JP2010063713A - Syringe - Google Patents

Abstract

A syringe capable of preventing air bubbles from being mixed into a chemical solution.
A syringe 1 includes a cylindrical cylinder 5, a plunger 10 slidably inserted in the cylinder, and an elastic ring as a seal member fitted in a square groove 17 formed on the outer periphery of the plunger. 25. The cross-sectional shape of the elastic ring 25 includes a rectangular inner portion that fits into the square groove and a substantially semicircular outer portion that protrudes outward from the inner portion.
[Selection] Figure 2

Description

  The present invention relates to a syringe for injecting a contrast medium or the like into a patient, for example, and particularly relates to a syringe capable of preventing air bubbles from being mixed into a chemical solution.

Conventionally, as a fluoroscopic imaging apparatus for medical use, a CT (Computed Tomography) scanner, an MRI (Magnetic Resonance Imaging) apparatus, a PET (Positron)
Emission Tomography) device, ultrasonic diagnostic device, CT angiography device, MR angiography device and the like.
When such an apparatus is used, for example, a contrast medium or physiological saline may be injected into the patient's body for the purpose of obtaining a clear image.

Patent Document 1 discloses a technique for sealing a space between a plunger and a cylinder using an O-ring with respect to a type of syringe that is used by sucking a chemical solution into the syringe.
Special Table 2002-505161

By the way, in the conventional configuration, when the drug is drawn into the syringe by pulling the plunger, air is drawn from a minute gap between the groove of the plunger and the O-ring, and bubbles are mixed in the drug solution (in the cylinder). There was something to do.
This invention is made | formed in view of the said subject, The objective is to provide the syringe which can prevent that a bubble mixes in a chemical | medical solution.

In order to achieve the above object, the syringe of the present invention comprises:
A cylindrical cylinder;
A plunger slidably inserted into the cylinder;
An elastic ring that is fitted in a square groove formed on the outer periphery of the plunger and seals between the plunger and the cylinder,
The cross-sectional shape of the elastic ring includes a rectangular inner portion that fits into the square groove, and a substantially semicircular outer portion that protrudes outward from the inner portion.

  Here, “fit into a square groove” means that the inner part of the ring fits into the square groove without generating a gap.

  In the syringe of the present invention, the inner part of the elastic ring fits into the square groove of the plunger without generating a gap, and air is not embraced in the square groove, so when pulling the plunger and sucking the chemical into the syringe Air bubbles are prevented from entering the chemical solution.

  As described above, according to the present invention, an elastic ring having a cross-sectional shape including a rectangular inner portion that fits into the square groove of the plunger and a substantially semicircular outer portion that protrudes outward from the inner portion is used. This makes it possible to prevent air bubbles from being mixed into the chemical solution.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a syringe according to an embodiment of the present invention. In the following description, words indicating directions such as “up and down” and “left and right” are used in accordance with the description of the drawings, but these do not limit the present invention.

As shown in FIG. 1, the syringe 1 of this embodiment includes a cylindrical cylinder 5 and a plunger 10 that is slidably inserted into an inner hole thereof.
The cylinder 5 has a conventional general shape and includes a straight tubular cylindrical portion 5a and a nozzle portion 5b formed at the tip thereof.

  The plunger 10 has a conical shape on the tip side (conical portion 15). On the back surface of the plunger 10 is formed a locking portion 12 to which a rod (not shown) for moving the plunger 10 forward and backward is connected. The latching | locking part 12 has the short axis | shaft 12a extended in the back surface direction, and the flange 12b formed in the edge part of the axis | shaft 12a. A rod (not shown) is moved in the axial direction by a driving means (not shown), whereby the plunger 10 slides in the cylinder 5.

  As shown in FIG. 2, an annular square groove 17 is formed on the outer periphery of the plunger 10. As shown in FIG. 3, an elastic ring 25 is fitted in the square groove 17.

  The elastic ring 25 is a seal member and is made of, for example, silicone rubber. As shown in FIG. 3, the ring 25 specifically has a semi-cylindrical cross-sectional shape, a rectangular inner portion 25b that fits in the square groove 17, and a substantially semicircular shape that protrudes outward from the inner portion 25b. And an outer portion 25a. The outer peripheral surface of the outer portion 25 is curved in an arc shape and protrudes outward from the outer peripheral surface of the plunger 10.

  As shown in FIG. 3, both side surfaces and the inner peripheral surface of the inner portion 25 b of the ring 25 are in close contact with both side surfaces and the inner bottom surface of the square groove 17, respectively. That is, in this example, there is no gap between the elastic ring 25 and the square groove 17. On the other hand, FIG. 4 is a view showing a state in which the O-ring 23 having a circular cross section is fitted into the square groove 17. In this case, a minute gap 31 is generated between the O-ring 23 and the square groove 17.

  When the plunger 10 is inserted into the cylinder 5 (see FIG. 2), the elastic ring 25 is crushed in the radial direction, and the outer peripheral portion of the ring 25 is pressed against the inner peripheral surface of the inner hole of the cylinder. Thereby, the space between the plunger 10 and the cylinder 5 is sealed.

The syringe 1 of the present embodiment configured as described above is used as follows as an example.
First, a tube (not shown) is connected to the nozzle portion 5 b of the cylinder 5 in order to suck the chemical solution into the syringe 1. The other end of the tube is connected to, for example, a storage container that stores a chemical solution.

  A rod (not shown) for moving the plunger is connected to the locking portion 12 on the back surface of the plunger 10. By moving the rod and pulling the plunger 10 from the back of the cylinder 5 to the front, the chemical solution is sucked into the cylinder 5.

  According to the configuration of the present embodiment, the inner portion 25b of the elastic ring 25 is fitted in the square groove 17 of the plunger without generating a gap, and air is not embraced in the square groove 17 (gap 31). When the plunger 10 is pulled to suck the chemical solution into the syringe 1, bubbles can be prevented from being drawn into the chemical solution.

  In the conventional O-ring 23 (see FIG. 4), there is a case in which the air held in the gap 31 in the groove 17 is mixed into the chemical solution (bubbles adhere to the inner peripheral surface of the cylinder). According to the configuration of the form, such bubbles are hardly mixed. Therefore, it is not necessary to remove bubbles adhering to the inner peripheral surface of the cylinder 5 by hitting a syringe before injection.

  Further, in the case of the elastic ring 25 whose cross-sectional shape is a kamaboko type as in the present embodiment (that is, in the case of a ring having an inner portion 25b that fits into a square groove), if the plunger groove into which it is fitted is a square groove Good. Many of the conventional plungers are pre-formed with a square groove for fitting the O-ring 23, and the kamaboko-type elastic ring 25 as in this embodiment is used by being attached to such a conventional plunger. It is also advantageous in that it can be done.

  In addition, this invention is not limited to the above, It can apply also to the general syringe by which the piston member comprised with a plunger and a rod was inserted in the cylinder. Moreover, you may provide multiple elastic rings 25 as needed. The material and cross-sectional shape of the elastic ring 25 can be appropriately changed within the scope of the present invention.

It is a figure which shows the syringe of one Embodiment of this invention. FIG. 2 is an enlarged view of a portion of FIG. 1 showing a seal between a plunger and a cylinder. It is a figure which shows the state which fitted the elastic ring in the square groove. It is a figure which shows the state which fitted the O-ring of circular cross section in the square groove (conventional example).

Explanation of symbols

1 Syringe 5 Cylinder 10 Plunger 12 Locking part 17 Square groove 23 O-ring 25 Elastic ring 31 Gap

Claims (3)

A cylindrical cylinder;
A plunger slidably inserted into the cylinder;
An elastic ring that is fitted in a square groove formed on the outer periphery of the plunger and seals between the plunger and the cylinder,
The syringe in which the cross-sectional shape of the elastic ring includes a rectangular inner portion that fits into the square groove, and a substantially semicircular outer portion that protrudes outward from the inner portion.   The syringe according to claim 1, wherein the syringe is used by drawing a chemical into the cylinder by pulling the plunger in the cylinder.   The syringe according to claim 1 or 2, wherein a locking portion to which a rod for sliding the plunger is connected is formed on the back surface of the plunger.

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