Patent Application
20110125101
The present invention relates to a syringe needle, particularly an otologic (otolaryngological) syringe needle for passing through eardrum and injecting a medical agent into a middle ear.
A conventional syringe needle used in an otologic treatment has a length of needle of approx. 60 mm, a diameter of needle of approx. 23 as gauge and a cutting angle of a tip portion of the needle of 17 to 21 degrees. The “gauge” indicating a diameter of the syringe needle means “X” of 1 inch/“X”. One inch is 25.4 mm and therefore 23 gauges mean approx. 1.10 mm.
As an effective treatment in an otorhinology including a treatment of hypacusia, instead of a systemic administration treatment done by oral route, injection or infusion of medical agents such as steroid, a local administration treatment that medical agents such as steroid is directly injected into inner year is proposed. In the latter case, it is necessary that the syringe needle is passed through an eardrum. Further, in case multiple injections using the syringe needle is carried out for the treatment, the eardrum suffers from multiple passes of the syringe needle. Furthermore, since the injection is carried out by passing through the eardrum, the injection is performed under such condition that the place to inject the medical agent cannot be looked. In more detail, when a medical agent for injection is injected into a round window located between an inner ear and middle ear, the treatment comes to be extremely difficult.
Patent Document 1 discloses a syringe needle for accurately injecting into a narrow place (area) of human body in an otologic treatment. In the invention of the Patent Document 1, the object is to provide a process highly facilitating the injection of treatment material into a mucous membrane in a region located within narrow tuba or between gathers and a syringe needle for using the process, and the syringe needle has a structure that only a portion for inserting into a mucous membrane of a tip of a syringe needle is bent diagonally forward and a guide part is provided so as to be projected forward from a starting portion of the bent part.
In more detail, an insert part provided on a tip of a shaft part having a lumen (tube) and provided with another lumen connecting the shaft part to the former lumen is projected diagonally forward in the longitudinal direction of the shaft, and the tip of shaft part further has a guide part which is projected forward in the longitudinal direction of the shaft. Hence, the tip of the syringe needle has a biforked shape.
The structure of the tip restricts the depth inserted by the needle to a predetermined range whereby excessive or insufficient insertion can be prevented. Hence, in a region rendering treatment with directly looking the region difficult, the region including, for examples, narrow tubes of human body such as auditory tube (otosalpinx) and ureter and gathers such as middle nasal meatus, the injection of treatment material into the mucous membrane can be easily and accurately carried out in the predetermined depth without skilled performance.
Patent Document 1: JP2005-211397 A
A conventional syringe needle used in an otologic treatment does not have a specific structure that is considered from the viewpoint of the needle passing through an eardrum, and therefore the needle having the diameter mentioned previously is required to pay attention to reduction of hearing ability because the eardrum suffers from occurrence of hole due to the multiple passes of the syringe needle. Further, there is a problem that general aches generated from an injection treatment for human body including child are reduced.
In addition, it is highly difficult to inject a medical agent into a narrow place (area) such as a round window through an eardrum, because the injection is necessarily carried out in a restricted area and thickness. Therefore the use of the general syringe needle requires high proficiency for preventing the adverse current of the medical agent and keeping accurate injection.
The technique described in Patent Document 1 enables the insertion in accurate depth of the syringe needle into a place to be injected. However, a technique for injecting and dispersing a medical agent into an extremely small area including a soft region such as cartilage within a middle ear, is desired.
Recently, it has been recognized that the technique for injecting a medical agent into an inner or middle ear is used not only in the treatment of the regions associated with ear but also suitably in the treatment of the other regions. Therefore, it is important to propose a new or improved syringe needle for injecting a medical agent into an inner or middle ear through an eardrum.
In view of the above-mentioned problems, the object of the present invention is to provide an otologic (otolaryngological) syringe needle for accurately injecting and dispersing a medical agent into an extremely small area such as a middle ear within an eardrum.
The present invention described in claim 1 to achieve the object can be provided by an otologic syringe needle for passing through an eardrum and injecting a medical agent into cartilage within a middle ear, wherein
a length of the needle is in the range of 40 to 60 mm,
a cutting angle of a tip portion of the needle is in the range of 10 to 16 degrees, and
a diameter of the needle has gauge of not less than 27.
The above-mentioned constitution enables accurate injection and dispersion of a medical agent into a desired place (area) of cartilage located in a middle ear within an eardrum. In more detail, since the needle is reduced in diameter and cutting angle compared with a conventional needle, the damage of an eardrum generated when the needle is passed through the eardrum can be avoided as much as possible. Further, aches generated in general injection treatments including an injection treatment for child in an otologic treatment can be reduced. Furthermore, the reduced cutting angle increases the opening area of the tip portion of the needle, and therefore brings about increase of area of the opening area in contact with a place to be injected. Hence, an area for injection of a medical agent is increased, and therefore the medical agent can be accurately dispersed in the injected place.
In the preferred embodiment of the otologic syringe needle described in claim 2, which has the constitution of claim 1, the cutting part in the tip portion has a length of not more than 2 mm in an axial direction of the needle. Thereby, the area of the cutting part has a length which fits a cartilage covering a round window in an inner ear where the cutting part is frequently applied, and hence it can be prevented that the opening part of the tip portion runs off the edge of the applied area to cause the medical agent to leak.
In the preferred embodiment of the otologic syringe needle described in claim 3, which has the constitution of claim 1, at least one small hole is formed on the cutting part, which corresponds to a remaining portion constituting an opening area in the tip portion. Thereby, the medical agent is injected and dispersed from not only the opening area of the cutting part but also the hole(s) of the tip potion, and therefore the injection of the medical agent in various directions is ensured whereby the dispersibility of the medical agent can be enhanced.
In the preferred embodiment of the otologic syringe needle described in claim 4, which has the constitution of claim 1, at least one slit having a predetermined length is formed on the cutting part, which corresponds to a remaining portion constituting an opening area in the tip portion. Thereby, the medical agent is injected and dispersed from not only the opening area of the cutting part but also the slit(s) of the tip potion, and therefore the injection of the medical agent in various directions is ensured whereby the dispersibility of the medical agent can be enhanced.
In the preferred embodiment of the otologic syringe needle described in claim 5, which has the constitution of claim 4, a width of the slit is gradually increased with moving to a pointed tip of the needle. Thereby, the gradually widened slit is provided on a different side from that of the conventional opening, and therefore the injection area of the medical agent can be increased.
In the preferred embodiment of the otologic syringe needle described scribed in claim 6, which has the constitution of claim 4 or 5, a plurality of slits are formed as the slit. Thereby, the dispersibility of the medical agent can be further enhanced compared with the embodiment of claim 4 or 5.
In the preferred embodiment of the otologic syringe needle described in claim 7, which has the constitution of any of claims 1 to 6, a longitudinal sectional shape in a needle axial direction of the cutting part in the tip portion is in the form of circular arc which forms convex on the cutting surface side. Thereby, in case the length in a needle axial direction of the cutting part is the same between the above-mentioned needle having the convex shape and the needle having no convex shape, the above-mentioned needle enables the increase of the area of the opening area in contact with an area to be injected. Further, in case the opening area of the cutting part is the same between the above-mentioned needle having the convex shape and the needle having no convex shape, the strength of the cutting part of the above-mentioned needle having the convex shape on the surface side is increased. Hence the above-mentioned needle shows the significance effects as mentioned above when both the diameter and cutting angle of the cutting part are reduced.
As mentioned previously, the use of the otologic syringe needle of the present invention brings about the reduction of damage of an eardrum and the enhancement of injection accuracy of a medical agent, in case the syringe needle is passed through the eardrum and the medical agent in the syringe is injected into a narrow cartilage part such as round window of an inner ear located within the eardrum. Further aches generated in an injection treatment for child in an otologic treatment can be reduced, and aches generated in a general injection treatment can be also reduced. Thus, a treatment rejecting a medical agent through an inner ear can be widely carried out.
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10 Syringe needle
12 Cutting part
12
a Cutting opening area
13 Small hole
14, 16, 18 Slit
20 Circular arc shaped cutting part
The preferred embodiments are explained below with reference to the drawings.
The syringe needle is reduced in diameter and cutting angle compared with a conventional needle as mentioned above, and therefore the damage of an eardrum generated when the needle is passed through the eardrum can be avoided as much as possible. Further, aches generated in general injection treatments including an injection treatment for child in an otologic treatment can be reduced.
In case a medical agent such as steroid is injected by using a syringe into an area of a place to be injected such as a soft region adjacent to a round window of an inner ear, which is narrow, it is required to allow the cutting part of the needle to run off the edge of the place (region) to be injected in order to accurately inject the medical agent. For instance, in case the medical agent is injected into the region adjacent to the round window by using a syringe, the cutting part 12 should have generally a length of not more than 2 mm in an axial direction of the needle. In this case, it is also possible to increase the gauge number of the needle diameter (reduction of the diameter), or to set the cutting angle R to 16 degrees and incline upward and steeply the cutting line in the nonlinear form whereby the length of the cutting part 12 is set to 2 mm without change of the gauge of the needle, as shown in
Further, the reduced cutting angle increases the opening area of the tip portion of the needle, and therefore brings about increase of area of the opening area in contact with a place to be injected. Hence, an area for injection of a medical agent is increased, and therefore the medical agent can be accurately dispersed in the injected place.
Here, it is possible to apply the technique of the circular arc shaped cutting part 20 having the rounded shape to a needle having cutting angle of more than 16 degrees. Although the large cutting angle brings about reduction of the opening area of the tip portion, the reduction can be compensated by the circular arc shape of the cutting part.
The present invention is not restricted by the embodiments mentioned above, and it is possible to change the invention to various embodiments as long as the embodiments are within the scope of the gist of the present invention. For example, the length of the slit formed on the cutting part (remaining part of opening area) can be varied unless the length runs off the edge of the place (area) to be injected.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/062756 | 7/15/2008 | WO | 00 | 1/14/2011 |
