JP4418372B2 - Surgical tool positioning unit - Google Patents

Description

  The present invention relates to a positioning unit for a surgical tool, and in particular, holds a surgical tool used for a surgical operation using an endoscope and positions the distal end of the surgical tool inserted into a human body with respect to a treatment site. Therefore, the present invention is suitable for application to an apparatus.

  2. Description of the Related Art In recent years, so-called minimally invasive surgical operations in which an endoscope is inserted into the body and the operation is performed without performing a laparotomy based on an in-vivo image projected by the endoscope have been expanded as a medical surgical operation on the human body. Since this minimally invasive surgical operation has the advantage that the influence on the human body is small and the burden on the patient can be greatly reduced as compared with the case of performing surgical treatment by opening the abdomen of the patient, Has become popular.

In the positioning unit used in the minimally invasive surgical operation having the above advantages, the present inventor has proposed the technique described in Patent Document 1. The technique described in Patent Document 1 includes a first and second output shafts whose tip is pivotally connected to a surgical instrument, and provided in parallel with each other and reciprocally movable. Drive means for giving an arbitrary advance / retreat amount to the first output shaft, and for the second output shaft, always giving an advance / retreat amount of the first output shaft to an advance / retreat amount of a constant ratio (≠ 1). In a surgical operation using an endoscope, it is possible to position the distal end of such a surgical tool to a site requiring treatment in the body without expanding a hole opened in the human body for inserting the surgical tool. In addition, this is a positioning unit technology that can realize the positioning operation of the surgical tool by remote control.
WO2004 / 035270 A1

  However, the surgical instrument positioning unit described in Patent Document 1 described above has the following problems. This problem will be described with reference to FIG. 6 and FIG. FIG. 6 shows a connection state between the surgical tool and the first unit and the second unit in the positioning unit described in Patent Document 1. FIG. 7 shows a minimally invasive surgery performed using the positioning unit according to the prior art. The state of surgery (endoscopy) is shown.

  As shown in FIG. 6, the two output shafts 164 and 165 of the second unit 130 are pivotally connected via the first unit 120 and the connection portion 140, respectively. In this connected state, the output shafts 164 and 165 of the second unit 130 are always orthogonal to the output shafts 121 and 122 of the first unit 120. That is, the plane including the first output shaft 121 and the second output shaft 122 of the first unit 120 is always orthogonal to the plane including the third output shaft 164 and the fourth output shaft 165 of the second unit 130. .

  And if each output shaft 121,122 of the 1st unit 120 is advanced / retreated, the arrangement | positioning angle of the rod 111 of the surgical tool 110 will be changed along the arrow X direction. On the other hand, when the output shafts 164 and 165 of the second unit 130 are advanced and retracted, the arrangement angle of the rod 111 of the surgical instrument 110 is changed along the Y direction orthogonal to the X direction.

In addition, as shown in FIG. 7, in a minimally invasive surgical operation using a positioning unit according to the prior art, several skins of a patient P, which is a treatment target, are incised by about 2 to 3 cm, and from these incised insertion sites. The distal end of the surgical instrument 110 such as an endoscope 110a such as a video scope, forceps 110b, and laser knife 110c is inserted into the body of the patient P. The surgeon picks up the affected part by operating other surgical tools 110 such as the forceps 110b and the laser knife 110c based on the image of the monitor while observing the image of the human body taken by the endoscope 110a on the monitor. Appropriate measures such as dripping, holding, or excising.

  Considering the relationship between the driving directions as described above, the first unit 120 and the second unit 130 have to be arranged in an L shape as viewed from above. This was an unavoidable arrangement due to the configuration of the unit for swinging the surgical instrument 110.

  However, when an L-shaped arrangement is seen from above, a rectangular area having two sides of these two units becomes a dead space. That is, when the operator who performs the operation moves the surgical tool because a rectangular area having two sides as two sides and a triangular area (exclusive area) having at least two units as two sides exist as a dead space, There was a problem that it was very annoying.

  Therefore, it has been desired to develop a technique capable of reducing the troublesome part for the surgeon and greatly reducing the above-described exclusive area.

  Therefore, an object of the present invention is to provide an operating angle of the surgical instrument that can move the distal end of the surgical instrument in the human body vertically and horizontally and can reduce the weight while widening the space for the operation. It is to provide a positioning unit for continuously changing.

In order to achieve the above object, the present invention provides:
In the surgical tool positioning unit configured to hold the medical surgical tool, change the arrangement angle of the surgical tool around the fixed point, and position the distal end of the surgical tool with respect to the treatment site.
The first unit, the second unit , the third unit, and the fourth unit arranged above the treatment site are sequentially connected to each other, and the surgical unit is attached to the fourth unit .
The second unit is connected to the first unit around a rotation axis connecting the first unit and the fixed point.
It is configured to be rotatable with respect to the
Third unit, together with the central axis extending in the longitudinal direction of the surgical instrument to support the fourth unit to intersect at a predetermined angle in the rotating shaft and the fixed point, changing the position where the center axis intersects the pivot axis Without being configured to be displaceable with respect to the second unit so that the angle at which the central axis and the rotation axis of the surgical instrument intersects changes .
The fourth unit is configured to reciprocate along the central axis of the surgical tool with respect to the third unit, and configured to hold the surgical tool rotatably about the central axis. A surgical tool positioning unit characterized by the above.

  With this configuration, when a surgical tool is attached to the fourth unit and a minimally invasive surgical operation is performed, the working portion at the tip of the surgical tool is moved by the movement of the fourth unit. Since it can be inserted in the longitudinal direction, that is, in the back or returned to the front, the degree of freedom can be further increased.

  According to the positioning unit for a surgical tool according to the present invention, in the positioning unit for continuously changing the arrangement angle of the surgical tool, the distal end of the surgical tool in the human body can be moved vertically and horizontally while working. The space can be expanded and the weight can be reduced.

  Next, an embodiment of the above invention will be described with reference to the drawings. In all the drawings of the following embodiment, the same or corresponding parts are denoted by the same reference numerals.

  As shown in FIG. 1, the positioning unit for a medical device according to this embodiment includes a first unit 1, a second unit 2, a third unit 3, and a fourth unit 4. .

  The first unit 1 and the second unit 2 are connected at a connecting portion 5 so that the second unit 2 can rotate with a predetermined rotation axis O ′ in common. That is, the first unit 1 rotates the second unit 2 around the rotation axis in the connecting portion 5.

  Moreover, in this one Embodiment, the longitudinal direction of the 1st unit 1 and a rotating shaft are substantially parallel. That is, when the positioning unit is in a flat state, the first unit 1 and the second unit 2 are arranged in a substantially straight line as viewed from above.

  Further, the second unit 2 and the third unit 3 are connected at the connecting portion 6 so that the entire third unit 3 is swung. That is, the second unit 1 is configured so that the third unit 3 can swing at the connecting portion 6 in a direction substantially perpendicular to the rotation direction of the first unit 1.

  The third unit 3 is provided with a fourth unit 4 that can reciprocate along the longitudinal direction of the third unit 3. That is, the fourth unit 4 is moved in the longitudinal direction of the third unit 3 by the third unit 3.

  Further, the fourth unit 4 is provided with a surgical instrument mounting portion 4a. The surgical tool mounting portion 4a is configured to be capable of mounting a rod-shaped surgical tool 7 provided with a surgical mechanism 7a such as a surgical laser knife or forceps at the tip. The fourth unit 4 is configured to be rotatable around a rotation axis O ″ that is parallel to the moving direction of the third unit 3 and passes through the attachment hole of the surgical instrument attachment portion 4a. That is, the fourth unit 4 can rotate the surgical instrument 7 around its central axis (rotation axis O ″) in a state where the surgical instrument 7 is attached along the longitudinal direction.

  In the surgical instrument positioning unit according to the embodiment configured as described above, the first unit 1 rotates the third unit 3 along the arrow A direction. Further, the third unit 3 is swung along the arrow B direction by the second unit 2. Further, the fourth unit 4 is reciprocated along the arrow C direction by the third unit 3. Further, the attached surgical tool 7 can freely rotate as indicated by an arrow D by the fourth unit 4.

Furthermore, although mentioned later for details, in this one Embodiment, the rotating shaft O 'of the 2nd unit 2 rotated by the 1st unit 1, and the rotating shaft O rotated by the 4th unit 4 are rotated. ″
Is configured to intersect at point O. That is, the point O does not move even if the first unit 1 and the second unit 2 rotate the third unit 3 in the vertical and horizontal directions (arrow A and arrow B directions). It is configured to be a “fixed point”.

  Next, the operation principle of the second unit 2 according to this embodiment configured as described above will be described. FIG. 2 shows the internal structure of the second unit 2.

  As shown in FIG. 2, the second unit 2 according to this embodiment includes a first output shaft 21 and a second output shaft 22 that are arranged in parallel to each other. The first output shaft 21 and the second output shaft 22 are configured to advance and retreat with respect to the casing 23 (see FIG. 1) while interlocking with each other.

  In addition, a connecting portion 40 for connecting to the third unit 3 is provided at the distal ends of the first output shaft 21 and the second output shaft 22. The connection unit 40 holds the third unit 3 in a swingable manner about the axes P and Q indicated by the alternate long and short dash lines. In addition to the structure drawn at the tip of the first output shaft 21, the structure of the connecting portion 40 may be a relatively compact structure drawn in the lower part of FIG.

  The first output shaft 21 and the second output shaft 22 are formed with helical male screw grooves 21a and 22a. A second ball screw nut 25 is screwed into the male screw groove 22 a of the second output shaft 22. A ball screw nut (not shown) connected to the motor 50 is screwed into the male screw groove 21a of the first output shaft 21 via a large number of balls circulating infinitely. Here, it is shown that the ball screw nut connected to the first output shaft 21 is housed in the motor 50, but preferably, as shown in FIG. It is desirable that the output shaft 21 and the second output shaft 22 be provided outside, and the driving force can be transmitted to the first output shaft 21 and / or the second output shaft 22 and stored in the casing 23.

  As shown in FIG. 2, when the ball screw nut (not shown) of the first output shaft 21 is rotated by driving the motor 50, the first output shaft 21 is rotated according to the number of rotations. It will advance and retreat. On the other hand, the drive of the motor 50 is not given to the ball screw nut 25 of the second output shaft 22 independently. Here, the second ball screw nut 25 is rotated by receiving power from a ball screw nut (not shown) of the first output shaft 21.

  Further, the transmission of these powers is performed by the timing belt 28. That is, when the ball screw nut of the first output shaft 21 is rotationally driven by the motor 50, the ball screw nut 25 of the second output shaft 22 is rotated at the same rotational speed. Since the second output shaft 22 is fixed to the third unit 3 at the tip thereof, the second output shaft 22 itself cannot rotate. Therefore, when the ball screw nut 25 rotates, the second output shaft 22 rotates. Depending on the number, the second output shaft 22 advances and retreats.

  Here, the driving force of the motor 50 is transmitted to the ball screw nut of the first output shaft 21, but the driving force of the motor 50 is transmitted to the ball screw nut 25 of the second output shaft 22. In this case, the driving force applied to the second output shaft 22 is configured to be transmitted to the first output shaft 21 via the timing belt 28.

  Further, in the second unit 2 according to this embodiment, the helical male screw groove 22 a formed in the second output shaft 22 is replaced with the helical male screw groove 21 a formed in the first output shaft 21. On the other hand, it is formed by x times (for example, 2 times) of leads. Therefore, when the first output shaft 21 advances and retreats according to the rotation of the motor 50, the second output shaft 22 always advances and retreats by an amount of advance / retreat of x times (for example, 2 times) the first output shaft 21. become.

  As a result, as shown in FIG. 4, the third unit 3 pivotally attached to the tips of the first output shaft 21 and the second output shaft 22 and the third unit 3 in the longitudinal direction. The arrangement angle with the surgical tool 7 held along is changed, and the mechanism portion 7a at the distal end of the surgical tool 7 can be positioned with respect to the surgically affected part.

  At this time, the arrangement angle of the surgical instrument 7 is changed around one point by the second unit 2 according to this embodiment. The center point O is generated at a position corresponding to the ratio of the advance / retreat amount between the first output shaft 21 and the second output shaft 22.

  Specifically, when the advance / retreat ratio is set to 1: 2 (x = 2), the first output shaft 21 and the first output shaft 21 with respect to the distance d between the first output shaft 21 and the second output shaft 22 are the same. It occurs at a distance d from the pivot Q connecting the three units 3. This is based on the similarity law of the triangle, and if the advance / retreat ratio between the first output shaft 21 and the second output shaft 22 is always constant, the wiring angle of the third unit 3 (surgical tool 7) is always determined. There will be a point O which is the center of change. In order to keep the advance / retreat ratio constant, there is a method in which the lead of the male screw groove 21a of the first output shaft 21 is different from the lead of the male screw groove 22a of the second output shaft 22. Further, the leads are the same, and a certain ratio is given between the rotation speed of the ball screw nut of the first output shaft 21 and the rotation speed of the ball screw nut 25 of the second output shaft 22. Anyway. Further, when the rotational power is transmitted from the first ball screw nut to the second ball screw nut 25 by the timing belt 28, the rotational speed ratio is changed by changing the number of teeth formed on the pulley. It is also possible.

  Next, the first unit 1 that rotates the second unit 2 around a predetermined rotation axis will be described. FIG. 3 shows a first unit 1 and a second unit 2 according to this embodiment.

  As shown in FIG. 3, the first unit 1 coupled to the second unit 2 includes a stepping motor 31, a U-shaped motor bracket 32, a shaft 33 that serves as a rotation axis of the coupling arm 36, and a sensor that accompanies the rotation. A sensor mounting plate 34 for mounting the sensor and a shielding plate 35 for the sensor called a sensor dog.

  The connecting arm 36 has an L-shaped shape and is used to connect the first unit 1 to the second unit 2 at a predetermined angle θ. That is, the acute angle formed by the rotation axis of the shaft 33 in the first unit 1 and the first output shaft 21 and the second output shaft 22 in the second unit 2 is a predetermined angle θ (0 ° <θ <90). °). Here, details of a method of determining the predetermined angle θ will be described later. Further, one side of the connecting arm 36 is fixed to the second unit 2 with, for example, a bolt. The other side of the connecting arm 36 is rotatably connected to the shaft 33 of the first unit.

  Here, the connection between the first unit 1 and the second unit 2 by the connection arm 36 will be described. That is, as described above, the center point O exists in the rotation of the third unit 3 and the surgical instrument 7 by the second unit 2 (arrow B in FIG. 1). Therefore, the predetermined angle θ is determined so that the rotation axis O ′ of the first unit 1 passes through the center point O. By connecting the first unit 1 and the second unit 2 in this way, the point O in FIG. 1 becomes the center of rotation of the swing along the arrow B and the rotation along the arrow A. It becomes the center of rotation of motion. That is, the center point O shown in FIG. 4 is such that the second unit 2 is rotated in the direction of the arrow A by the first unit 1, and the third unit 3 is in the direction of the arrow B by the second unit 2. Is “fixed point O” (see FIG. 1).

  The positioning unit is adjusted by adjusting the distance between the positioning unit according to the embodiment and the patient's affected part so that the “fixed point O” matches the insertion opening formed by incising the patient's affected part. Even if the disposition angle of the surgical tool 7 is changed by using the surgical tool 7, the surgical tool 7 does not cause the patient's insertion port to be expanded, so that the surgical tool is not damaged without damaging the skin tissue around the insertion port. 7 can be positioned with respect to the affected part in the human body.

  In the positioning unit according to this embodiment, the mechanism portion 7a at the distal end of the surgical instrument 7 can be moved vertically and horizontally by the arrow A direction and the arrow B direction shown in FIG. The mechanism part 7a can be moved in the vertical direction by movement along the arrow C direction by the movement of the fourth unit 4, and the mechanism part 7a such as forceps is used by rotation along the arrow D direction by the fourth unit 4. It can be rotated for ease. In other words, in the positioning unit according to this embodiment, the first unit 1 to the fourth unit 4 are driven to determine an arbitrary amount of rotation or movement, whereby the mechanism unit 7a at the distal end of the surgical instrument 7 is determined. Can be freely moved to the position desired by the surgeon and positioned, and the presence of the fixed point O eliminates the possibility of expanding the insertion opening of the patient.

  FIG. 5 shows a state in which the positioning unit (FIG. 5A) according to the prior art and the positioning unit (FIG. 5B) according to the embodiment of the present invention are viewed from above during operation.

  As shown in FIG. 5A, in the positioning unit according to the prior art, when viewed from above, the two units have to be arranged in an L shape. The existence of a rectangular area or a triangular area, each having one side, is very disturbing to the surgeon.

  On the other hand, as shown in FIG. 5B, according to the positioning unit according to the embodiment of the present invention, the second unit 2 is rotationally driven with the longitudinal direction of the first unit 1 and the rotation axis being substantially parallel. By connecting the first unit 1 and the second unit 2 to be connected at a predetermined angle θ (see FIG. 3), the first unit 1 and the second unit 2 are linearly viewed from above. Can be arranged. Therefore, it is possible to greatly reduce the space that is obstructed by the surgeon, and the operability of the surgical instrument 7 can be further improved.

  The embodiment of the present invention has been specifically described above, but the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible.

1 is a schematic perspective view showing a positioning unit for a surgical instrument according to an embodiment of the present invention. It is a perspective view for demonstrating the principle of the 2nd unit in the positioning unit of the surgical tool by one Embodiment of this invention. It is sectional drawing which shows the 1st unit and the 2nd unit in the positioning unit of the surgical tool by one Embodiment of this invention. The relationship between the advance / retreat ratio of the first output shaft and the second output shaft in the second unit of the positioning unit of the surgical tool according to the embodiment of the present invention and the arrangement angle with the third unit (surgical tool) It is a basic diagram for demonstrating. It is a basic diagram for contrasting the positioning unit of the surgical tool by a prior art, and the positioning unit of the surgical tool by this invention. It is a top view for demonstrating the connection state of the 1st unit by a prior art, and a 2nd unit. It is a basic diagram which shows the mode of the minimally invasive surgery performed using the positioning unit of the surgical tool by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st unit 2 2nd unit 3 3rd unit 4 4th unit 4a Surgical tool attachment part 5,6 Connection part 7 Surgical tool 7a Mechanism part 21a, 22a Male screw groove 21 1st output shaft 22 2nd Output shaft 23 casing 25 nut 28 timing belt 31 stepping motor 32 motor bracket 33 shaft 34 sensor mounting plate 35 shielding plate 36 connecting arm 40 connecting portion 50 motor

Claims (1)

In a positioning unit for a surgical tool configured to hold a medical surgical tool and change an arrangement angle of the surgical tool around a fixed point so that the distal end of the surgical tool can be positioned with respect to a treatment site. ,
The first unit, the second unit , the third unit, and the fourth unit arranged above the treatment site are sequentially connected to each other, and the surgical instrument is attached to the fourth unit. And
Upper Symbol second unit is configured to be rotatable relative to the first unit and the fixed point and the first unit around the pivot axis connecting,
Upper Symbol third unit, together with the central axis extending in the longitudinal direction of the surgical instrument to support the fourth unit to intersect at a predetermined angle in the rotating shaft and the fixed point in the shaft above times Without changing the position where the central axis intersects, it is configured to be displaceable with respect to the second unit so that the angle at which the central axis of the surgical instrument and the rotation axis intersect is changed ,
The fourth unit is configured to reciprocate along the central axis of the surgical tool relative to the third unit, and is configured to hold the surgical tool rotatably about the central axis. A positioning unit for a surgical instrument characterized by the above.

Images