Dual chamber mixing syringe and method for use
A mixing syringe and method for using the mixing syringe are provided. The mixing syringe comprises a housing having a first compartment for containing a first component, an outer plunger having a second compartment for containing a second component, and an inner plunger. Prior to use, a seal separates the first and second components. To prepare the mixture, the seal is pierced and the two components are mixed. The mixing syringe and its method of use are particularly suited to applications in which at least one of the mixture components is a relatively highly viscous material.
The present application claims priority to U.S. Provisional Application No. 60/514,045, filed on Oct. 24, 2003, which is hereby incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates devices for mixing two components to form a mixture. More specifically, the present invention relates to a syringe having two chambers for receiving two constituents that are to be mixed, and the method for using such a device.
BACKGROUND OF THE INVENTIONMany drugs are stored in separate components that are mixed before use. Typically, the separate components include a powder and a liquid diluent. By storing the components separately, shelf life of the drug is increased.
With many of these drugs, the separate components are stored in a syringe and mixed within the syringe prior to use. The components are stored in separate chambers in the syringe prior to use. To prepare the medicine, the separate components are combined into a single chamber in the syringe, shaken and then the solution is ready for injection into a patient.
Although such a system works well for mixtures that are highly soluble, they are ineffective for less soluble mixtures. Specifically, the known systems combine the two components of a medicine into a single chamber and the mixture is then shaken to dissolve the components into solution. However, certain components cannot be adequately mixed by simply combining and shaking the two elements together.
SUMMARY OF THE INVENTIONIn light of the foregoing shortcomings of the prior art and in order to provide an improved syringe, the present invention provides an improved syringe that is operable to mix separate components to prepare a medicinal fluid for use. The syringe is particularly suited to mix drugs having low viscosity and/or low solubility.
More specifically, the present invention provides a mixing syringe having a housing that includes a first fluid chamber for containing a first component of a medicine. Within the housing is a first plunger having a second fluid chamber for containing a second component of the medicine. Within the first plunger is a second plunger. A seal separates the first and second components, to prevent the components from becoming mixed during storage. Preferably, the syringe also includes a needle and a valve for preventing the discharge of the medicine through the needle while the components are being mixed.
Another aspect of the invention provides a method for mixing a medicine using a dual chamber syringe having a housing, a first plunger and a second plunger. A first component of the medicine is stored in a fluid chamber within the housing and a second component of the medicine is stored in a second chamber within the housing. Preferably, the second chamber is within the first plunger. A seal separates the two components during storage.
The method includes opening the separation seal to permit fluid flow between the first and second chambers to allow the two components to mix. The first plunger is displaced to drive the first components of the medicine into the second chamber. The second plunger is then displaced to drive the first and second components into the first chamber. The first and second plungers are then repeatedly displaced in an alternating fashion to drive the combined first and second components back and forth between the first and second chambers to mix the two components. After the components are mixed, either the first or second plunger is displaced forwardly to eject the mixture from the syringe.
Another aspect of the invention provides a syringe having two fluid chambers containing two medicinal components and a seal separating the components from one another. A needle is attached to the syringe housing, and a valve controls the flow of fluid from the housing through the needle.
BRIEF DESCRIPTION OF THE DRAWINGSThe foregoing summary and the following detailed description of the preferred embodiments of the present invention will be best understood when read in conjunction with the appended drawings, in which:
Referring now to the figures generally, and to
More specifically, the syringe 10 includes a hollow housing 20, a hollow outer plunger 30 disposed within the housing and an inner plunger 50 disposed within the outer plunger. A seal 25 on the end of the housing seals the housing closed. Preferably, a first medicinal component is stored within the housing 20 and a second component is stored within the outer plunger 30.
To mix the components, the first component is transferred into the outer plunger 30 by pushing the outer plunger forwardly. The two components are then transferred into the housing 20 by pushing the inner plunger 50 forwardly. To thoroughly mix the components together, the components are repeatedly transferred back and forth between the housing 20 and the chamber within the outer plunger 30 by alternatively pushing forward the outer plunger and the inner plunger. After the two components are thoroughly mixed, the seal 25 is removed and the medicine is expelled from the syringe by pushing forward one of the plungers.
Referring now to
Adjacent the rearward open end of the housing are a pair of opposing flanges 27 that project outwardly from the housing. The flanges form finger gripping elements for the operator to grasp during use. The interior of the housing forms a fluid chamber 24 and preferably the first medicinal component is stored in the fluid chamber in the housing as discussed further below.
The outer plunger 30 is configured to slide within the interior of the housing 20, similar to a plunger in a standard syringe. However, the outer plunger is hollow to receive the second medicinal component and the inner plunger 50 as discussed further below.
The outer plunger 30 comprises an elongated hollow plunger rod 35 and a piston 32 attached to the forward end of the plunger rod. The rearward end of the outer plunger 30 is generally opened for receiving the inner plunger 50. The forward end of outer plunger is generally closed, having a reduced diameter opening forming a fluid path for transferring the medicinal components between the housing and the interior of the outer plunger, as discussed further below.
Referring still to
The piston 32 is an elastomeric element that forms a fluid-tight seal with the interior wall of the housing. The piston 32 has a bore forming a fluid path through the piston. A pierceable wall or septum 34 is formed in the piston to seal the fluid path through the piston. When the outer plunger is pushed further into the piston, the sharpened end of the needle 41 pierces the septum 34 and extends into a recess formed in the forward end of the piston 32. The recess in the forward end of the piston opens to the interior of the housing 20 so that when the needle 41 projects into the forward recess, the needle is in fluid communication with the interior of the housing, allowing medication to flow between the housing and the interior of the outer plunger.
At least one, and preferably two recesses 33 in piston 32 matingly engage the barb 45 of the outer plunger 30. Specifically, the piston 32 preferably includes two radially relieved portions or recesses 33a, 33b that mate with the head of the barb 45. The first radial recess 33a is formed in the piston 32 toward the rearward end of the piston, and the second radial recess 33b is formed in the interior of the piston adjacent to the septum 34. As shown in
The connection between the outer plunger 30 and the piston 32 is preferably a one-way engagement. In other words, when the piston 32 is mounted on the outer plunger 30, the plunger can be displaced forwardly relative to the piston, but the outer plunger can not be displaced rearwardly relative to the piston. In this way, the outer plunger cannot be readily removed from the piston 32, such that the outer plunger is substantially permanently attached to the piston.
The one-way connection is provided by a one-way sliding engagement between the barb 45 and the radial recesses 33a, 33b in piston 32. The barb 45 has forward-facing tapered edges that mate with tapered faces in the radial recesses 33a, 33b. The barb 45 also has sharp or square forward facing edges that mate with square edges in the radial recesses 33a, 33b. The tapered edges on the barb 45 and radial recesses 33a, 33b are tapered in the forward direction, permitting forward sliding displacement of the outer plunger 30 relative to the piston 32. The square edges on the barb 45 and in the recesses 33a, 33b operate as stops that impede forward displacement of the outer plunger 30 relative to the piston 32.
Adjacent the rearward open end of the outer plunger 30 are a pair of opposing flanges 39 that project outwardly from the outer plunger. The flanges form finger gripping elements for the operator to grasp during use. The interior of the outer plunger 30 is hollow, forming a fluid chamber 37 and preferably the second medicinal components is stored in the fluid chamber in the outer plunger as discussed further below.
The inner plunger 30 comprises an elongated hollow plunger rod 54 and a piston 52 attached to the forward end of the plunger rod. The inner plunger 50 is configured to slide within the interior chamber 37 of the outer plunger 30. More specifically, the piston 52 forms a fluid-tight seal with the interior wall of the fluid chamber 37 in the outer plunger 30. In this way, the inner plunger is operable to slide within the outer plunger to expel fluid from within the outer plunger.
Method Of Use Referring now to
The two components of the medicine may both be fluids, however, one components can be a liquid diluent and the other element may be a powder. In the present instance, preferably, a liquid component is preferably stored in the housing 20 and a powder component is preferably stored in the outer plunger 30. In the “as-shipped” configuration in
Referring now to
Referring now to
As described above, the transfer of the fluid from the housing 20 to the outer plunger 30 is aided by the fact that the forward end of the housing is sealed by seal 25. Accordingly, it is desirable to provide a connection between the seal 25 and the nozzle 22 that can withstand the high fluid pressures created during the transfer, and maintain the fluid seal. Although a frictional engagement between the nozzle and the seal may be sufficient in certain instances, preferably the nozzle and seal have a stronger mechanical engagement such as a threaded engagement.
Referring to
Accordingly, preferably the mixture is transferred back and forth between the outer plunger 30 and the housing 20. The mixture is transferred to the housing 20 by displacing the inner plunger 50 forwardly, as shown in
To continue mixing the mixture, the mixture is transferred back into the outer plunger 30 by pushing the outer plunger forward, as described above. Again, the mixture can be further mixed by transferring the mixture back into the housing by pushing forward the inner rod. In this way, the mixture can be thoroughly mixed by repeatedly transferring the mixture between the chamber 24 in the housing and the chamber 37 in the outer plunger. The repeated transfer is accomplished by alternatively pushing forward the outer plunger 30 and the inner plunger 50. The number of times that the mixture needs to be transferred to mix the medicine sufficiently depends upon the characteristics of the two components. In some instances it may only require a few transfers of the components. In other instances it may require upwards of 100 or more transfers to mix the components sufficiently.
Referring now to
The dispenser tip 60 can be any of a variety of tips depending upon the procedure employed for using the medicine. As shown in
Referring now to
Referring now to
The syringe 110 includes a hollow housing 120 having a nozzle 122, a fluid chamber 124, a seal 125 and finger grips 127. Each of these elements is substantially similar to the housing 20, nozzle 22, fluid chamber 24, seal 25 and finger grips described previously for the first embodiment, except as otherwise discussed below. In addition, the syringe 110 includes an inner plunger 150 that has an elongated plunger rod 154 and a piston 152, that are substantially similar to the plunger 50, plunger rod 54 and piston 52 described previously for the first embodiment, and forming a fluid-tight seal with the interior of the outer plunger 130.
The outer plunger 130 includes a plunger rod 135 and a piston 132 that forms a fluid-tight seal with the inner wall of the fluid chamber 124 in the housing 120. The outer plunger 130 is hollow, forming a fluid chamber 137 for receiving a component of the medicine.
The piston 132 is attached to the plunger rod 135 using a barbed connector 145 similar to the syringe 10 described previously. More specifically, as in the previous embodiment, preferably the piston 132 includes a pair of recess 133 that are configured to cooperate with the barbed connector in a manner similar to the connection described above in detail in connection with the first syringe 10. Accordingly, the description of the details of the recesses 133 and the barbed connector 145 and the details of operation of these elements are similar to those described above in connection with the recess 33a, 33b and the barbed connector 45 of the first syringe 10.
The piston 132 and the plunger rod 135 are configured differently from the previously described piston 32 and plunger rod 35 to provide a different seal between the housing fluid chamber 124 and the outer plunger fluid chamber 137. Specifically, the end of the plunger rod 135 forms a tip 147 having an circumferential rib that seats with the bore in the piston 132 to form a fluid-tight seal. A side port 146 in the end of the plunger rod 135 spaced rearwardly from the tip 147 provides a fluid passageway around the tip.
Referring to FIGS. 7, 10-11, in the “as-shipped” configuration, the barb 145 is in the first recess 133. In this position, the tip 147 is disposed within the piston 132 and the interior bore of the piston forms a fluid-tight seal with the tip to seal the fluid path through the piston and the end of the plunger rod 135. Referring to FIGS. 8, 10-11, by pushing forward on the outer plunger, the barb is displaced into engagement with the second recess 133 and the tip is displaced forwardly from the piston 132 so that the side port 146 is no longer sealed by the piston. In this way, the piston 132 and the end of the plunger rod 135 operate similarly to a sliding valve. In the open position illustrated in
Referring now to
Referring now to
The syringe 210 includes a housing 220 having a fluid chamber 224. An outer plunger 230 having a piston 232, plunger rod 235, fluid chamber 237, barbed connector 245, side port 246 and tip 247 that are substantially similar to the piston 132, plunger rod 135, fluid chamber 137, barbed connector 145, side port 146 and tip 147 described above in connection with the previous embodiment 110.
The syringe further includes an inner plunger having an elongated piston rod and piston seal that are substantially similar to the piston rod and piston of the previous embodiments 52, 54,152,154. In addition, as in previous embodiments, the inner piston forms a fluid-tight seal with the fluid chamber in the outer plunger 230.
Referring to
A flexible conduit 228 is disposed within the tip 222 of the housing. The flexible conduit 228 is formed of an elastomeric material so that the walls of the conduit are resiliently radially deformable. Accordingly, when the arms 223 are displaced radially inwardly the ends of the arms pinch the flexible conduit 228 sealing off the fluid pathway through the flexible conduit.
As shown in
Referring now to
Referring to
Referring now to
The syringe 310 includes a housing 320 having a fluid chamber 324. An outer plunger 330 having a piston 332, plunger rod 335, fluid chamber 337, barbed connector 345, side port 346 and tip 347 that are substantially similar to the piston 132, plunger rod 135, fluid chamber 137, barbed connector 145, side port 146 and tip 147 described above in connection with previous embodiment 110.
The syringe 310 further includes an inner plunger 350 having an elongated piston rod 354 and piston seal 352 that are substantially similar to the piston rod and piston of the previous embodiments 52, 54,152,154. In addition, as in previous embodiments, the inner piston forms a fluid-tight seal with the fluid chamber in the outer plunger 330.
Referring to
The valve 370 is a cylindrical element having a fluid passageway 372. When the fluid passageway 372 is aligned with the fluid passageway through the tip (see
Configured in this way, the syringe 310 is operable to mix two components as described above while the needle is attached, while also preventing the medicine from being discharged from the syringe during the mixing process. After the medicine is mixed, the valve is rotated into the opened position and the medicine can be expelled by pushing the outer plunger forwardly.
Referring now to
The syringe 410 includes a hollow housing 420 having a nozzle 422, a fluid chamber 424, and a seal 425. Each of these elements is similar to the housing 20, nozzle 22, fluid chamber 24, and seal 25 described previously for the first embodiment, except as otherwise discussed below. In addition, the syringe 410 includes an inner plunger 450 that has an elongated plunger rod 454 and a piston 452, that are substantially similar to the plunger 50, plunger rod 54 and piston 52 described previously for the first embodiment, and forming a fluid-tight seal with the interior of the outer plunger 430.
The outer plunger 430 includes a plunger rod 435 and a piston 432 that forms a fluid-tight seal with the inner wall of the fluid chamber 424 in the housing 420. The outer plunger 430 is hollow, forming a fluid chamber 437 for receiving a component of the medicine.
The piston 432 is attached to the plunger rod 435 using a barbed connector 445 similar to the syringe 10 described previously. More specifically, as in the previous embodiment, preferably the piston 432 includes a pair of recess 433 that are configured to cooperate with the barbed connector in a manner similar to the connection described above in detail in connection with the first syringe 10. Accordingly, the description of the details of the recesses 433 and the barbed connector 445 and the details of operation of these elements are similar to those described above in connection with the recess 33a, 33b and the barbed connector 45 of the first syringe 10.
The piston 432 and the plunger rod 435 are configured differently from the previously described piston 32 and plunger rod 35 to provide a different piercing mechanism. Specifically, the end of the plunger rod 435 forms a conical tip 447 forming a point or spear. In the present embodiment, the tip 447 is integrally formed with the outer plunger rod 435 as a single molded part. A side port 446 in the end of the plunger rod 435 spaced rearwardly from the tip 447 provides a fluid passageway around the tip.
Referring to
Referring now to
It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. For instance, the device has been described as operable to mix together two components of a medicinal fluid. The components may be a fluid and a dry powder. Alternatively, the two components may both be fluid. In certain applications, one or more of the materials may be a relatively highly viscous material. Furthermore, the present mixing syringe and the method of use are not limited to applications in which medicinal fluids are mixed. For instance, the syringe and its use are applicable to a wide range of applications for mixing two-part mixtures. For example, the syringe and method of use can be used mix two-part epoxy. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.
Claims
1. A method for mixing a mixture with a syringe, comprising the steps of:
- providing a mixing syringe having a housing containing a first constituent of the mixture, a first plunger slideably displaceable within the housing having a mixing chamber containing a second constituent of the mixture, and a second plunger slideably displaceable within the first plunger, wherein a separation seal separates the first constituent from the second constituent prior to use;
- opening the separation seal to permit flow between the housing and the mixing chamber to allow the mixing of the first and second constituents;
- driving the first plunger forwardly to displace the first constituent into the mixing chamber;
- driving the second plunger forwardly to displace the first and second constituents from the mixing chamber into the housing;
- repeatedly alternatingly displacing the first and second plungers forwardly to repeatedly displace the first and second constituents between the mixing chamber and the housing to mix the first and second constituents; and
- displacing one of the first and second plungers forwardly to eject the mixed first and second constituents from the mixing syringe.
2. The method of claim 1 wherein the mixing syringe comprises a discharge seal sealing a discharge opening of the syringe, wherein the method comprises the step of unsealing the discharge seal after mixing the first and second constituents.
3. The method of claim 2 wherein the seal comprises a valve, and the step of unsealing the seal comprises opening the valve.
4. The method of claim 2 wherein the seal is a removable seal and the step of unsealing the seal comprises removing the seal.
5. The method of claim 2 wherein the mixing syringe comprises a needle attached to the housing during the mixing of the first and second constituents.
6. The method of claim 1 wherein the mixing syringe comprises a needle attached to the housing during the mixing of the first and second constituents.
7. The method of claim 1 wherein the separation seal comprises a pierceable seal and the step of opening the separation seal comprises the step of piercing the separation seal.
8. The method of claim 1 wherein the separation seal comprises a valve and the step of opening the separation seal comprises the step of opening the valve.
9. The method of claim 8 wherein the step of opening the valve comprises the step of displacing one of the first plunger and the second plunger.
10. The method of claim 1 wherein the step of opening the separation seal comprises the step of displacing one of the first plunger and the second plunger.
11. A mixing syringe for mixing a mixture, comprising:
- a housing having a first fluid chamber containing a first component of the mixture;
- a first plunger slideably displaceable within the housing having a second fluid chamber containing a second component of the mixture wherein the first plunger is operable to eject the first component from the first chamber by displacing the first plunger forwardly;
- a seal separating the first component from the second component prior to use;
- a second plunger slideably displaceable within the first plunger wherein the second plunger is operable to expel the second component from the second chamber by displacing the second plunger forwardly, whereby upon unsealing the separation seal, alternatively repeatedly displacing the first and second plungers operates to displace the first and second components between the first and second fluid chambers to mix the first and second components;
- a needle attached to the housing; and
- a valve operable to prevent flow of fluid through the needle during the mixing of the first and second components.
12-42. (canceled)
43. A method for mixing a mixture with a syringe, comprising the steps of:
- providing a mixing syringe having a housing configured to receive a first constituent of the mixture, a first plunger slideably displaceable within the housing having a mixing chamber configured to receive a second constituent of the mixture, and a second plunger slideably displaceable within the first plunger,
- selecting the first constituent such that the first constituent is a fluid having a relatively high viscosity;
- filling the housing with the first constituent;
- filling the first plunger with the second constituent;
- sealing the first constituent from the second constituent;
- opening the seal between the first and second constituents to permit flow between the housing and the mixing chamber to allow the mixing of the first and second constituents;
- driving the first plunger forwardly to displace the first constituent into the mixing chamber;
- driving the second plunger forwardly to displace the first and second constituents from the mixing chamber into the housing;
- repeatedly alternatingly displacing the first and second plungers forwardly to repeatedly displace the first and second constituents between the mixing chamber and the housing to mix the first and second constituents; and
- displacing one of the first and second plungers forwardly to eject the mixed first and second constituents from the mixing syringe.
44. The method of claim 43 comprising the step of selecting the second constituent such that the second constituent is a fluid having a relatively high viscosity.
45. The method of claim 43 wherein the mixing syringe comprises a discharge seal sealing a discharge opening of the syringe, wherein the method comprises the step of unsealing the discharge seal after mixing the first and second constituents.
46. The method of claim 1 wherein the step of opening the seal comprises the step of piercing a pierceable seal.
47. The method of claim 46 wherein the step of opening the seal comprises the step of displacing one of the first plunger and the second plunger.
48. The method of claim 1 wherein the step of repeatedly displacing the first and second plungers comprises displacing the first plunger forwardly to expel the first and second constituents from the housing into the mixing chamber.
49. The method of claim 48 wherein the step of displacing the first plunger forwardly to expel the first and second constituents is operable to displace the second plunger within the first plunger.
50. The method of claim 43 wherein the step of repeatedly displacing the first and second plungers comprises displacing the first plunger forwardly to expel the first and second constituents from the housing into the mixing chamber.
51. The method of claim 50 wherein the step of displacing the first plunger forwardly to expel the first and second constituents is operable to displace the second plunger within the first plunger.
Type: Application
Filed: Oct 25, 2004
Publication Date: Aug 11, 2005
Inventors: Derek Harper (Goleta, CA), Charles Johnson (Ventura, CA), Joseph Kovalski (Ventura, CA)
Application Number: 10/972,985