CN114699142A - Pneumatic rigidity-variable six-freedom-degree CT-MRI needle puncture robot - Google Patents

Abstract

The invention discloses a pneumatic rigidity-variable six-freedom-degree CT-MRI needle puncture robot. The device comprises a plane positioning module, a pneumatic posture adjusting module and a needle inserting module. The plane positioning module drives the locking stator sliding block to move in the moving female sliding block through pneumatic muscles to complete the locking and the unlocking of the movement of the moving female sliding block; the pneumatic posture adjusting module is in an inflation and deflation state in the air bag to limit the rotational freedom degree of the puncture needle on the spherical hinge; the needle inserting module drives the steering gear through the long gear column to realize the rotation angle control of the puncture needle around the needle shaft, and simultaneously drives the needle inserting slide block to linearly move along the screw rod through the rotation of the screw rod to realize the degree of freedom of the needle inserting of the puncture needle. The invention has compact structure and simple control, the processing materials are all non-metallic materials, the CT-MRI is compatible, the posture fixation of the puncture needle is realized by utilizing pneumatics, and the quantitative needle insertion is realized by utilizing a ceramic motor, a wire drive mechanism or manual drive.

Description

Six-DOF CT-MRI Needle Puncture Robot with Pneumatic Variable Stiffness

technical field

The invention belongs to a puncture robot in the field of medical device manufacturing and application, in particular to a six-degree-of-freedom CT-MRI needle puncture robot with pneumatic variable stiffness.

Background technique

Clinically, if a lung lesion is found by CT examination, but it is not sure whether it is caused by infection, non-lesion infection, or tumor, especially if malignant tumor cannot be ruled out, a lung biopsy is required to clarify the nature of the lesion. Lung puncture is also performed under the positioning of CT to puncture the lesion to take out some tissues for routine examination. However, CT-guided puncture also has disadvantages: for example, because the imaging is not timely, the breathing movement will cause errors in accurate positioning, and the patient must be trained to master the breathing phase. When the puncture needle needs to form a certain angle with the cross section, the puncture technique has certain difficulties, so it is necessary to continuously adjust the pose of the puncture needle through CT images. However, it takes a certain amount of time to generate the CT image, and the observation of the CT image needs to leave the operating table. Therefore, in the process of lung puncture, the puncture needle needs to be continuously adjusted according to the CT image before the procedure. After the initial determination of the posture, the doctor sticks the positioning paper in the appropriate place to preliminarily determine the position of the puncture point. Therefore, the surgeon needs to constantly adjust the puncture needle and then fix the puncture needle. After completing the initial positioning, the doctor needs to leave the operating room and perform a CT scan on the patient again to determine the needle insertion direction and angle to determine the insertion point. After the needle insertion is determined and the puncture needle enters the predetermined depth, it is necessary to scan again to determine the position of the needle tip; if the needle tip does not reach the lesion, it needs to be adjusted according to the scanning results, and the puncture is completed by repeating this process. Nowadays, in most cases, medical staff fix the puncture needle that is pierced halfway on the patient by puncturing the positioning needle. However, because the patient's breathing will drive the puncture needle to move together, the puncture needle is easily displaced or even falls off during the operation. Finally, it leads to problems such as failure of surgery, inaccurate positioning, and excessive removal of lung tissue. The current solution for medical staff is to directly use tape or gauze to wrap and fix it, and some use a gantry bracket on the operating table to fix the puncture needle. However, due to the patient's breathing, this effect is often poor. So it is difficult to really fix the puncture needle. In addition, considering the health of the medical staff, the medical staff cannot be exposed to the radiation for a long time, and the CT scanning process cannot be interfered, so it is not possible to arrange a medical staff to fix it manually. Therefore, it is urgent to develop a small puncture needle fixing device that can be attached to the patient, and the fixing device needs to realize multi-degree-of-freedom motion, so as to facilitate the doctor to realize the puncture angle movement trajectory control and puncture of the puncture needle. Procedure for the fixation of the puncture needle.

In practical application, the fixing device is used for liver puncture surgery, so the device needs to move within a plane of 100mm*100mm to ensure that the puncture needle can pierce any position. At the same time, the uncertainty of the puncture position often not only needs to control the plane position of the puncture needle, but also needs to control the spatial posture of the puncture needle, that is, the puncture angle. Therefore, the fixing device also needs to control the swing angle of the puncture needle. However, too many degrees of freedom control means a more complicated transmission mechanism, and at the same time, the fixing device must be attached to the chest cavity of the patient, so the device needs to be compact and small. Therefore, under the condition of normal use, the device is designed to control the four degrees of freedom of the puncture needle, so as to realize the movement along the horizontal plane, the rotation in the vertical plane, and the rotation in the horizontal plane. Finally, in the actual puncture process, the puncture depth and puncture rotation angle of the puncture needle also affect the hit accuracy. Therefore, on the basis of the fixed four degrees of freedom, additional modules for quantitative rotation of the puncture needle and puncture depth control are added.

Invention patent content

In order to realize the functions required in the background art, the present invention provides a six-degree-of-freedom CT-MRI needle puncturing robot with pneumatic variable stiffness. It can provide six degrees of freedom auxiliary fixed puncture needle to assist the doctor to complete the accurate fixation of the biopsy needle in the CT-MRI working environment, improve the doctor's ability to control the puncture needle during the operation, and ensure that the puncture robot is not affected by the patient's breathing during the puncture process. influence of exercise.

The technical scheme adopted in the present invention is as follows:

The invention is mainly composed of a two-degree-of-freedom plane positioning module, a two-degree-of-freedom attitude fixing module and a two-degree-of-freedom rotating needle feeding module; the two-degree-of-freedom attitude fixing module is installed on the two-degree-of-freedom plane positioning module, and the two-degree-of-freedom rotating needle feeding module It is installed on the two-degree-of-freedom attitude fixing module, and the biopsy needle is installed on the two-degree-of-freedom rotating needle-in module.

The two-degree-of-freedom plane positioning module includes a base, a plane positioning mechanism and a posture fixing mechanism; two of the bases are placed in parallel and opposite to each other, and an adapter is installed at both ends of each base. A plane positioning mechanism is installed between the two ends of the seat, and each plane positioning mechanism includes a carbon fiber tube, a locking bar and a female slider; the two carbon fiber tubes pass through the female slider in parallel and at a relative interval, and then pass through the rotation. The connector is fixedly connected to one end of the two bases, and the two locking bars also pass through the female slider in parallel and at intervals, and are fixedly connected to one end of the two bases through the adapter, The two locking bars are located under the carbon fiber tubes and are respectively placed in parallel with the two carbon fiber tubes and spaced apart from each other; between the female sliders of the two plane positioning mechanisms, there is also a structure substantially the same as that of the plane positioning mechanism. An attitude fixing mechanism, the female slider in the attitude fixing mechanism is used as a needle seat female slider, and the carbon fiber tube and the locking strip in the attitude fixing mechanism are fixedly connected to the two female sliders.

The female slider and the needle seat female slider are both hollow inside, and in their respective interiors, the air guide tube, the pneumatic muscle, the tension rope and the two sub-locking sliders are arranged horizontally perpendicular to the sliding directions of the female slider and the needle seat female slider. The pneumatic muscle and the tension rope are located between the two sub-locking sliders, and the air tube is installed on the pneumatic muscle; after the air tube is inflated to the pneumatic muscle, the pneumatic muscle begins to expand and push the sub-locking slider to both sides Move inside the female slider or the needle seat female slider until the sawtooth surface provided on the outside of the locking slider coincides with the sawtooth surface provided on the inner side of the locking strip to form a structural limit, and the female slider or the needle seat female slider is blocked. Fixed at the current position, while the tension rope is tightened; when the pneumatic muscle does not work, the tension rope pulls the sub-locking sliders on both sides to the inside, and the serrated surface on the outside of the sub-locking slider is separated from the serrated surface on the inner side of the locking bar. , the female slider or the needle seat female slider to release the structural limit.

The two female sliders and one needle seat female slider both use the carbon fiber tube as a guide rail and slide freely along the carbon fiber tube; both the female slider and the needle seat female slider are in sliding contact with the upper and lower surfaces of the locking bar to slide freely along the locking bar without contact with the inner serrated surface of the locking bar.

The posture fixing mechanism further includes a ball hinge, which is sleeved at the inner center position of the needle seat female slider and is movably connected with the needle seat female slider;

The two-degree-of-freedom posture fixing module includes a locking airbag base, a locking airbag, a puncture needle sleeve and an airbag locking particle; the puncture needle sleeve passes through the locking airbag, the locking airbag base and the needle seat mother sequentially from top to bottom The center through hole of the slider is fixedly installed on the ball hinge installed inside the needle seat female slider; the locking airbag base is fixedly installed on the upper part of the needle seat female slider, and the locking airbag is fixedly installed on the airbag base, An air inlet pipe is arranged on the side of the locking air bag, and a plurality of air bag locking particles are arranged inside the locking air bag, and the locking air bag is connected with the external vacuum pump through the air inlet pipe.

The two-degree-of-freedom rotating needle insertion module includes a lower fixed seat of the needle insertion module, a carbon fiber tube B, a needle insertion slider, a boss gear, a screw, a gear limiter, a biopsy needle, an upper limit seat of the needle insertion module, and a coupling. and long gear column; the upper seat of the needle entry module is located just above the lower fixed seat of the needle entry module, wherein the lower fixed seat of the needle entry module and the upper seat of the needle entry module are connected by a vertical carbon fiber tube B, the screw and the long The gear column is vertically arranged parallel to the carbon fiber tube B between the lower fixed seat of the needle feeding module and the upper seat of the needle feeding module. The screw rod and the upper end of the long gear column pass through the upper seat of the needle feeding module and pass through their respective coupling shafts. connected to the external drive source;

A needle entry slider is arranged between the upper seat of the needle entry module and the lower fixed seat of the needle entry module, a boss gear is hinged on the needle entry slider, and the needle entry slider is provided with a central through hole, so The biopsy needle sequentially passes through the central through hole of the needle entry slider from bottom to top and then is fixedly sleeved on the through hole where the central axis of the boss gear is located;

The two-degree-of-freedom rotating needle entry module further includes a gear stopper, the needle entry slider is provided with a gear stopper for protecting the boss gear, and the biopsy needle moves through the through hole opened on the gear stopper at the same time.

The inner thread provided on the side of the needle sliding block forms a rotating pair with the screw, the rotation of the screw drives the needle sliding block to move linearly along the axis of the screw, and the biopsy needle passes through the gear limit sequentially from top to bottom. The central through hole of the part, the boss gear and the needle feed slider are fixedly sleeved on the central axis of the boss gear. The boss gear is meshed with the long gear column to form a gear pair, and the long gear column passes through the gear pair. Drive the boss gear to rotate in a circle, and then drive the biopsy needle to rotate around its own axis. The lower holder of the needle entry module connects down to the locking bladder.

The locking airbag utilizes negative pressure contraction to limit the fluidity of the locked particles in the airbag inside the locking airbag, and controls the puncture needle sleeve to be fixed in any posture.

The long gear column cooperates with the boss gear to control the biopsy needle to rotate quantitatively; the screw rod cooperates with the needle insertion slider to control the needle insertion length of the biopsy needle to achieve quantitative needle insertion.

The whole mechanism is made of non-metallic materials.

The two-degree-of-freedom rotating needle feeding module is connected to a ceramic machine and a wire drive mechanism through a coupling to realize machine drive, or directly manually drive to realize man-machine switching.

The ball hinge is movably connected with the needle seat female slider inside the needle seat female slider to form a rotating pair.

The beneficial effects of the present invention are:

All components of the present invention are made of non-metallic materials, which ensures that there are no metal dense objects in the CT section and in the MRI during the needle puncture operation, and can be compatible with CT-MRI equipment to realize CT-MRI imaging.

The present invention adopts the idea of modular design, and the three sub-modules do not depend on each other and can be used independently.

According to the principle of reducing the fluidity of particles inside the airbag under the state of pneumatic negative pressure, the present invention designs and manufactures a variable-stiffness puncture needle cylinder fixing module, that is, a two-degree-of-freedom posture fixing module, which can fix the puncture needle in any posture, and has a simple and compact design.

The invention provides the puncture needle with a four-degree-of-freedom passive posture fixation function and a two-degree-of-freedom active needle feeding function, and can provide any posture fixation of the puncture needle and quantitative needle feeding and rotating operation functions.

Description of drawings:

Fig. 1 is the general assembly drawing of the present invention;

Fig. 2 is the two-degree-of-freedom plane positioning module of the present invention;

3 is a two-degree-of-freedom two-degree-of-freedom pneumatic attitude adjustment module of the present invention;

Fig. 4 is a two-degree-of-freedom needle feeding module of the present invention;

Fig. 5 is the part drawing of component 4;

Fig. 6 is the part drawing of component 5;

Figure 7 Part 4 locking bar parts diagram.

1- Base, 2- Adapter, 3- Carbon Fiber Tube A, 4- Locking Strip, 5- Female Slider, 6- Airway Tube, 7- Needle Block Female Slider, 8- Locking Airbag Base, 9- Needle Insertion Module Lower Fixture, 10-Locking Airbag, 11-Carbon Fiber Tube B, 12-Needle Insertion Slider, 13-Boss Gear, 14-Screw, 15-Gear Limiter, 16-Biopsy Needle, 17-Inlet Needle module upper holder, 18-coupling, 19-puncture needle sleeve, 20-ball hinge, 21-pneumatic muscle, 22-tension rope, 23-child locking slider, 24-balloon locking particle, 25-long Gear column, 26 - intake pipe.

Detailed ways

As shown in the overall assembly diagram in Figure 1, the robot is divided into three independent working modules through modular design, which are mainly composed of a two-degree-of-freedom plane positioning module, a two-degree-of-freedom attitude fixing module and a two-degree-of-freedom module. The two-degree-of-freedom attitude fixing module is installed on the two-degree-of-freedom plane positioning module, the two-degree-of-freedom rotating needle-entering module is installed on the two-degree-of-freedom attitude fixing module, and the biopsy needle 16 is installed on the two-degree-of-freedom rotating needle module. on the needle module. The two-degree-of-freedom attitude fixing module is driven to move horizontally by the two-degree-of-freedom plane positioning module, the two-degree-of-freedom rotating needle insertion module is driven to tilt along the needle insertion direction by the two-degree-of-freedom attitude fixing module, and the biopsy needle 16 is driven by the two-degree-of-freedom rotating needle insertion module. Up and down lift and rotation.

Specifically, the two-degree-of-freedom plane positioning module includes a base 1, a plane positioning mechanism and an attitude fixing mechanism; two bases 1 are placed in parallel and opposite to each other, and an adapter 2 is installed at both ends of each base 1, and the two A plane positioning mechanism is installed between the two ends of the base 1, and each plane positioning mechanism includes a carbon fiber tube 3, a locking bar 4 and a female slider 5; the two carbon fiber tubes 3 pass through the female slider in parallel and opposite to each other. The block 5 is fixedly connected to one end of the two bases 1 through the adapter 2, and the two locking bars 4 also pass through the female slider 5 in parallel and at intervals, and then are fixedly connected to the two bases 1 through the adapter 2. At one end, the two locking bars 4 are located under the carbon fiber tubes 3 and are placed in parallel and opposite to the two carbon fiber tubes 3 and spaced apart respectively; between the female sliders 5 of the two plane positioning mechanisms, there is also a structure substantially the same as that of the plane positioning mechanism. Attitude fixing mechanism, the female slider 5 in the attitude fixing mechanism is used as the needle seat female slider 7, the carbon fiber tube 3 and the locking bar 4 in the attitude fixing mechanism are fixedly connected to the two female sliders 5, wherein the base 1 passes through The adapter 2 provides support and fixation for the carbon fiber tube 3 and the locking strip 4 .

As shown in Figures 2 and 5, the two-degree-of-freedom plane positioning module and the parts of the needle seat female slider 7, the female slider 5 and the needle seat female slider 7 are both hollow inside, and in their respective interiors, the female slider 5 is perpendicular to each other. The air guide tube 6, the pneumatic muscle 21, the tension rope 22 and the two sub-locking sliders 23 are arranged horizontally with the sliding direction of the needle seat female slider 7; The trachea 6 is installed on the pneumatic muscle 21; after the airway 6 is inflated to the pneumatic muscle 21, the pneumatic muscle 21 begins to expand and push the sub-locking slider 23 to both sides to move inside the female slider 5 or the needle seat female slider 7 until it is locked. The serrated surface provided on the outer side of the slider 23 overlaps with the serrated surface provided on the inner side of the locking bar 4 to form a structural limit, the female slider 5 or the needle seat female slider 7 is fixed at the current position, and the tension rope 22 is pulled at the same time. When the pneumatic muscle 21 does not work, the tension rope 22 pulls the sub-locking sliders 23 on both sides to the inside, and the serrated surface on the outer side of the sub-locking slider 23 is separated from the inner serrated surface of the locking bar 4, and the female slider 5 or the needle The seat mother slider 7 releases the structural limit. The pneumatic muscle 21 drives the sub-locking slider 23 to cooperate with the sawtooth surface to complete the switching of the sliding/locking state of the female slider 5 and the needle seat female slider 7 on the guide rail to complete the plane positioning.

Two female sliders 5 and one needle seat female slider 7 both use the carbon fiber tube 3 as a guide rail and slide freely along the carbon fiber tube 3; the female slider 5 and the needle seat female slider 7 slide with the upper and lower sides of the locking bar 4 Contact to slide freely along the locking bar 4, without contact with the inner serrated surface of the locking bar 4. The part diagram of the locking bar 4 is shown in FIG. 7 . In addition, the posture fixing mechanism also includes a ball hinge 20 , which is sleeved at the inner center position of the needle seat female slider 7 and is movably connected with the needle seat female slider 7 .

As shown in FIG. 3, the two-degree-of-freedom pneumatic attitude adjustment module includes a locking airbag base 8, a locking airbag 10, a puncture needle sleeve 19 and airbag locking particles 24; the puncture needle sleeve 19 is from top to bottom It passes through the central through hole of the locking airbag 10, the locking airbag base 8 and the needle seat female slider 7 in sequence, and then is fixedly installed on the spherical hinge 20 installed inside the needle seat female slider 7; the locking airbag base 8 is fixedly installed on the On the upper part of the needle seat female slider 7, the locking air bag 10 is fixedly installed on the air bag base 8. The needle seat female slider 7 is the ball hinge 20, which provides the installation fulcrum for the locking air bag base 8. The side of the locking air bag 10 is provided with an air intake pipe 26 , and a number of airbag locking particles 24 are arranged inside the locking airbag 10, wherein the airbag locking particles 24 are round balls that can flow freely inside the airbag, and the locking airbag 10 is connected with the external vacuum pump through the air intake pipe 26; when the inside of the locking airbag 10 is pumped Vacuum, the locking airbag 10 is contracted, and the airbag locking particles 24 are squeezed. After the fluidity of the airbag locking particles 24 disappears, a fixed body is formed together with the locking airbag 10 in the current posture. The puncture needle sleeve 19 on the spherical hinge 20 is fixed by the current state The posture is locked, thereby restricting the two degrees of freedom corresponding to the spherical hinge 20, that is, the degrees of freedom of rotation around the x-axis and around the y-axis.

As shown in Figure 4, the two-degree-of-freedom needle-feeding module includes a needle-feeding module lower fixing base 9, a carbon fiber tube B11, a needle-feeding slider 12, a boss gear 13, a screw 14, and a gear limiter 15, biopsy needle 16, upper seat 17 of the needle insertion module, coupling 18 and long gear column 25; The seat 9 and the upper position seat 17 of the needle feeding module are connected by a vertical carbon fiber tube B11, and the screw 14 and the long gear column 25 are vertically arranged parallel to the carbon fiber tube B11 on the lower fixed seat 9 of the needle feeding module and the upper position of the needle feeding module. Between the seats 17, the screw 14 and the upper end of the long gear column 25 are connected to the external drive source through their respective couplings 18 after passing through the upper seat 17 of the needle entry module;

A needle insertion slider 12 is arranged between the upper seat 17 of the needle insertion module and the lower fixed seat 9 of the needle insertion module. The needle insertion slider 12 is hinged with a boss gear 13, and the needle insertion slider 12 is provided with a central through hole for biopsy. The needle 16 sequentially passes through the central through hole of the needle-in slider 12 from bottom to top, and then is fixedly sleeved on the through hole where the central axis of the boss gear 13 is located.

Wherein, the two-degree-of-freedom rotating needle insertion module further includes a gear stopper 15 , a gear stopper 15 for protecting the boss gear 13 is provided on the needle insertion slider 12 , and the biopsy needle 16 moves through the gear stopper 15 at the same time. through holes opened on.

The needle sliding block 12 forms a rotating pair with the screw 14 through the inner thread provided on the side. The rotation of the screw 14 drives the needle sliding block 12 to move linearly along the axis of the screw 14, that is, to move along the z-axis. The biopsy needle 16 moves from top to bottom. The lower part passes through the gear limiter 15, the boss gear 13 and the central through hole of the needle entry slider 12 in sequence, and then is fixedly sleeved on the central axis of the boss gear 13, and the boss gear 13 is meshed with the long gear column 25. Gear pair, the long gear column 25 drives the boss gear 13 to rotate circularly through the gear pair, and then drives the biopsy needle 16 to rotate around its own axis, that is, along the z-axis. The parts diagram of the long gear column 25 is shown in Figure 6. The biopsy needle 16 passes through the needle insertion module bracket and continues to pass through the puncture needle sleeve 19 to finally reach the target human body; the needle insertion module lower fixing seat 9 in the needle insertion module bracket is downwardly connected to the locking balloon 10 . The gear limiter 15 is used to maintain the relative position of the boss gear 13 and the needle advancing slider 12 .

In specific implementation, the locking airbag 10 utilizes negative pressure contraction to limit the fluidity of the airbag locking particles 24 inside the locking airbag 10 to achieve variable stiffness and stiffness transformation, and controls the puncture needle sleeve 19 to be fixed in any posture.

The long gear column 25 cooperates with the boss gear 13 to control the biopsy needle 16 to rotate quantitatively; the screw 14 cooperates with the needle insertion slider 12 to control the needle insertion length of the biopsy needle 16 to achieve quantitative needle insertion. The ball hinge 20 is movably connected with the needle seat female slider 7 inside the needle seat female slider 7 to form a rotating pair.

Among them, the two-degree-of-freedom rotary needle feeding module is connected to a ceramic machine and a wire drive mechanism through a coupling to realize machine drive, or direct manual drive to realize man-machine switching. And the whole mechanism is made of non-metallic materials, which can be compatible with CT-MRI detection equipment.

Claims (10)

1. A pneumatic rigidity-variable six-freedom CT-MRI needle puncture robot is characterized in that; mainly comprises a two-degree-of-freedom plane positioning module, a two-degree-of-freedom attitude fixing module and a two-degree-of-freedom rotary needle inserting module; the two-degree-of-freedom posture fixing module is arranged on the two-degree-of-freedom plane positioning module, the two-degree-of-freedom rotary needle feeding module is arranged on the two-degree-of-freedom posture fixing module, and the biopsy needle (16) is arranged on the two-degree-of-freedom rotary needle feeding module.

2. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 1, wherein: the two-degree-of-freedom plane positioning module comprises a base (1), a plane positioning mechanism and a posture fixing mechanism; the two bases (1) are oppositely arranged in parallel at intervals, the two ends of each base (1) are respectively provided with an adapter (2), a plane positioning mechanism is arranged between the two ends of each base (1), and each plane positioning mechanism comprises a carbon fiber tube (3), a locking strip (4) and a female sliding block (5); the two carbon fiber tubes (3) penetrate through the female sliding block (5) in parallel at intervals and are fixedly connected to one ends of the two bases (1) through the adaptor (2), the two locking strips (4) penetrate through the female sliding block (5) in parallel at intervals and are fixedly connected to one ends of the two bases (1) through the adaptor (2), and the two locking strips (4) are located below the carbon fiber tubes (3) and are respectively placed in parallel with the two carbon fiber tubes (3) at intervals; a posture fixing mechanism which has the same structure as the plane positioning mechanism basically is also arranged between the female sliding blocks (5) of the two plane positioning mechanisms, the female sliding block (5) in the posture fixing mechanism is used as a needle base female sliding block (7), and the carbon fiber tube (3) and the locking strip (4) in the posture fixing mechanism are both fixedly connected to the two female sliding blocks (5);

the female sliding block (5) and the needle seat female sliding block (7) are hollow, and in the respective interiors, an air duct (6), a pneumatic muscle (21), a tension rope (22) and two sub-locking sliding blocks (23) are horizontally arranged in a direction perpendicular to the sliding direction of the female sliding block (5) and the needle seat female sliding block (7); the pneumatic muscle (21) and the tension rope (22) are positioned between the two sub-locking sliding blocks (23), and the air duct (6) is installed on the pneumatic muscle (21); after the air duct (6) inflates the pneumatic muscle (21), the pneumatic muscle (21) begins to expand to push the sub-locking sliding blocks (23) to move inside the main sliding block (5) or the needle seat main sliding block (7) to two sides until the sawtooth surfaces arranged on the outer sides of the locking sliding blocks (23) are overlapped with the sawtooth surfaces arranged on the inner sides of the locking strips (4) to form structural limit, the main sliding block (5) or the needle seat main sliding block (7) is fixed at the current position, and meanwhile, the tension rope (22) is tensioned; when the pneumatic muscle (21) does not work, the tension rope (22) tensions the sub-locking sliding blocks (23) on the two sides inwards, the sawtooth surfaces on the outer sides of the sub-locking sliding blocks (23) are separated from the sawtooth surfaces on the inner sides of the locking strips (4), and the structure limiting of the main sliding block (5) or the needle seat main sliding block (7) is released.

3. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 2, wherein: the two female sliding blocks (5) and the needle seat female sliding block (7) both take the carbon fiber tube (3) as a guide rail and freely slide along the carbon fiber tube (3); the female slider (5) and the female slider (7) of the needle seat are in sliding contact with the upper surface and the lower surface of the locking strip (4) so as to freely slide along the locking strip (4) and are not in contact with the inner side sawtooth surface of the locking strip (4).

4. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 2, wherein: the posture fixing mechanism also comprises a spherical hinge (20), and the spherical hinge (20) is sleeved at the central position inside the needle seat female sliding block (7) and is movably connected with the needle seat female sliding block (7);

the two-degree-of-freedom posture fixing module comprises a locking air bag base (8), a locking air bag (10), a puncture needle sleeve (19) and air bag locking particles (24); the puncture needle sleeve (19) sequentially penetrates through the central through holes of the locking air bag (10), the locking air bag base (8) and the needle seat female sliding block (7) from top to bottom and then is fixedly installed on a spherical hinge (20) installed inside the needle seat female sliding block (7); locking gasbag base (8) fixed mounting is in female slider (7) upper portion of needle file, locking gasbag (10) fixed mounting is on gasbag base (8), locking gasbag (10) side is provided with intake pipe (26), and locking gasbag (10) inside is equipped with a plurality of gasbag locking particles (24), locking gasbag (10) link to each other with outside vacuum pump through intake pipe (26).

5. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 1, wherein: the two-degree-of-freedom rotary needle inserting module comprises a needle inserting module lower fixing seat (9), a carbon fiber tube B (11), a needle inserting slider (12), a boss gear (13), a screw (14), a gear limiting piece (15), a biopsy needle (16), a needle inserting module upper limiting seat (17), a coupler (18) and a long gear column (25); the upper limiting seat (17) of the needle inserting module is positioned right above the lower fixing seat (9) of the needle inserting module, the lower fixing seat (9) of the needle inserting module is connected with the upper limiting seat (17) of the needle inserting module through a vertical carbon fiber tube B (11), a screw rod (14) and a long gear column (25) are vertically arranged between the lower fixing seat (9) of the needle inserting module and the upper limiting seat (17) of the needle inserting module in parallel to the carbon fiber tube B (11), and the upper ends of the screw rod (14) and the long gear column (25) are connected with an external driving source through respective couplers (18) after penetrating out of the upper limiting seat (17) of the needle inserting module;

a needle inserting sliding block (12) is arranged between the needle inserting module upper limiting seat (17) and the needle inserting module lower fixing seat (9), a boss gear (13) is hinged to the needle inserting sliding block (12), a central through hole is formed in the needle inserting sliding block (12), and the biopsy needle (16) sequentially penetrates through the central through hole of the needle inserting sliding block (12) from bottom to top and then is fixedly sleeved on the through hole where the central axis of the boss gear (13) is located;

the two-degree-of-freedom rotary needle inserting module further comprises a gear limiting piece (15), a needle inserting sliding block (12) is provided with the gear limiting piece (15) used for protecting the boss gear (13), and a biopsy needle (16) simultaneously and movably penetrates through a through hole formed in the gear limiting piece (15);

the needle inserting slider (12) and the screw rod (14) form a rotating pair through internal threads arranged on the side face, the screw rod (14) rotates to drive the needle inserting slider (12) to do linear motion along the axis direction of the screw rod (14), the biopsy needle (16) sequentially penetrates through a gear limiting piece (15), a boss gear (13) and a central through hole of the needle inserting slider (12) from top to bottom and is fixedly sleeved on the central axis of the boss gear (13), the boss gear (13) and a long gear column (25) are meshed and connected to form a gear pair, the long gear column (25) drives the boss gear (13) to do circumferential rotation through the gear pair so as to drive the biopsy needle (16) to rotate around the axis of the biopsy needle pair, and the biopsy needle (16) penetrates through a needle inserting module support and then continues to penetrate through the puncture needle sleeve (19) to finally reach a target human body; and a lower needle inserting module fixing seat (9) in the needle inserting module bracket is downwards connected to a locking air bag (10).

6. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 4, wherein: the locking air bag (10) utilizes negative pressure contraction to limit the fluidity of air bag locking particles (24) in the locking air bag (10) and control the puncture needle sleeve (19) to be fixed at any posture.

7. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 5, wherein: the long gear column (25) is matched with the boss gear (13) to control the biopsy needle (16) to rotate quantitatively at an angle; the screw rod (14) is matched with the needle inserting slider (12) to control the needle inserting length of the biopsy needle (16) to realize quantitative needle inserting.

8. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 1, wherein: the whole mechanism is made of non-metal materials.

9. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 1, wherein: the two-degree-of-freedom rotary needle inserting module is externally connected with a ceramic machine and a wire driving mechanism through a coupler to realize machine driving or directly driven manually to realize man-machine switching.

10. The pneumatic variable-stiffness six-degree-of-freedom CT-MRI needle puncture robot of claim 4, wherein: the spherical hinge (20) is movably connected with the needle seat female sliding block (7) in the needle seat female sliding block (7) to form a revolute pair.

Images