Patent Application
20100023053
The present invention relates to an eyeless suture needle. It particularly relates to a silicone coated eyeless suture needle and a fabrication method for the same.
Suture needles thrust a patient's living body tissue, and since pain afflicting the patient increases when thrust resistance is great, processing to reduce the thrust resistance is carried out. Silicone is generally applied as a method of reducing thrust resistance; more specifically, suture needles are put in a basket spread apart and soaked in a silicone solution.
Meanwhile, the eyeless suture needle is fixed by forming a hole in a base end of a suture needle along the length thereof, inserting the end of a suture thread therein, and crimping the hole from the outside. In the case of coating such eyeless suture needles with silicone, when they are put in a basket spread apart and soaked in a silicone solution, the silicone solution penetrates into the holes, coating the inner wall of the holes with the silicone. Coating of the inner wall of the holes with silicone makes it slippery between the inner wall and the suture thread. Therefore, even if the suture thread is crimped, it slips off easily, which is a problem when it is used in surgery.
As a result, a method of putting water into the hole so that silicone does not get in (refer to Patent Document 1, for example), and a method of removing the silicone that got into the hole using a solvent (Patent Document 2, for example) have been proposed. Moreover, a method of coating silicone and then forming a hole has been proposed in Patent Document 3.
Patent Document 1: Japanese Published Unexamined Application No. Hei 4-317644
Patent Document 2: U.S. Pat. No. 3,124,564
Patent Document 3: U.S. Pat. No. 3,471,004
However, the method of putting water into the hole so that silicone does not get in of Patent Document 1, and the method of removing the silicone that got into the hole using a solvent of Patent Document 2 presents cumbersome work with an increase in the number of steps.
The present invention is devised in consideration of such problems, and provides a simple fabrication method for a suture needle coated with silicone, which prevents silicone from penetrating into the hole.
In order to achieve the aforementioned objective, a fabrication method for an eyeless suture needle according to the present invention is characterized in that it includes the steps of: supporting an eyeless suture needle with a gripping unit; and facing a hole at a base of the supported eyeless suture needle downward and coating with silicone such that the silicone does not coat inside of the hole.
In addition, an eyeless suture needle according to the present invention is characterized in that it is coated with silicone, the coating of the outside portion of a hole of the eyeless suture needle and part of the main body is unsmooth, the coating of other parts is smooth, and the inner wall of the hole is not coated with silicone.
The gripping unit may be made of a metal and hold the eyeless suture needle with the help of the energization force of an elastic body, and support the outside of a hole of the eyeless suture needle while a holding fixture may hold near the middle of a main body of the eyeless suture needle.
According to the fabrication method for an eyeless suture needle coated with silicone according to the present invention, an eyeless suture needle smoothly coated with silicone on the outside and not coated inside the hole may be provided.
Moreover, since the eyeless suture needle according to the present invention has an unsmooth coating on the outside of the hole of the eyeless suture needle and part of the main body, and smooth coating on other parts, thrust resistance may be reduced, thereby reducing the burden on a patient. In other words, since the outside of the hole or the area to be crimped and part of the main body are supported and coated in order to surely coat the needlepoint and coat as much of the outer surface of the suture needle as possible, it is not coated smoothly.
Furthermore, since the suture thread is crimped with the inner wall of the hole not coated with silicone, the suture thread may be gripped tightly, and the suture thread slipping off while suturing live body tissue may be prevented.
a) is a diagram of the eyeless suture needle in a held state, and (b) is a cross section cut along line A-A of (a); and
An embodiment according to the present invention is described with reference to attached drawings forthwith.
As shown in
The eyeless suture needle 10 may be a sharpened suture needle in which the cross section of the cutting blades 15 as shown in
Many types of suture thread 20 different in thickness and material (nylon, silk, etc.) and/or different in structure such as monofilament or multifilament are provided. An appropriate type of suture thread is selected and used according to live body tissue and region to be sutured. An end of the suture thread 20 is inserted in the hole 12, and the base end of the eyeless suture needle 10 is fixed by crushing and crimping the hole 12 using a press machine. The eyeless suture needle 10 has an advantage in that a thread long enough for suturing is fastened from the start, and thus there is no need to pass thread through a hole as with an eyed needle.
It is required during a suturing operation that the suture thread 20 attached to the eyeless suture needle 10 should not come out and snap off. In the case of an eyed needle, since suture thread is passed through a spring hole, two pieces of thread are lined up from both sides of the spring hole; however, the thread does not snap off as long as tension is not given to only one side.
However, with the eyeless suture needle, joining of the needle and thread is dependent on contact friction of the needle and the thread at the crimped portion, and loose crimping or a slippery inner wall of the hole could lead to disengagement of the thread from the suture needle while passing through living body tissue. On the other hand, crimping too tightly could lead to the thread partially breaking, decreasing in strength, and severing while passing through living body tissue. Therefore, the allowable thread snap-off strength of the eyeless suture needle 10 is preset according to the size of the suture thread 20 to be used, and a pull-off test is conducted to check whether the allowable thread snap-off strength is satisfied.
a) is a diagram of the eyeless suture needle 10 in a held state, and (b) is a cross section cut along line A-A of (a). The eyeless suture needle 10 is held in open space by a gripping unit 30 with the hole 12 facing downward. The gripping unit 30 is made up of a V block 31 including a V groove 31a, a needle holding member 32, and an elastic body 33. The gripping unit 30 is preferably made of a material such as a metal or the like that is not affected by the silicone solution. The needle holding member 32 presses down on the eyeless suture needle 10 within the V groove 31a by the elastic body 33 such as a spring, holding the eyeless suture needle 10 by the frictional force thereof. In this embodiment, a supporting member 34 supporting at the middle of the main body 11 is also used. The reason for using this supporting member 34 is that it allows the gripping unit 30 to reduce the force of gripping the outside of the hole 12. In other words, when only supporting with the gripping unit 30, a certain amount of strength is necessary. However, it cannot grip strongly since the wall of the hole 12 is thin and the hole is subjected to annealing in order to improve efficiency of the crimping operation. Use of the supporting member 34 here allows support by a light force. Note that the fabrication method for the eyeless suture needle according to the present invention is not limited to this method, and controlling the posture of a robot to carry out the coating by soaking, spraying, and the like may be considered. A gripping unit for supporting the main body is not required in this case.
In this embodiment according to the present invention, the eyeless suture needle 10 has its base side upright, and central axis a of the hole 12 overlaps with perpendicular line b falling straight down. However, when the eyeless suture needle 10 is put at an angle, angle α made by the central axis a of the hole 12 and the perpendicular line b in the direction of gravitational force should be within the range of 0 to 45 degrees.
Once the eyeless suture needle 10 is held in this manner, the entire eyeless suture needle 10 is then soaked in the silicone solution in this state. Through this process, the entire outer surface of the eyeless suture needle 10 is coated with silicone.
Although the hole 12 is facing downward, since the surface tension of the hole 12 inlet increases relatively due to the air pressure within the hole 12 and the small diameter thereof, silicone does not get into the hole 12 or a very tiny bit of silicone enters the hole 12 inlet, and thus most of the inner wall of the hole 12 remains as the base material of the eyeless suture needle 10.
While the coated eyeless suture needle 10 is coated smoothly with silicone over the entire outside, portions making contact with the gripping unit 30 have areas to which silicone is not adhered and are rough surfaces. However, these portions make up a small portion of the entire eyeless suture needle 10, and do not increase the thrust resistance. Moreover, since the outside of the hole is crimped, the coating may become unsmooth in later steps anyway.
The simplest and shortest method of coating silicone is to soak in the silicone solution as in the above embodiment. Alternatively, a method of coating with a brush or by spraying with a spray gun may be used. However, with either method, silicone must be coated to sufficiently reach even the contact section between the gripping unit 30 and the eyeless suture needle 10.
While it is understood from
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-234726 | Aug 2006 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/066592 | 8/28/2007 | WO | 00 | 10/6/2009 |
