DEVICE FOR REGULATING LIQUID MEDICINE SUPPLY AND LIQUID MEDICINE INJECTION APPARATUS HAVING THE SAME

Abstract

The present invention provides a device for regulating liquid medicine supply, wherein air that exists in a liquid medicine or between portions of a liquid medicine is removed in advance by an air removal filter provided on a discharge path in the device so that priming as a preparatory operation for injection of the liquid medicine into a patient can be accelerated and it is possible to reduce an unnecessary loss of the liquid medicine, which is caused by discharge of the liquid medicine for removal of the air existing in the liquid medicine or between portions of the liquid medicine. Further, the present invention provides a device for regulating liquid medicine supply, wherein air existing between portions of a liquid medicine, which may be produced by a difference in flow speeds of the portions of the liquid medicine flowing in the device, is removed by an air removal filter provided on a discharge path in the device so that an increment of the liquid medicine can be rapidly injected and a user can directly and conveniently regulate the injection amount of the liquid medicine as desired.

Claims

1. A device for regulating liquid medicine supply, comprising: a casing; a body disposed within the casing, and having an inflow inlet through which a liquid medicine from a liquid medicine inflow tube extending to be in communication with a liquid medicine storage space flows into the body, and a discharging outlet for discharging the liquid medicine, which has flowed into the body through the inflow inlet, to a liquid medicine outflow tube; a continuous supply flow passage provided inside the body and configured to regulate a flow rate of the liquid medicine flowing into the body through the inflow inlet so that a certain amount of liquid medicine is continuously supplied to the liquid medicine outflow tube through the discharging outlet of the body; an increment-supplying flow passage configured to divide and store the liquid medicine flowing into the body through the inflow inlet of the body and then to allow the divided and stored liquid medicine to join at an outlet end of the continuous supply flow passage so as to increase the amount of the liquid medicine discharged through the discharging outlet of the body; and an air removal means provided between the outlet end of the continuous supply flow passage and the discharging outlet of the body and configured to discharge air, which is entrained in the liquid medicine passing through the outlet end of the continuous supply flow passage or is between portions of the liquid medicine passing through the outlet end of the continuous supply flow passage, to the outside of the body so as to remove the air.

2. The device of claim 1, wherein the continuous supply flow passage comprises a connection passage being in communication with the inflow inlet within the body, a first capillary tube passage being in communication with the connection passage, and a first internal flow passage for connecting the first capillary tube passage to the discharging outlet within the body so as to discharge the liquid medicine, which has passed through the first capillary tube passage, through the discharging outlet.

3. The device of claim 2, wherein the increment-supplying flow passage comprises an internal flow passage provided inside the body, and an external flow passage provided outside the body and being in communication with the internal flow passage.

4. The device of claim 3, wherein the internal flow passage comprises a connection passage being in communication with the inflow inlet within the body, a second capillary tube passage being in communication with the connection passage, a second internal flow passage being in communication with the second capillary tube passage, and an outlet of the second internal flow passage for guiding the liquid medicine, which has passed through the second capillary tube passage, to the external flow passage.

5. The device of claim 4, wherein the external flow passage comprises a reservoir inflow tube for connecting the outlet of the second internal flow passage to a reservoir inlet at the outside of the body, a reservoir having a liquid medicine storage space for storing the liquid medicine provided through the reservoir inflow tube, and a reservoir outflow tube for allowing the liquid medicine, which is discharged from the liquid medicine storage space of the reservoir through a reservoir outlet, to join at the first internal flow passage.

6. The device of claim 1, wherein the air removal means comprises a groove concavely formed on one side of the body so as to allow a portion of the continuous supply flow passage to be in communication with the outside of the body, a cover member coupled to an opening portion of the groove so as to seal the groove, at least one air vent formed in the cover member so as to outwardly discharge air from the liquid medicine passing through the groove in the continuous supply flow passage, and a filter member accommodated between the groove and the cover member so as to allow the air in the liquid medicine introduced into the groove to pass through the filter member and to be discharged through the air vent and not to allow the liquid medicine to pass through the filter member, thereby preventing leakage of the liquid medicine.

7. The device of claim 6, wherein the filter member is formed as a dual filter comprising a hydrophilic filter layer and a gas-permeable and liquid-impermeable hydrophobic filter layer stacked on the hydrophilic filter layer.

8. The device of claim 4, wherein the first capillary tube passage and the second capillary tube passage have identical to or different from each other in at least one of diameter or length, and the at least one of the diameter or the length of the first capillary tube passage or the second capillary tube passage is adjusted to regulate the supply amount of the liquid medicine.

9. A liquid medicine injection apparatus comprising the device of claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0042] FIG. 1 is an external perspective view showing a state where a user grips a device for regulating liquid medicine supply 200 according to one embodiment of the present invention.

[0043] FIG. 2 is a front view showing arrangement of components in a casing 201 in a state where the device for regulating liquid medicine supply 200 according to the embodiment of the present invention is disassembled.

[0044] FIG. 3 is a side view of a body 210 of the device for regulating liquid medicine supply 200 according to the embodiment of the present invention.

[0045] FIG. 4 is a perspective view showing an interrelationship between the body 210 and a reservoir 300 in the device for regulating liquid medicine supply 200 according to the embodiment of the present invention.

[0046] FIG. 5 is an exploded perspective view of the body 210 of the device for regulating liquid medicine supply 200 according to the embodiment of the present invention.

[0047] FIG. 6 is a longitudinal sectional view of the body 210 of the device for regulating liquid medicine supply 200 according to the embodiment of the present invention, taken along line A-A of FIG. 3.

[0048] FIG. 7 is a sectional view taken along line B-B of FIG. 6.

[0049] FIG. 8 is an enlarged view of C portion of FIG. 7, showing an air removal means.

[0050] FIG. 9 is a view showing a configuration of one example of a liquid medicine injection apparatus 100 including the device for regulating liquid medicine supply 200 according to the embodiment of the present invention.

DETAILED DESCRIPTION

[0051] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The following embodiments of the present invention are just to implement the present invention and are not intended to limit or restrict the scope of the present invention. Thus, those that can be easily contemplated by persons skilled in the art from the detailed description and examples of the present invention are interpreted to fall within the scope of the present invention. References cited herein are incorporated herein by reference.

[0052] Throughout the present specification, it is to be understood that, when any part is referred to as comprising any component, it does not exclude other components, but may further include other components, unless otherwise specified.

[0053] FIG. 1 is an external perspective view showing a state where a user grips a device for regulating liquid medicine supply 200 according to one embodiment of the present invention. As shown in FIG. 1, a liquid medicine flows into the device for regulating liquid medicine supply 200 from a liquid medicine inflow tube 121a connected to a liquid medicine storage space (not shown), and the liquid medicine which has flowed into the device for regulating liquid medicine supply 200 is discharged to a liquid medicine outflow tube 121b. For reference, the device in a longitudinally extending form as shown in FIG. 1 is merely one example, and it will be apparent that a body 210, a continuous supply flow passage CL, increment-supplying flow passages VL1 and VL2, a liquid medicine increment-controlling means 220, a reservoir 300, air removal means 224, 225, 225a and 226 and the like, which are main components of the present invention as described below, may be applied to cases having various forms and also applicable to a form disclosed in Korean Patent Publication No. 10-0516446, for example.

[0054] In general, a liquid medicine such as an anticancer drug, an antibiotic, an analgesic or the like is stored in the liquid medicine storage space. For example, various kinds of injectable drug-pumping devices such as a mechanical injection device in which a plunger of a syringe is moved forward slowly by a driving force of a motor so as to push out the liquid medicine filled in the liquid medicine storage space, a balloon type injection device in which the liquid medicine filled in the liquid medicine storage space is slowly pushed out by an elastic restoring force of a balloon, or a gas-generating type injection device (see Korean Patent Publication No. 10-0507593) in which a gas at a certain pressure slowly moves a piston forward so as to push out the liquid medicine filled in the liquid fluid storage space, and the like may be connected to the device for regulating liquid medicine supply 200 through the liquid medicine inflow tube 121a.

[0055] As an example which does not limit the present invention, FIG. 9 schematically shows an overall configuration of a liquid medicine injection apparatus 100 including the device for regulating liquid medicine supply 200 of the embodiment of the present invention. In FIG. 9, reference numeral 100 generally denotes the liquid medicine injection apparatus, reference numeral 110 denotes a gas-generating type injection device which is an example of an injectable drug-pumping device, and reference numeral 200 denotes the device for regulating liquid medicine supply. As one example, the liquid medicine injection apparatus 100 includes the gas-generating type injection device 110 and the device for regulating liquid medicine supply 200. The device for regulating liquid medicine supply 200 connected to the gas-generating type injection device 110 through a conduit 120 and the liquid medicine inflow tube 121a regulates the amount of the liquid medicine supplied from the gas-generating type injection device 110 through the conduit 120 and the liquid medicine inflow tube 121a, and then supplies the liquid medicine to a catheter or injection needle (not shown) connected to an end cap 125 provided at an end of the liquid medicine outflow tube 121b. In the gas-generating type injection device 110, a piston 114 is moved forward by a pressure of a gas generated in a gas generating part 112, and as the piston 114 is moved forward, the liquid medicine in a liquid medicine storage space 111 is supplied into the device for regulating liquid medicine supply 200 through the conduit 120 connected to a cylinder tip 113 and the liquid medicine inflow tube 121a. However, it will be apparent that instead of the aforementioned gas-generating type injection device 110, various kinds of injectable drug-pumping devices, such as a mechanical injection device, a balloon type injection device, or the like may be used to be connected to the device for regulating liquid medicine supply 200.

[0056] FIG. 2 is a front view showing arrangement of components in a casing in the device for regulating liquid medicine supply 200 according to the embodiment of the present invention. As shown in FIG. 2, the device for regulating liquid medicine supply 200 has a casing 201; the body 210 provided inside a lower part of the casing 201 so that the liquid medicine supplied from the injectable drug-pumping device flows into the body through an inflow inlet 211, is regulated to a predetermined amount in the body, and is then discharged through a discharging outlet 212; and a liquid medicine increment-controlling means 220 for increasing the amount of the liquid medicine flowing outwardly through the discharging outlet 212 of the body 210, as desired.

[0057] Here, the casing 201 may be constructed of a front casing and a rear casing which are divided in half along a longitudinal direction, and the front casing may be detachably assembled to the rear casing. In addition, a finger insertion aperture 202 is formed at an upper portion of the casing 201 such that a user can insert a finger thereinto to perform an operation of pressing an actuation button 203.

[0058] The body 210 is provided at a lower portion of the casing 201. A configuration of the body 210 is shown in FIGS. 3 to 7.

[0059] The body 210 controls the liquid medicine, which has flowed from the injectable drug-pumping device through the inflow inlet 211 into the body, to a predetermined amount and supplies the liquid medicine to the discharging outlet 212 and the liquid medicine outflow tube 121b. Optionally, the body 210 may further supply the liquid medicine, which has been stored in the reservoir 300, to the discharging outlet 212 by means of an operation of the liquid medicine increment-controlling means 220, thereby discharging an increased amount of liquid medicine through the discharging outlet 212 and the liquid medicine outflow tube 121b.

[0060] A continuous supply flow passage CL, configured to regulate a flow rate of the liquid medicine that has flowed through the inflow inlet 211 and to continuously supply a certain amount of liquid medicine to the liquid medicine outflow tube 121b through the discharging outlet 212, is provided within the body 210 (see FIGS. 4, 6 and 7). As shown in FIGS. 4 and 7, the liquid medicine flows into the body 210 in an I.sub.CL direction, and is discharged out of the body 210 in an O.sub.CL direction.

[0061] In addition, the liquid medicine increment-controlling means 220 has the increment-supplying flow passages VL1 and VL2 which divide and store the liquid medicine flowing into the body 210 through the inflow inlet 211 of the body 210 and then selectively allow the divided and stored liquid medicine to join at an outlet end of the continuous supply flow passage CL so as to selectively increase the amount of the liquid medicine discharged through the discharging outlet 212 (see FIGS. 4, 6 and 7).

[0062] In one embodiment of the present invention, the body 210 preferably consists of a lower body 210a and an upper body 210b, and the upper body 210b is coupled to an upper end of the lower body 210a. The inflow inlet 211 is provided in the lower body 210a, and the discharging outlet 212 is provided in the upper body 210b. A leading end of the liquid medicine inflow tube 121a for guiding the liquid medicine from the injectable drug-pumping device is connected to the inflow inlet 211, and the liquid medicine outflow tube 121b for guiding the liquid medicine to the end cap 125 is connected to the discharging outlet 212.

[0063] As shown in FIGS. 5 and 6, a first capillary tube 221 is inserted into the body 210, and a first capillary tube passage 222 of the first capillary tube 221 introduces the liquid medicine, which has flowed thereinto from the inflow inlet 211, into a first internal flow passage 223 due to a capillary phenomenon. At this time, the liquid medicine flows into the first capillary tube passage 222 through an inlet 222a of the first capillary tube 221 and is then regulated to a certain flow rate by passing through the first capillary tube passage 222. The liquid medicine regulated to the certain flow rate escapes from an outlet 222b of the first capillary tube passage 222 and is then introduced into the first internal flow passage 223. The liquid medicine, which has been regulated to the certain flow rate by passing through the first capillary tube passage 222 and the first internal flow passage 223, is discharged out of the upper body 210b through the discharging outlet 212, and is then supplied to the end cap 125 through the liquid medicine outflow tube 121b.

[0064] The first capillary tube 221 is fitted into a hole of an approximately O-shaped ring 253, and the O-shaped ring 253 into which the first capillary tube 221 has been fitted is snugly fitted into an empty space between the lower body 210a and the upper body 210b to be coupled to the bodies (see FIGS. 5 and 6). Furthermore, a first sealing ring 251 is fitted between the inlet 222a of the first capillary tube 221 and the lower body 210a to be coupled thereto and a second sealing ring 252 is fitted between the outlet 222b of the first capillary tube 221 and the upper body 210b to be coupled thereto, thereby preventing the liquid medicine from leaking from a junction between the first capillary tube 221 and the lower body 210a and a junction between the first capillary tube 221 and the upper body 210b.

[0065] As shown in FIGS. 6 and 7, the inflow inlet 211, a connection passage 211a, the first capillary tube passage 222, the first internal flow passage 223, an outlet end 223a of the first internal flow passage, a groove 224, an outlet 224a, and the discharging outlet 212 are sequentially connected to one another to form the continuous supply flow passage CL.

[0066] Moreover, the embodiment of the present invention includes a liquid medicine increment means which can selectively increase the flow rate of the liquid medicine supplied to the liquid medicine outflow tube 121b through the discharging outlet 212 after the liquid medicine has passed through the continuous supply flow passage CL, if necessary.

[0067] The liquid medicine increment means of the embodiment of the present invention may include the increment-supplying flow passages VL1 and VL2 which divide and store the liquid medicine flowing into the body 210 through the inflow inlet 211 of the body 210 and then selectively allow the dived and stored liquid medicine to join at the outlet end of the continuous supply flow passage CL so as to selectively increase the amount of the liquid medicine discharged through the discharging outlet 212; and the liquid medicine increment-controlling means 220 which is provided in the casing 201 to be movable between an operating position at which the increment-supplying flow passages VL1 and VL2 are opened and a non-operating position at which the increment-supplying flow passages VL1 and VL2 are closed and blocked, and which is shifted from the non-operating position to the operating position or from the operating position to the non-operating position so as to supply an increment of the liquid medicine stored in the increment-supplying flow passages VL1 and VL2 to the liquid medicine outflow tube 121b through the outlet end of the continuous supply flow passage CL or to block the supply of the increment of the liquid medicine.

[0068] As shown in FIG. 6, the increment-supplying flow passage VL includes an internal flow passage VL1 provided inside the body 210, and an external flow passage VL2 provided outside the body 210 and being in communication with the internal flow passage VL1. As shown in FIG. 4, the reservoir 300 is connected to the external flow passage VL2. Referring to FIG. 4, the liquid medicine flows into the reservoir 300 from the body 210 (specifically, an outlet 234 of a second internal flow passage) through a reservoir inflow tube 301 in an I.sub.R direction and is then stored in a liquid medicine storage space 302, and the liquid medicine in the liquid medicine storage space 302 flows into the body 210 (specifically, an inlet 238 of the first internal flow passage) through a reservoir outflow tube 303 in an O.sub.R direction.

[0069] As shown in FIGS. 5 and 6, the internal flow passage VL1 includes the connection passage 211a which is in communication with the inflow inlet 211 in the body 210, a second capillary tube passage 232 which is in communication with the connection passage 211a, the second internal flow passage 233 which is in communication with the second capillary tube passage 232, and the outlet 234 of the second internal flow passage for guiding the liquid medicine, which has passed through the second capillary tube passage 232, to the external flow passage VL2. A second capillary tube 231 is inserted into the body 210, and the second capillary tube passage 232 of the second capillary tube 231 guides the liquid medicine, which has flowed from the inflow inlet 211, to the second internal flow passage 233 due to the capillary phenomenon. At this time, the liquid medicine flows into the second capillary tube passage 232 through an inlet 232a and is regulated to the certain flow rate by passing through the second capillary tube passage 232. The liquid medicine regulated to the certain flow rate escapes through an outlet 232b of the second capillary tube passage 232 and is then introduced into the second internal flow passage 233. The liquid medicine, which has been regulated to the certain flow rate by passing through the second capillary tube passage 232 and the second internal flow passage 233, is introduced into the external flow passage VL2 through the outlet 234 of the second internal flow passage.

[0070] The second capillary tube 231 is fitted into a hole of the approximately O-shaped ring 253, and the O-shaped ring 253 into which the second capillary tube 231 has been fitted is snugly fitted into the empty space between the lower body 210a and the upper body 210b to be coupled to the bodies (see FIGS. 5 and 6). Moreover, a third sealing ring 254 is fitted between the inlet 232a of the second capillary tube 231 and the lower body 210a to be coupled thereto and a fourth sealing ring 255 is fitted between the outlet 232b of the second capillary tube 231 and the upper body 210b to be coupled thereto, thereby preventing the liquid medicine from leaking from a junction between the second capillary tube 231 and the lower body 210a and a junction between the second capillary tube 231 and the upper body 210b.

[0071] As shown in FIGS. 4 and 6, the external flow passage VL2 includes, outside of the body 210, the reservoir inflow tube 301 for connecting the outlet 234 of the second internal flow passage 233 of the internal flow passage VL1 to a reservoir inlet; the reservoir 300 having the liquid medicine storage space 302 for storing the liquid medicine supplied through the reservoir inflow tube 301; and the reservoir outflow tube 303 for allowing the liquid medicine, which has been discharged from the liquid medicine storage space 302 of the reservoir 300 through a reservoir outlet, to join at the first internal flow passage 223 through the inlet 238 of the first internal flow passage.

[0072] As shown in FIGS. 1, 2 and 6, when the liquid medicine increment-controlling means 220 is operated, the actuation button 203 can press the liquid medicine storage space 302 of the reservoir 300 so as to allow the liquid medicine stored in the liquid medicine storage space 302 to join at the first internal flow passage 223 through the reservoir outflow tube 303, thereby increasing the amount of the liquid medicine discharged from the discharging outlet 212.

[0073] As shown in FIG. 2, the finger insertion aperture 202 may be provided in one end of the casing 201 so that a user can insert a finger thereinto for manipulation. The body 210 is disposed within the casing 201 and below the finger insertion aperture 202, the reservoir 300 is disposed above the body 210, and the liquid medicine increment-controlling means 220 is disposed above the reservoir 300. The liquid medicine increment-controlling means 220 has the actuation button 203 of which one end being disposed to inwardly protrude toward a center of the finger insertion aperture 202, and of which the other end being disposed toward an upper side of the reservoir 300 so as to pressurize the reservoir 300. Preferably, the liquid medicine increment-controlling means 220 may further include a pressing part disposed at a lower end of the actuation button 203 to press the reservoir 300 whenever the actuation button 203 is pressed.

[0074] An upper end of the actuation button 203 may protrude toward the finger insertion aperture 202, and may be resiliently supported by an elastic member, e.g., a spring, within the casing 201. By pressing the actuation button 203, the liquid medicine increment-controlling means 220 is shifted from the non-operating position to the operating position. That is, when the user inserts a finger into the finger insertion aperture 202 of the device for regulating liquid medicine supply 200 and presses the actuation button 203 in an F direction (see FIG. 1), the liquid medicine increment-controlling means 220 is shifted from the non-operating position to the operating position to perform the injection of the increment of the liquid medicine.

[0075] For example, a coil spring is installed between a side wall provided at a lower end of the liquid medicine increment-controlling means 220 and a rotatable lever, wherein the coil spring applies an elastic restoring force to the lever with respect to the fixed side wall, and the lever to which the elastic restoring force of the coil spring is applied is rotated at a predetermined angle (for example, in a counterclockwise direction) and then presses the reservoir outflow tube 303. The lever to which the elastic restoring force of the coil spring is transmitted presses the reservoir outflow tube 303 to block the flow of the liquid medicine from the liquid medicine storage space 302. When the user presses the actuation button 203, a pressing force of the actuation button 203 overcomes the elastic restoring force of the coil spring, which is pressing the lever, and causes the lever to rotate in an opposite direction (for example, in a clockwise direction) so as to lift the lever from the reservoir outflow tube 303. At this time, the blockage of the reservoir outflow tube 303 is released, and at the same time, the pressing part of the actuation button 203 presses the liquid medicine storage space 302, so that the liquid medicine in the liquid medicine storage space 302 flows in the O.sub.R direction (see FIG. 4). Mutual coupling relationships, operations and functions of the actuation button 203, the liquid medicine increment-controlling means 220 and the reservoir 300 are the same as those described in International Publication No. WO 2016/137247 A2.

[0076] Meanwhile, since the actuation button 203, the liquid medicine increment-controlling means 220, the reservoir 300, various tubes and coupling relationships thereof, and other components in the device for regulating liquid medicine supply 200 of the embodiment of the present invention are described in International Publication WO 2016/137247 A2 and those skilled in the art can easily apply and adapt them to the present invention, detailed descriptions of these components will be omitted.

[0077] In addition, the first capillary tube passage 222 and the second capillary tube passage 232 may have identical to or different from each other in diameter and/or length, and the diameter and/or length thereof may be appropriately adjusted depending on a desired flow rate of the liquid medicine. Therefore, the supply amount of the liquid medicine can be regulated by changing the diameter and/or length of the first capillary tube passage 222 or the second capillary tube passage 232. The change of the diameter and/or length of the first capillary tube passage 222 or the second capillary tube passage 232 may be achieved by replacing the first capillary tube 221 or the second capillary tube 231 with a capillary tube having a different diameter and/or length.

[0078] In order to remove air that may exist in the liquid medicine or between portions of the liquid medicine, to accelerate priming which is a preparatory operation for injection of the liquid medicine into a patient, and to prevent an unnecessary loss of the liquid medicine, there is provided the air removal means configured to outwardly discharge air entrained in the liquid medicine or air between portions of the liquid medicine, on a discharge path 223a, 224 and 224a which discharges the liquid medicine through the discharging outlet 212. The air removal means is provided between the outlet end of the continuous supply flow passage CL and the discharging outlet 212 of the body 210.

[0079] As shown in FIGS. 4 to 8, the air removal means includes the groove 224 concavely formed on one side of the body 210 so as to allow a portion of the continuous supply flow passage CL to be in communication with the outside of the body 210, a cover member 225 coupled to an opening portion of the groove 224 so as to seal the groove 224, at least one air vent 225a formed in the cover member 225 so as to outwardly discharge air from the liquid medicine passing through the groove 224 in the continuous supply flow passage CL, and a filter member 226 accommodated between the groove 224 and the cover member 225 so as to allow air in the liquid medicine introduced into the groove 224 to pass through the filter member and to be discharged through the air vent 225a and not to allow the liquid medicine to pass through the filter member, thereby preventing leakage of the liquid medicine.

[0080] In the device for regulating liquid medicine supply 200 of the embodiment of the present invention, even though air exists in the continuous supply flow passage CL and/or the increment-supplying flow passages VL1 and VL2, air, which is entrained in the liquid medicine passing through the outlet end of the continuous supply flow passage CL or is between portions of the liquid medicine passing through the outlet end of the continuous supply flow passage CL, is removed by the air removal means, and thus the priming for injection of an increment of the liquid medicine is accelerated. When the continuous supply flow passage CL has been primed, air that may possibly exist is removed from the increment-supplying flow passages VL1 and VL2 by the air removal means, so that the priming may be completed without waiting for the inflow of the liquid medicine from the increment-supplying flow passages VL1 and VL2. Furthermore, since the air removal means removes air entrained in the liquid medicine or between portions of the liquid medicine, it is not necessary for a physician or medical staff to waste some of the liquid medicine when injecting the liquid medicine into a patient, thereby preventing a problem of the waste of the liquid medicine and minimizing a loss of the liquid medicine.

[0081] Moreover, the filter member 226 may be comprised of a single filter but may be formed as a dual filter composed of a hydrophilic filter layer 226a and a gas-permeable and liquid-impermeable hydrophobic filter layer 226b stacked on the hydrophilic filter layer 226a (See FIG. 8). The liquid medicine that has arrived earlier relative to air is absorbed by the hydrophilic filter layer 226a having a liquid absorption power before the liquid medicine reaches the gas-permeable and liquid-impermeable hydrophobic filter layer 226b. When all of the liquid medicine that has introduced earlier relative to air is absorbed by the hydrophilic filter layer 226a, air that is being introduced after the absorption of the liquid medicine reaches and passes through the gas-permeable and liquid-impermeable hydrophobic filter layer 226b and is then discharged to the outside of the body 210 through the air vent 225a of the cover member 225. Therefore, the filter member 226 with the aforementioned configuration can effectively remove air and prevent leakage of the liquid medicine if the liquid medicine reaches the filter member earlier relative to air.

[0082] Although the present invention has been described with reference to the embodiments, the scope of the present invention is not limited to these embodiments. Any person skilled in the art will appreciate that various modifications and changes are possible without departing from the spirit and scope of the present invention and these modifications and changes also fall within the scope of the present invention.