transformation matrix ^MT _CConstant, only need record the transformation matrix that O, A, the coordinate of three spatial point of C in the optical positioning device coordinate system can be asked ^MT _C

In the ultrasonic uncalibrated image of each collection, utilize optical positioning device to obtain the coordinate of three characteristic points on ultrasonic probe, can obtain transformation matrix ^CT _T(i), corresponding transformation matrix of every width uncalibrated image.

By above-mentioned condition obtain calibration formula P (M)= ^MT _C ^CT _T(i) ^TT _IP (I), P in formula (M) are the coordinate of spatial point in stereo calibration template coordinate system; P (I) is the image coordinate of corresponding point in ultrasonoscopy; Dimension is 4 * 4 matrix ^MT _CBe the transformation matrix of coordinate system C to coordinate system M, this matrix is fixed value; Dimension is 4 * 4 matrix ^CT _T(i) be the transformation matrix of coordinate system T to coordinate system C, each uncalibrated image gathers corresponding matrix ^CT _T(i); Dimension is 4 * 4 matrix ^TT _IBe required transformation matrix.

If object function f (i)=| P _M(i)- ^MT _C ^CT _T(i) ^TT _IP _I(i) | ², make f (i)=0 o'clock ^TT _IBe demarcation required, gather several uncalibrated image at least 2 width images, can use the method optimization of method of least square to obtain after stacking data on engineering ^TT _I

The above; it is only the better specific embodiment of this utility model; but protection domain of the present utility model is not limited to this; anyly be familiar with those skilled in the art in the technical scope that this utility model discloses; be equal to replacement or changed according to the technical solution of the utility model and utility model design thereof, within all should being encompassed in protection domain of the present utility model.

Claims (2)

1. the optical calibrating device of a ultrasound probe is characterized in that having:

The optical positioning device (1) of perception ultrasound probe position: this optical positioning device has camera I(101), camera II(102) and horizontal fixed mount (103), described horizontal fixed mount (103) has slideway, described camera I(101) and camera II(102) be flexibly connected by bolt and the horizontal fixed mount (103) that matches with described slideway;

Stereo calibration template (2): the place ahead that is arranged on described optical positioning device (1), comprise: two rectangular frame I(201 that are oppositely arranged) and rectangular frame II(202), described two rectangular frame I(201) and rectangular frame II(202) in full accord; Demarcate the summit that straight line (203) connects described two rectangular shaped rim for many.

2. the optical calibrating device of ultrasound probe according to claim 1 is further characterized in that: described camera I(101) and camera II(102) identical.

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