CN110934642A

CN110934642A - Rigidity-variable soft mechanical arm for minimally invasive surgery and use method thereof

Info

Publication number: CN110934642A
Application number: CN201911203424.7A
Authority: CN
Inventors: 胡俊峰; 温涛; 梁龙; 林茂虎; 杨帅; 刘一飞
Original assignee: Buddhist Tzu Chi General Hospital
Current assignee: Jiangxi University of Science and Technology; Buddhist Tzu Chi General Hospital
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-03-31

Abstract

The invention belongs to a soft mechanical arm, in particular to a variable rigidity soft mechanical arm for minimally invasive surgery and a use method thereof, the variable rigidity soft mechanical arm for minimally invasive surgery comprises a variable rigidity supporting arm and a sleeve sleeved on the variable rigidity supporting arm, the sleeve comprises a bending section and a twisting section, a plurality of wire loops and spiral wires are respectively wound outside the bending section and the twisting section, at least more than 2 chambers which are communicated with a charging and discharging module and are distributed along the radial direction of the variable rigidity supporting arm are respectively arranged in the bending section and the twisting section, media are charged and discharged in the chambers to realize the bending and twisting of the mechanical arm, the integral variable rigidity supporting arm, the bending section and the twisting section have consistent structures, the types of the bending and the twisting can be changed only by changing the wire loops wound on the outer wall or the spiral wires, the structural design and the difficulty of the arrangement and combination of the mechanical arm are greatly simplified, and the mechanical arm is, the combination of different bending sections and twisting sections is carried out, so that the device has better compliance.

Description

Rigidity-variable soft mechanical arm for minimally invasive surgery and use method thereof

Technical Field

The invention belongs to a soft mechanical arm, and particularly relates to a rigidity-variable soft mechanical arm for minimally invasive surgery and a using method thereof.

Background

The rapid development of science and technology improves the human review of machine safety, and the consideration of safety in human-computer interaction in modern mechanical design is greatly improved, so that a soft robot with good compliance and human-computer interaction safety quickly becomes a hot spot of the robot, and is considered as an important future development direction in the field of robots by related practitioners.

The traditional mechanical arm applied to the operation is integrated in a surgical operation robot system, so that the smooth operation of the surgical operation is assisted, and the stable, accurate and flexible mechanical arm can complete the operation in a narrow space which can not be reached by hands. However, the mechanical arm with a rigid structure is easy to damage fragile tissues of a human body, and the surgical robot is expensive, so that the soft mechanical arm for minimally invasive surgery is widely concerned as soon as the soft mechanical arm appears.

The small-size soft mechanical arm can enter a human body through a cut wound of the human body to realize the examination function of endoscopes like gastroscopes and the like, and can also realize the operations like grabbing and the like through a tail end loading functional module. The flexibility has numerous advantages, but the existing soft mechanical arm has the problems that the stability is poor due to insufficient rigidity, the internal structure is complex, the arrangement and combination design of modules or bent modules is not convenient to twist, the control modes among the modules are different, and the same soft mechanical arm needs various power equipment.

The Chinese patent with application number CN201810935837.3 entitled "a variable stiffness soft mechanical arm controlled by electrorheological fluid" describes: the variable-rigidity middle device is filled with electrorheological fluid, and the liquid-solid-liquid conversion of the electrorheological fluid is realized by changing the voltage, so that the rigidity change is realized; three air cavities are uniformly distributed around the soft mechanical arm body, and the soft mechanical arm body is connected with a quick connector through a sealing device to convey air so as to bend the soft mechanical arm body. The variable stiffness module is controlled by the voltage, and the bending is controlled by the conveying gas, so that the problems of inconvenient operation and the need of various control devices are caused.

Disclosure of Invention

The invention aims to provide a variable-rigidity soft mechanical arm for minimally invasive surgery, which has multiple torsion section and bending section combination modes, is convenient to control and simple in structure, and a using method thereof.

The variable-rigidity mechanical arm comprises a variable-rigidity supporting arm and a sleeve sleeved on the variable-rigidity supporting arm, wherein the sleeve comprises a bending section and a twisting section, a plurality of wire rings and spiral wires are respectively wound outside the bending section and the twisting section, at least more than 2 cavities which are communicated with a charging and discharging module and radially distributed along the variable-rigidity supporting arm are respectively arranged in the bending section and the twisting section, and media are charged and discharged in the cavities to realize bending and twisting of the mechanical arm.

The charging and discharging module can fill and suck media in the cavity, the media can be gas or liquid, preferably compressed air, and in addition, the size of the cavity and the lengths of the bending section and the twisting section can be adjusted according to actual working requirements so as to obtain the optimal using effect.

Furthermore, the variable-rigidity support arm comprises an inner tube communicated with the charge-discharge module and an outer tube sleeved on the inner tube, blocking particles are filled between the inner tube and the outer tube, the blocking particles are particles with large friction coefficients, and the stability of the variable-rigidity support arm in a tight state is improved.

Further, the chamber may be circular, oval, rectangular, fan-shaped, etc., and preferably is a fan-shaped chamber, and the chamber may be a balloon structure or a cavity structure.

Furthermore, a support strip is arranged between every 2 chambers of the bending section or the twisting section distributed along the radial direction of the sleeve.

Furthermore, a reserved through hole is formed in the supporting bar along the axis direction of the sleeve, a pipeline III is arranged in the reserved through hole, one end of the pipeline III is communicated with the charge and discharge module, and the other end of the pipeline III is communicated with the cavity of the other bending section.

Further, the chambers are circumferentially distributed about the central axis of the cannula by 3.

Furthermore, the bending section and the twisting section are arranged in a separating mode, the control accuracy of twisting and bending is improved due to the separating arrangement, and adjacent bending sections or twisting sections cannot interfere with each other.

Further, the wire loops are closely arranged along the curved section.

Furthermore, the spiral wire is arranged on the outer wall of the twisting section in a single spiral, double spiral or multi-spiral mode with a large inclination angle.

A method for using a variable stiffness soft mechanical arm for minimally invasive surgery comprises the following steps:

step 1: the charge-discharge module is controlled to independently charge and discharge media to each cavity in the bending section to realize bending deformation of the bending section, and bending in different degrees and different directions is realized by controlling the pressure of the media and the charge-discharge sequence; meanwhile, the charge-discharge module is controlled to charge and discharge media to and from each cavity in the torsion section at the same time, so that the torsion deformation of the torsion section is realized.

Step 2: the charging and discharging module is controlled to fill media in the inner pipe, the inner pipe expands radially, blocking particles are extruded to increase the rigidity of the variable-rigidity supporting arm, and the pressure of the media in the inner pipe corresponds to different rigidities of the variable-rigidity supporting arm.

The invention has the advantages that the integral variable-rigidity supporting arm, the bending section and the torsion section have the same structure, the bending and torsion types can be changed by only changing the outer wall winding wire ring or the spiral wire, the difficulty of structural design and arrangement combination of the mechanical arm is greatly simplified, the combination of different bending sections and torsion sections is convenient to carry out according to actual requirements, the mechanical arm has better compliance, and in the production and manufacturing process, the manufacturing procedures are reduced, and the utilization rate of a mold is improved;

the variable-rigidity supporting arm adopts the modes of inner pipe, outer pipe and filling blocking particles, adopts positive pressure control as the bending section and the torsion section, can complete the control of variable rigidity, bending and torsion by only one compressed gas device or hydraulic device, reduces the variety of power sources, and solves the problems of small rigidity and terminal force of the existing soft mechanical arm;

the cavity of the invention adopts a sector cavity, and has the characteristics of large cross sectional area and high utilization rate of the mechanical arm.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic cross-sectional view of the present invention.

Fig. 3 is a schematic view of the installation of the pipe iii according to the present invention.

Fig. 4 is a schematic view of the installation of the pipes i-iii according to the invention.

Fig. 5 is a schematic structural diagram of a variable stiffness support arm according to the present invention.

Fig. 6 is a schematic view of the structure of the bending section in the present invention.

Fig. 7 is a schematic structural view of a torsion section in the present invention.

FIG. 8 is a schematic view of the structure of the pipe II according to the present invention.

Fig. 9 is a schematic view of the installation of the pipe ii according to the present invention.

Fig. 10 is a schematic view of the installation of a pipe iv according to the present invention.

Fig. 11 is a schematic structural view of a fixing module according to the present invention.

Fig. 12 is a schematic structural view of the accessory connecting module of the present invention.

In the figure, 1 inner pipe, 2 outer pipe, 3 sleeve, 4 support bar, 5 blocking particle, 6 reserved through hole, 7 chamber, 8 pipeline I, 9 pipeline II, 901 branch pipe, 10 pipeline III, 11 wire loop, 12 spiral wire, 13 fixing module, 1301 fixing body, 1302 carrying platform connecting bolt hole, 1303 fastening slider, 1304 fastening bolt, 1305 triangular chute, 1306 triangular slider, 14 accessory connecting module, 1401 accessory connecting body, 1402 accessory connecting bolt hole, 1403 fastening bolt hole, 1404 fixing cavity, 15 pipeline IV, 16 torsion section I, 17 bending section I, 18 torsion section II, 19 bending section II, 20 torsion section III.

Detailed Description

As shown in fig. 1-12, the present invention includes a variable stiffness support arm and a sleeve 3 sleeved on the variable stiffness support arm, the variable stiffness support arm and the sleeve 3 are both made of soft material, such as silica gel, the sleeve 3 includes a bending section and a twisting section, the bending section is externally wound with a plurality of wire loops 11, the twisting section is externally wound with a spiral wire 12, the wire loops 11 and the spiral wire 12 are both made of stretch-resistant and difficult-to-tear material, such as fiber, kevlar or nylon, the wire loops 11 and the spiral wire 12 can be wound on the outer wall of the sleeve 3 or embedded in the outer wall of the sleeve 3, at least 2 or more chambers 7 radially distributed along the variable stiffness support arm of the charge-discharge module are respectively arranged in the bending section and the twisting section, media are charged into the chambers 7, so that the bending section or the twisting section expands, and the expansion is simultaneously limited by the wire loops 11 and the spiral wire 12, bending deformation and torsion deformation are respectively generated, and the bending and torsion of the mechanical arm are realized.

The bending section is wound with a plurality of wire rings 11, the plurality of wire rings 11 limit outward radial expansion of the chamber 7 when the chamber 7 is filled with a medium, so that the bending section is reversely bent towards the chamber filled with the medium, the twisting section is wound with spiral wires 12, the twisting sections which are expanded and deformed simultaneously in the axial direction and the radial direction are converted into twisting forces which are deformed obliquely along the spiral angle direction of the spiral wires 12, and finally the twisting sections are deformed in a twisting mode.

As shown in fig. 5, in order to improve the rigidity of the deformed mechanical arm, the rigidity-variable support arm includes an inner tube 1 communicating with the charge and discharge module and an outer tube 2 sleeved on the inner tube 1, and blocking particles 5 are filled between the inner tube 1 and the outer tube 2, wherein the blocking particles are preferably made of ore, crystal or various particle materials with larger friction coefficients and the diameter of which is less than 1mm, the blocking particles 5 are filled in a volume of 100% -120% of a containing cavity between the inner tube 1 and the outer tube 2, after the inner tube 1 is filled with a medium, the medium is continuously filled, the inner tube 1 expands under the influence of the pressure of the medium, the expanded inner tube 1 extrudes the blocking particles 5, and under the action of static friction force, the blocking particles 5 are changed from a loose state to a tight state, so that different rigidities are presented, and the larger the pressure of the medium is, the.

As shown in fig. 2, the chamber 7 is a fan-shaped chamber, and is provided with a large cross-sectional area and a high space utilization, and simultaneously reduces the material of the mechanical arm, thereby being more beneficial to the light design, and secondly, the fan-shaped chamber is provided with a larger area of the cavity surface close to one side of the wire coil 11 or the spiral wire 12, so that the expansion area of the outer wall of the sleeve 3 of the chamber 7 is larger after the sleeve is filled with the medium, and the deformation of the sleeve is larger after the sleeve is converted into the torsion or bending deformation.

The chambers 7 may be balloon-like airbag structures or cavity structures located between the sleeve 3 and the outer tube 2, in order to improve the integrity of the mechanical arm, in this embodiment, a cavity structure as shown in fig. 2 is preferred, in this structure, a support strip 4 is disposed between every 2 chambers 7 of the bending section or the twisting section distributed along the radial direction of the sleeve 3, two side surfaces of the variable-stiffness support arm 4 are side walls of two adjacent chambers, the cavity structure improves the connection strength of the mechanical arm and the integrity of the sleeve and the variable-stiffness support arm, the support strip 4 is transmitted to the sleeve 3 while the stiffness of the variable-stiffness support arm is changed, so that the stiffness of the entire mechanical arm is changed synchronously, and meanwhile, the number of the variable-stiffness support arms 4 is consistent with the number of the chambers 7 with the same cross section.

Of course, when the chamber 7 is of an airbag structure, the variable stiffness support arms 4 may be also disposed, and the chamber 7 of the airbag structure is disposed between the variable stiffness support arms 4, so that when the bending section is bent and deformed, after the chambers 7 of the airbag structures at different positions are filled with media, only the sector area on the sleeve 3 corresponding to the chamber 7 is bent and deformed, and further, the precision of controlling the bending deformation direction is improved.

Follow 3 axis directions of sleeve in the support bar 4 and be provided with reserved through-hole 6, reserve the setting of through-hole 6, at first can be provided with pipeline III 10, the module is filled in to the intercommunication of pipeline III 10 one end, the other end communicates with the cavity 7 of another curved segment, with this cavity 7 in the second curved segment that can keep away from the module is filled in through the connection of pipeline III 10, under this condition, the cavity 7 crisscross distribution of curved segment internal section department, in addition, reserve the setting of through-hole 6, the weight of support bar 4 has been alleviateed, further alleviate the weight of arm.

The cavity 7 is circumferentially distributed around the central shaft of the

sleeve

3, and 3 cavities 7 are designed, so that the layout design of subsequent pipelines is simplified, and the accuracy of controlling the bending deformation direction is improved.

As shown in fig. 1, the bending section and the twisting section are arranged in a separated manner, so that the adjacent bending section and the twisting section are not interfered with each other in deformation, and the accuracy of controlling the twisting, bending and deformation of the mechanical arm is improved.

As shown in fig. 6, the wire loops 11 may be distributed at equal intervals, in this embodiment, the wire loops 11 are closely arranged along the curved section, similar to a bellows structure, and a plurality of wire loops 11 are closely connected to each other, so as to limit radial expansion of the cavity 7 outwards of the curved section caused by medium pressure as much as possible, and at the same time, to play a role in limiting and protecting.

As shown in fig. 7, the spiral wire 12 is a single spiral, a double spiral or a multiple spiral with a large inclination angle and is disposed on the outer wall of the twisting section, and the spiral wire 12 is disposed with a large inclination angle, so as to avoid the situation that the twisting deformation is too large due to the expansion of the twisting section, and to more accurately control the twisting deformation amount of the twisting section, meanwhile, the spiral wire 12 may be a single spiral, a double spiral or a multiple spiral, and to also accurately control the twisting deformation amount of the twisting section, in this embodiment, the spiral wire 12 is preferably a double spiral.

step 1: the charge-discharge module is controlled to independently charge and discharge media to each cavity 7 in the bending section to realize the bending deformation of the bending section, and the bending in different degrees and different directions is realized by controlling the pressure of the media and the charge-discharge sequence; meanwhile, the charge-discharge module is controlled to charge and discharge media to and from each cavity 7 in the torsion section at the same time, so that the torsion deformation of the torsion section is realized.

Step 2: the charging and discharging module is controlled to fill the medium into the inner pipe 1, the inner pipe 1 expands radially, the blocking particles 5 are squeezed to increase the rigidity of the variable-rigidity supporting arm, and the medium pressure in the inner pipe 1 corresponds to different rigidities of the variable-rigidity supporting arm.

The head end and the tail end of the soft mechanical arm are respectively provided with a fixed module 13 and an accessory connecting module 14.

The fixing module 13 comprises a fixing main body 1301 and a fastening slider 1303 which are screwed with each other through a fastening screw 1304, a triangular chute 1305 and a triangular slider 1306 which are used for clamping the sleeve 3 are correspondingly arranged on the fixing main body 1301 and the fastening slider 1303, during installation, the sleeve 3 is installed between the triangular chute 1305 and the triangular slider 1306, the fixing main body and the fastening slider 1303 are screwed and locked through the fastening screw 1304, a carrying platform connecting bolt hole 1302 extends upwards on the fixing main body 1301 and is used for fixing with a carrying platform, and a sufficient reserved space for placing a pipeline and a charging and discharging module is reserved above the extending part.

The accessory connecting module 14 comprises two accessory connecting bodies 1401 which are mutually screwed through fastening bolt holes 1403, the accessory connecting bodies 1401 are combined to be cylindrical, fixing cavities 1404 used for installing the sleeves 3 are formed in the cylinders, fixing protrusions are arranged on the bending sections or the twisting sections located at the ends of the cylinders and correspond to the fixing cavities, it is guaranteed that connection is stable and cannot be separated after matching, the accessory connecting bolt holes 1402 are formed in one ends of the accessory connecting bodies 1401, the accessory connecting bolt holes 1402 can be connected with functional accessories such as cameras and clamping jaws according to actual requirements, and function expansion is achieved.

Because the charging and discharging media of a plurality of cavities 7 in the bending section need to be controlled independently, the control mode is as follows:

as shown in fig. 4, the charging and discharging medium in the cavity 7 in the curved section is connected with the charging and discharging module through the pipe i 8, in this connection manner, one end of the pipe i 8 is directly connected with the cavity 7, and the other end of the pipe i 8 passes through the cavity 7 near all the curved sections or torsion sections on one side of the fixed module 13 to be connected with the charging and discharging module, when the cavity 7 is in a cavity structure, a plurality of pipes i 8 can be simultaneously arranged in each cavity 7, and this connection manner can communicate a plurality of curved sections, in this embodiment, three pipes i 8 can be arranged in one cavity, so this connection manner can communicate three curved sections;

as shown in fig. 3 and 4, the charging and discharging medium in the cavity 7 in the bent section is connected with the charging and discharging module through a pipeline iii 10, in this connection manner, one end of the pipeline iii 10 is communicated with the cavity 7 of one bent section, and the other end of the pipeline iii 10 passes through the reserved through holes 6 of all the bent sections or the twisted sections close to one side of the fixed module 13 to be connected with the charging and discharging module; at this point, the chambers 7 of the curved segment are staggered from the chambers 7 of the other curved segments or twisted segments between the curved segment to the fixed module 13.

As shown in fig. 10, the charging and discharging media in the chambers 7 in the curved section can also be connected with the charging and discharging module through pipes iv 15, each chamber 7 in the curved section is provided with a pipe iv 15 through the sleeve 3, and the other ends of the plurality of pipes iv 15 are connected with the charging and discharging module, due to the connection mode, part of the pipes are exposed outside the mechanical arm and are preferentially arranged on the curved section near one side of the fixing module 13.

The charging and discharging media of the multiple cavities 7 in the torsion section need to be synchronously controlled in the following modes:

as shown in fig. 8 and 9, the medium that fills of chamber 7 in the section of twisting passes through pipeline ii 9 and fills the module and be connected, pipeline ii 9 sets up in inner tube 1, the terminal surface of pipeline ii 9 is provided with the branch pipe 901 that corresponds with a plurality of chambers 7, branch pipe 901 runs through inner tube 1, blocking granule 5 and outer tube 2 extend to in the chamber 7, the medium circulates to branch pipe 901 through pipeline ii 9, fill the medium simultaneously to a plurality of chambers 7 in the section of twisting, can set up multiunit pipeline ii 9 in the inner tube 1, correspond multiunit section of twisting.

Because the charging and discharging of the media in the chambers 7 in the twisting section need to be carried out synchronously, the control mode can also adopt any one of the three charging and discharging modes of the bending section, and the media can be charged and discharged simultaneously by the pipelines I8, III 10 and IV 15.

As the structure of the mechanical arm and the modes of various charging and discharging media can adjust the arrangement combination and the number of the torsion section and the bending section according to actual needs, as shown in figure 1, a torsion section I16, a bending section I17, a torsion section II 18, a bending section II 19 and a torsion section III 20 are sequentially arranged between a fixing module 13 and an accessory connecting module 14, in the embodiment, the torsion section I16, the torsion section II 18 and the torsion section III 20 can be charged and discharged with media in a pipeline II 9 mode, the bending section I17 and the bending section II 19 respectively adopt a pipeline I8 mode and a pipeline III 10 mode, at the moment, a chamber 7 in the bending section II 19 and a chamber 7 in the torsion section I16, the bending section I17 and the torsion section II 18 are distributed in a staggered mode, namely, the pipeline III 10 communicated with the bending section II 19 is arranged in a reserved through hole 6 in the torsion section I16, the bending section I17 and the torsion section II 18, the structure optimally keeps the areas in the cavity 7 in the torsion section I16, the bending section I17 and the torsion section II 18, no external pipeline is connected, and the charging and discharging module is simple to control, high in control precision and good in effect.

Claims

1. The utility model provides a variable rigidity software arm for minimal access surgery, characterized by, including becoming rigidity support arm and suit sleeve (3) on becoming the rigidity support arm, sleeve (3) are including bending section and torsion segment, the bending section respectively twine outward with a plurality of silk circles (11) and spiral silk (12) with torsion segment, be provided with respectively in bending section and the torsion segment and fill at least more than 2 cavity (7) that fill the radial distribution of rigidity support arm of filling the module, fill the medium in order to realize the crooked of arm and twist reverse to cavity (7).

2. The variable-rigidity soft mechanical arm for minimally invasive surgery as claimed in claim 1, wherein the variable-rigidity supporting arm comprises an inner tube (1) communicated with the charging and discharging module and an outer tube (2) sleeved on the inner tube (1), and blocking particles (5) are filled between the inner tube (1) and the outer tube (2).

3. The variable stiffness soft mechanical arm for minimally invasive surgery as claimed in claim 1 or 2, wherein the chamber (7) is a sector chamber.

4. The variable stiffness soft body manipulator for minimally invasive surgery as claimed in claim 3, wherein support strips (4) are arranged between every 2 chambers (7) of the bending section and the torsion section distributed along the radial direction of the sleeve (3).

5. The variable-rigidity soft mechanical arm for minimally invasive surgery as claimed in claim 4, wherein a reserved through hole (6) is formed in the supporting bar (4) along the axial direction of the sleeve (3), a pipeline III (10) is arranged in the reserved through hole (6), one end of the pipeline III (10) is communicated with the charging and discharging module, and the other end of the pipeline III (10) is communicated with the cavity (7) of the other bending section.

6. A variable stiffness soft body manipulator for minimally invasive surgery as claimed in claim 4 or 5, wherein the chambers (7) are distributed circumferentially in 3 around the central axis of the cannula (3).

7. The variable stiffness soft body manipulator for minimally invasive surgery of claim 1, wherein the curved section and the twisted section are arranged in an isolated manner.

8. The variable stiffness soft body manipulator for minimally invasive surgery as claimed in claim 7, wherein the wire loops (11) are closely arranged along a curved section.

9. The variable stiffness soft mechanical arm for minimally invasive surgery as claimed in claim 7, wherein the spiral wire (12) is arranged on the outer wall of the torsion section in a single spiral, double spiral or multiple spirals with a large inclination angle.

10. The method of using a variable stiffness soft mechanical arm for minimally invasive surgery of any one of claims 1-9, comprising the steps of:

step 1: the charge and discharge module is controlled to charge and discharge media into and out of each cavity (7) in the bending section independently to realize bending deformation of the bending section, and bending in different degrees and different directions is realized by controlling the pressure of the media and the charge and discharge sequence; meanwhile, the charge-discharge module is controlled to charge and discharge media to and from each cavity (7) in the torsion section at the same time, so that the torsion deformation of the torsion section is realized;

step 2: the charging and discharging module is controlled to fill media in the inner pipe (1), the inner pipe (1) expands radially, the plugging particles (5) are squeezed to increase the rigidity of the variable-rigidity supporting arm, and the medium pressure in the inner pipe (1) corresponds to different rigidities of the variable-rigidity supporting arm.