Abstract:
A centrifuge tube assembly which allows for a single centrifuge cycle and which permits the aspiration of fluids from multiple levels with the centrifuge tube assembly. A modified centrifuge assembly is described wherein the inner tube has an externally threaded portion at its upper end. The method of using the centrifuge tube assembly is also described wherein the centrifuge tube assembly may be used for the aspiration, separation, isolation and extracting of discrete layer in a liquid suspension.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates to an improved centrifuge tube assembly which allows for a single centrifugation cycle and the aspiration of fluids from multiple levels within the centrifuge tube assembly. More particularly, the device may be used for the aspiration, separation, isolation and extraction of discrete layers in a liquid suspension. 
     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 healing and bone regeneration. Over the last decade, many devices have been developed which allow a clinician to isolate and concentrate the platelet component from a whole blood sample including that described in U.S. Pat. No. 7,829,022 which uses a dual centrifugal cycle process. Alternate devices have been developed which employ a single centrifugation cycle including that described in U.S. Pat. Nos. 7,976,796 and 7,179,391. 
     Although the devices of the above-identified patents have experienced some commercial success, it is believed that the devices have certain drawbacks or disadvantages. For example, none of the prior art devices are capable of collecting the target fluid (platelet rich plasma) with a single aspiration after a single centrifugation cycle. Further, none of the prior art devices have an integrated locking mechanism to secure the inner tube at any targeted component locations from 15 ml to 40 ml. None of the prior art devices incorporate an O-ring to introduce a tactical feedback, similar to the dispense/aspirating action of a syringe, and containment seal. The tubes of U.S. Pat. Nos. 7,976,796 and 7,179,391 are prone to kinking. The device of this invention eliminates the utilization of the integral flexible tube employed in U.S. Pat. Nos. 7,976,796 and 7,179,391. The device of this invention eliminates the need for a second spin requirement employed in U.S. Pat. No. 7,829,022. The feature of the instant invention which is not found in the listed US Patents is a manual adjust aspiration tube to visually align the target layer of choice. The device of this invention features an aspiration tube design that has a dimensional relationship between the visual indicator and aspiration port to maintain an RBC and Buffy coat ratio that allows a range of volume choices. The device of this invention eliminates the need to remove or isolate the RBC prior to PRP aspiration, a feature not found in other PRP devices. The device of this invention allows a min/max PRP volume selection from 3 ml to 30 ml, a feature not found in other devices. The device of this invention integrates a single centrifugation, a single aspiration, a single syringe and a single biohazard disposable to deliver an end product, which is not possible in any prior art device. 
     SUMMARY OF THE INVENTION 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter. 
     A centrifuge tube assembly is disclosed which includes an elongated and vertically disposed outer containment tube having an open upper end and a closed lower end. The outer containment tube is comprised of a transparent material. The outer containment tube has a vertically disposed cylindrical post centrally positioned therein at the lower end thereof with the post extending upwardly from the lower end of the outer containment tube. The cylindrical post has an elongated and vertically disposed keyway formed therein which extends inwardly thereinto between the lower and the upper ends thereof. 
     The centrifuge tube assembly also includes an elongated and vertically disposed inner tube, having an open lower end and an open upper end which is positioned in the outer containment tube. The lower end of the inner tube is vertically slidably mounted on the cylindrical post. The inner tube has an alignment key therein at its lower end which is slidably received by the keyway in the cylindrical post to prevent rotation of the inner tube with respect to the cylindrical post and the outer containment tube. 
     The inner tube has an aspiration port formed therein above the lower end and has an imprinted band thereon above the aspiration port. The outer tube also has an imprinted 50 mm line thereon below the upper end thereof. A cup-shaped cap is selectively removably mounted on the upper end of the outer containment tube. The cup-shaped cap has a filtered vent port which is in communication with the upper interior containment tube. The inner tube is selectively slidably extended upwardly through the cap whereby the upper end of the inner tube is positioned above the cap. A seal means is provided in the cap between the cap and the inner tube to prevent fluids from passing outwardly from the interior of the outer containment tube around the inner tube. 
     A locking assembly is associated with the cap for selectively locking the inner tube in various vertical positions with respect to the outer containment tube. The upper end of the inner tube has a male luer thereon. A female luer cap is provided for selective engagement with the male luer to close the male luer. 
     A modified form of the centrifuge assembly is also described. The method of using the centrifuge tube assembly is also described. 
     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 device may serve both as a collection vessel and a tube for the centrifugation of fluids into their discreet components. 
     A further object of the invention is to provide a device of the type described which includes a single port at the top of the device which may be used to fill and aspirate fluid, pre-centrifugation and post-centrifugation therefrom. 
     Yet another object of the invention is to provide a device of the type described 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 device assembly which may be used with any centrifuge machine capable of at least 1900 rcf and 85-50 ml swing out rotor. 
     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, stem cells or adipose tissue. 
     A further object of the invention is to provide a centrifuge tube assembly having the ability to extract the blood component of choice after centrifugation. 
     A further object of the invention is to provide a centrifuge tube assembly in which the surfaces that interface with blood are constructed of a plastic material that is slippery and prevents the adhesion of platelets or other cells. 
     These and other objects will be apparent to those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
         FIG. 1  is a partial sectional view of the centrifuge tube assembly of this invention; 
         FIG. 2  is a side view of the inner tube of the centrifuge tube assembly of this invention; 
         FIG. 3  is a bottom view of the inner tube of the centrifuge tube assembly of this invention with the cylindrical post being shown in section; 
         FIG. 4  is a sectional view of the outer containment tube of the centrifuge tube assembly of this invention; 
         FIG. 5  is a partial sectional view of the cap and inner tube lock and their relationship with the inner tube of the centrifuge tube assembly of this invention; 
         FIG. 6  is a sectional view of the cap of the centrifuge tube assembly of this invention; 
         FIG. 7  is a bottom elevational view of the cap of the centrifuge tube assembly of this invention; 
         FIG. 8  is a top view of the inner tube lock mechanism of the centrifuge tube assembly of this invention; 
         FIG. 9  is a top view of the disc of the inner tube lock mechanism; 
         FIG. 10  is a bottom elevational view of the inner tube lock mechanism; 
         FIG. 11  is a partial sectional view illustrating the orientation and inter-connection between the outer containment tube, the inner tube and a syringe connected to a male luer at the upper end of the inner tube; 
         FIG. 12  is a sectional view of the centrifuge tube assembly and which illustrates a biohazard safety luer cap secured to the upper end of the inner tube during centrifugation; 
         FIG. 13  is a sectional view of the transparent outer containment tube which permits a person to view the component&#39;s demarcation of plasma, red cells and buffy coat; 
         FIG. 14  is a partial sectional view illustrating the inner tube of the assembly being vertically raised for connection to a syringe; 
         FIG. 15  is a side view of a modified inner tube with the cylindrical post being shown in section; 
         FIG. 16  is a bottom view of the modified inner tube; 
         FIG. 17  is a partial sectional view which shows the modified form of the inner tube and a modified inner tube adjuster; 
         FIG. 18  is a sectional view of the body portion of the modified inner tube lock; 
         FIG. 19  is a top view of the locking disc of the inner tube lock of  FIG. 18 ; and 
         FIG. 20  is a bottom elevational view of the inner tube lock of  FIG. 17 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiments are described more fully below with reference to the accompanying figures, which form a part hereof and show, by way of illustration, specific exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense in that the scope of the present invention is defined only by the appended claims. 
     The numeral  10  refers generally to the centrifuge tube assembly of this invention which will be referred to hereinafter as “assembly”. Assembly  10  includes an outer containment tube  12  having a tapered and closed lower end  14  and an open upper end  16 . The upper outer side of tube  12  has mating geometry in the form of a protruding annular bulge  18 . An upstanding cylindrical post  20  is integrally formed with tube  12  and extends upwardly from lower end  14  into the interior  22  of tube  12 . For purposes of description, post  20  will be described as having an upper end  23 . A vertically disposed keyway or slot  24  is formed in post  20 . Tube  12  also has a 50 mm line  26  imprinted thereon below the upper end  16 . Tube  12  also has a stop  28  which protrudes laterally from the outer side of tube  12  below the upper end thereof. 
     Assembly  10  also includes a cup-shaped cap  30  having a cylindrical side wall portion  32  with an upper end  34 , a lower end  36 , an outer side  38  and an inner side  40 . The upper inner side  40  of side wall portion  32  has an annular recessed portion  42  thereon. A horizontally disposed top wall portion  44  extends laterally inwardly from the upper end of side wall portion  32 . A cylindrical throat or neck portion  46  extends upwardly from the inner end of top wall portion  44  and has an outer side  48  and an inner side  50  which define a central opening  52 . Throat portion  46  has an annular recess or groove  54  formed therein at its upper end which receives an O-ring  56  therein. Top wall portion  44  has a filtered vent port  57  associated therewith. The side walls of central opening  52  have a pair of oppositely disposed chords  58  and  60  formed therein. The underside of top wall portion  44  has an annular wall  62  extending downwardly therefrom inwardly of the annular recessed portion  42 . 
     The assembly  10  also includes an elongated inner tube  68  having an open lower end  70  and an open upper end  72  in the form of a male luer. Inner tube  68  has an anti-rotation key  74  formed thereon at its lower end which is configured to extend into the keyway  24  of post  20  as will be discussed in detail hereinafter. 
     Inner tube  68  has an aspiration port  76  formed therein above its lower end. Inner tube  68  also has an inside diameter stop  78  therein just below aspiration port  76 . Inner tube  68  also has an imprinted black band  80  thereon above aspiration port  76 . Inner tube  68  also has an undercut  81  formed therein below aspiration port  76 . 
     The numeral  82  refers to an inner tube lock assembly. Assembly  82  includes a horizontally disposed and rotatable disc  84  having a central opening  86  extending therebetween. The wall surface around opening  86  has an annular channel  88  formed therein which has an O-ring  90  positioned therein. Assembly  82  includes a generally cylindrical and hollow body portion  92  which extends downwardly from disc  84 . Body portion  92  has four radially spaced-apart and vertically disposed slits  94  formed therein. The lower end of body portion  92  has four radially spaced-apart inner tube lock tabs  96  extending horizontally outwardly therefrom. Body portion  92  has a pair of 180 degree spaced-apart chord tabs  98  formed therewith which extend outwardly from the outer surface of body portion  92 . The O-ring  56  embraces body portion  92  above the slits  94 . 
     The inner tube lock assembly  82  is mounted on and in the cap  30  as follows. The inner tube lock assembly  82  is initially rotated with respect to cap  30  so that the chord tabs  98  are located at 90 degrees from the chords  58  and  60  in central opening  52  of throat  46  of cap  30 . The body portion  92  of assembly  82  is then pushed downwardly through the central opening  52  in throat  46  of cap  30 . The four slits  94  permit the body portion  92  to slightly collapse or spring out so that the body portion  92  may be completely inserted downwardly in the central opening  52  and then spring back so that the four inner tube lock tabs  96  are positioned below the top wall portion  44  of cap  30  as seen in  FIG. 5 . 
     The inner tube  68  is inserted downwardly into the tube  12  by inserting the inner tube  68  downwardly through central opening  86  in disc  84 , and through body portion  92 . The inner tube  68  is then rotated until the anti-rotation key  74  is aligned with keyway  24  of post  20 . The inner tube  68  is then pushed downwardly until the lower end of inner tube  68  is positioned at the lower end of post  20 . 
     The numeral  102  refers to a 60 ml blood sample syringe having a female luer  104  which is configured to be threaded onto the male luer  72  at the upper end of inner tube  68 . The syringe  102  is filled with a blood sample mixture  106  containing a mixture of 41 ml whole blood and 9 ml of ACD-A. The blood sample mixture  106  is dispensed from syringe  102  into the outer tube  12  to the 50 ml fill line  26 . The 60 ml syringe  102  is then unthreaded from the inner tube male luer  72 . A biohazard safety luer cap  108  is then threaded onto the inner tube male luer  72 . 
     The assembly is then placed in a centrifuge and spun at 1900 rcf for approximately 8.5 minutes. The assembly is then removed from the centrifuge. The technician, holding the device in a vertical position, removes the female luer cap  108  from the male luer  72  and threads a 10 ml syringe  110  onto the inner tube male luer  72  and visually locates the buffy coat layer  112 . The technician slowly raises the inner tube  78  by grasping the male luer  72  and syringe connection until the lower (trailing) edge of the colored band  80  is visible and the buffy coat layer  112  and plasma  114  fractionation line  116 . The technician then locks the inner tube lock assembly  82  by rotating the lock assembly  82  ninety degrees so that the chord tabs  98  engage the chords  58  and  60  which causes the body portion  92  to squeeze the inner tube  68  to lock the inner tube in the desired vertical position. The technician aspirates the desired volume into the syringe  110 . 
       FIG. 15  illustrates an optional design for the inner tube  68  and which is designated the numeral  68 ′. The only difference between inner tube  68 ′ and inner tube  68  is that inner tube  68 ′ has an externally threaded portion  118  below the male luer  72 . All other features and functions of inner tube  68 ′ are the same as inner tube  68 . 
       FIG. 17  illustrates a modified method of vertically moving the inner tube  68 ′. Disc  84  and body portion  92  have internally threads  120  which threadably receive the threaded portion  118  of inner tube  68 ′. The O-ring  56  provides a seal at the mating point of the modified inner tube  68 ′ and the threaded disc  84 . The O-ring  56  provides a tactical feedback and surface fraction between the threaded disc  82  and the cap  30  to secure the inner tube  68 ′ in place. 
     Thus it can be seen that an improved centrifuge tube assembly has been provided. The assembly of this invention serves both as a collection vessel and a tube for the centrifugation of fluids into their discrete components. Further, the assembly of this invention includes a single port at the top of the device which may be used to fill and aspirate fluid, pre-centrifugation and post-centrifugation therefrom. It can also be seen that the device of this invention enables a clinician to have complete control over the concentration and volume of the end product. A further advantage of the assembly of this invention is that it provides the most cost effective solution specifically designed for the concentration of platelets, stem cells or adipose tissue. Yet another advantage of the invention is that it has the ability to extract the blood component of choice after centrifugation. 
     Thus it can be seen that the invention accomplishes at least all of its stated objectives. 
     Although the invention has been described in language that is specific to certain structures and methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed invention. Since many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.