CN100536792C - Navigation system and method backing up several modes - Google Patents

Abstract

The present invention is navigation system and method backing up several modes. The navigation system includes fixed imaging equipment, tracking system, surgical operation equipment, sick bed, calibrating pin, calibrating mold and navigation software. It has at least one tracer constituting the world coordinate system, one surgical operation equipment tracer as the surgical operation equipment coordinate system, one sick bed tracer constituting the sick bed coordinate system, one characteristic point set I and one characteristic point set II set inside and outside the calibrating mold separately. After calibration, the disease focus image and the surgical operation equipment are shown in the same coordinate system. The present invention may be used widely in the navigation course of different surgical operations.

Description

A kind of navigation system and air navigation aid of supporting various modes

Technical field

The present invention relates to a kind of operation guiding system and air navigation aid, particularly about a kind of navigation system and air navigation aid of supporting various modes.

Background technology

Operation guiding system is (to comprise MR imaging apparatus at medical imaging device, ct apparatus (CT), C type arm, X line equipment, ultrasonic imaging system etc.) become under the guiding of image, utilize tracking system to measure the position of operating theater instruments, thereby can and be presented on the screen the 3-D view of focus and virtual operation instrument fusion, help the doctor accurately to locate the position of focus and operating theater instruments, and observe perilesional organ and tissue, help the doctor to avoid important organ and tissue, operating theater instruments is arrived at the predetermined area safely, so that finish treatment.Operation navigation device enters surgery and improves or improve the ability of surgeon to carry out operations with computer, as: monitoring location and directed, formulate treatment plan, best access path is provided, reduce the damage that surgical intervention caused to a certain extent, shortened operating time.In some traditional operation, focus can not directly detect by an unaided eye (Minimally Invasive Surgery of for example not operating on or non-invasive procedures), perhaps be inconvenient to detect by an unaided eye (for example brain neuroblastoma surgical operation), the doctor can only rely on the image of perusal focus, by rule of thumb operating theater instruments is placed into the target location, error between operation device that this mode causes and the lesions position location, the time of operation can be delayed, the quality of influence operation, particularly this error are brought unnecessary painful and damage to the patient sometimes.

Summary of the invention

At the problems referred to above, the purpose of this invention is to provide a kind of navigation system and air navigation aid of supporting various modes, utilizing the present invention focus picture and virtual operating theater instruments can be put under the same coordinate system observes, the doctor can see focus by the observation screen, also can see operating theater instruments, and then accurately and apace operating theater instruments being placed into the target location, treatment undergos surgery.

The present invention takes following technical scheme: a kind of navigation system of supporting various modes is characterized in that: it comprises the fixedly software program of imaging device, tracking system, operating theater instruments, sick bed, demarcation pin, demarcation mould and navigation system; Be fixed into as the corresponding tracer that is provided with at least one cover formation world coordinate system of device location with described, the pose of described world coordinate system can be measured by described tracking system; Described operating theater instruments is provided with the operating theater instruments tracer as the operating theater instruments coordinate system, and the pose of described operating theater instruments coordinate system can tracked systematic survey; Described sick bed is provided with the sick bed tracer that constitutes the sick bed coordinate system, and described sick bed coordinate system can be measured by described tracking system; Described demarcation pin is made of jointly a pin and a tracer with certain-length, and it contacts certain point through calibrated needle point, can measure the position of this point; Described demarcation mould inside and surface are provided with one group of asymmetrically distributed feature point set I and feature point set II respectively, and the characteristic point of described feature point set I can be by the imaging of described fixedly imaging device, and the characteristic point of described feature point set II can be measured by described tracking system; The relative position relation of feature point set I and feature point set II is known; After demarcating, can be by the mutual transformation relation between each coordinate system, with described focus coordinate and operating theater instruments coordinate transform in same coordinate system.

Patient's skin surface is provided with the navigation marker corresponding with lesions position on described sick bed, and described navigation marker can be by the imaging of described fixedly imaging device, and can be measured by described tracking system.

A kind of air navigation aid of using the navigation system of above-mentioned support various modes, it may further comprise the steps: (1) is in by the system that fixedly imaging device, tracking system, operating theater instruments and sick bed are formed, be fixed into as equipment self have be fixed into the picture device coordinate system, the place that is not moved in the position is installed tracer and is constituted world coordinate system, the operating theater instruments tracer is set on described operating theater instruments constitutes the operating theater instruments coordinate system; (2) demarcate the coordinate of modular character point set I with being fixed into the picture device measuring, the coordinate with tracking system measurement feature point set II calibrates the transformation relation that is fixed between picture device coordinate system and the world coordinate system by these two groups of coordinate datas; (3) sick bed that will be loaded with the patient pushes the fixedly imaging region of imaging device, the view data of focus is provided and is fixed into the pose of picture device coordinate system by fixing imaging device, provide the pose of tracking system coordinate system, operating theater instruments coordinate system by tracking system, the calibration result of integrating step 2 is set up the transformation relation between each coordinate system; (4) utilize the conversion of coordinate system, described focus and operating theater instruments are put into observation under the same coordinate system; (5) according to the image of focus and operating theater instruments relative position, mobile operating theater instruments with its drop target position, undergos surgery and treats operation.

The another kind of air navigation aid of using the navigation system of above-mentioned support various modes, it may further comprise the steps: (1) is in by the system that fixedly imaging device, tracking system, operating theater instruments and sick bed are formed, be fixed into as equipment self have be fixed into the picture device coordinate system, the place that is not moved in the position is installed tracer and is constituted world coordinate system, the operating theater instruments tracer is set on described operating theater instruments constitutes the operating theater instruments coordinate system, on described sick bed or with the constant place of focus relative position, sick bed tracer formation sick bed coordinate system is set; (2) demarcate the coordinate of modular character point set I with being fixed into the picture device measuring, the coordinate with tracking system measurement feature point set II calibrates the transformation relation that is fixed between picture device coordinate system and the world coordinate system by these two groups of coordinate datas; (3) sick bed that will be loaded with the patient pushes the fixedly imaging region of imaging device, provides the view data of focus by fixing imaging device, and the posture information of sick bed coordinate system is provided by tracking system; (4) sick bed is hauled out the fixedly imaging region of imaging device, move to operative region, the pose of tracking system coordinate system, sick bed coordinate system and operating theater instruments coordinate system is provided by tracking system, provided by fixing imaging device to be fixed into the picture device coordinate system, the calibration result of integrating step 2 is set up the transformation relation between each coordinate system; (5) utilize the conversion of coordinate system, described focus and operating theater instruments are put into observation under the same coordinate system; (6) according to the image of focus and operating theater instruments relative position, mobile operating theater instruments with its drop target position, undergos surgery and treats operation.

Use the demarcation mould to each coordinate system timing signal in the above steps (2), the method that has adopted rotation amount and translational movement separately to demarcate, its step is as follows: (a) utilizing fixedly, imaging device 1 measurement feature point set I each point is being fixed into as the coordinate in the device coordinate system

(i=1,2 ..., n _Ph), by coordinate

Generate L vector

This L vector

Be distributed in different directions; (b) utilize tracking system 2 to measure the coordinate of feature point set II each point in the tracking system coordinate system, thereby obtain the coordinate of feature point set I each point in the tracking system coordinate system

(i=1,2 ..., n _Ph), generate and vector in the tracking system coordinate system Vectorial one to one (c) these two groups of vectors satisfy transformation relation and are: $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}});$ (d) by equation group $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}})$ Can solve spin matrix

Then with its substitution equation group $R_{\mathrm{scan}}^{\mathrm{track}}{X}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=X_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}}),$ Can solve Obtain transformation relation And then be fixed the imaging device coordinate system and follow the tracks of transformation relation between the coordinate system

Another uses the air navigation aid of the navigation system of above-mentioned support various modes, it may further comprise the steps: (1) on one's sick bed at least three of patient's body surface settings and focus between do not have the navigation marker relatively move, the operating theater instruments tracer is set on described operating theater instruments constitutes the operating theater instruments coordinate system; (2) sick bed that will be loaded with the patient pushes the fixedly imaging region of imaging device, provides the view data of focus and the view data of navigation marker by fixing imaging device; (3) sick bed is hauled out the fixedly imaging region of imaging device, move to operative region, at first be fixed into as the coordinate in the device coordinate system at extraction navigation marker on the lesion image with software, the reuse tracking system is measured the coordinate of navigation marker in the tracking system coordinate system, is fixed transformation relation between imaging device coordinate system and the tracking system coordinate system according to these two groups of data; (4) provided the pose of tracking system coordinate system, operating theater instruments coordinate system by tracking system, provide the pose that is fixed into the picture device coordinate system by fixing imaging device, the calibration result of integrating step 3 is set up the transformation relation between each coordinate system; (5) utilize the conversion of coordinate system, described focus and operating theater instruments are put into observation under the same coordinate system; (6) according to the image of focus and operating theater instruments relative position, mobile operating theater instruments with its drop target position, undergos surgery and treats operation.

Use in the above steps (2) and demarcate mould each coordinate system timing signal, be provided with in the software program of described navigation system by characteristic point imaging results among the feature point set I is carried out the localized program of the centre of sphere, it may further comprise the steps: (1) supposes at first on the sectional view that the area S and the cross section of circle satisfy normal distribution between the coordinate figure on the scanning direction; (2) along the cross section circular image of ball at same axial arbitrary scan three width of cloth diverse locations, or scanning obtain the cross section circular image of two width of cloth diverse locations after, simulate the 3rd width of cloth cross section circular image, form a class value at the coordinate figure of scanning direction by this cross section area of a circle and this cross section circle; Three class values that (3) will obtain simulate a Gaussian curve, and the coordinate figure of area maximum point correspondence is the coordinate figure of the centre of sphere on this scanning direction on the curve; (4) after the same method, obtain the coordinate figure of the centre of sphere,, combine and be sphere centre coordinate each axial coordinate value at two other change in coordinate axis direction.

The present invention is owing to take above technical scheme, it has the following advantages: 1 the present invention is owing to be provided with various tracers, demarcate pin and demarcate mould, therefore can demarcate with the demarcation mould the coordinate system that each tracer forms, and then make between each coordinate system and can carry out conversion mutually, realization transforms to lesion image and operating theater instruments in the same coordinate system, make the doctor can see the relative position of real operating theater instruments and focus, and under the guiding of image, carry out accurate operation technique by image.2, the present invention is directed to the uncertain problem of sphere center position that the characteristic point of demarcating on the mould occurs in fixing imaging device imaging process, a kind of sphere center locating method has been proposed, and it is preset in the software of navigation system, therefore the mould timing signal can demarcated, from image, obtain accurate sphere center position, make navigation system navigation effect of the present invention more accurate.3, because the present invention is provided with tracer respectively to operating theater instruments, sick bed etc., therefore after demarcating by the demarcation mould, no matter be in fixing imaging device imaging, still move or the variation operating theater instruments, even mobile sick bed is to other position, can under the control of navigation system of the present invention, carry out the surgical navigational of various modes, and guarantee navigation accuracy.4, the present invention has improved stated accuracy effectively owing to take translational movement and rotation amount are separated the mode of demarcating.5, the present invention's characteristic point of demarcating mould is distributed in the solid space, with respect to plane reference mould (being that characteristic point is positioned on the plane), easy to operate, can provide a component to be distributed in point in the solid space once, having overcome use plane reference mould demarcates, need manual translation to demarcate the shortcoming of mould, make calibration result in the imaging region of fixing imaging device accurately and reliably, the geometric distribution of characteristic point of each face of particularly demarcating mould is different, matching and calibration modular character point automatically when calculating.The present invention can be widely used in the various surgical navigational processes.

Description of drawings

Fig. 1 is a structural representation of the present invention

Fig. 2 is that the present invention demarcates the mode structure sketch map

Fig. 3 is that the characteristic point that the present invention demarcates a face of mould is provided with sketch map

Fig. 4 is the characteristic point distribution schematic diagram that the present invention demarcates mould

Fig. 5 adopts fixedly that imaging device becomes the image sketch map

Fig. 6 is the sketch map of three sectional positions of Fig. 5

Fig. 7 is the Gaussian curve that the present invention simulates along the scanning of the z axle in the three-dimensional coordinate

Fig. 8 is a centre of sphere of the present invention location geometrical relationship sketch map

The specific embodiment

Below in conjunction with drawings and Examples the present invention is described in detail.

As shown in Figure 1, the present invention supports that the navigation system of various modes is on the basis of the various device that uses in the general treatment operation process, increase the navigation system that special some equipment that are provided with of the present invention are formed, only just relevant with navigation system of the present invention below equipment is briefly described.

Navigation system of the present invention comprises fixedly imaging device 1, tracking system 2, world coordinate system tracer 3, operating theater instruments 4 and operating theater instruments tracer 5, sick bed 6 and sick bed tracer 7, demarcation pin 8, demarcation mould 9 and navigation system software program etc., and the present invention can also comprise the navigation marker 10 that is arranged on patient's body surface.

The present invention fixedly " fixing " of imaging device 1 refers in the process of imaging and operation, and its position is not moved, for example MR imaging apparatus, ct apparatus (CT), C type arm, X line equipment, ultrasonic imaging system etc.Fixedly imaging device 1 be used for to the patient focus, demarcate imagings such as characteristic point in the mould 9, navigation marker 10, being fixed into as device coordinate system is the fixing attribute of imaging device 1 self, can set up coordinate transform relation between it and other coordinate system by the demarcation of demarcating mould.

Tracking system 2 of the present invention is made up of position sensor, work station and interlock circuit etc., tracking system 2 can be in the visual field of tracking system (area of space that keeps certainty of measurement) coordinate of detection of a target point, position and attitude (being called pose) information that also can the measurement target coordinate system, tracking system 2 can be optical tracking system, electromagnetic tracking system and robot etc.Tracking system 2 utilizes the position sensor on it that world coordinate system tracer 3, operating theater instruments tracer 5, sick bed tracer 7 etc. are surveyed, and finishes the pose tracking measurement to world coordinate system, operating theater instruments coordinate system and sick bed coordinate system.

World coordinate system tracer 3 of the present invention, operating theater instruments tracer 5 and sick bed tracer 7 can adopt in the prior art forms tracer by the minimum spike unit's (spike ball that has fluorescent material such as the surface) of several (more than 3 or 3), the position sensor observation that the unitary position of this spike direct tracked system of energy is 2 li, thereby tracer 3,5,7 can provide the posture information of the equipment that depends on respectively as a coordinate system.The position of world coordinate system is general to link together with fixing imaging device 1, also can be arranged on other position, and the position of world coordinate system does not produce mobile in treatment.More world coordinate system can or overlap tracer 3 by a cover and constitute, be placed in diverse location if will overlap tracer 3 more, in navigation procedure, can change the position of position sensor as required, guarantee that position sensor can detect 1 tracer wherein, thereby obtain the pose of world coordinate system.

Operating theater instruments 4 of the present invention comprises accurate apparatuses such as conduit, seal wire, be introduced into human body in the operation, internal lesions is diagnosed and topical therapeutic, be connected with operating theater instruments tracer 5 on the operating theater instruments 4 as the operating theater instruments coordinate system, because operating theater instruments 4 is determined with the physical size and the relative position of operating theater instruments tracer 5, so the posture information of operating theater instruments 4 can tracked system 2 be measured.

Place the patient on the sick bed 6 of the present invention, but and relative fixed imaging device 1 move to imaging region or operative region etc. from original position.Behind fixing sick bed tracer 7 as the sick bed coordinate system on the sick bed 6, the posture information of sick bed 6 just can tracked system 2 be measured.(for example neurosurgery of brain) is fixed with support on the patient body on the sick bed 6 in some applications, and also can be fixed on sick bed tracer 7 on the support this moment.In the purpose of placing tracer 7 on sick bed 6 or the support all is the position of accurately following the tracks of focus under the situation that focus is moved.On sick bed 6, place tracer 7, when focus and sick bed 6 do not have when relatively moving, sick bed 6 to move with the mobile of focus be the same; Same, on support, place tracer 7, when focus and support do not have when relatively moving, support to move with the mobile of focus be the same.In the narration below, sick bed tracer 7 also can be regarded as the tracer of support, and the pose of sick bed also can be regarded as the pose of support, does not do tangible difference on mathematical symbol.

Demarcation pin 8 of the present invention is to be made of jointly a pin and a tracer with certain-length, because the physical size and the relative position of needle point and tracer are determined, therefore through after demarcating, the position of needle point can tracked system 2 be measured, thereby utilize the needle point of demarcating pin 8 to contact certain point, just can measure the position of this point.

Navigation marker 10 of the present invention is arranged near the sign on skin patient's focus, and navigation marker 10 can also can tracked system 2 be measured, by registering the coordinate transformation relation that can calculate between these two coordinate systems in imaging in the fixing imaging device 1.Navigation marker 10 has two purposes, and the one, the checking tracking accuracy, the 2nd, the registration lesion image is with image and the alignment of focus entity.

Above-mentioned registration is meant the coordinate datas of two groups of points, and what these two groups points were described is same object, but because the coordinate system differences at two groups of some places cause its coordinate different, can calculate coordinate transformation relation between these two coordinate systems by registration.Also be called " registration " or " alignment ".

Demarcation mould 9 of the present invention can adopt various structures, all provide two stack features point set I and II in essence, point set I can imaging in imaging device, thereby obtain among the point set I each point at the coordinate that is being fixed in the picture device coordinate system, the tracked systematic survey of point set II energy, thus the coordinate of every bit in the tracking system coordinate system among the point set II obtained.Relative position relation between feature point set I and the feature point set II is known (being called the geological information of demarcating mould), if promptly know the coordinate of feature point set I each point, just can calculate the coordinate of feature point set II each point; If know the coordinate of feature point set II each point, also can calculate the coordinate of feature point set I each point.

As Fig. 2, shown in Figure 3, demarcation mould 9 of the present invention comprises the rectangle demarcation mould body 91 of being made 300mm * 240mm * 200mm by pmma material, it is similar to demarcate mould body 91 other five faces except that the bottom surface, each face all has certain thickness characteristic layer 92, adopts bonding between each face or alternate manner is tightly connected.All be arranged at intervals with one group of spheroid as characteristic point 93 (such as the cod-liver oil bead) in each characteristic layer 92 inside, all characteristic points 93 of five faces have been formed feature point set I jointly.Outer surface at each characteristic layer 92 is corresponding with the position of each characteristic point 93, and a pit as characteristic point 94 is set, and the characteristic point 94 on five outer surfaces has been formed feature point set II jointly.Demarcating mould body 91 inside, is to demarcate mould solution 95 in the space that six bread gets up promptly, also can not demarcate mould solution.Demarcate mould solution 95 and can adopt sodium chloride solution, copper-bath etc., it has the effect that improves load and signal to noise ratio.Imaging device 1 imaging that can be fixed of characteristic point 93 among the feature point set I, and can go out its center according to the image calculation that obtains; The characteristic point 94 of feature point set II just can 2 identifications of tracked system as long as click by demarcating pin 8.

In the foregoing description, if the characteristic point of each characteristic layer 92 the 93, the 94th is symmetrically arranged, but owing to demarcate two back-to-back faces of mould body 1 is symmetric, not by priori just can not know certain a bit be in this face or back to that face, so in software when registration must artificial notice software features point set I and II between point correspondence; If when each face is provided with characteristic point 93 or characteristic point 94, (with characteristic point 93 is example, and as shown in Figure 4), the position that promptly has is vacant, and then software can be sought corresponding relation automatically to select asymmetric spatial distribution.The present invention is in order to realize coupling automatically when registering computing, therefore feature point set I that is provided with in demarcation mould body 91 and the characteristic point 93,94 of feature point set II all adopt asymmetric distribution.This asymmetric distribution comprises each the characteristic point 93 asymmetric distribution among the feature point set I, also comprise the characteristic point 94 asymmetric distributions among the feature point set II, also comprise not having relation one to one between the characteristic point 93 of feature point set I and the characteristic point 94 among the feature point set II.Although these characteristic point 93,94 asymmetric distributions, in case demarcate molded finishing, the mutual alignment between each characteristic point 93,94 is determined, each characteristic point 93,94 labels input computer can be taken at any time with convenient.

The above-mentioned mould 9 of respectively demarcating mainly is to be used to demarcate and to check mutual alignment between each coordinate system, because the characteristic point 93 of feature point set I can be analyzed from the image that fixedly imaging device 1 is become and obtain, the characteristic point 94 of feature point set II can measure in 2 identifications of tracked system, and the relation between feature point set I and the feature point set II known (being called the geological information of demarcating mould), as long as know the coordinate of characteristic point 93 (perhaps characteristic point 94 among the feature point set II) among the feature point set I wherein, just can extrapolate the coordinate of characteristic point 94 among the feature point set II (or among the feature point set I characteristic point 93), just can set up the transformation relation that is fixed between picture device coordinate system and the tracking system coordinate system by the relation between them.

Yet, according to various imaging device (MR imaging apparatus, ct apparatus (CT), C type arm X line equipment, ultrasonic imaging system etc.) imaging characteristics as can be known, when fixedly 1 pair of characteristic point 93 of demarcating in the mould 9 of imaging device scans (as shown in Figure 5), because characteristic point 93 is not a point, but spheroid, scanning gained image is that integration obtains, and resulting image is also irregular, position particularly far away more apart from the device scan center, the anamorphose that obtains is big more (as a among Fig. 6, b, shown in the c), therefore can not from image, directly obtain the centre of sphere of spheroid.For this reason, in the software program of navigation system of the present invention, need to add a kind of centre of sphere finder, specifically describe as follows below based on the high accuracy imaging:

As shown in Figure 7, in order to obtain the characteristic point 93 real centre ofs sphere, the present invention supposes that at first the area S and the cross section of circle on the sectional view satisfy normal distribution between the coordinate figure on the scanning direction; With fixing imaging device 1 scan feature point 93, and the cross section circular image of arbitrary scan three width of cloth diverse locations along the same axis, a certain cross section area of a circle S on the scanning direction and can form a class value at the coordinate figure of scanning direction with this cross section; By geometry as can be known, as long as obtain three groups of such values, just can simulate a Gaussian curve, the coordinate figure that area maximum point (peak point) is corresponding on the curve is exactly the coordinate figure of the centre of sphere on this scanning direction.Curve 0 on the z axle reaches peak value, illustrates that this point is exactly that the centre of sphere is at the axial coordinate figure of z.After the same method, can obtain the coordinate figure of the centre of sphere, utilize on axially three cross sections to calculate the centre of sphere each, combine and to determine sphere centre coordinate at this coordinate figure on axially in two other coordinate axes (x, y) direction.

In scanning process, may have to two width of cloth sectional views sometimes, at this moment at first need simulate the 3rd width of cloth sectional view, and then calculate the coordinate position of the centre of sphere with said method by this two width of cloth figure through the center of circle.Such as:

As shown in Figure 8, go to cut a spheroid (characteristic point 93) with a plane, can obtain a circle, (x, y z) represent sphere centre coordinate, and d represents the distance of the centre of sphere to the cross section circle, R among the figure ₀Represent the radius of a ball, r represents the cross section radius of circle, and (a, b c) represent the round heart in cross section, and t1 represents cross section circule method line direction.There is such geometrical relationship between them:

d ²+r ²＝R ₀ ²

The approximate radius R of known spheroid ₀Be 3mm, pass through analysis image, can obtain the central coordinate of circle (a of cross section circle, b, c), the circle area S, utilize area of a circle S can obtain cross section radius of circle r, utilize the centre of sphere and central coordinate of circle can obtain the centre of sphere to cross section circle apart from d, thereby can utilize formula (1) obtain this sphere centre coordinate on axially (x, y, z).

By geometrical relationship, we know, as long as known the parameter of two faces, just can list following simultaneous equations with how much method, and the coordinate figure that solves the centre of sphere comes:

To first face:

$\left\{\begin{array}{c}{(x-a_1)}^2+{(y-b_1)}^2+{(z-c_1)}^2+\frac{S_1}{\mathrm{\π}}={R_0}^2\\ \frac{x-a_1}{{t1}_x}=\frac{y-b_1}{{t1}_y}=\frac{z-c_1}{{t1}_z}\end{array}\right.$

Can solve two class values like this, be each one up and down from how much.

To second face:

$\left\{\begin{array}{c}{(x-a_2)}^2+{(y-b_2)}^2+{(z-c_2)}^2+\frac{S_2}{\mathrm{\π}}={R_0}^2\\ \frac{x-a_2}{{t2}_x}=\frac{y-b_2}{{t2}_y}=\frac{z-c_2}{{t2}_z}\end{array}\right.$

Also can solve two class values, also be each one up and down.

Four centre ofs sphere that solve above should have two to be same point (having error certainly certainly) in fact.We ask the distance of every point-to-point transmission, l ₁, l ₂, l ₃, l ₄, then minimum 2 of distance should be exactly correct centre of sphere point, so be averaged, obtain the initial value of the centre of sphere that we want at these 2.

The initial value that the centre of sphere has been arranged is also known radius of a ball R ₀, also just having obtained crossing the cross section circle information of the centre of sphere, comprehensive existing two cross sections circle information just can be utilized the inventive method calculating centre of sphere.Owing to the information (center of circle, radius) of three cross section circles has been arranged, can calculate the area of a circle; Because the central coordinate of circle value is known, three class values have also just been obtained, every class value is formed at the coordinate figure of scanning direction by a certain cross section area of a circle on the scanning direction with this cross section, this three class value as the point coordinates on the Gaussian curve, just can simulate a Gaussian curve, thereby obtain the coordinate figure of the centre of sphere on this scanning direction.Profit uses the same method, and can obtain the coordinate figure of the centre of sphere on other both direction, thereby obtains the sphere center position coordinate.

The essence of navigation system of the present invention is focus picture and virtual operating theater instruments to be put under the same coordinate system observe, promptly be simultaneously displayed on the screen of work (can be the demonstration equipment of LCD screen, projection screen or other form), and both relative positions are identical with the relative position of real focus and operating theater instruments on the screen, thereby the doctor can see focus by the observation screen, also can see operating theater instruments, and then accurately and apace operating theater instruments be delivered to the target location.

Adopt navigation system of the present invention, the present invention can finish the operation of following two kinds of mode of operations (real-time and non real-time):

Mode of operation one: the patient lies on the sick bed 6, sick bed 6 is pushed in the imaging region of fixing imaging device 1, in the scanning focus, undergos surgery in real time.Wherein, fixedly imaging device 1 provides the view data of focus, tracking system 2 provides the posture information of operating theater instruments 4, utilizing coordinate transform that focus and operating theater instruments 4 are put under the same coordinate system observes, be simultaneously displayed on the screen, being the focus seen on screen of doctor and the relative position of operating theater instruments 4, is exactly the actual focus and the relative position of operating theater instruments 4.

Mode of operation two: the patient lies on the sick bed 6, sick bed 6 is pushed in the imaging region of fixing imaging device 1, obtains the image of focus, then sick bed 6 is hauled out undergo surgery to a place (do not have mutually between patient and the sick bed and move), undergos surgery in non real-time.Wherein, fixedly imaging device 1 provides the view data of focus, tracking system 2 provides the posture information of operating theater instruments 3, sick bed 6, utilizing coordinate transform that focus and operating theater instruments 4 are put under the same coordinate system observes, be simultaneously displayed on the screen, being the focus seen on screen of doctor and the relative position of operating theater instruments 4, is exactly the actual focus and the relative position of operating theater instruments 4.

For supporting above two kinds of mode of operations, system of the present invention supports following three kinds of navigation modes, before specifically describing navigation mode of the present invention, and the variable-definition following (as shown in table 1) of elder generation to occurring in describing:

Table 1: the definition of variable

Navigation mode A: in order to carry out first kind of mode of operation, the present invention adopts tracer 3 as world coordinate system (as shown in Figure 1), it is arranged on the fixing imaging device 1, therefore itself and fixedly the relative position of imaging device 1 remain unchanged, fixation surgical instrument tracer 5 is as the operating theater instruments coordinate system on operating theater instruments 4.Demarcate by demarcating mould 9, can be fixed the coordinate transform relation between imaging device coordinate system and the world coordinate system, make focus (fixedly imaging device 1 provides its image and posture information) can transform in the world coordinate system that (this staking-out work only needs do once when erection unit, as long as tracer 3 and fixedly not relatively moving between the imaging device 1, its calibration result can be directly adopted in later operation).(each operation all will be demarcated to obtain the pose of operating theater instruments 4 in the operating theater instruments coordinate system by 9 demarcation of demarcation mould simultaneously, because generally just that operating theater instruments tracer 5 is fixing before operation, and the separating of in operation process, undergo surgery probably apparatus 4 and operating theater instruments tracer 5, fixing).In operation process, tracking system 2 is measured the pose of world coordinate systems, obtains the coordinate system of tracking system 2 oneself and the transformational relation of world coordinate system; Simultaneously, tracking system 2 is measured the pose of operating theater instruments coordinate system, obtains the transformational relation between operating theater instruments coordinate system and the world coordinate system, thereby operating theater instruments 4 is also transformed to world coordinate system observation.Except unified focus and operating theater instruments 4 are transformed to world coordinate system observation, also they can be transformed to other coordinate system observation, for example be fixed into picture device coordinate system or tracking system coordinate system etc.

The derivation that navigation mode A coordinate transform relation is concrete is as follows:

Observation focus and operating theater instruments 4 in world coordinate system, fixedly imaging device 1 scanning focus obtains its view data, comprising a bit being fixed into as the coordinate in the device coordinate system arbitrarily of focus According to good being fixed into of prior demarcation as the transformation relation between device coordinate system and the world coordinate system

Any point coordinates of focus can be transformed to the world coordinate system from being fixed into as device coordinate system, obtain this coordinate in world coordinate system

$V_{\mathrm{lesion}}^{\mathrm{world}}=C_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion}}^{\mathrm{scan}}---\left(1\right)$

Tracking system 2 is measured the posture information of operating theater instruments tracer 5

Also measure simultaneously the pose of world coordinate system

Thereby obtain the transformation relation between operating theater instruments coordinate system and the world coordinate system

$C_{\mathrm{tool}}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{tool}}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}---\left(2\right)$

The coordinate of any 1 T in the operating theater instruments coordinate system on the operating theater instruments 4

Be known, it is transformed in the world coordinate system

$C_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{C}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(3\right)$

So far, focus and operating theater instruments 4 have been placed to observation in the same coordinate system (world coordinate system), and they can be displayed on the screen.The relative position of focus that the doctor sees on screen and operating theater instruments 4 is exactly the focus of reality and the relative position of operating theater instruments 4.

Except world coordinate system, focus and operating theater instruments 4 also can be transformed in other the coordinate system and observe, and for example are fixed into picture device coordinate system or tracking system coordinate system.

Use is fixed into picture device coordinate system observation, is fixed into the picture device coordinate system because focus has been in, its arbitrarily any coordinate be

Do not need to carry out conversion, and only need conversion operating theater instruments 4 to being fixed into the picture device coordinate system

$V_T^{\mathrm{scan}}=C_{\mathrm{world}}^{\mathrm{scan}}{V}_T^{\mathrm{world}}=C_{\mathrm{world}}^{\mathrm{scan}}{\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(4\right)$

Use the observation of tracking system coordinate system, any some coordinate in the tracking system coordinate system of a bit any and operating theater instruments 4 of focus is respectively

$V_{\mathrm{lesion}}^{\mathrm{track}}=C_{\mathrm{scan}}^{\mathrm{track}}{V}_{\mathrm{lesion}}^{\mathrm{scan}}=C_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion}}^{\mathrm{scan}}---\left(5\right)$

$V_T^{\mathrm{track}}=C_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(6\right)$

Navigation mode B: in order to carry out second kind of mode of operation, can on the basis of the scaling method of navigation mode A and tracking, expand.Similarly, use tracer 3 as world coordinate system, it and fixedly the relative position of imaging device 1 remain unchanged fixation surgical instrument tracer 5 on operating theater instruments 4.In addition, in order to adapt to moving of sick bed 6 (patient), also will be on sick bed 6 fixing sick bed tracer 7.In operation process, focus is after fixing 1 li imaging of imaging device, along with sick bed 6 moves to the position that undergos surgery, utilize to be fixed into as the coordinate transform relation between device coordinate system and the world coordinate system and the posture information of sick bed 6, focus can be transformed in the world coordinate system and observe.The tracking of operating theater instruments 4 is the same with method among the navigation mode A.Except unified focus and operating theater instruments 4 are transformed to world coordinate system observation, also they can be transformed to other coordinate system, for example be fixed into the picture device coordinate system, tracking system coordinate system or sick bed coordinate system etc.

The derivation that navigation mode B coordinate transform relation is concrete is as follows:

Observation focus and operating theater instruments 4 in world coordinate system, when the patient was pushed into fixedly imaging device 1 imaging, some coordinate in world coordinate system arbitrarily of focus was that formula (1) is described

$V_{\mathrm{lesion},0}^{\mathrm{world}}=C_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(1\right)$

Wherein subscript 0 expression sick bed 6 is pushed into fixedly imaging device 1, at this moment sick bed coordinate system pose

Tracked system 2 surveys, and its pose in world coordinate system is

$C_{\mathrm{PT},0}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{PT},0}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},0}^{\mathrm{track}}---\left(7\right)$

By formula (1) and (7) as can be known this moment focus arbitrarily some the coordinate in the sick bed coordinate system be

$V_{\mathrm{lesion},0}^{\mathrm{PT},0}=C_{\mathrm{world}}^{\mathrm{PT},0}{V}_{\mathrm{lesion},0}^{\mathrm{world}}={\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(8\right)$

After imaging finished, focus (patient) was along with sick bed 6 moves to surgery location (representing with subscript 1).Do not relatively move because patient and sick bed 6 have, the coordinate of focus on sick bed 6 remains unchanged

$V_{\mathrm{lesion},1}^{\mathrm{PT},1}=V_{\mathrm{lesion},0}^{\mathrm{PT},0}---\left(9\right)$

This moment sick bed 6 pose

Tracked system 2 surveys, and its pose in world coordinate system is

$C_{\mathrm{PT},1}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{PT},1}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}---\left(10\right)$

Can draw the coordinate of focus this moment in world coordinate system by formula (8)～(10) is

$V_{\mathrm{lesion},1}^{\mathrm{world}}=C_{\mathrm{PT},1}^{\mathrm{world}}{V}_{\mathrm{lesion},1}^{\mathrm{PT},1}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(11\right)$

It is the same that any some coordinate in world coordinate system of operating theater instruments 4 and formula (3) are described

$V_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{V}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(3\right)$

So far, focus and operating theater instruments have been placed to observation in the same coordinate system (world coordinate system).

Except world coordinate system, focus and operating theater instruments also can be transformed in other the coordinate system and observe, and for example are fixed into picture device coordinate system, tracking system coordinate system or sick bed coordinate system.

Use is fixed into the observation of picture device coordinate system, and any of a bit any and operating theater instruments 4 of focus a bit is respectively at the coordinate that is fixed into as in the device coordinate system

$V_{\mathrm{lesion},1}^{\mathrm{scan}}=C_{\mathrm{world}}^{\mathrm{scan}}{V}_{\mathrm{lesion},1}^{\mathrm{world}}=C_{\mathrm{world}}^{\mathrm{scan}}{\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}$ (12)

${={\left(C_{\mathrm{scan}}^{\mathrm{world}}\right)}^{-1}\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}$

$V_T^{\mathrm{scan}}=C_{\mathrm{worlk}}^{\mathrm{scan}}{V}_T^{\mathrm{world}}=C_{\mathrm{world}}^{\mathrm{scan}}{\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(4\right)$

Use the observation of tracking system coordinate system, any some coordinate in the tracking system coordinate system of a bit any and operating theater instruments 4 of focus is respectively

$V_{\mathrm{lesion},1}^{\mathrm{track}}=C_{\mathrm{PT},1}^{\mathrm{track}}{V}_{\mathrm{lesion},1}^{\mathrm{PT},1}=C_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(13\right)$

$V_T^{\mathrm{track}}=C_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(6\right)$

Use the observation of sick bed coordinate system, any some coordinate in the sick bed coordinate system of a bit any and operating theater instruments 4 of focus is respectively

$V_{\mathrm{lesion},1}^{\mathrm{PT},1}={\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(7\right)$

$V_T^{\mathrm{PT},1}=C_{\mathrm{track}}^{\mathrm{PT},1}{V}_T^{\mathrm{track}}={\left(C_{\mathrm{PT},1}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(14\right)$

Navigation mode C:, can adopt scaling method and the tracking different with navigation mode B in order to carry out second kind of mode of operation.It is patient's body surface is fixing can be at the navigation marker 10 (quantity is no less than 3) of imaging in the fixing imaging device 1, and imaging in fixing imaging device 1, in the operation process, nothing relatively moves between navigation marker 10 and the focus.After sick bed 6 (patient) is drawn out the arrival operative region, be fixed into as the coordinate in the device coordinate system at extraction navigation marker 10 on the lesion image, and measure the coordinate of navigation marker 10 in the tracking system coordinate system of patient's body surfaces with tracking system 2, with these two groups of data registrations, thereby the position with lesion image and real focus in certain coordinate system (for example tracking system coordinate system) coincides together, because this moment, operating theater instruments 4 also was transformed this coordinate system (for example tracking system coordinate system), therefore can realize the observation together of focus and operating theater instruments 4, just can begin operation then.

The derivation that navigation mode C coordinate transform relation is concrete is as follows:

After sick bed 6 puts in place, on lesion image with n _NavIndividual navigation marker 10 (n _Nav〉=3, general n _NavEqual 4), extract, obtain navigation marker 10 at the three-dimensional coordinate that is fixed in the picture device coordinate system

(i=1,2 ..., n _Nav); Use tracking system 2 to measure navigation marker point 10, obtain their coordinates in the tracking system coordinate system

Transformation relation between focus and the operating theater instruments coordinate is:

$C_{\mathrm{img}}^{\mathrm{track}}{M}_i^{\mathrm{img}}=M_i^{\mathrm{track}}---\left(15\right)$

Wherein Tie up to pose in the tracking system coordinate system for being fixed into as device coordinate.Through type (15) can obtain n _NavIndividual equation, and solve

Thereby a bit being fixed into arbitrarily of focus as the coordinate in the device coordinate system

May be shifted into the tracking system coordinate system

$V_{\mathrm{lesion}}^{\mathrm{track}}=C_{\mathrm{img}}^{\mathrm{track}}{V}_{\mathrm{lesion}}^{\mathrm{img}}---\left(16\right)$

The coordinate of any 1 T in the operating theater instruments coordinate system on the operating theater instruments 4

Be known, it is transformed in the tracking system coordinate system

$V_T^{\mathrm{track}}=C_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}---\left(6\right)$

So far, focus and operating theater instruments 4 have been placed to observation in the same coordinate system (tracking system coordinate system), they can be displayed on the screen, and the relative position of focus that the doctor sees on screen and operating theater instruments 4 is exactly the focus of reality and the relative position of operating theater instruments 4.

Measure navigation marker point 10 in order to make the doctor not need to reuse tracking system 2, can increase a tracer as world coordinate system, its pose

Tracked system 2 is measured.This world coordinate system is different with the world coordinate system of navigation mode A, B, and it is not to be fixed in fixedly on the imaging device 1, but and the relative position of focus remain unchanged, when for example focus is head, can tracer and head be fixed by machinery.

Represent initial calibration position with subscript 0, the position sensor of 1 expression tracking system 2 moves to reposition.With focus arbitrarily a bit by the tracking system coordinate system transformation to world coordinate system

$V_{\mathrm{lesion}}^{\mathrm{world}}=C_{\mathrm{track},1}^{\mathrm{world}}{V}_{\mathrm{lesion}}^{\mathrm{track},1}=C_{\mathrm{track},1}^{\mathrm{world}}{C}_{\mathrm{track},0}^{\mathrm{track},1}{V}_{\mathrm{lesion}}^{\mathrm{track},0}={\left(C_{\mathrm{world}}^{\mathrm{track},1}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track},1}{\left(C_{\mathrm{world}}^{\mathrm{track},0}\right)}^{-1}{C}_{\mathrm{img}}^{\mathrm{track},0}{V}_{\mathrm{lesion}}^{\mathrm{img}}---\left(17\right)$

Operating theater instruments 4 transformed to world coordinate system more arbitrarily

$V_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{V}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track},1}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track},1}{V}_T^{\mathrm{tool}}---\left(18\right)$

We just are put into focus and operating theater instruments 4 in the world coordinate system and observe like this, and after position sensor moved, world coordinate system was at the pose of position sensor

Upgrade, the conversion of through type (17) and (18) guarantees the accurate positioning of focus and operating theater instruments.

Also can in tracking system, observe focus and operating theater instruments

$V_{\mathrm{lesion}}^{\mathrm{track},1}=C_{\mathrm{track},0}^{\mathrm{track},1}{V}_{\mathrm{lesion}}^{\mathrm{track},0}=C_{\mathrm{world}}^{\mathrm{track},1}{\left(C_{\mathrm{world}}^{\mathrm{track},0}\right)}^{-1}{C}_{\mathrm{img}}^{\mathrm{track},0}{V}_{\mathrm{lesion}}^{\mathrm{img}}---\left(19\right)$

$V_T^{\mathrm{track},i}=C_{\mathrm{tool}}^{\mathrm{track},1}{V}_T^{\mathrm{tool}}---\left(20\right)$

In the demarcation of said fixing imaging device coordinate system, fixedly object of imaging device 1 scanning obtains image, used space coordinates is to be fixed into the picture device coordinate system, for with image from being fixed into the coordinate system (as world coordinate system) that transforms to other as device coordinate system, just need carry out staking-out work, obtain the transformation relation between imaging coordinate system and certain the coordinate system R (as world coordinate system or tracking system coordinate system etc.)

This relation has been arranged, and focus just can transform in this coordinate system and observe.If know other the coordinate system (for example tracking system coordinate system) and the relation of world coordinate system, focus can also be transformed in other the coordinate system.

The present invention adopts demarcation mould 9 and tracking system 2 to demarcate the transformation relation that is fixed between picture device coordinate system and the world coordinate system

According to the description of above-mentioned demarcation mould 9 structures as can be known, be fixed into the picture device scan and demarcate mould 9, each characteristic point 93 that obtains feature point set I is at the coordinate that is being fixed in the picture device coordinate system

(i=1,2 ..., n _Ph); Tracking system 2 is measured and is demarcated mould 9, obtains the coordinate of each characteristic point 94 of feature point set II, has also just obtained the coordinate of every bit in the tracking system coordinate system of feature point set II

(i=1,2 ..., n _Ph).These two groups of coordinates satisfy equation

$C_{\mathrm{scan}}^{\mathrm{track}}{V}_i^{\mathrm{scan}}=V_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}})---\left(21\right)$

Can solve the transformation relation that is fixed between picture device coordinate system and the tracking coordinate system by these solution of equations

And then be fixed transformation relation between imaging device coordinate system and the world coordinate system

$C_{\mathrm{scan}}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{scan}}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{reack}}\right)}^{-1}{C}_{\mathrm{scan}}^{\mathrm{track}}---\left(22\right)$

Wherein Measuring world coordinate system by tracking system 2 obtains.

In order to improve the stated accuracy among navigation mode A and the navigation mode B, the present invention is carrying out timing signal, the method that has adopted rotation amount and translational movement separately to demarcate with demarcating mould 9

Comprise spin matrix (3 * 3 matrix) and translation vector (3 * 1 matrix), promptly

$C_{\mathrm{scan}}^{\mathrm{track}}=\left(\begin{array}{cc}{R}_{\mathrm{scan}}^{\mathrm{track}}& T_{\mathrm{scan}}^{\mathrm{track}}\\ 0& 1\end{array}\right)---\left(23\right)$

With point coordinates

V＝(X?1) ^T＝(x?y?z?1) ^T

And formula (23) substitution (21) obtains

$R_{\mathrm{scan}}^{\mathrm{track}}{X}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=X_i^{\mathrm{track}}---\left(24\right)$

General demarcation way is to utilize fixedly imaging device 1 to measure feature point set I each point be fixed into the coordinate that looks like in the device coordinate system

(i=1,2 ..., n _Ph), utilize tracking system 2 to measure the coordinate of feature point set II each point in the tracking system coordinate system, because the relative position relation of feature point set I and II is known, thereby obtain the coordinate of feature point set I each point in the tracking system coordinate system

(i=1,2 ..., n _Ph), solve spin matrix simultaneously by equation (24)

And translation vector

Do the local calibration result that can obtain like this near the zone feature point set I, the II, but because the visual field is bigger, and the sub-fraction that the characteristic point 93 of demarcating mould is just put in the visual field, therefore the precision of demarcating in the whole visual field of fixing imaging device 1 is subjected to spin matrix

Error effect big, make and to have only characteristic point 93 near zone accurate positionings, and big away from the domain error of characteristic point 93.Spin matrix and translation matrix are separately demarcated, can guarantee that spin matrix has best calibration result, though do near the minimum calibrated error of having sacrificed the characteristic point 93,94, the calibration result that in whole visual field, can obtain like this.Separately the concrete process of demarcating is as follows:

At first, utilizing fixedly, imaging device 1 each characteristic point 93 of measurement feature point set I is being fixed into as the coordinate in the device coordinate system

(i=1,2 ..., n _Ph), by coordinate

Generate L vector Principle is to make vector be distributed in all directions (it would be desirable the vector set that the mind-set all directions are sent from the visual field) of visual field as far as possible.Then, utilize tracking system 2 to measure the coordinate of feature point set II each point in the tracking system coordinate system, thereby obtain the coordinate of feature point set I each point in the tracking system coordinate system (i=1,2 ..., n _Ph), generate and vector in the tracking system coordinate system

Vectorial one to one

(meaning is if vector one to one

By characteristic point

And characteristic point

Generate, so vector

Also by same characteristic point

And characteristic point Generate).

These two groups of vectors satisfy transformation relation

$R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}})---\left(25\right)$

Can solve spin matrix by equation group (25)

Then its substitution equation group (24) can be solved Obtain transformation relation

And then be fixed the imaging device coordinate system and follow the tracks of transformation relation between the coordinate system $C_{\mathrm{scan}}^{\mathrm{track}}.$

State on the implementation in three kinds of navigation mode A, B, the C process, in order to increase the visual field of tracking system 2, can use a plurality of tracer 3 common world coordinate systems of forming, these tracers 3 are distributed in different position (between each tracer 3 coordinate transform relation be good after measured), and the best tracer 3 of chosen position pick off Effect on Detecting is as world coordinate system during navigation.Thereby the position sensor that allows tracking system 2 can move to a plurality of positions carries out the position tracking to operating theater instruments 4, has enlarged the working region of position sensor.This moment, focus and operating theater instruments still can be calculated with the formula of front.

Claims (13)

1, a kind of navigation system of supporting various modes is characterized in that: it comprises the fixedly software program of imaging device, tracking system, operating theater instruments, sick bed, demarcation pin, demarcation mould and navigation system; Be fixed into as the corresponding tracer that is provided with at least one cover formation world coordinate system of device location with described, the pose of described world coordinate system can be measured by described tracking system; Described operating theater instruments is provided with the operating theater instruments tracer as the operating theater instruments coordinate system, and the pose of described operating theater instruments coordinate system can tracked systematic survey; Described sick bed is provided with the sick bed tracer that constitutes the sick bed coordinate system, and described sick bed coordinate system can be measured by described tracking system; Described demarcation pin is made of jointly a pin and a tracer with certain-length, and it contacts certain point through calibrated needle point, can measure the position of this point; Described demarcation mould inside and surface are provided with one group of asymmetrically distributed feature point set I and feature point set II respectively, and the characteristic point of described feature point set I can be by the imaging of described fixedly imaging device, and the characteristic point of described feature point set II can be measured by described tracking system; The relative position relation of feature point set I and feature point set II is known; After demarcating, by the mutual transformation relation between each coordinate system, with focus coordinate and operating theater instruments coordinate transform in same coordinate system.

2, a kind of navigation system of supporting various modes as claimed in claim 1, it is characterized in that: patient's skin surface is provided with the navigation marker corresponding with lesions position on described sick bed, described navigation marker can be by the imaging of described fixedly imaging device, and can be measured by described tracking system.

3, a kind of navigation system of supporting various modes as claimed in claim 1, it is characterized in that: described demarcation mould comprises that one demarcates mould body, described demarcation mould body other five faces except that the bottom surface, each face all has certain thickness characteristic layer, each described characteristic layer inside is provided with one group of spheroid forming a feature point set I, each described characteristic layer surface is provided with another group pit of composition characteristic point set II, is full of in the space that described demarcation mould body is got up by six bread and demarcates mould solution.

4, a kind of navigation system of supporting various modes as claimed in claim 2, it is characterized in that: described demarcation mould comprises that one demarcates mould body, described demarcation mould body other five faces except that the bottom surface, each face all has certain thickness characteristic layer, each described characteristic layer inside is provided with one group of spheroid forming a feature point set I, each described characteristic layer surface is provided with another group pit of composition characteristic point set II, is full of in the space that described demarcation mould body is got up by six bread and demarcates mould solution.

5, as claim 1 or 2 or 3 or 4 described a kind of navigation system of supporting various modes, it is characterized in that: in described world coordinate system,

Any point coordinates of described focus

Put the coordinate in fixing imaging device thus

Conversion:

$V_{\mathrm{lesion}}^{\mathrm{world}}=C_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion}}^{\mathrm{scan}}$

Wherein

For demarcating good being fixed in advance as the transformation relation between device coordinate system and the world coordinate system;

More any coordinate of described operating theater instruments

Put the coordinate in the operating theater instruments coordinate system thus Conversion:

$V_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{V}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}$

$C_{\mathrm{tool}}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{tool}}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{reack}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}$

Wherein,

Be the world coordinate system of tracking system measurement and the transformation relation between the tracking system coordinate system,

Be the operating theater instruments coordinate system of tracking system measurement and the transformation relation between the tracking system coordinate system.

6, as claim 1 or 2 or 3 or 4 described a kind of navigation system of supporting various modes, it is characterized in that: when described focus is positioned on the sick bed, in described world coordinate system,

Any point coordinates of described focus Put the coordinate in fixing imaging device thus

Conversion:

$V_{\mathrm{lesion},0}^{\mathrm{world}}=C_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(1\right)$

Wherein

For demarcating good being fixed in advance as the transformation relation between device coordinate system and the world coordinate system; When wherein subscript 0 expression sick bed is pushed into imaging device, the coordinate system pose of sick bed

Tracked system surveys, and its pose in world coordinate system is:

$C_{\mathrm{PT},0}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{PT},0}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},0}^{\mathrm{track}}---\left(2\right)$

This moment, the pose of focus in the sick bed coordinate system was as can be known by above two formulas:

$V_{\mathrm{lesion},0}^{\mathrm{PT},0}=C_{\mathrm{world}}^{\mathrm{PT},0}{V}_{\mathrm{lesion},0}^{\mathrm{world}}={\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}---\left(3\right)$

When imaging finishes, focus along with bed motion to the operation position, represent that with subscript 1 do not relatively move owing to focus and sick bed have, focus pose on one's sick bed remains unchanged:

$V_{\mathrm{lesion},1}^{\mathrm{PT},1}=V_{\mathrm{lesion},0}^{\mathrm{PT},0}---\left(4\right)$

This moment sick bed pose

Tracked system surveys, and its pose in world coordinate system is:

$C_{\mathrm{PT},1}^{\mathrm{world}}=C_{\mathrm{track}}^{\mathrm{world}}{C}_{\mathrm{PT},1}^{\mathrm{track}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}---\left(5\right)$

Can draw the pose of focus this moment in world coordinate system by formula (3)～(5) is:

$V_{\mathrm{lesion},1}^{\mathrm{world}}=C_{\mathrm{PT},1}^{\mathrm{world}}{V}_{\mathrm{lesion},1}^{\mathrm{PT},1}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{PT},1}^{\mathrm{track}}{\left(C_{\mathrm{PT},0}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track}}{C}_{\mathrm{scan}}^{\mathrm{world}}{V}_{\mathrm{lesion},0}^{\mathrm{scan}}$

The pose of operating theater instruments in world coordinate system is:

$V_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{V}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track}}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}.$

7, as claim 2 or 4 described a kind of navigation system of supporting various modes, it is characterized in that: described navigation marker being fixed into as the coordinate in the device coordinate system is

I=1 wherein, 2 ..., n _Nav, n wherein _NavQuantity for navigation marker; The coordinate of described navigation marker in the tracking system coordinate system is

Transformation relation between the coordinate of focus and operating theater instruments is:

$C_{\mathrm{img}}^{\mathrm{track}}{M}_i^{\mathrm{img}}=M_i^{\mathrm{track}}---\left(1\right)$

Wherein

Tie up to pose in the tracking system coordinate system for being fixed into as device coordinate, through type (1) can obtain n _NavIndividual equation, and solve

Then lesion image more arbitrarily

May be shifted into the tracking system coordinate system:

$V_{\mathrm{lesion}}^{\mathrm{track}}=C_{\mathrm{img}}^{\mathrm{track}}{V}_{\mathrm{lesion}}^{\mathrm{img}}---\left(2\right)$

The coordinate of certain some T in the operating theater instruments coordinate system on the operating theater instruments

Be known, it transformed to the tracking system coordinate system:

$V_T^{\mathrm{track}}=C_{\mathrm{tool}}^{\mathrm{track}}{V}_T^{\mathrm{tool}}$

Wherein Be the operating theater instruments coordinate system of tracking system measurement and the transformation relation between the tracking system coordinate system.

8, a kind of navigation system of supporting various modes as claimed in claim 7 is characterized in that: increase a relative tracer that remains unchanged with described lesions position as the New World coordinate system, its pose

Tracked systematic survey represents that with subscript 0 position sensor of tracking system is in initial calibration position, and the position sensor of 1 expression tracking system moves to reposition; Some coordinate in world coordinate system arbitrarily of focus

Put thus at the coordinate that is fixed in the picture device coordinate system

Conversion:

$V_{\mathrm{lesion}}^{\mathrm{world}}=C_{\mathrm{track},1}^{\mathrm{world}}{V}_{\mathrm{lesion}}^{\mathrm{track},1}=C_{\mathrm{track},1}^{\mathrm{world}}{C}_{\mathrm{track},0}^{\mathrm{track},1}{V}_{\mathrm{lesion}}^{\mathrm{track},0}={\left(C_{\mathrm{world}}^{\mathrm{track},1}\right)}^{-1}{C}_{\mathrm{world}}^{\mathrm{track},1}{\left(C_{\mathrm{world}}^{\mathrm{track},0}\right)}^{-1}{C}_{\mathrm{img}}^{\mathrm{track},0}{V}_{\mathrm{lesion}}^{\mathrm{img}}$

Wherein

Be the transformation relation between the tracking system coordinate system on world coordinate system and the initial position,

Be the transformation relation between the tracking system coordinate system on world coordinate system and the reposition 1,

Be fixed into the transformation relation between the tracking system coordinate system on picture device coordinate system and the initial position 0;

More any coordinate of described operating theater instruments

Put the coordinate in the operating theater instruments coordinate system thus Conversion:

$V_T^{\mathrm{world}}=C_{\mathrm{tool}}^{\mathrm{world}}{V}_T^{\mathrm{tool}}={\left(C_{\mathrm{world}}^{\mathrm{track},1}\right)}^{-1}{C}_{\mathrm{tool}}^{\mathrm{track},1}{V}_T^{\mathrm{tool}}$

Wherein, Be the transformation relation between the tracking system coordinate system on world coordinate system and the reposition 1,

Be the transformation relation between operating theater instruments coordinate system and the tracking system coordinate system.

9, as claim 1 or 2 or 3 or 4 described a kind of navigation system of supporting various modes, it is characterized in that: described demarcation mould is to each coordinate system timing signal, be provided with in the software program of described navigation system by characteristic point imaging results among the feature point set I is carried out the localized program of the centre of sphere, its flow process is as follows:

(1) normal distribution is satisfied in area S and the cross section of at first supposing circle on the sectional view between the coordinate figure on the scanning direction;

(2) along the cross section circular image of ball at same axial arbitrary scan three width of cloth diverse locations, or scanning obtain the cross section circular image of two width of cloth diverse locations after, simulate the 3rd width of cloth cross section circular image, form a class value at the coordinate figure of scanning direction by each cross section area of a circle and this cross section circle through the center of circle;

Three class values that (3) will obtain simulate a Gaussian curve, and the coordinate figure of area maximum point correspondence is the coordinate figure of the centre of sphere on this scanning direction on the curve;

(4) after the same method, obtain the coordinate figure of the centre of sphere,, combine and be sphere centre coordinate each axial coordinate value at two other change in coordinate axis direction.

10, a kind of navigation system of supporting various modes as claimed in claim 5, it is characterized in that: described demarcation mould is to each coordinate system timing signal, be provided with in the software program of described navigation system by characteristic point imaging results among the feature point set I is carried out the localized program of the centre of sphere, its flow process is as follows:

(1) normal distribution is satisfied in area S and the cross section of at first supposing circle on the sectional view between the coordinate figure on the scanning direction;

(2) along the cross section circular image of ball at same axial arbitrary scan three width of cloth diverse locations, or scanning obtain the cross section circular image of two width of cloth diverse locations after, simulate the 3rd width of cloth cross section circular image, form a class value at the coordinate figure of scanning direction by every each cross section area of a circle and this cross section circle through the center of circle;

Three class values that (3) will obtain simulate a Gaussian curve, and the coordinate figure of area maximum point correspondence is the coordinate figure of the centre of sphere on this scanning direction on the curve;

(4) after the same method, obtain the coordinate figure of the centre of sphere,, combine and be sphere centre coordinate each axial coordinate value at two other change in coordinate axis direction.

11, a kind of navigation system of supporting various modes as claimed in claim 6, it is characterized in that: described demarcation mould is to each coordinate system timing signal, be provided with in the software program of described navigation system by characteristic point imaging results among the feature point set I is carried out the localized program of the centre of sphere, its flow process is as follows:

(1) normal distribution is satisfied in area S and the cross section of at first supposing circle on the sectional view between the coordinate figure on the scanning direction;

(2) along the cross section circular image of ball at same axial arbitrary scan three width of cloth diverse locations, or scanning obtain the cross section circular image of two width of cloth diverse locations after, simulate the 3rd width of cloth cross section circular image, form a class value at the coordinate figure of scanning direction by each cross section area of a circle and this cross section circle through the center of circle;

Three class values that (3) will obtain simulate a Gaussian curve, and the coordinate figure of area maximum point correspondence is the coordinate figure of the centre of sphere on this scanning direction on the curve;

(4) after the same method, obtain the coordinate figure of the centre of sphere,, combine and be sphere centre coordinate each axial coordinate value at two other change in coordinate axis direction.

12, a kind of navigation system of supporting various modes as claimed in claim 7, it is characterized in that: described demarcation mould is to each coordinate system timing signal, be provided with in the software program of described navigation system by characteristic point imaging results among the feature point set I is carried out the localized program of the centre of sphere, its flow process is as follows:

(1) normal distribution is satisfied in area S and the cross section of at first supposing circle on the sectional view between the coordinate figure on the scanning direction;

(2) along the cross section circular image of ball at same axial arbitrary scan three width of cloth diverse locations, or scanning obtain the cross section circular image of two width of cloth diverse locations after, simulate the 3rd width of cloth cross section circular image, form a class value at the coordinate figure of scanning direction by each cross section area of a circle and this cross section circle through the center of circle;

Three class values that (3) will obtain simulate a Gaussian curve, and the coordinate figure of area maximum point correspondence is the coordinate figure of the centre of sphere on this scanning direction on the curve;

(4) after the same method, obtain the coordinate figure of the centre of sphere,, combine and be sphere centre coordinate each axial coordinate value at two other change in coordinate axis direction.

13, as each described a kind of scaling method of supporting the navigation system of various modes of claim 1～6, it is characterized in that: with demarcating mould to each coordinate system timing signal, adopted the separately method of demarcation of rotation amount and translational movement, its step is as follows:

(a) utilization is fixed into as device measuring feature point set I each point at the coordinate that is being fixed in the picture device coordinate system N wherein _PhFor always counting of feature point set I, by coordinate Generate L vector

This L vector

Be distributed in different directions;

(b) utilize tracking system to measure the coordinate of feature point set II each point in the tracking system coordinate system, thereby obtain the coordinate of feature point set I each point in the tracking system coordinate system

Generate and vector in the tracking system coordinate system

Vectorial one to one

(c) these two groups of vectors satisfy transformation relation and are: $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}});$

(d) by equation group $R_{\mathrm{scan}}^{\mathrm{track}}{D}_i^{\mathrm{scan}}=D_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}})$ Can solve spin matrix

Then with its substitution equation group $R_{\mathrm{scan}}^{\mathrm{track}}{X}_i^{\mathrm{scan}}+T_{\mathrm{scan}}^{\mathrm{track}}=X_i^{\mathrm{track}}(i=\mathrm{1,2},...,n_{\mathrm{ph}}),$ Can solve translation vector

Obtain transformation relation And then be fixed the imaging device coordinate system and follow the tracks of transformation relation between the coordinate system

Wherein

Comprise spin matrix And translation vector Promptly

$C_{\mathrm{scan}}^{\mathrm{track}}=\left(\begin{array}{cc}{R}_{\mathrm{scan}}^{\mathrm{track}}& T_{\mathrm{scan}}^{\mathrm{track}}\\ 0& 1\end{array}\right).$

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