Centrifuge tube assembly and method of using the same

A centrifuge tube assembly comprising an elongated vial having an open upper end and a closed lower end with a lid mounted on the upper end thereof. The lid has a central opening formed therein which rotatably receives an elongated inner tube extending downwardly into the vial with the bottom of the inner tube being received by an upstanding bottom tube. The lower end of the inner tube has a pair of vertically spaced-apart upper and lower ports. The bottom tube has a pair of upper and lower ports formed therein which are radially offset with respect to one another. A tube actuator is secured to the upper end of the inner tube to facilitate the rotation of the inner tube between first and second positions. When the inner tube is in its first position, the lower ports of the inner tube and bottom tube are in register. When the tube actuator is in its second position, the upper ports of the inner tube and the bottom tube are in register. The method of using the centrifuge tube assembly of the invention is also described.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an improved centrifuge tube assembly which allows for the induction or aspiration of fluids from two distinct levels within the centrifuge tube assembly. More particularly, the device may be used for the separation, isolation and extraction of discrete layers in a liquid suspension.

2. Description of the Related Art

Various medical procedures utilize platelet-rich blood plasma. The blood product is effective due to its growth promoting features, which are proven to assist greatly in wound and bone regeneration such as described in U.S. Published Application 2002/0185457 A1.

Although the device of the above-identified published application has apparently experienced some success, it is believed that the device of the application suffers from certain drawbacks or disadvantages. For example, the centrifuge tube assembly of the published patent application does not draw blood from the elongated tubular receptacle in a manner which is parallel to the layers of separation which detracts from the integrity of the layers and retards the speed of component aspiration. Further, the centrifuge tube assembly of the published application involves the use of two aspiration ports which increases the risk of accidental contamination. Additionally, the centrifuge tube assembly of the published application, by utilizing a pair of aspiration pipes36and38, increases the cost of manufacture of the assembly. An additional drawback of the device of the publication application is that its aspiration pipes are not supported at their bases. This may lead to resonance and vibration during the centrifugation process that may disrupt the separation of the layers and prematurely activate the platelets.

SUMMARY OF THE INVENTION

A centrifuge tube assembly and the method of using the same is disclosed. The centrifuge tube assembly of this invention comprises an elongated vial having an open upper end and a closed lower end with the upper end of the vial being closed by a lid or cover which is snap-fitted onto the upper end of the vial. The lid is provided with a centrally disposed, hollow tubular portion which defines a central opening. The vial has a centrally disposed hollow bottom tube, having upper and lower ends, which extends upwardly from the lower end thereof. The hollow bottom tube has vertically spaced-apart upper and lower ports formed therein which are radially offset with respect to one another. The separator also includes an inner tube which has upper and lower ends. The inner tube is positioned within the vial so as to rotatably extend through the central opening in the lid with the lower end of the inner tube being rotatably received by the bottom tube. The inner tube has vertically spaced-apart upper and lower ports formed therein. The inner tube is selectively rotatable between first and second positions with respect to the bottom tube and the lid. A tube actuator is secured to the upper end of the inner tube so that the inner tube may be conveniently and selectively rotated with respect to the vial to its first and second positions. The tube actuator includes a centrally disposed, hollow tube member which is in communication with the upper end of the inner tube. When the inner tube is in its first position, the lower port of the inner tube registers with the lower port of the bottom tube. When the inner tube is in its first position, the upper ports of the bottom tube and the inner tube are not in register. When the inner tube is in its second position, the upper port of the inner tube is in register with the upper port of the bottom tube. When the inner tube is in its second position, the lower port of the inner tube is not in register with the lower port of the bottom tube.

The method of using the centrifuge tube assembly is also disclosed. The method comprises the following steps. A 60 cc syringe is filled with 5 ml of CPDA. 50 ml of blood is then drawn into the syringe. The syringe is then gently agitated to mix the blood and the CPDA. The tube actuator or the vial is then rotated to its first position. 50 ml of blood is then introduced into the vial through the open upper end of the tubular member of the tube actuator and the upper end of the inner tube. The vial is placed in a centrifuge and spun at 3300 rpm for approximately eight minutes. The vial is then removed from the centrifuge. With the tube actuator in its first position, the technician subtracts three from the RBC/plasma interface level and draws the calculated amount of red blood cells from the inner tube through the upper end thereof. In position one, the lower ports of the bottom tube and the inner tube are in register so that the red blood cells in the vial may be drawn into the inner tube. The vial is then placed in the centrifuge and spun at 3300 rpm for eight minutes. The vial is then removed from the centrifuge. The tube actuator on the vial is then moved to position number two so that the upper ports of the inner tube and tool bar are in register. The desired amount of plasma is withdrawn from the inner tube by a syringe or the like. It should be noted that if all of the plasma is drawn off, 5 ml of concentrated platelets will remain in the tube. The remaining blood in the vial is then gently agitated and with the tube actuator in its first position, the remaining platelet concentrate is extracted from the vial with a 20 ml syringe.

A modified form of the assembly is also shown and described.

Although the above-described procedure refers to a single vial being prepared, centrifuged, etc., a pair of vials would normally be utilized to balance the centrifuge.

It is therefore a principal object of the invention to provide an improved centrifuge tube assembly and the method of using the same.

A further object of the invention is to provide a device of the type described wherein the aspiration tube thereof draws blood parallel to the layers of separation which preserves the integrity of the layers and allows for faster component aspiration.

A further object of the invention is to provide a device of the type described which includes a single port which is of the self-sealing design to greatly reduce the risk of accidental contamination and which may be easily swabbed with alcohol.

Still another object of the invention is to provide a tube actuator which may be positioned with the thumb and forefinger.

Yet another object of the invention is to provide a device wherein the clinician has complete control over the concentration and volume of the end product.

Still another object of the invention is to provide a centrifuge tube assembly which has the same dimensions as a standard 50 ml centrifuge tube and can be used within any centrifuge machine capable of at least 3000 rpms.

A further object of the invention is to provide a centrifuge tube assembly of the type described which provides the most cost effective solution specifically designed for the concentration of platelets.

A further object of the invention is to provide a centrifuge tube assembly wherein the aspiration tube thereof is supported in such a manner so as to reduce the possibility of resonance and vibration thereof during the centrifugation process.

These and other objects will be obvious to those skilled in the art.

DETAILED DESCRIPTION OF THE INVENTION

With respect toFIGS. 1,2,3A,3B and3C, the numeral10refers generally to the centrifuge tube assembly of this invention which will be referred to hereinafter as “assembly”. Assembly10includes an elongated vial12having an open upper end14and a lower end16. The numeral18refers to a bottom wall which is positioned within the vial12above the lower end thereof and which may be integrally molded with the vial12or separately formed and inserted into the lower end of the vial12and secured thereto in position by any convenient means. Bottom wall18defines an inverted, truncated conical-shaped configuration which has a centrally disposed tubular portion20.

The numeral22refers to a lid or cover which is snap-fitted onto the upper end of the vial12. Lid22includes a skirt portion24which embraces the upper end of the vial12with the lower end of the skirt portion24engaging the annular flange26which extends outwardly from the outer surface of the vial12. Lid22also includes a centrally disposed hollow tubular portion28which extends downwardly from the top wall30of lid22. Lid22also includes a ring31which extends upwardly from top wall30.

The numeral32refers to a bottom tube having an upper end34and a lower end36. The lower end36of bottom tube32is snap-fitted into the centrally disposed tubular portion20of bottom wall18, as illustrated in the drawings. Bottom tube32is provided with a lower port38formed in the side wall thereof which is positioned just above the upper end of the centrally disposed tubular portion20of bottom wall18. Bottom tube32is also provided with an upper port40formed in the side wall thereof below the upper end thereof and which is radially offset with respect to the lower port38. An optional liquid guide member or deflector42may be secured to the side wall of bottom tube32below upper port40and which extends upwardly and outwardly therefrom, as illustrated in the drawings.

The numeral44refers to an elongated inner tube having a lower end46and an open upper end48. Tube44has a lower port47formed therein above the lower end thereof which may be moved into register with the lower port38of bottom tube32. The inner tube44also has an upper port49formed therein above lower port47which may be brought into register with the upper port40of bottom tube32. The upper end of inner tube44is rotatably received by the centrally disposed tubular portion28of lid22in a sealing relationship. A tube actuator50is rotatably mounted on ring31on the upper end of lid22and includes an upstanding centrally disposed tubular portion52which communicates with the open upper end of the inner tube44in a sealed relationship with respect thereto so that as fluid is withdrawn from the upper end of the tube44, the fluid will not escape from any place other than the open upper end of the tubular portion52of tube actuator50. Preferably, a seal56is provided between the upper end of the inner tube44and the tube actuator50(FIG. 3A).

Preferably, the components of the assembly10are formed from a clear polypropylene or polycarbonate material. The vial12is designed so that it holds at least 50-60 ml of fluid volume and fits inside a standard or custom non-aerosol container in a centrifuge bucket. The exterior surface of the vial12must have volume graduations imprinted on one side thereof in milliliters (FIG. 2). Preferably, lid22includes a vent opening56which is closed by a suitable material such as Gore-Tex or the like which permits the flow of air therethrough but which prevents the flow of liquids therethrough.

Preferably, the vial12is tapered so that the diameter of the lower end thereof is slightly less than the diameter of the upper end thereof. Preferably, the inner tube44is also tapered so that its lower end has a diameter which is slightly less than the diameter of the upper end thereof. Although the drawings illustrate that the lower end of the inner tube44is positioned within bottom tube32, the tubes32and44could be sized so that the lower end of tube44rotatably embraces tube32. The tube44is supported by the tube32to reduce, if not eliminate, the possibility of resonance and vibration of the tube44during the centrifugation process which could disrupt the separation of the layers and prematurely activate the platelets.

The assembly10of this invention is utilized as follows. A 60 cc syringe is filled with 5 ml of CPDA. 50 ml of blood is then drawn into the syringe. The syringe is then gently agitated to mix the blood and the CPDA. The tube actuator50is then rotated into position one wherein lower port47of inner tube44registers with lower port38of bottom tube32. In the first position, upper port49of inner tube44is not in register with upper port40in bottom tube32. With the device in hand, exactly 50 ml of the blood/CPDA mixture is injected into the tube44by means of the open upper end of the actuator50.

The assembly10is then placed in a centrifuge and spun at 3300 rpm for eight minutes. The assembly is then removed from the centrifuge and the RBC/plasma interface level is observed.FIG. 3Aillustrates the tube actuator in position one and illustrates the various layers within the vial wherein the reference numeral58refers to plasma, the numeral60refers to the platelets and the numeral62refers to the red blood cells. The technician determines the RBC/plasma interface level and mentally subtracts three from the RBC/plasma interface level. With the tube actuator in position number one, a syringe is used to draw the calculated amount of red blood cells from the vial by means of the open upper end of the tubular portion52of the actuator50.

The assembly is then again placed in the centrifuge and spun at 3300 rpm for eight minutes. The assembly is then removed from the centrifuge and with the tube actuator in position number two, wherein the upper port49of tube44registers with the upper port40of bottom tube32, the desired amount of plasma is withdrawn from the tube44.FIG. 3Billustrates the various layers prior to the plasma being withdrawn from the vial12whileFIG. 3Cillustrates the various levels after the plasma has been withdrawn. If all of the plasma is withdrawn, approximately 5 ml of concentrated platelets will remain in the tube. The remaining red blood cells, platelets and plasma is gently agitated and with the tube actuator in position number one, the remaining platelet concentration is removed with a 20 ml syringe.

Although the method described above speaks of using a single assembly, two of the assemblies10would normally be prepared and placed in the centrifuge to balance the centrifuge.

The aspiration tube assembly of this invention permits blood to be drawn parallel to the layers of separation which preserves the integrity of the layers and allows for faster component aspiration. The single port, self-sealing design of the invention greatly reduces the risk of accidental contamination and may be easily swabbed with alcohol. The tube actuator50of this invention may be easily rotated between its various positions with the thumb and forefinger. The assembly of this invention allows the clinician complete control over the concentration and volume of the end products and has the same dimensions as a standard 50 ml centrifuge tube which may be used with any centrifuge machine capable of at least 3000 rpms. The assembly of this invention is believed to provide the most cost effective solution specifically designed for the concentration of platelets. The fact that the lower end of the tube44is supported or stabilized by the tube32prevents resonance and vibration during the centrifugation process as discussed above.

FIGS. 4-7illustrate a slight modified form of the invention wherein the assembly is referred to by the reference numeral110. Assembly110includes an elongated vial112having an open upper end114and a lower end116which defines an inverted, truncated conical-shaped configuration which has a centrally disposed tubular portion120.

The numeral122refers to a lid/actuator which is rotatably snap-fitted onto the upper end of the vial112. Lid/actuator122also includes a centrally disposed, hollow, tubular portion128which extends downwardly from the top wall130of lid122and which also includes an upper end portion131which extends upwardly from top wall130.

The numeral132refers to a bottom tube having an upper end34and a lower end36. Bottom tube132is provided with a lower port138formed in the side wall thereof which is positioned just above the upper end of the centrally disposed tubular portion120. Bottom tube132is also provided with an upper port140formed in the side wall thereof below the upper end thereof and which is radially offset with respect to the lower port138.

The numeral144refers to an elongated tube having a lower end146and an open upper end148. Lower end146of tube144rotatably embraces bottom tube132. Tube144has a lower port147formed therein above the lower end thereof which may be moved into register with the lower port138of bottom tube132. The tube144also has an upper port149formed therein above lower port147which may be brought into register with the upper port140of bottom tube132. The upper end of tube144is received by the centrally disposed tubular portion128of lid122in a sealing relationship (FIG. 7). Tube144is provided with an annular flange150below its upper end which is secured to tubular portion128by the pins151extending downwardly from tubular portion128which are received by openings153formed in flange150so that rotation of lid/actuator122causes tube144to also rotate. A flexible seal152is positioned in tubular portion128and has intersecting slits154and155formed in the upper end thereof to seal the upper end thereof while permitting a syringe needle to be inserted therethrough. The exterior portion of the upper end portion131is provided with threads156to permit a syringe to be threadably secured thereto.

The assembly110is substantially identical to assembly10except that the tube144rotatably embraces bottom tube132and the lid also acts as a tube actuator. The assembly110is utilized in an identical fashion to that described above with respect to assembly10.