GB2443799A

GB2443799A - Two-compartment syringe

Info

Publication number: GB2443799A
Application number: GB0705098A
Authority: GB
Inventors: Ami Ballin; Salomon Dov
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-15
Filing date: 2007-03-18
Publication date: 2008-05-21
Also published as: GB0705098D0

Abstract

The syringe comprises two coaxial barrels 12, 14. The inner barrel 14 is movable relative to the external one and has an aperture 24. A locker 20 controls the opening or closing of the aperture. The walls of the external barrel and the bottom of the inner barrel enclose one compartment. The second compartment is enclosed by the sidewall and bottom of the internal barrel. An optional plunger provides for changing the volume of the second compartment (fig 6). The locker may be spring biased to close the aperture.

Description

TWO COMPARTMENT SYRINGE

FIELD OF THE INVENTION

The present invention relates in general to syringes. In particular the present invention relates to a syringe having two compartments providing for separating between two portions of substance and/or for mixing two different substances prior to dispension.

BACKGROUND OF THE INVENTION

A two-compartment synnge (TPS) is normally employed for injecting a mixture of two components within which it is desired to keep one component isolated from the other prior to their usage. One component, such as a particulate or powdered substance, is stored in a first compartment, which is typically sealable, whereas the other component, such as a diluent or solvent, is stored in the other compartment of a TPS. The sealed compartment is opened is just before usage for withdrawing the diluent or solvent into the first compartment and further mixing the two components and immediately ejecting the mixture out of the TPS.

World patent application WO 02/067778A2 discloses a TPS providing for withdrawing supematant plasma separated from compacted blood cells, such as by centrifuging, for testing. Compacted blood cells are contained in one compartment of a TPS whereas the supernatant plasma is withdrawn into the other compartment. The compacted blood cells are further injected back to the patient whose blood was sampled.

An improved TPS that is economical to manufacture and is reliable in usage either for separating between two components or for combining them prior to their ejection is beneficial.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. I is an isometric view of a TPS according to a preferred embodiment of the invention; Fig. 2 is a side view of the TPS shown in Fig. 1; Fig. 3 is a sectional view of the TPS along the line AA shown in Fig. 2; Fig. 4 is an enlarged presentation of the segment designated by B of the sectional view shown in Fig. 3; Fig. 5 is an enlarged presentation of the segment designated by C of the sectional view shown in Fig. 3.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

A two-compartment syringe (TPS) according to the invention has an inner receptacle whose volume is either fixed or changeable, which is disposed within an external receptacle whose volume is changeable. A sealable aperture s disposed at the bottom of the inner receptacle provides for connecting between both receptacles. A user controls opening or dosing the connecting aperture by means of a locker. Compartments refer hereinafter the receptacles.

Reference is first made to Figs I -5 in which an isometric view, a side view, a sectional view and two enlarged segments of the same sectional view of a two compartment syringe (TPS) in accordance with a preferred embodiment of the present invention are respectively shown. Such TPSes are referred hereinafter as gravitational TPSes. Gravitational TPS 10 has external barrel 12 in which internal barrel 14 is inserted such that the wall of barrel 12 and the respective bottoms of barrel 12 and barrel 14 enclose the first cylindrical compartment of TPS 10. Barrel 14 is slidingly fitted to the lumen of barrel 12 and is movable within the lumen of barrel 12 serving as a plunger for expanding or decreasing the volume of the first cylindrical compartment. Gripping handles 15 assist a user in reciprocally moving barrel 14 along the common axis of both barrels. Nozzle 16 surrounds an inlet/outlet aperture for respectively withdrawing/ejecting fluids into or from the first compartment. Withdrawal is effected by outwardly moving barrel 14 along the direction of arrow 17. Ejecting the contained fluid is effected by inwardly moving barrel 14 in the opposite direction. Nozzle 16 is adapted to be slidingly attached to a needle normally employed with an injecting syringe or to a cap for sealing it off. Handle 18 is removably attached, such as by threading, to barrel 14 and provides for conveniently moving barrel 14 inwards or outwards off barrel 12.

In Fig. 3 a sectional view along line AA shown in Fig. 2 is shown.

Locker 20 consists of downwardly extending sealing shaft 21, locker body 22 and locking handle 23. Sealing shaft 21 is removably attached to locker body 22.

Sealing shaft 21 is tapered at its end, such that it seals off connecting aperture 24 when its end is pressed by means of biasing spring 26 against the rim of connecting aperture 24. At this stage the locker is in a locking position in which fluid cannot be transferred from one compartment into the other. Locker body 22, which is cylindrical, is coaxially disposed within the lumen of barrel 14. The sidewall of barrel 14, its bottom and the bottom surface of locker body 22 s enclose the second cylindrical compartment of the TPS. Locker body 22 is slidingly fitted to the lumen of inner barrel 14. 0-ring 28 seals off the spacing between the locker body 22 and the inner surface of barrel 14. Reference is again made to Fig. 2 in which locking handle 23 outwardly extends from barrel 14 through aperture 30 disposed on the wall of barrel 14.

The TPS described above has a first compartment having a changeable volume and a second compartment whose volume is fixed. Both compartments are fluid connected through the connecting aperture when the locker is being at an open position. Pulling both locking handles while compressing the biasing spring, not shown, towards handle 18 effects opening.

Such pulling moves the sealing shaft off the connecting aperture and causes the lumens of the two compartments to form a continuum. Opening the connecting aperture while concomitantly pressurizing the fluid contained in the first compartment transfers fluid from the first compartment into the second. Moving the inner barrel towards the bottom of the external barrel effects such pressurizing. Fluid is transferred from the second compartment into the first by gravity on the condition that there is free space available above the level of the fluid contained in the first compartment and the connecting aperture is open.

A pressurized TPS of the invention has two compartments whose volumes are independently changeable. Reference is now made to Fig. 6 showing a sectional view of a segment of a pressurized TPS in accordance with a preferred embodiment of the present invention. Plunger 40, coaxially movable within the lumen of inner barrel 42, provides for changing the volume of one compartment of pressurized TPS 44 referred hereinabove as the second compartment Inner barrel 42 slidingly movable along the inner surface of the sidewall of external barrel 46 provides for changing the volume of the first compartment, in a similar way as in the case of the gravitational TPS described hereinabove. Gripping handles 47 assists a user in reciprocally moving the inner barrel along the common axis of both barrels. Locker 48 consists of locker body 50, locking handle 52 and sealing shaft 54. Two locking bulges, such as bulge 56, are resiliently attached to inner walls of recesses 58, which are symmetrically disposed on the sidewall of locker body 50. These bulges are sprung into two s pairs of apertures, such as aperture 60, when facing them, thereby bringing locker 48 into a locking position. Two apertures of a pair are successively disposed, and the pairs are symmetrically disposed, on the walls of inner barrel 42 and external barrel 46 respectively. The locking bulges while being placed in their respective apertures practically serve as the biasing spring described hereinabove, to force the sealing shaft such that its tapered end presses against the rim of the connecting aperture, not shown. The locking bulges are therefore collectively referred hereinafter as biasing spring. Alternatively the tapered end of the sealing shaft can,according to the present invention, be forced to seal off the connecting aperture by screwing in one direction whereas screwing in the opposite direction opens it. Optionally a sealable aperture such as common valve serves as the connecting aperture of the invention. Such an exemplary sealable aperture is a valve comprising two concentric spheres through which a bore is drilled; the inner of which is connected to the sealing shaft, such that reciprocally moving the sealing shaft in opposite directions rotates the inner sphere to respectively close or open both apertures of the bore disposed on the surface of the external sphere.

Releasing handles resiliently attached to the wall of external barrel 46, such as releasing handle 62, respectively provide for releasing the locking bulges off their apertures. A tapered end of sealing shaft 54 seals off the aperture connecting between the two compartments of the TPS, not shown, when locker 48 is in a locking position similarly as in the case of the gravitational TPS described hereinabove. To open the connecting aperture, not shown, the operator pressesboth releasing handles and slightly pulls off locker handle 52.

To close the connecting aperture the operator slightly push inwards locker handle 52 by which locker 48 gets into the locking position. A few shafts, such as shaft 66, coaxially attached to plunger 40 at their one end and to plunger handle 68 at their other end, provide for moving plunger 40. These shafts pass through bores, such as bore 70, drilled through the locker body. 0-rings 72 seal off the spaces disposed between plunger 40 and sealing shaft 54 and between plunger and the surface of inner barrel 42. The other end of this pressurized TPS is the same as the respective end of the gravitational TPS described with reference to Figs 1-4 to which reference is again made.

Fluid is transferred from the first compartment of a pressurized TPS into the second in the same method described hereinabove. Namely, pressurizing the fluid contained in the first compartment; concomitantly with opening the connecting aperture effects such transferring. However, pressurizing the fluid contained in the second compartment by inwardly pushing the plunger handle concomitantly with opening the connecting aperture, provides for transferring fluid from the second compartment to the first. Such transferring of fluids is provided only if the entire volume of the first compartment is not filled with material and it contains available free space. A fluid can be directly withdrawn through the TPS nozzle into the second compartment as follows: first by decreasing the volume of the first compartment to its minimal value; then releasing the locking bulges by pressing both locking handles and concomitantly slightly puling outwards the locker handle to open the connecting aperture; and then by expanding the volume of the second compartment while retaining the volume of the first compartment at its minimal value. Pulling the plunger handle outwards effects such expansion.

Gravitational as well as pressurized TPSes of the invention provide for two different applications: a. withdrawing a portion of substance contained in the first compartment into the second compartment to separate between the two portions of fluids; and b. mixing two components and ejecting the mixture out of the TPS through its nozzle. Gravitational TPSes are preferable when fluids having a relatively lower viscosity are utilized; whereas pressurized TPSes are more suitable for handling fluids of moderate or relatively high viscosity. For mixing particulate or powdered substance with a fluid, normally the first compartment provides for storing the fluid whereas the second compartment is filled with the particulate or powdered substance. First the TPS handle and the locker body of a gravitational TPS or the locker and the plunger of a pressurized TPS are removed off by which an inlet aperture of the second compartment is opened. The sealing shaft is retained pressed against the rim of the connecting aperture by means of a gripping device for pressing the tapered end of the sealing shaft against the rim of the connecting aperture. A desired quantity of the particulate substance is dispensed through the opened aperture of the inner barrel into the second compartment in the following step. In the following step, the locker body and its handle are mounted back onto the gravitational TPS, or the plunger and the locker are mounted into the inner barrel of a pressurized TPS, while the gripping device is removed. A desired quantity of the respective Jo fluid is then withdrawn into the first compartment during the last step of the filling process.

EXAMPLE

A process for extracting plasma enriched with thrombocytes by employing a gravitational TPS of the invention is hereby described. First, a suitable syringe needle is attached to the nozzle of a TPS the inner barrel of which is pushed inward, such that the volume of the first compartment of the TPS is minimal. A blood sample of a predefined quantity is taken from a patient as known, by outwardly puling the inner barrel along a predefined length whilst the locker is retained at a closed position. By the end of this step the entire volume of the first compartment contains the sample of blood having a predefined quantity. The needle is removed from the nozzle, which is further sealed off with a cap during the next step. The sealed TPS is mounted into a centrifuge having a suitable holding bracket accommodated to securely lock the gripping handles of the TPS. The TPS is centrifuged for a predetermined time suitable for separating the sample of blood into three distinct layers, of which one layer contains mostly the red blood cells; the intermediate layer contains mostly white cells and thrombocytes, and the third layer mostly contains plasma. By the end of this stage, either a portion of the plasma is transferred into the second compartment by moving the locker into an open position while concomitantly inwardly pushing the inner barrel along a predefined time interval as described hereinabove,or alternatively the layer containing the red cells is ejected off the g first compartment by removing the sealing cap off the nozzle and further pushing inward the inner barrel accordingly. When ejection of the red cells is accomplished, the nozzle is resealed by the cap and the IPS is remounted into the centrifuge for further centrifuging for a second predefined time interval. The end of this stage separates the remaining portion of the sample into a layer enriched with thrombocytes covered with a layer of plasma. The extracted plasma enriched with thrombocytes can be ejected off the TPS by removing the sealing cap and inwardly pushing the inner barrel along a predefined length.

Claims

A two compartment syringe (TPS) compnsing * an external barrel having two apertures, one of which surrounded by a nozzle, wherein each of said two apertures respectively disposed at the ends of said barrel; * an inner barrel having a bottom, said inner barrel coaxially disposed within the lumen of said external barrel; * a connecting aperture disposed on said bottom; * a locker disposed within the lumen of said inner barrel, wherein said locker is moveable between two positions of which one is a locking position and the other is an open position, and wherein said connecting aperture has a lumen, and wherein the lumen of said connecting aperture simultaneously forms a continuum with the lumen of said inner barrel and the lumen of said external barrel whilst said locker being at said open position, and wherein a surface enclosing the first of said two compartments comprises a surface of a wall of said external barrel and a surface of said bottom, and wherein a surface enclosing the second of said two compartments comprises a surface of a wall of said inner barrel and a surface of said bottom, and wherein said inner barrel is slidingly fitted to the lumen of said external barrel, and wherein said inner barrel is reciprocally moveable along said common axis thereby changing the volume of said first compartment.
2. A TPS as in claim 1, wherein said locker comprises a sealing shaft attached to a locker body.
3. A TPS as in claim 2, wherein said sealing shaft is removably attached to said locker body.
4. A TPS as in claim 2, wherein the volume of said second compartment is fixed.
5. A TPS as in claim 2, wherein the volume of said second compartment is changeable.
6. A TPS as in claim 2, wherein said sealing shaft has a tapered end, and wherein said tapered end seals off said connecting aperture whilst being pressed against a rim of said connecting aperture.
7. A TPS as in claim 6, further comprising a biasing spring for pressing said tapered end against said rim.
8. A TPS as in claim 7, wherein said biasing spring comprises at least one locking bulge resiliently attached to a surface of a sidewall of said locker body.
9. A TPS as in claim 8, further comprising at least one releasing handle for releasing said at least one locking bulge off an aperture disposed at a sidewall of said inner barrel, wherein said at least one releasing handle is resiliently attached to a wall of said external barrel.
10. A TPS as in claim 2, wherein a locking handle for pulling said tapered end off said connecting aperture attached to said locker body.
11. A TPS as in claim 4, wherein said locker body slidingly fitted to the lumen of said inner barrel.
12. A TPS as in claim 11, wherein an 0-ring seals off the space between a sidewall of said locker body and an inner surface of said inner barrel.
13. A TPS as in claim 11, wherein said surface enclosing said second compartment further comprises a surface of said locker body.
14. A TPS as in claim 5, further comprising a plunger for changing the volume of said second compartment slidingly fitted to the lumen of said inner barrel, wherein said plunger is reciprocally movable along said common axis.
15. A TPS as in claim 14, wherein said surface enclosing said second compartment further comprises a surface of said plunger.