The present invention relates to a device for opening a hole in an eyeless needle or surgical suture needle using a laser beam and a hole drilling method for the same. It particularly relates to technology suitable for a thin eyeless needle.
With an eyeless needle used in surgical operations, a hole is formed along the length of the needle from a base end and a suture thread is inserted in the hole and fixed by caulking. As a hole opening method, a method using a laser beam has been well known (e.g., Patent Document 1).
However, since the aforementioned hole opening operation is performed by hand, efficiency is not improved and cost is high.
Patent Document 2 has been proposed to resolve this problem. This conventional example will be described next while referring to drawings.
The table 3 is movable independently in three mutually-orthogonal axial directions by an X-axis drive motor 4, a Y-axis drive motor 5, and a Z-axis drive motor 6. The X-axis drive motor 4, the Y-axis drive motor 5, and the Z-axis drive motor 6 move the table 3 using something capable of moving with high precision, such as ball screws or the like.
A laser oscillator 7 is a device for oscillating a laser beam 8 for opening a hole in the respective base ends 1b of the needle materials 1. The laser beam 8 oscillated by the laser oscillator 7 opens the hole 1c by proceeding downward in the drawing guided by a dichroic mirror 9 and converged by a lens 10 so as for it to be applied to the base end 1b of the needle material 1.
A collection B of the needle materials 1 is photographed by a camera 11, which uses a photoelectric transducer such as a CCD and is provided behind the dichroic mirror 9.
However, the hole opening method of the aforementioned Patent Document 2 has the following problem. Firstly, since the camera 11 photographs the entire collection B of the needle materials 1, the pixel count for photographing the needle materials 1 is lower, and accuracy of identifying the center locations is decreased. Moreover, while the center of the needle materials 1 to be processed by the X-axis drive motor 4 and the Y-axis drive motor 5 are aligned with the optical axis 8a of the laser beam, the needle materials 1 cannot be arranged in a straight line along the X axis or the Y axis, as shown with the needle materials 1d, 1e, and 1f of
While the table 3 can shift precisely in units of several micrometers to several hundred micrometers using ball screws, when shifting in the reverse direction, error equivalent to the backlash occurs. As a result of this error, a problem occurs where the optical axis of the laser beam and the centers of the needle materials 1 are misaligned, and holes are opened at misaligned positions from the centers of the needle materials 1. Particularly, the thinner the needle material 1, the greater adverse influence of this error, and a hole cannot be opened precisely with the needle material 1 having a diameter of 200 micrometers or less by the aforementioned method.
The present invention is devised through consideration of the aforementioned problems. An objective thereof is to provide a hole opening device and a hole opening method for an eyeless needle capable of accurately aligning the center of a needle material and the optical axis of a laser beam as well as opening holes precisely even with a thin needle material of 200 micrometers or less.
In order to attain the objective described above, the hole opening device for an eyeless needle, according to the present invention, is characterized by including a table comprising a mounting surface for arranging in parallel a plurality of rod-like needle materials with respective base ends of the plurality of rod-like needle materials aligned in a row; a shifter for shifting the table linearly; a camera for photographing base ends of several needle materials which are a part of the plurality of needle materials arranged in a row; a laser oscillator arranged opposite the base ends for irradiating a laser beam of an optical axis parallel to the needle materials; an image processing means for locating a needle material to be processed from the photographed image taken by the camera and locating the center location of the base end of the located needle material from the image of the base ends of the needle materials; and a control unit for driving the shifter so as to overlap the center location of the base end located by the image processing means and the optical axis of the laser beam irradiated by the laser oscillator.
This device may adopt a configuration further including an adjusting mechanism for adjusting so as for a shifting direction of the table by the shifter to be parallel with a direction in which the needle materials are arranged. Alternatively, the needle material to be processed located by the image processing means is the first needle material in the shifting direction when there is no needle material in which a hole has been opened, while the needle material to be processed located by the image processing means is an adjacent needle material to the last needle material to have a hole opened when there is a needle material in which a hole has been opened. Further alternatively, when shifting the plurality of needle materials, the shifter first shifts the table a distance equivalent to diameter of one needle material, and then shifts a distance equivalent to misalignment between the center of the base end of the needle material to be processed and the optical axis of the laser beam accordingly. Yet even further alternatively, the image processing means determines a needle material to be processed next and locates the center location of that needle material, and the shifter shifts the plurality of needle materials so as to make the center location of the needle material to be processed next and the optical axis of the laser beam match.
In order to attain the objective described above, the hole drilling method for an eyeless needle, according to the present invention, is characterized by including: a step of arranging in parallel a plurality of rod-like needle materials with respective base ends of the plurality of rod-like needle materials aligned in a row, and mounting them on a table; a step of photographing, by a camera, the base ends of several needle materials which are a part of the plurality of needle materials aligned in a row; a step of locating a needle material to be processed from the photographed image and locating the center location of the base end of the located needle material from the image of the base ends of the needle materials; a step of matching the center location of the base end of the needle material to be processed and an optical axis of a laser of a laser oscillator arranged opposite the base ends of the located needle materials for irradiating a laser beam of an optical axis parallel to the needle materials by shifting the table; a step of opening a hole of a predetermined depth along the length of the needle material from the base end by the laser; and a step of locating a needle material to be processed next of the plurality of needle materials from the photographed image taken by the camera and a step of locating a center location of the base end of the located needle material from the image of the base ends of the needle materials, shifting the table so as to match the optical axis of the laser of the laser oscillator and the center location of the needle material to be processed, and opening a hole; wherein these immediately previous two steps are repeated until there are no remaining needle materials.
This method may adopt a structure where after the plurality of rod-like needle materials are mounted on the table, a shifting direction of shifting the table linearly and direction in which the needle materials are arranged are adjusted so as to be parallel. Alternatively, it may further include a step of aligning in parallel and in a row a plurality of rod-like needle materials, fixing them with a tape, and cutting an end of all of the needle materials to form base ends before the step of arranging in parallel the plurality of rod-like needle materials with respective base ends of the plurality of rod-like needle materials aligned in a row, and mounting them on a table. Further alternatively, in the method of locating the needle material to be processed next, the first needle material in the shifting direction is located when there is no needle material in which a hole has been opened while an adjacent needle material to the last needle material in which a hole has been opened is located when there is a needle material in which a hole has been opened. Yet even further alternatively, when shifting the table so as to shift the plurality of needle materials, first shifting a distance equivalent to the diameter of one needle material is carried out, and then shifting a distance equivalent to the misalignment between the center of the base end and the optical axis of the laser beam is carried out. Yet even further alternatively, when shifting the table so as to shift the plurality of needle materials, first, a needle material to be processed next is determined from the image photographed by the camera, a center location of that needle material is located, and the table is shifted so as to match the center of the base end of the needle material to be processed and the optical axis of the laser beam.
The needle materials are aligned on the table, and several of them are photographed by the camera. A needle material to be processed is identified from the camera image, and a center location of that needle material is found from that image. Next, the plurality of needle materials are shifted by shifting the table, the center location of the needle material to be processed and the optical axis of a laser beam are matched, and the laser beam is irradiated so as to open a hole therein.
The table is shifted, a needle material to be processed next is found from the image photographed by the camera, the same process is repeated, and a hole is opened until the last needle material, thereby ending processing.
If a plurality of rod-like needle materials are aligned in parallel, fixed with a tape, and an end of all of the needle materials cut to form base ends, orientation of the base ends may be uniform, allowing easier image analysis.
When opening a hole in the next needle material, adopting a configuration where it is first shifted a distance equivalent to the diameter of one needle material, and then the misalignment between the center of the base end of the processing object needle material and the optical axis of the laser beam is shifted allows shifting quickly. Alternatively, a needle material to be processed next may be determined from the image photographed by the camera and the center location of that needle material found so as to match the center of the base end of the needle material to be processed and the optical axis of the laser beam.
According to the present invention, since the base ends of several needle materials which are a part of a plurality of needle materials aligned in row are photographed by the camera, the pixel count per needle material may be increased, and center locations may be accurately found. Moreover, according to the present invention, shifting the plurality of needle materials by linearly shifting the table only by the shifter simplifies the configuration. In the case of the present invention, the table shifts only in one direction and not in the reverse direction. Therefore, influence of backlash is omitted and the original highly accurate positioning of ball screws is possible. This allows precise hole opening even in thin needle materials of 200 micrometers or less.
An embodiment according to the present invention is described with reference to accompanying drawings forthwith.
The collection B of the conventional needle materials 1 had inconsistencies in orientation of the base ends of the respective needle materials. Therefore, there is a problem of lack of image sharpness, making analysis difficult. With the present invention, the needle materials 1 may be prepared cut to a predetermined length, and the base ends aligned and fixed by the tape 29, as in the conventional way. However, orientation of the base ends is inconsistent in this case. As a method to resolve this problem, the needle materials 1 are kept longer than the predetermined length, fixed by jigs or the tape 29, and excessive portions are then cut off together. As a result, orientation of the base ends 1b of the respective needle materials 1 are aligned, allowing achievement of a clear image when photographed by a camera and easier image analysis.
A camera 25 is deployed so as to face the base ends 1b on the table 21, and a laser oscillator 26 is deployed perpendicular thereto. Reference numeral 27a denotes a dichroic mirror for reflecting the laser beam and transmitting visible light, and reference numeral 28 denotes a lens. The lens 25, the laser oscillator 26, the dichroic mirror 27a and the lens 28 are the same as those described in the conventional example, and arrangement thereof is also the same.
Virtual lines shown in
Note that while the camera 25 is a digital camera, a camera for photographing moving pictures may be used.
In
a) to 4(f) are diagrams describing steps of a process for opening a hole in the needle material, and
As shown in
Since a hole has not been opened in any of the needle materials 1, the first needle material 1 in the feeding direction (the far left needle material 1 in
In
According to the present invention, the needle materials 1 are aligned in a row on the table 21. Therefore, in order to overlap the center C1 and the point O, the table 21 needs to be shifted only in the X-axis direction by the shifter 22a, where the sub-shifter 22b and the auxiliary shifter 22c are normally not used.
Moreover, in
Once the center C1 and the point O are confirmed to be overlapping as shown in
Next, the shifter 22 shifts the table 21 only a distance equivalent to the diameter D of the needle material 1 (step S113). Returning to step S101, the needle material 1 is then photographed.
Once the center C2 of the second needle material 1 and the point O are confirmed to be matching as in
Aside from the above shifting method, the method described next may be employed as well. Once hole-opening is completed in step S111, processing returns to step S101 as indicated by a dotted line, and the next image is photographed. A needle material to be processed next is determined (step S103) and the center location thereof is found (step S105). The new center location is located in the image and that center is shifted to the center point of the laser (step S107). The match is confirmed in step S109 and a hole is opened. In this case, shifting of the table only requires the shifting of step S107 and the shifting of step S113 may be omitted.
When the image processing means 31 is locating the center in the aforementioned process, even if there is an impairment for some reason in a part of the circular base end, or spatter adheres thereto at the time of opening a hole, thereby a part of the circle not being displayed in the image, the center location can be found from the remaining circular portion. Aside from the above, an image processing method such as a pattern matching method using normalized correlation may be used.
While the cross-sectional shape of the needle material 1 is circular in the above embodiment, the same processes may be performed in the case of shapes other than a circle such as a triangle or a trapezoid.
a) to 4(f) are diagrams describing steps of a process for opening a hole in a needle material;
Number | Date | Country | Kind |
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2008-253614 | Sep 2008 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/066722 | 9/28/2009 | WO | 00 | 6/27/2011 |