CN100515523C - 3-D image guided-moving positioning system based on viewpoint in focus supersonic therapy - Google Patents

Abstract

The three-dimensional image guide movement positioning system based on view point in focusing ultrasonic therapeutic equipment includes the following several portions: therapeutic bed, upper supporting plate for supporting therapeutic bed movement, x-axis straight-line movement mechanism, mechanism capable of controlling rotation of ultrasonic scanner probe, swinging mechanism around Y axis, swinging mechanism around X-axis, middle supporting plate, lower supporting plate, Z-axis lifting straight-line movement mechanism and Y-axis lifting straight-line movement mechanism, etc. Said invention also provides its working principle and application method.

Description

In the focused ultrasound therapy based on the 3-D image guided-moving positioning system of viewpoint

Technical field

The invention belongs to Biomedical Instruments and apparatus field, relate to the motion locating system of a kind of image guiding, be specifically related in the focused ultrasound therapy 3-D image guided-moving positioning system based on viewpoint.

Background technology

High intensity focused ultrasound (High Intensity Focused Ultrasound, HIFU) be with the external supersonic energy focusing at human body deep destination organization, reach the purpose of accurate thermal damage selected target tissue.The effect of high-strength focusing ultrasonic therapy stereotactic system: the one, determine the deep disease sites under the image guiding, the 2nd, determine that the orientation and the short focus supersonic path that are fit to position treatment.

According to the data-searching that the applicant carried out, it is as follows to retrieve document related to the present invention:

Chinese invention patent ZL98100283.8 " high-intensity focus supersonic tumor scanning therapy system " (discloses day on May 5th, 1999, publication number 1215616) disclosed in is that single array element treatment transducer and Ultrasonic-B probe are combined into coupling probe, be arranged on the multidimensional numerical control telecontrol equipment, this telecontrol equipment carries out external scanning motion and reaches required therapeutic effect under computer control.Among the China utility model patent ZL99201009.8 " six coordinate scanning devices in the high-strength focus supersonic therapeutic system ", have 6 degree of freedom completely, realized the space orientation of ultrasound wave focus and the attitude control of ultrasonic wave propagation path.The sweep mechanism of these two kinds of forms is in full accord with 6 traditional coordinate numerally controlled machine tools in fact, main engine bed connects by the shell of centre bore left side connecting plate and leaning device, the leaning device left end is connected with four-dimensional mechanism shell by screw, in the four-dimensional mechanism by three mutual vertical coordinates and a horizontal rotation coordinate, realize 6 degree of freedom completely, ensure the ultrasound wave focus by any specified path and attitude to the target tissue treatment.But, these two kinds of form complicated in mechanical structure, the volume heaviness, manufacturing and installation cost are higher, and the precision of whole system is relatively poor, and from the stressed angle of system, weak link is more, is unfavorable for the maintenance of precision, and maintenance and adjusting are also cumbersome.

Chinese invention patent 03128117.6 " the 5DOF scanning means of focused ultrasound therapy machine " has proposed a kind of focused ultrasound therapy robot of 5 coordinate series parallel structures, this robot adopts 3-PRS parallel institution and two series parallel structures that the polyphone linear moving mechanism is formed, and realizes 5 coordinate motions.3-PRS parallel scan mechanism is equilateral triangle by three driving shafts and vertically arranges, three slide units are loaded on three driving shafts respectively and also can move up and down, and three are waited long connecting rod one end to be revolute pair, to be installed on the slide unit that the other end is connected in moving platform with the ball pair; The 3-PRS moving platform can realize the z axle, around the x axle, around the motion of y axle.Cross table can be installed in the rectilinear motion of realizing two-dimentional x axle, y axle above or below the 3-PRS moving platform.The critical component available standards part of this invention realizes, and is simple in structure, cost is lower, can satisfy the location requirement of focus supersonic.But this parallel mechanism structure is to the requirement of real-time control height, the motion control arithmetic complexity.

Chinese invention patent application number 02145322.5 " stereotactic system in the high-strength focusing ultrasonic therapy " adopts C shape arm mechanism to realize oscillating motion, treatment mechanism assembly and three-dimensional motion bed body, has realized the solid location in the high-strength focusing ultrasonic therapy.Weak point is that C shape arm takes up room bigger.

Summary of the invention

At defective that exists in the above-mentioned prior art or deficiency, the purpose of this invention is to provide in a kind of focused ultrasound therapy 3-D image guided-moving positioning system based on viewpoint, this system can realize the motor control of 6 degree of freedom, the routing motion control algolithm allows the viewpoint angle of doctor from the guiding of B ultrasonic image intuitively, conveniently positioned operation, overcome each operation separately in the existing stereoscan mechanism, make the doctor be difficult to set up the relation of position in the B ultrasonic image and each kinematic axis, and image is looked for the difficulty of position and para-position.

The technical solution adopted in the present invention is, in a kind of focused ultrasound therapy based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that: this system includes high-intensity focusing ultrasonic transducer and Ultrasonic-B probe, described high-intensity focusing ultrasonic transducer is with the attitude location of 5 degree of freedom, wherein the attitude of 3 degree of freedom is x axle, y axle, the orthogonal rectilinear motion of z axle, the attitude of 2 degree of freedom be two mutually vertical and around x axle, the oscillating motion of y axle; The attitude location of above-mentioned 5 degree of freedom is finished by driving mechanism separately; High-intensity focusing ultrasonic transducer also with the coaxial installation of Ultrasonic-B probe, Ultrasonic-B probe carries out ± 90 ° of rotations in high-strength focused transducer, Ultrasonic-B probe is provided with the driving mechanism of control Ultrasonic-B probe rotation, constitutes the B ultrasonic image guiding stereotactic system with 6DOF conversion attitude.

In the focused ultrasound therapy of the present invention based on the 3-D image guided-moving positioning system of viewpoint, it is a stereotactic system, can realize the control of 6 degree of freedom, the 6DOF device adopts cascaded structure, compact conformation, high accuracy, the no synchronous requirement of each motion in the motor process, this stereotactic system is from the viewpoint angle of doctor's B ultrasonic image guiding intuitively, cooperation is based on the motion operation relation of viewpoint, can be intuitively (orientation) on the B ultrasonic image directly on, down, a left side, right, before, the back operation, and need not to take into account each concrete motion, thereby realize the interlock of each.

Description of drawings

Fig. 1 is the shape assumption diagram that the present invention is applied to the focused ultrasound therapy bed;

Fig. 2 is the structural representation that the present invention is applied to the motion locating system of therapeutic bed;

Fig. 3 is a Ultrasonic-B probe free-wheeling system structural representation in the motion locating system of the present invention;

Fig. 4 be among the present invention around a kind of exemplary construction sketch map of x axle, y axle swing mechanism, wherein, a is a front view, b is a vertical view;

Fig. 5 is y axle among the present invention, the straight-line exemplary construction sketch map of z axle, and wherein, a is a front view, and b is a vertical view;

Fig. 6 is the straight-line exemplary construction sketch map of bed body x axle among the present invention;

Fig. 7 is a coordinate transformation sketch map of the present invention, and wherein, a is based on the relation signal of the motion rectangular coordinate system uvw and the axle motion rectangular coordinate system xyz of B ultrasonic viewpoint, and b is the signal of Ultrasonic-B probe rotation coordinate, and c is the coordinate signal of arbitrfary point on the B ultrasonic fan sweeping face.

The present invention is described in further detail below in conjunction with concrete Application Example that accompanying drawing and inventor provide.

The specific embodiment

Referring to accompanying drawing 1～2, Fig. 1 is the shape assumption diagram that the present invention is applied to the focused ultrasound therapy bed, as can be seen from Figure 1, high-intensity focusing ultrasonic transducer places the below of therapeutic bed, therapeutic bed central porose, motion locating system of the present invention very are arranged in the lower space of focusing ultrasonic therapeutic system therapeutic bed compactly.

Referring to Fig. 2, Fig. 2 is the structural representation that the present invention is used for the treatment of the motion locating system of bed, it includes high-intensity focusing ultrasonic transducer 1 and Ultrasonic-B probe 7, and high-intensity focusing ultrasonic transducer is made orthogonal x axle, y axle, z axle rectilinear motion and around the swing of x axle, y axle; The top of high-intensity focusing ultrasonic transducer 1 is useful on last planker 6 and the straight-line driving mechanism 11 of x axle that supports couch motion, leave macropore on the last planker 6, the probe of high-intensity focusing ultrasonic transducer 1 is exposed from macropore, Ultrasonic-B probe 7 is coaxial to be installed in the probe of high-intensity focusing ultrasonic transducer 1, and Ultrasonic-B probe 7 carries out ± 90 ° of rotations in high-strength focused transducer 1.Below high-intensity focusing ultrasonic transducer 1 and Ultrasonic-B probe 7, be provided with driving mechanism 2 around the swing of y axle, the below of driving mechanism 2 also has middle carriage 10, driving mechanism 3 around the swing of x axle is arranged on the middle carriage 10, middle carriage 10 belows are provided with z axle lifting straight-line motion mechanism 4, it is seated down on the planker 9, and the y axle straight-line motion mechanism 5 of following planker 9 and its underpart is seated and places near on the base plate 8 on ground.Constituted B ultrasonic image and guided three-dimensional locating therapy system with 6DOF conversion attitude.The B ultrasonic image can constitute the three-dimensional data image reconstruction on the xy plane along the arbitrary axis parallel sweep, also can allow the Ultrasonic-B probe autobiography constitute the three-dimensional data image reconstruction.

Fig. 3 is the structural representation of Ultrasonic-B probe rotation.The driving mechanism of Ultrasonic-B probe rotation is made up of the gear 12 of servomotor 18, driven wheel 13 and the coaxial assembling of Ultrasonic-B probe, and servomotor 18 drives driven wheel 13 and will make Ultrasonic-B probe 7 rotations with certain rotating ratio driven gear 12.Because high-intensity focusing ultrasonic transducer 1 underlying, Ultrasonic-B probe 7 parts of rotation are provided with sealing ring and effectively prevent from down to leak, be provided with pressure ring 15 at high-strength focused transducer 1 and between the mechanism 2 of y axle swing, pressure ring 15 tops link to each other with the water pocket 16 of purifying waste water that outgases that holds of the high-intensity focusing ultrasonic transducer 1 of underlying.

Fig. 4 is around a kind of exemplary construction sketch map of x axle, y axle swing mechanism among the present invention.Two can form around the cone of the vertex of a cone (confocal point) in around axle swing and to swing.Driving mechanism 2 around the swing of y axle places in the mechanism 3 of x axle swing, and two oscillating motions are vertical mutually; The structure of diaxon swing mechanism is the same, thus at this one of them swinging structure of explanation promptly around the mechanism 2 of y axle swing.In the mechanism 2 of y axle swing, servomotor 17 drives ball screw 18 rotations and makes nut 19 moving linearlies, two in the sandwich of nut 19 and be with moving linearly synchronously one, band is supported on four synchronizing wheels 20 synchronously, and band drives mechanism's 2 motions around the swing of y axle synchronously; External arc runway 21 around the mechanism 2 that the y axle is swung is tangent with synchronizing wheel 20, and a plurality of bearings 14 are housed on the external arc runway 21, and bearing 14 (Fig. 3 shows) moves on the circular arc runway, so rectilinear motion just is converted into swing; Its oscillation center is a focus, swing cone-apex angle ± 30 ° of scopes in.This two mechanism has realized swing in the two-dimentional cone, and its structure is very compact, and the rotation and the pivot angle of motor are linear, high accuracy, stepless, super-silent motion.

Fig. 5 is the straight-line a kind of exemplary construction sketch map of y axle among the present invention, z axle.Y axle straight-line motion mechanism 5 is seated on the base plate 8, comprises that y axle servomotor 29 drives ball screw 30 and rotates, and the nut on the ball screw 30 is connected with following planker 9, and both sides are equipped with line slideway 31 on the base plate 8; The rotation of ball screw 30 can drive down planker 9 and make the axial linear reciprocating motion of y along line slideway 31.

Z axle lifting straight-line motion mechanism 4 is seated in down on the planker 9, in the z axle lifting straight-line motion mechanism 4, z axle servomotor 25 and synchronizing wheel be with 26 to be connected synchronously, synchronizing wheel be with 26 to be connected with ball screw 27 again synchronously, z axle servomotor 25 makes synchronizing wheel and rotates with the nut on the 26 rotating band movable wire bars synchronously and then drive ball screw 27 and do the elevating movement of z axle; Vertical fixing has three z axle line slideways 28 on middle carriage 10 above the z axle lifting straight-line motion mechanism 4, and the motion of ball screw 27 drives middle carriage 10 and makes z axle lifting rectilinear motion along z axle line slideway 28.

Fig. 6 is a kind of exemplary construction sketch map of bed body x axle rectilinear motion 11 among the present invention.X axle straight-line motion mechanism 11 comprises x axle servomotor 32, x axle servomotor 32 is connected with ball screw 33, be set with nut 35 on the ball screw 33, x axle servomotor 32 drives ball screw 33 and rotates, make nut 35 along x axle rectilinear motion, the bottom that is fixed on the therapeutic bed on the x axle straight-line motion mechanism 11 also is provided with 6 x axle line slideways 34, and the motion of nut 35 drives therapeutic bed and makes x axle linear reciprocating motion along 6 line slideways 34.

Based on the motion algorithm of viewpoint referring to Fig. 7.

At first calculate the position of Ultrasonic-B probe observation station:

Oscillating motion of the present invention is that two arching trajectorys have a common center of circle (focus), is made as A (x ₀, y ₀, z ₀); This is also observed on the segmental central shaft at B ultrasonic on the central shaft of high-intensity focusing ultrasonic transducer 1 simultaneously; Therefore, the position of this point is with changing around x Shaft angle α with around the motion of y Shaft angle β and angle of rotation θ.What determine this point coordinates is the rectilinear motion of x axle, y axle, z axle.B (x ₁, y ₁, z ₁) be the central point of phased array supersonic probe, and straight line BA is exactly the axis of high-intensity focusing ultrasonic transducer and B ultrasonic sector.

Cross the parallel lines L that some B do the x axle, π plane and plane xy plane parallel, | AB|=l, by following three equations:

|y ₀-y ₁|＝l*sin?α (1)

|x ₀-x ₁|＝l*cosα*sinβ (2)

|z ₀-z ₁|＝l*cosα*cosβ (3)

Can obtain observing the coordinate B (x of probe B point ₁, y ₁, z ₁).

Be based on the motion algorithm of B ultrasonic viewpoint then:

Foundation is based on the motion rectangular coordinate system uvw of B ultrasonic viewpoint, and wherein the straight line at BA place is u.

The unit vector of v axle is v in the coordinate system:

$v=(\frac{1}{\sqrt{(1+k^2)}},\frac{k}{\sqrt{(1+k^2)}},0)---\left(4\right)$

$k=-\frac{(x_1-x_0)}{(y_1-y_0)}$

Again because the unit vector of u is u:

$u=(\frac{x_0-x_1}{l},\frac{y_0-y_1}{l},\frac{z_0-z_1}{l})$

l＝|AB| (5)

Unit vector w and u, v are the right-handed helix coordinate system, then

w＝u×v

Can calculate the length of r and ρ referring to Fig. 7 c by the G point at the coordinate of B ultrasonic coordinate system.

The r vector at v, is decomposed into two orthogonal vectors on the w, the vector of establishing on the v axle is r ', and the vector on the w axle is r ", following relation is then arranged:

Ask r ':

Equation by straight line v can obtain, and unit vector v is:

$v=(\frac{1}{\sqrt{(1+k^2)}},\frac{k}{\sqrt{(1+k^2)}},0)$

$k=-\frac{(x_1-x_0)}{(y_1-y_0)}---\left(6\right)$

∴ $r^{\′}=v*(r*\cos \mathrm{\θ})=(\frac{r*\cos \mathrm{\θ}}{\sqrt{(1+k^2)}},\frac{k*r*\cos \mathrm{\θ}}{\sqrt{(1+k^2)}},0)$

$k=-\frac{(x_1-x_0)}{(y_1-y_0)}---\left(7\right)$

Ask r "

Unit vector because of u is again:

$u=(\frac{x_0-x_1}{l},\frac{y_0-y_1}{l},\frac{z_0-z_1}{l})$

l＝|AB| (8)

Unit vector w and u, v are the right-handed helix coordinate system, then

w＝u×v

∴r″＝w*(r*sinθ) (9)

(wherein " * " is the cross product of vector)

In addition, for 1 D (x on the straight line BA ₂, y ₂, z ₂), because BA linear equation and BD length are known, therefore, the coordinate that D is ordered is:

D＝B+u*ρ (10)

That is:

$x_2=x_1+\frac{x_0-x_1}{l}*\mathrm{\ρ}$

${\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="C20051009606600141.png"\; state="\{\{state\}\}">y</figure-callout>}}_2=y_1+\frac{y_0-y_1}{l}*\mathrm{\&rho;}$

${\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="C20051009606600141.png"\; state="\{\{state\}\}">z</figure-callout>}}_2=z_1+\frac{z_0-z_1}{l}*\mathrm{\&rho;}---\left(11\right)$

∴ $\stackrel{\&RightArrow;}{G}=\stackrel{\&RightArrow;}{D}+{\stackrel{\&RightArrow;}{r}}^{\&prime;}+{\stackrel{\&RightArrow;}{r}}^{\&prime;\&prime;}---\left(12\right)$

Can realize doctor's directly up, down, left, right, before and after operation on the B ultrasonic image thus, and use the motion that is converted to 6 axles with co-relation.

With stereotactic system of the present invention, cooperate above motion operation relation based on viewpoint, can (orientation) directly up, down, left, right, before and after operation on the B ultrasonic image intuitively, need not to take into account each concrete motion, thereby realize the interlock of each.

Claims (7)

1. In the focused ultrasound therapy based on the 3-D image guided-moving positioning system of viewpoint, this system includes high-intensity focusing ultrasonic transducer and Ultrasonic-B probe, it is characterized in that: the top of high-intensity focusing ultrasonic transducer is useful on last planker and the straight-line driving mechanism of x axle that supports couch motion, leave macropore on the last planker, the probe of high-intensity focusing ultrasonic transducer is exposed from macropore, below high-intensity focusing ultrasonic transducer and Ultrasonic-B probe, be provided with driving mechanism around the swing of y axle, the below of driving mechanism also has middle carriage, driving mechanism around the swing of x axle is arranged on the middle carriage, the middle carriage below is provided with z axle lifting straight-line motion mechanism, it is seated down on the planker, and the y axle straight-line motion mechanism of following planker and its underpart is seated and places near on the base plate on ground; Described high-intensity focusing ultrasonic transducer is with the attitude location of 5 degree of freedom, wherein the attitude of 3 degree of freedom is x axle, y axle, the orthogonal rectilinear motion of z axle, the attitude of 2 degree of freedom be two mutually vertical and around x axle, the oscillating motion of y axle, its oscillation center is a focus; The attitude location of above-mentioned 5 degree of freedom is finished by driving mechanism separately; The driven by servomotor ball screw of swing mechanism rotates and makes the nut moving linearly, two in the sandwich of nut and is with moving linearly synchronously one, and band is supported on four synchronizing wheels synchronously, and band drives the driving mechanism motion around the swing of y axle synchronously; External arc runway and synchronizing wheel around the driving mechanism of y axle swing are tangent, and a plurality of bearings are housed on the external arc runway, and bearing moves on the circular arc runway;

   High-intensity focusing ultrasonic transducer also with the coaxial installation of Ultrasonic-B probe, Ultrasonic-B probe carries out ± 90 ° of rotations in high-strength focused transducer, Ultrasonic-B probe is provided with the driving mechanism of control Ultrasonic-B probe rotation, constitutes the B ultrasonic image guiding stereotactic system with 6DOF conversion attitude.
2. 2. based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that in the focused ultrasound therapy as claimed in claim 1 that two can form in the confocal cone of the vertex of a cone around axle swing and to swing, swing cone-apex angle ± 30 ° of scopes in.
3. 3. in the focused ultrasound therapy as claimed in claim 1 based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that, the straight-line driving mechanism of described y axle comprises y axle servomotor (29), y axle servomotor (29) is connected with y shaft ball screw (30), be used to drive ball screw (30) and rotate, planker (9) was made the axial linear reciprocating motion of y along line slideway (31) under the nut on the ball screw (30) drove.
4. 4. in the focused ultrasound therapy as claimed in claim 1 based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that, the straight-line driving mechanism of described z axle lifting comprises z axle servomotor (25), z axle servomotor (25) is connected with synchronous band (26) with synchronizing wheel, synchronizing wheel is connected with ball screw (27) again with synchronous band (26), z axle servomotor (25) makes synchronizing wheel and band (26) rotation synchronously and then drive ball screw (27) do the elevating movement of z axle, with the perpendicular z axle line slideway (28) that is fixed with of z axle lifting rectilinear motion driving mechanism top middle carriage (10), the motion of ball screw (27) drives middle carriage (10) and makes z axle lifting rectilinear motion along z axle line slideway (28).
5. According in the described focused ultrasound therapy of claim 4 based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that described z axle line slideway is provided with three.
6. According in the described focused ultrasound therapy of claim 1 based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that, the straight-line driving mechanism of described x axle comprises x axle servomotor (32), x axle servomotor (32) is connected with ball screw (33), be set with nut (35) on the ball screw (33), x axle servomotor (32) drives ball screw (33) and rotates, make nut (35) along x axle rectilinear motion, the bottom that is fixed on the therapeutic bed on the x axle straight-line motion mechanism (11) also is provided with x axle line slideway (34), and the motion of nut (35) drives therapeutic bed and makes x axle rectilinear motion along line slideway (34).
7. 7. based on the 3-D image guided-moving positioning system of viewpoint, it is characterized in that in the focused ultrasound therapy as claimed in claim 6 that described x axle line slideway is provided with 6.

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