KR100778387B1 - Surgery robot for laparoscope with multi-degree of freedoms and force measurement method thereof - Google Patents

Abstract

A surgery robot for a laparoscope having multi-degree of freedom and a force measuring method thereof are provided to be applied to a laparoscope surgery and an ultra precision surgery field by having a robot which is movable freely in the laparoscope. A surgery robot for a laparoscope having multi-degree of freedom includes first and second surgery instruments(101,102), a rotatable wrist unit(105), a load cell(200), an elbow unit(400), and an arm unit(500). The first and second surgery instruments are rotated from a rotation axis of a surgery instrument. The rotatable wrist unit has the rotation axis of the surgery instrument, and is rotated from a wrist rotation axis(107). An end of the load cell is connected to the wrist rotation axis. The elbow unit is connected to the other end of the load cell, and is rotated along an axial line direction. The arm unit is connected to an end of the elbow unit from a rotation axis of the elbow unit. The surgery robot has a driving unit of the first surgery instrument, a driving unit of the second surgery instrument, a driving unit of the rotation axis of the surgery instrument, a rotation unit of the axial line direction of the elbow unit, and a driving unit of the rotation axis of the elbow unit.

Description

Surgery robot for laparoscope with multi-degree of freedoms and force measurement method

1 is a perspective view of a laparoscopic surgical robot having a multiple degree of freedom according to the present invention,

2 is a perspective view showing a wire connection configuration around the wrist portion 105 of FIG.

3 is a perspective view illustrating a wire connection configuration around an elbow portion 400 of FIG. 1;

Figure 4 is a perspective view showing the overall wire connection configuration of the laparoscopic surgical robot having a multiple degree of freedom according to the present invention,

5 is a perspective view of the load cell 200 shown in FIG.

6 is an explanatory view illustrating a principle of measuring the force acting on the end of the surgical tool load cell 200 in the robot according to the present invention.

<Description of the symbols for the main parts of the drawings>

101: first surgical instrument,

102: second surgical instrument,

103: surgical instrument rotation axis,

105: wrist,

107: wrist rotation axis,

200: load cell,

210: first arm part,

220: screw hole,

250: beam,

300: second arm part,

400: elbow,

500: upper arm,

510: elbow rotation axis,

520: axis of rotation,

L1: first loop,

L2: second loop,

L3: third loop,

L4: fourth loop,

P1: first pulley,

P2: second pulley,

P3: third pulley,

P4: fourth pulley,

P5: fifth pulley,

P6: 6th pulley,

P7: 7th pulley,

P8: 8th pulley,

P9: 9th pulley,

P10: 10th pulley,

P11: 11th pulley,

P12: 12th pulley,

Wire: C1, C2, C3, C4, C5, C6, C7, C8, C9, C10,

S1, S2: ****

M1: the first motor,

M2: second motor,

M3: third motor,

M4: fourth motor,

M5: the fifth motor.

The present invention relates to a laparoscopic surgical robot, and more particularly to a laparoscopic surgical robot having a multiple degree of freedom.

In general, minimally invasive surgery is to perform the desired operation accurately and safely with few small incisions, with little damage to surrounding organs or tissues. Therefore, minimally invasive surgery can relatively reduce postoperative metabolic processes, thereby accelerating recovery. In addition, hospitalization period is shortened and it is possible to return to normal life within a short time after surgery. Minimally invasive surgery, which has many of these advantages, has been made possible by the development of surgical techniques, machines, and instruments.

However, despite these advantages, laparoscopic surgery has been known to require complicated operations due to the difficulty of moving the tool through surgical instruments and incisions. The most serious limiting factor is the reduction in the degree of freedom of surgical instruments. Surgical instruments currently in use have four degrees of freedom because they can only move in the direction of the trocar and rotate around the trocar through the inlet trocar.

As a result, the surgeon could move the surgical instrument to the desired position, but could not control the approach direction of the instrument. These four degrees of freedom would be enough for a simple task, but there were many difficulties in complex tasks such as suture of the surgical site and knotting the surgeon. In addition, the trocar's movement, which acts as the support for the lever, and the limited working space are also factors that make surgery difficult. Due to these shortcomings, the necessity of a surgical robot through remote control is constantly raised.

Accordingly, the present invention has been made to solve the above problems, an object of the present invention, to provide a laparoscopic surgical robot having five degrees of freedom in the laparoscope.

An object of the present invention as described above, the first and second surgical instruments (101, 102) rotatable around the surgical tool rotation axis 103, respectively;

A wrist portion 105 including a surgical tool rotary shaft 103 and rotatable about a wrist rotary shaft 107;

A load cell 200 having one end connected to the wrist rotation shaft 107;

An elbow portion 400 connected to the other end of the load cell 200 and rotatable in the axial direction;

Consists of the upper arm portion 500 connected to one end of the elbow portion 400 around the elbow rotation axis 510,

Drive means for the first surgical tool 101, drive means for the second surgical tool 102; Can be achieved by a laparoscopic surgical robot having a multiple degree of freedom, characterized in that it comprises a drive means of the surgical tool rotary shaft 103, an axial rotation means of the elbow portion 400 and a drive means of the elbow rotation shaft 510, respectively. have.

In addition, the load cell 200 may have a cylindrical shape and four beams 250 may be formed in the circumferential direction.

In addition, the drive means of the first surgical tool 101, the second motor (M2) capable of forward and reverse rotation;

A pulley (A) that rotates integrally with the first surgical tool (101);

Second and third pulleys P2 and P3 installed on the wrist rotation shaft 107;

It consists of the 6th pulley P6 installed in the vicinity of the 2nd motor M2,

The second loop in which the wire turns the second motor M2, the second pulley P2, the pulley A, the third pulley P3, and the sixth pulley P6 sequentially and returns to the second motor M2. It can be driven by forming (L2).

In addition, the drive means of the second surgical tool 102, the first motor (M1) capable of forward and reverse rotation;

A pulley (B) rotating integrally with the first surgical tool (102);

First and fourth pulleys P1 and P4 installed on the wrist rotation shaft 107;

It consists of the 5th pulley P5 installed in the vicinity of 1st motor M1,

The first loop in which the wire turns the first motor M1, the first pulley P1, the pulley B, the fourth pulley P4, and the fifth pulley P5 sequentially to return to the first motor M1. It can be driven by forming (L1).

In addition, the driving means of the surgical tool rotating shaft 103, the third motor (M3) capable of forward and reverse rotation;

It consists of the 7th pulley P7 installed in the vicinity of the 3rd motor M3,

One end may be a wire connected to the driving means of the first surgical tool 101 and the other end may be a wire connected to the driving means of the second surgical tool 102 by turning the third motor M3 and the seventh pulley P7.

In addition, the axial rotation means of the elbow portion 400, the fourth motor (M4) capable of forward and reverse rotation;

A rotating shaft 520 integrally rotating with the elbow portion 400;

S1 and S2 installed on the rotating shaft 520 to change the winding direction of the wire;

Eighth and ninth pulleys P8 and P9 installed on the elbow rotation shaft 510;

It consists of the 11th pulley P11 installed in the vicinity of the 4th motor M4,

The wire sequentially turns to the fourth motor M4, the ninth pulley P9, S1, the rotating shaft 520, S2, the eighth pulley P8, and the eleventh pulley P11, and returns to the fourth motor M4. Coming may be driven by forming a third loop L3.

And, the drive means of the elbow rotation shaft 510, the fifth motor (M5) capable of forward and reverse rotation;

A tenth pulley P10 integrally rotating with the elbow rotation shaft 510;

It consists of the 12th pulley P12 installed in the vicinity of the 5th motor M5,

The wire may be driven by forming a fourth loop L4 that sequentially turns the fifth motor M5, the tenth pulley P10, and the twelfth pulley P12 to return to the fifth motor M5.

The motor may be a servo motor or a step motor.

The first and second surgical instruments 101 and 102 to the upper arm 500 may be inserted into the patient's body.

One end of the upper arm 500 may be detachable to the robot means capable of moving the position.

An object of the present invention as described above, as another category, the first and second surgical instruments (101, 102) rotatable around the surgical tool rotation axis 103, respectively; A wrist portion 105 including a surgical tool rotary shaft 103 and rotatable about a wrist rotary shaft 107; A load cell 200 having one end connected to the wrist rotation shaft 107 and having a cylindrical shape and four beams 250 formed in a circumferential direction; An elbow portion 400 connected to the other end of the load cell 200 and rotatable in the axial direction; In the force measuring method of a laparoscopic surgery robot consisting of; upper arm portion 500 connected to one end of the elbow portion 400 around the elbow rotation axis 510,

Measuring strains ε ₁ , ε ₂ , ε ₃ , ε ₄ from strain gauges installed on each beam 250 of the load cell 200;

Calculating an approximation of the force (Fzs) and the moment (Mxs, Mys) acting on the ends of the first and second surgical instruments (101, 102) from the following equation;

Where E is the Young's Modulus of the material of the load cell 200, C is the radius of the load cell 200, A is the cross-sectional area of the load cell 200, and I is the laparoscope It can be achieved by the force measuring method of the surgical robot.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and the preferred embodiments described in conjunction with the accompanying drawings.

The invention will now be described in detail with reference to the accompanying drawings, in which preferred embodiments are shown. First, the laparoscopic robot according to the present invention is divided into a part moving in the abdomen of the patient and a part moving out of the ship. The part moving outside the ship has 4 degrees of freedom, and the present invention is a robot moving at 5 degrees of freedom inside the ship. The robot according to the present invention can be detachably attached to a moving part of the ship, and when attached, has a total of nine degrees of freedom.

1 is a perspective view of a laparoscopic surgical robot having a multiple degree of freedom according to the present invention.

The first surgical tool 101 and the second surgical tool 102 serve as a finger of the robot, and may be manufactured by scissors, tongs, cauterizers, and the like. These first and second surgical instruments 101 and 102 are each independently controlled. If the first and second surgical instruments 101 and 102 rotate in the same direction, the direction change of the surgical instruments may be expressed, and if the first and second surgical instruments 101 and 102 rotate, the scissors or forceps may be represented. The first and second surgical instruments 101 and 102 rotate about the surgical tool rotation axis 103.

Wrist portion 105 is rotatable about the wrist axis of rotation (107).

The load cell 200 is a sensor for measuring the force acting on the first and second surgical instruments (101, 102). The load cell 200 measures such a force so that too much force is applied when sewing the thread so that it is not broken or less force is applied so that it is not tied well. The load cell 200 is installed between the first arm 210 and the second arm 300, and in particular, the second arm part 300 connects the first arm part 210 and the load cell 200 to the elbow part 400. It has a configuration to rotate relative to. The elbow portion 400 has a configuration that rotates about the elbow rotation axis 510 with respect to the upper arm 500.

FIG. 2 is a perspective view illustrating a wire connection configuration around the wrist part 105 in FIG. 1 to avoid complexity. As shown in FIG. 2, the first surgical tool 101 and the second surgical tool 102 are configured to independently rotate about the surgical tool rotation axis 103. Accordingly, when the first and second surgical instruments 101 and 102 are rotated in the same direction, the first and second surgical instruments 101 and 102 represent rotational degrees of freedom of rotation of the wrist, which rotates about the surgical tool axis of rotation 103. When moving in the opposite direction, it shows the degree of freedom of rotation of the tongs that are open and closed. In addition, the rotation of the surgical tool rotation axis 103 around the wrist rotation axis 107 to express another degree of rotation 1 degree of freedom of the wrist.

The second motor M2, which is a servo motor or a step motor, is used to move the first surgical tool 101. Wires C2 and C3 connected to the second motor M2 are connected to each other. The wire C2 is wound around the second pulley P2 once and passes through the pulley A that is integral with the first surgical tool 101. Then, the wire C3 is again connected to the third pulley P3 and the sixth pulley. Pass P6 and return to the 2nd motor M2. That is, one second loop L2 is formed. At this time, the second and third pulleys P2 and P3 completely wind one or more turns so that the tension of the wire can be maintained even when the wrist rotation shaft 107 is rotated. When the second motor M2 rotates by the connection as described above, the second loop L2 rotates to operate the first surgical tool 101.

Similarly, in the first motor M1 that rotates the second surgical tool 102, the wires C1 and C4 passing through the first and fourth pulleys P1 and P4 turn around the second surgical tool 102 and the first loop L1. ). Therefore, when the first motor M1 moves, the second surgical tool 102 moves.

The wires C5 and C6 connected to the third motor M3 are tied to the fifth and sixth pulleys P5 and P6, and the two meet each other by turning the seventh pulley P7. Therefore, when the third motor M3 is turned, the fifth or sixth pulley P5 or P6 is pulled out. If the sixth pulley P6 is pulled in the direction of the seventh pulley P7, that is, the sixth pulley C6 is reduced, the wires C2 and C3 are simultaneously pulled toward the seventh pulley P7 and the wrist rotation axis The surgical tool rotating shaft 103 is rotated about the 107. At this time, the wires C1 and C4 are pulled in the opposite direction to the seventh pulley P7, and the wire C5 is extended to compensate for it. The opposite direction can also be moved in the same way. At this time, the second motor M2 is turned in the same direction as the third motor M3, and the first motor M1 is turned in a different direction from the third motor M3 so that the wires C1 to C4 are pulled by the same length. Help Thus, the three first, second, and third motors M1, M2, and M3 allow three degrees of freedom of movement.

3 is a perspective view illustrating a wire connection configuration around the elbow 400 of FIG. 1. As shown in FIG. 3, two fourth and fifth motors M4 and M5 are used to simulate elbow movement, and the two fourth and fifth motors M4 and M5 are formed by a C axis and an elbow rotation shaft ( It is possible to rotate around the 510.

The wire C8 from the fourth motor M4 is wound around the rotating shaft 520 after passing through the ninth pulley P9 through S1 and connected to the wire C7. The wire C7 is wound around the eighth pulley P8 after S2, and then is connected to the wire C8 by turning the eleventh pulley P11. That is, the third loop L3 is formed. Therefore, when the fourth motor M4 rotates, the third loop L3 rotates to rotate the rotation shaft 520 around the C axis.

A wire C9 is wound around the fifth motor M5, and the wire C9 is wound around the tenth pulley P10 and connected to the wire C10. The wire C10 is connected to the wire C9 by turning the twelfth pulley P12 to form a fourth loop L4. Therefore, when the fifth motor M5 is rotated, the rotation shaft 520 rotates around the elbow rotation shaft 510.

Therefore, the two degrees of freedom of rotation of the elbow can be expressed by the two fourth and fifth motors M4 and M5. Through the use of five motors as shown in Figures 2 and 3 as a whole, a total of five degrees of freedom can be performed as a pinch 1 degree of freedom, wrist 2 degree of freedom, and elbow 2 degree of freedom.

Figure 4 is a perspective view showing the overall wire connection configuration of the laparoscopic surgical robot having a multiple degree of freedom according to the present invention. In FIG. 4, the wiring of the motor is omitted for simplicity.

5 is a perspective view of the load cell 200 shown in FIG. As shown in FIG. 5, two screw holes 220 are formed above and below the load cell 200, and four beams 250 are formed in the center thereof. A strain gauge (not shown) may be attached to the outer surface of each beam 250 of the load cell 200 to measure the deformation amount of the pillar. The amount and direction of force applied to the load cell 200 can be known based on the electrical signal proportional to the amount of deformation.

6 is an explanatory view illustrating a principle of measuring the force acting on the end of the surgical tool load cell 200 in the robot according to the present invention. As shown in Fig. 6, the force is expressed as one because it considers only when the first and second surgical instruments 101 and 102 are closed (for example, when the thread is held). That is, since the end of the surgical tool is applied only when the thread is pulled or hit somewhere, it is assumed that only three-dimensional forces of X, Y, and Z are applied to the ends of the first and second surgical tools 101 and 102.

That is, the ends of the first and second surgical instruments 101 and 102 have only a force in each axial direction, and no moment exists. It is also assumed that there is no deformation due to the elasticity of the wire at each joint. Then, the force (Fx, Fy, Fz) and the load cell acting on the ends of the first and second surgical instruments (101, 102) using the angle (θ ₁ , θ ₂ ) and the distance (d ₁ , d ₂ , d _S ) The relationship between the forces (Fxs, Fys, Fzs, Mxs, Mys, and Mzs) acting on the center of 200 can be made into a determinant as shown in Equation 1 below using static mechanics.

Here, θ ₁ is the relative rotation angle of the wrist portion 105 relative to the load cell 200, θ ₂ is the relative rotation angle of the first, second surgical instruments 101, 102 relative to the wrist portion 105. d ₁ is the distance of the wrist portion 105, d ₂ is the distance of the first, second surgical instruments (101, 102), d _S is the distance between the wrist axis of rotation 107 and the load cell 200. F represents force and M represents moment.

At this time, the distances d ₁ , d ₂ , d _S are constants determined mechanically, and the angles θ ₁ , θ ₂ are values determined every moment. Therefore, the intermediate 6 X 3 matrix becomes a matrix of constants every moment. Therefore, knowing three of the six forces (F) and the moment (M) of the matrix on the left side of Equation 1, the forces (Fx, Fy, Fz) can be obtained. Here, the forces Fx, Fy, and Fz are obtained using the forces Fzs and moments Mxs and Mys, which are relatively easy to measure in the load cell 200. Subtracting the part about the force (Fzs) and the moment (Mxs, Mys) in [Equation 1] is as shown in the following [Equation 2].

In addition, the force (Fzs) and the moment (Mxs, Mys) can be seen in the following principle. When the force Fz is applied to the load cell 200, the beam 250 facing each other receives one compression and one tension force. Therefore, the amount of the four beams 250 can be measured by measuring the compression and tensile force and decomposing it into forces Fzs and moments Mxs and Mys. This is shown in Equation 3 below.

Where E is the Young's Modulus of the material of the load cell 200, C is the radius of the load cell 200, A is the cross-sectional area of the load cell 200, and I is the area moment of inertia. Therefore, since E, C, A, and I are all constants, the strains ε ₁ , ε ₂ , ε ₃ , ε ₄ of each beam 250 of the load cell 200 shown in FIG. 5 are measured. Equation 3] and the list-square method can obtain an approximation of the force (Fzs) and the moment (Mxs, Mys).

In this case, the reason for using the list-square method is that since the left-side matrix is 4 X 1 and the right-side matrix is 3 X 1, the left-side matrix is used to calculate an approximation value that minimizes the error of the right 3 value using the left 4 value. will be. When the approximation of the forces (Fzs) and the moment (Mxs, Mys) is obtained, an approximation of the forces (Fx, Fy, Fz) can be obtained from Equation (2).

The calculation method of the present invention as described above is a calculation method for obtaining various assumptions and approximations, and cannot accurately measure the force acting on the end of the surgical instrument. However, since a value within a certain error range is calculated, it can be used to prevent inadvertent accidents such as sewing, tying, or damaging other organs.

Therefore, according to one embodiment of the present invention as described above, it is possible to operate freely within the laparoscope. In other words, the high degree of freedom allows the human arm to be more accurately simulated. The development of a robot with such multiple degrees of freedom may be applied not only to laparoscopic surgery but also to ultra precision surgery.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be readily apparent to those skilled in the art that various other modifications and variations can be made without departing from the spirit and scope of the invention. It is obvious that all modifications fall within the scope of the appended claims.

Claims (10)

First and second surgical instruments 101 and 102 rotatable about the surgical tool rotating shaft 103; A wrist portion 105 including the surgical tool rotary shaft 103 and rotatable about a wrist rotary shaft 107; A load cell 200 having one end connected to the wrist rotation shaft 107; An elbow portion 400 connected to the other end of the load cell 200 and rotatable in an axial direction; Consists of an upper arm 500 connected to one end of the elbow 400 around the elbow rotation axis 510, Drive means for the first surgical tool 101, drive means for the second surgical tool 102; Laparoscopic surgical robot having a multiple degree of freedom, characterized in that it comprises a drive means of the surgical tool axis of rotation (103), the axial rotation means of the elbow portion 400 and the drive means of the elbow rotation axis (510), respectively. The method of claim 1, The load cell 200 has a cylindrical shape, laparoscopic surgery robot having multiple degrees of freedom characterized in that four beams 250 are formed in the circumferential direction. According to claim 1, wherein the drive means of the first surgical tool 101, A second motor M2 capable of forward and reverse rotation; A pulley (A) rotatably integrated with the first surgical tool (101); Second and third pulleys P2 and P3 installed on the wrist rotation shaft 107; It consists of the 6th pulley P6 installed in the vicinity of the said 2nd motor M2, A wire turns the second motor M2, the second pulley P2, the pulley A, the third pulley P3, and the sixth pulley P6 sequentially to the second motor M2. Laparoscopic surgical robot having multiple degrees of freedom, characterized in that it is driven by forming a second loop (L2) to return. According to claim 1, wherein the drive means of the second surgical tool 102, A first motor M1 capable of forward and reverse rotation; A pulley (B) rotatably integrated with the first surgical tool (102); First and fourth pulleys P1 and P4 installed on the wrist rotation shaft 107; It consists of the 5th pulley P5 installed in the vicinity of the said 1st motor M1, A wire sequentially turns the first motor M1, the first pulley P1, the pulley B, the fourth pulley P4, and the fifth pulley P5 to the first motor M1. Laparoscopic surgical robot having a multiple degree of freedom characterized in that it is driven by forming a first loop (L1) returning to. According to claim 1, wherein the drive means of the surgical tool rotating shaft 103, A third motor M3 capable of forward and reverse rotation; And a seventh pulley P7 installed near the third motor M3, One end is connected to the driving means of the first surgical tool 101, the wire is connected to the driving means of the second surgical tool 102 by turning the third motor (M3) and the seventh pulley (P7) Laparoscopic surgical robot having a multiple degree of freedom characterized in that. According to claim 1, wherein the axial rotation means of the elbow portion 400, A fourth motor M4 capable of forward and reverse rotation; A rotating shaft 520 integrally rotating with the elbow portion 400; S1 and S2 installed on the rotation shaft 520 to change the winding direction of the wire; Eighth and ninth pulleys P8 and P9 installed on the elbow rotation shaft 510; An eleventh pulley P11 installed near the fourth motor M4, The wire sequentially turns the fourth motor M4, the ninth pulley P9, the S1, the rotation shaft 520, the S2, the eighth pulley P8, and the eleventh pulley P11. Laparoscopic surgical robot having a multiple degree of freedom characterized in that it is driven by forming a third loop (L3) returning to the fourth motor (M4). According to claim 1, The drive means of the elbow rotation shaft 510, A fifth motor M5 capable of forward and reverse rotation; A tenth pulley (P10) integrally rotating with the elbow rotation shaft (510); It is composed of a twelfth pulley (P12) provided near the fifth motor (M5), A wire is driven by forming a fourth loop L4 that sequentially turns the fifth motor M5, the tenth pulley P10, and the twelfth pulley P12 to return to the fifth motor M5. Laparoscopic surgical robot having a multiple degree of freedom, characterized in that. The method according to any one of claims 3 to 7, The motor is a laparoscopic surgical robot having a multiple degree of freedom, characterized in that the servo motor or step motor. The method of claim 1, From the first and second surgical instruments (101, 102) to the upper arm 500 can be inserted into the body of the patient, One end of the upper arm 500 is a laparoscopic surgical robot having a multiple degree of freedom, characterized in that detachable to the robot means capable of moving position. First and second surgical instruments 101 and 102 rotatable about the surgical tool rotating shaft 103; A wrist portion 105 including the surgical tool rotary shaft 103 and rotatable about a wrist rotary shaft 107; A load cell 200 having one end connected to the wrist rotation shaft 107 and having a cylindrical shape and four beams 250 formed in a circumferential direction; An elbow portion 400 connected to the other end of the load cell 200 and rotatable in an axial direction; In the force measuring method of a laparoscopic robot consisting of; upper arm portion 500 connected to one end of the elbow portion 400 around the elbow rotation axis 510, Measuring strain (ε ₁ , ε ₂ , ε ₃ , ε ₄ ) from the strain gauges installed on the beams 250 of the load cell 200; Calculating an approximation of the force (Fzs) and the moment (Mxs, Mys) acting on the ends of the first and second surgical instruments (101, 102) from the following equation;

Here, E is the Young's Modulus of the material of the load cell 200, C is the radius of the load cell 200, A represents the cross-sectional area of the load cell 200, I is the area inertia moment Force measuring method of laparoscopic surgery robot.

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