Abstract:
A needle aspiration biopsy device includes a syringe, a valve coupler for controlling a vacuum in the syringe barrel, and an anti-reflux head. The head includes a hub, defining a large collection well preferably several hundred micro liters in volume, and a needle mounted to the hub. A passageway is defined either by a contoured needle or a straight needle and an internal channel in the hub wall such that a proximal end of the passageway extends inside the hub and opens in spaced relation to a floor of the collection well. A method of biopsy using the device is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit to U.S. provisional patent application Ser. No. 60/518,069 filed on Nov. 6, 2003. 
     
    
     STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates to medical devices, and in particular to needle aspiration biopsy devices.  
         [0005]     2. Background of the Art  
         [0006]     Fine needle aspiration biopsy (hereinafter “FNAB”) is a widely practiced technique for acquiring diagnostic sample specimen of various tumors and lesions, and is generally considered a safe, rapid and economical non-surgical alternative to conventional surgical biopsy.  
         [0007]     The FNAB technique is conventionally practiced with a standard hypodermic needle syringe with a fine gauge needle, possibly suited with special syringe grips and modified to include a small specimen collection chamber at the base of the needle. The FNAB technique as conventionally practiced generally consists of inserting the needle of the syringe into the tumor, lesion or tissue of interest and then pulling the syringe piston to draw a vacuum in the needle before or while the tissue is probed several times in a to and fro motion. The vacuum and reciprocating motion of the syringe aspirates the tissue and causes specimens to pass through the needle and into the small space at the top of the needle. After some specimens have been collected, the piston is returned to the bottom of the syringe barrel to break the vacuum in the needle and the needle is withdrawn from the tissue. The needle is then removed from the syringe and the collected specimens are squirted onto a glass slide for analysis.  
         [0008]     Conventional FNAB techniques can often yield insufficient specimens to conduct a thorough diagnostic analysis. This problem arises because of several deficiencies in conventional FNAB devices, particularly with regard to the delivery of the specimens into the needle, their retention in the device, and their transfer from the device to the diagnostic stage or vessel. Among other things, these deficiencies are in part due to the insufficient space for specimens, the way the specimens are introduced into the device and the way the vacuum is achieved and released.  
         [0009]     More specifically, conventional hypodermic needles used for FNAB produces typically have a collection space of about 10-50 micro liters (μL). A 50 μL sample is usually enough specimens to conduct a single study, much less than this amount would likely not provide for meaningful analysis. The small collection space means that less specimens can be collected per biopsy. It also means that to maximize yield, the available space must essentially be filled with specimens in order to obtain a sufficient quantity for meaningful analysis.  
         [0010]     In conventional FNAB devices specimens are susceptible to being drawn into the syringe barrel under vacuum or lost be reflux back through the needle, in both cases diminishing the overall yield usable for analysis. This problem is exacerbated by coagulation of the aspirated specimens in the collection chamber. Another problem with the small collection space is that small micro-specimen or portions of the accumulated specimens cannot be readily transferred to the examination site in a controlled manner. The narrowness of the opening essentially requires the specimens to be dumped or poured out into the test tube or onto the slide, and thus the more accurate “pick and spread” transfer method may not be used because conventional forceps may be too large.  
         [0011]     U.S. Pat. No. 5,645,537 to Powles et al. discloses a needle aspiration biopsy device in which a body to which a syringe and needle are attached defines a relatively large internal collection chamber. The body is preferably formed of two parts with a joint formed across the collection chamber so that following the biopsy procedure a top of the body can be removed to allow access to the collection chamber. This device is disadvantageous, however, because collected specimens are lost by reflux back through the needle.  
         [0012]     As illustrated by the above patent, conventional FNAB devices are susceptible to losing part of the sample through reflux of the collected specimens back through the needle. This arises in part because the vacuum in the needle is at all times in communication with the vacuum in the syringe barrel. To prevent the accumulated specimens in the collection well from entering the syringe barrel when the needle is withdrawn from the tissue, the vacuum must be broken before the needle is removed. The vacuum is released by returning the syringe piston to the initial retracted position in the barrel. This invariably causes reflux of the specimens back into the tissue by virtue of evacuated air being pushed from the syringe barrel through the collection chamber and out the needle. The typical way to make up for the specimens lost by reflux is to conduct multiple biopsies and/or increase the number of probes into the tissue per biopsy, thus increasing the time of the procedure and the patient&#39;s discomfort.  
         [0013]     U.S. Pat. No. 4,549,554 to Markham and U.S. Pat. No. 5,413,115 to Baldwin disclose FNAB devices in which valves are interposed between the needles and syringes. The valves are designed to control the vacuum in the needle, and thereby avoid the aforementioned problem contributing to reflux. Both of these devices include a simple open-shut valve having an opening that can be slid or rotated into and out of alignment with the passageway between the needle and the syringe and thereby open and close off, respectively, the vacuum in the syringe to the needle. The valve disclosed by Baldwin has a third, vent position in which the needle lumen can be opened to ambient after the specimens are collected and before the needle is removed from the tissue, while at the same time occluding the opening to the syringe. Two problems with these devices are that there is no provision for adequately retaining sufficient quantities of specimens or for transferring the specimens in a controlled manner. The Markham device has the conventional small collection chamber at the of the needle, and the Baldwin device merely contemplates collecting the specimens in the lumen of the needle and expressing them back through the needle under air pressure from the syringe. In fact, the Baldwin patent even acknowledges that in practice some of the accumulated specimens will enter into the vacuum area (within the syringe barrel).  
         [0014]     Another reason for the reflux problem is that the proximal end of the needle is typically adjacent the accumulated specimens such that gravity or the pressure differential between the needle and collection chamber can readily force specimens back through the needle. U.S. Pat. No. 5,027,827 to Cody et al. discloses an FNAB device, essentially addressing this issue with the intention of preventing contamination, employing a considerably different arrangement of components. Here, the needle is mounted directly to the syringe barrel and the piston forms a hollow vacuum chamber with a septum at the leading end. When piston is pushed down into the barrel, the septum is punctured by a longitudinal tubular extension, leading to the needle, sticking straight up from the bottom of the barrel. A small opening in the side of the syringe barrel allows the needle to be inserted into the specimens and the piston advanced within the barrel without introducing air into the patient&#39;s body. When the piston is advanced far enough so that the septum penetrated by the tubular extension, the needle is evacuated and specimens can be collected into the hollow piston. After the biopsy procedure is completed, this arrangement allows the physician to advance the piston while holding his or her finger over the side opening in the barrel so as to safely blow out any residual biopsy material left in the needle lumen into a biohazard receptacle, while the accumulated specimens remain isolated inside the piston. This arrangement also allows the vacuum in the needle to be achieved and released with minimal loss of the accumulated specimens by simply sliding the piston in and out of engagement with the tubular extension. When the piston is fully retracted into the barrel, the tubular extension extends up above a recessed part of the septum so that when a small amount of specimens is collected, the opening to the pathway of the needle may be spaced from the accumulated specimens. However, reflux is likely when a relatively large amount of specimens is collected, as when a significant portion of the hollow piston was filled. Moreover, the operation of releasing the vacuum in the needle requires the piston to move out of the barrel, which moves the accumulated specimens in the piston proximate the opening in the tubular extension. Consequently, the reflux problem would remain. Another issue with this device is that it is designed for use with a centrifuge, and thus, given the length of the piston, is not well suited for the pick and spread transfer method.  
         [0015]     Accordingly, an advanced FNAB device is needed in the art allowing physicians to offer patients a more reliable and higher yield non-surgical biopsy procedure.  
       SUMMARY OF THE INVENTION  
       [0016]     The present invention provides a needle aspiration biopsy, or FNAB, device, with an anti-reflux head designed specifically to increase the yield of specimens obtained during the biopsy procedure. The anti-reflux head transfers the specimens from the needle to the top of a collection well in a wide-mouth hub. Preferably, the vacuum in the needle is initiated and terminated while the needle is inserted into the tissue. Moreover, the needle can have special side scoops for increasing the amount of specimens collected on each pass of the needle through the specimen sample site, such as a tumor, lesion or other soft tissue region of interest.  
         [0017]     In particular, one aspect of the present invention provides a high specimen yield anti-reflux head for a needle aspiration biopsy device including a unique hub. The hub defines a collection wall and mounts a needle with an open pointed tip. A passageway is defined by one or both of the needle and hub which extends from the pointed tip of the needle to a segment extending inside the hub opening in spaced relation to a floor of the collection well.  
         [0018]     In one preferred form, the entire passageway is defined by the needle. In this case, the hub has an opening in the floor of the collection well through which a straight segment of the needle shaft extends. The hooked end can take on a modified C-shape configuration so as to follow the contour of the collection well. A segment of the passageway thus follows a sideways or laterally extending path relative to a long axis and opens at a side opening inside the collection well. This lateral segment preferably extends and opens about a lateral axis which is preferably essentially perpendicular to the long axis.  
         [0019]     In another preferred form, the passageway is defined in part by the needle and in part by the hub. Specifically, the needle is hollow and straight between its ends and the hub is formed with an internal channel which defines the laterally extending segment. The straight, preferably barbed, proximal end of the needle fits into an opening in the hub in communication with the internal channel. The needle can also be a conventional needle attached to the hub using a standard Luer type locking connection. In either case, the channel can follow a similar C-shaped contour and have the sideways segment and side opening.  
         [0020]     In another preferred forms, the collection well has an anti-coagulant surface, preferably being an ACD or EDTA coating, and the needle has a silicon coated lumen and a Teflon coated exterior. The hub has a wide mouth for enhanced access to collected sample inside the collection well. The collection well defined by the hub is relatively large having a volume of at least 100 μL and more preferably a volume of 500 μL to 1 mL or more.  
         [0021]     In yet another preferred form, the needle has one or more scoop openings that open to one or more sides of the needle and which are in communication with the passageway. The scoop opening can be of any suitable configuration, such as oblong or round, and preferably extend through the walls at an oblique angle not perpendicular to the long axis of the needle.  
         [0022]     In still other preferred forms, the head can be stored before and after use in a sheath stand which defines an elongated cavity containing the needle and has an open end that is mountable to the hub. Preferably, the sheath stand has a wide base for standing the head upright with the needle pointing down and the hub opening upwardly. A cover can be used to seal the collection well so that specimens can be stored in the head after the biopsy procedure.  
         [0023]     Another aspect of the invention provides an anti-reflux FNAB device. The FNAB device includes a syringe with a barrel and a sliding piston, a valve for controlling flow to and from the syringe and the anti-reflux head described above. One or more piston locks can be snapped onto the shaft of the piston to hold in place and maintain the vacuum. The FNAB device can also include a sheath stand as described above to conceal the needle as well as to support the device upright. The valve gives the physician or technician precise, one-handed control of the vacuum at the needle so that it can be both initiated and terminated while the needle is within the specimen sample site. This establishes a vacuum suitable to withdraw specimens into the collection well while preventing reflux back into the needle.  
         [0024]     In another aspect of the invention the device thus provides for an improved needle aspiration biopsy procedure using the new FNAB device. The procedure or method includes the steps of: creating a vacuum in the syringe; inserting the needle into a specimen sample site; creating a vacuum in the needle; probing the site with the needle; collecting specimens in the hub; releasing the vacuum in the needle; withdrawing the needle from the site; separating the hub from the device; and transferring specimens collected within the hub to an examination site. Preferably, the vacuum is achieved in the syringe by closing the valve and pulling the syringe piston away from the syringe barrel, and the vacuum is achieved in the needle by opening the valve. The vacuum in the needle is resealed simply by reclosing the valve.  
         [0025]     The objects and advantages of the present invention will be apparent from the description which follows. The following description merely provides preferred embodiments of the invention. Thus, the claims should be looked to in order to understand the full scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a perspective view of a preferred embodiment of the FNAB device according to the present invention;  
         [0027]      FIG. 2  is a cut-away perspective view of an anti-reflux head thereof;  
         [0028]      FIG. 2A  is a top view thereof looking into a specimen collection well;  
         [0029]      FIG. 3  is a cross-sectional view taken along line  3 - 3  of  FIG. 2A ;  
         [0030]      FIG. 4  is a perspective view of the FNAB device with a syringe piston pulled from its barrel;  
         [0031]      FIG. 5  is another perspective view of the FNAB device with the syringe piston in the barrel and showing a sheath stand for concealing the needle and supporting the device upright;  
         [0032]      FIG. 6  is another perspective view of the device shown supported by the sheath stand;  
         [0033]      FIG. 7  is a perspective view showing the anti-reflux head containing collected specimens and being covered and inserted into the sheath stand;  
         [0034]      FIG. 8  is a perspective view of the covered head in the sheath stand;  
         [0035]      FIG. 9  is a side view of an alternate embodiment of the FNAB device having a hook ended needle and a coupler with a separate valve section;  
         [0036]      FIG. 10  is an enlarged partial sectional view of the anti-reflux head of the embodiment of  FIG. 9 ;  
         [0037]      FIG. 11  is a partial sectional view showing the tip of the needle used in the embodiment of  FIG. 9 , which is also suitable for use in any of the other described embodiments;  
         [0038]      FIG. 12  is a partial perspective view of the tip of the needle showing an oblong side scoop near the tip of the needle;  
         [0039]      FIG. 13  is a view similar to  FIG. 12  showing a circular side scoop;  
         [0040]      FIG. 14  is a partial sectional view showing an alternate sheath stand configuration for the embodiment of  FIG. 9 , or any other embodiment described herein;  
         [0041]      FIG. 15  is a partial sectional view of another alternate embodiment of the FNAB device having a built-in centrifuge vial; and  
         [0042]      FIG. 16  is a partial section view of another embodiment of the FNAB device having a conventional needle and Luer type connection of the needle to the hub. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]     The present invention provides an FNAB device with an anti-reflux head designed specifically to increase the yield of tissue specimens obtained during the biopsy procedure. The anti-reflux head transfers the specimens from the needle and deposits them down into a collection well in a wide-mouth hub. Preferably, the vacuum in the needle is initiated and terminated while the needle is inserted into the specimen sample site, which could be a tumor, lesion or other soft tissue region of interest. Moreover, the needle can have special side scoops for increasing the specimen yield from each pass of the needle through the site.  
         [0044]     Referring now to  FIGS. 1 and 4 , the FNAB device  20  generally includes a needle  22  mounted to a hub  24  which is connected by a coupler  25 , having a valve  26 , to an end of a syringe  28 . The syringe  28  is generally of standard construction having a tubular barrel  30 , extending along a longitudinal axis  32 , with a narrow opening (not shown) at one end and a wide opening  34  at the other end through which a piston  36  can slide inside of the barrel  30 . As is conventional, the piston  36  has a head (not shown) that seals against the inner diameter of the barrel  30  to trap gas or liquid within the barrel  30  between the piston head and the narrow end. Preferably, the exposed end of the piston  36  has an enlarged platform  38  for depressing and pulling the piston  36  with respect to the barrel  30 . One or more piston locks  35  (one shown in  FIGS. 1 and 4 ) snaps onto the piston  36  between the end of barrel  30  and the platform  38  of the piston  36  to keep the piston in an extended position (pulled out from the barrel  30 ) to maintain the vacuum in the syringe without holding the piston  36 .  
         [0045]     At the narrow end of the syringe  28 , a neck  40  receives a tubular longitudinal extension  42  of the coupler  25 , which is preferably a suitable plastic, such as a polystyrene or a polycarbonate having good sealing properties. This connection is generally liquid and air tight by the close fit of the mating components. If necessary, this connection can be permanently joined and sealed by a bonding agent or a fusion technique such as ultrasonic welding. Referring to  FIG. 3 , the extension  42  defines a passageway from the barrel  30  of the syringe  28  to another longitudinal extension  44  of the coupler  25  opposite a lateral cylindrical section  46  housing a cylindrical body  48  of the open-shut valve  26  with an axial opening  50  therethrough. The body  48  is rotated about its lateral axis by a turn lever  52  at the end of the body  48 . The valve body  48  and turn lever  52  are preferably formed as one piece of a suitable plastic, such as high or low density polyethylene. The lever  52  can be rotated 90 degrees to align the opening  52  in the body  48  with the passageways of the extensions  42  and  44  of the coupler  25 . Rotating the lever  52  90 degrees into the position shown in  FIG. 3  again closes off communication between the passageways of extensions  42  and  44 . The extension  44  leads to a wide collar  54 . The collar  54  has a feature for removably coupling the hub  24 . In one preferred form, the collar  54  is formed with a groove  51  opening at the open end of the collar  54  and having axial and lateral runs. The groove  51  receives a boss  56  projecting from the hub  24  in a bayonet type connection in which the boss  56  slides into the axial run of the groove  51  and then the lateral run as the hub  24  is rotated with respect to the collar  54 .  
         [0046]     Referring to  FIGS. 2, 2A  and  3 , the hub  24  has a wide mouth  58  sized to fit just inside the collar  54 . The hub  24  is preferably made of a translucent plastic, or more preferably a transparent plastic, such as transparent polycarbonate, polystyrene, or polypropylene, allowing visual inspection inside the hub  24 . The exterior of the hub  24  defines two flat, ribbed grip pads  60  that are 180 degrees apart, allowing the FNAB device  20  to be held with a pencil grip during the biopsy and when disengaging the hub  24  from the coupler  25 . A generally annular lip  62  provides a stop feature by abutting the end of the collar  54 . The mouth  58  of the hub  24  forms the opening to a collection well  64 , having a floor  66 , defined by the interior of the hub  24 . The hub  24  also defines a narrowed end  68  with an opening  70  from which an internal channel  72  leads to an interior side opening  74  that opens to the collection well  64 . The channel  72  follows a gentle C-shaped path from the narrow hub opening  70  and defines a sideways or laterally extending segment  76  adjacent the side opening  74 . The side opening  74  opens about, and the lateral segment  76  extends along, an axis essentially perpendicular to the long axis  32  of the device. The channel  72  thus defines a path for specimens to pass to the interior of the hub  24  and into the collection well  64 . Importantly, the specimens are deposited down into the collection well  64  from near the top of the well through the side opening  74 , which is spaced longitudinally from the floor  66  of the collection well  64 . The specimens are not injected into the syringe barrel or up in the direction of the valve. The collection well  64  defines an interior volume of at least 100 μL, and preferably 500 μL to 1 mL (or 1 cc) or more allowing a corresponding volume of specimens to be collected therein. The diameter of the hub mouth is preferably about 1 to 2 centimeters, more preferably of about 1.5 cm. The collection well also has an anti-coagulant coating, such as acid citrate dextrose (ACD) or ethylene diamine tetracetic acid (EDTA), which is designed to prevent the collected sample material from coagulating and attaching to the interior surface of the collection well  64 , which would reduce the quantity and compromise the quality of specimens that could be examined.  
         [0047]     The narrow hub opening  70  receives a straight proximal end  78  of the needle  22 . The proximal end  78  is barbed to resist separation of the needle  22  from the hub  24  during the biopsy procedure. The needle  22  is preferably a fine gauge, such as 18-25 gauge, surgical stainless steel of any suitable length, such as 1 to 8 centimeters. Longer lengths particularly can be adapted for use with radiological or other guidance systems. The needle  22  is hollow from the proximal end  78  to a pointed tip  80  defining an internal, preferably silicon coated, lumen. A flat is formed at the side of the needle  22  near the tip  80  to intersect the opening and form a concave scoop  82  generally oriented axially for increased specimen yield. The open tip  80  and the hollow needle  22  thus combines with the internal passageway  72  of the hub  24  to define a path for specimens to pass into the collection well  64 . Also, the exterior surface of the needle  22  is preferably coated with an anti-friction substance, such as Teflon®, to promote good sliding of the needle  22  within the specimen sample site and thereby inhibit the specimens from sticking to the exterior of the needle  22 . The needle  22  may also be specially coated with an acoustic media for ultrasound guided FNAB. Further, the shaft of the needle  22  may have graduated markings to show the depth of the needle in the sample tissue during the biopsy procedure.  
         [0048]     Referring now to  FIGS. 5 and 6 , the FNAB device  20  can also include a sheath stand  90  for covering the needle  22  and supporting the hub  24 , coupler  25  and syringe  28  in an upright position, as shown in  FIG. 6 . The sheath stand  90  has a retainer cup  92  that receives the hub  24 , with side openings  93  accommodating the grip pads  60 , and a hollow base  94  supporting the retainer cup  92 . An opening (not shown), generally concentric with the long axis  32 , at the bottom of the retainer cup  92  allows the needle  22  to pass into the interior of the base  94 . If desired, provisions can be made for the hub  24  to snap into the retainer cup  92  so that the sheath stand  90  stays attached to the hub  24  during transport or when not in the upright position.  
         [0049]     The sheath stand  90  thus allows the FNAB device  20  to be in an upright position before use and following a biopsy procedure. In particular, the sheath stand  90  can be used with the head (hub  24  and needle  22 ) removed from the coupler  25  and syringe  28 , as shown in  FIGS. 7 and 8 . For example, following a biopsy procedure, the head can be removed and a lid  100  can be screwed or snapped over the mouth  58  of the hub  24  to enclose the collection well  64 . Thus, the head and sheath stand  90  can be used to store the collected sample material in a safe and secure manner. In this way, the used needle  22  is concealed and guarded from accidental contact, and the collected specimens are kept contained in the collection well  64  of the hub  24  with the lid  100  preventing accidental spillage or loss of specimens.  
         [0050]     The above described device can thus be used advantageously in a needle aspiration biopsy procedure that improves the yield of specimens overall and the quantity of specimens collected on each pass of the needle  22  through the specimen sample site. The device can be used in human and veterinary medicine on living patients as well as in various research applications. Generally, the biopsy procedure achieves improved yield because of the unique features of the FNAB device  20 , primarily the way specimens are delivered into the collection well  64  and by achieving, sustaining and releasing a vacuum in the sample collection path while the needle  22  is inserted into the specimen sample site. More specifically, the method includes: creating a vacuum in the syringe; inserting the needle into the sample area; creating a vacuum in the needle; probing the specimen sample site with the needle; collecting specimens in the hub; releasing the vacuum in the needle; withdrawing the needle from the site; separating the hub from the device; and transferring specimens collected inside the hub to an examination site.  
         [0051]     Still more specifically, in one preferred method of the inventive biopsy procedure, the above described device is held by the user (physician, nurse, veterinarian, researcher, etc.) and the turn lever  52  is rotated until the valve  26  is closed. The syringe piston  36  is then pulled away from the barrel  30  to create a vacuum within the barrel  30  and the piston lock(s) are snapped onto the shaft of the piston  36 . After sufficiently cleaning, sterilizing and otherwise preparing the specimen sample site, the needle  22  is inserted into the site. Then, the turn lever  52  is rotated ¼ turn to open the valve  26 . This transfers the air in the needle  22  up into the syringe barrel  30  and effectively creates a vacuum in the needle  22 . The FNAB device  20  is then moved up and down (or back and forth) so that the needle  22  repeatedly probes and aspirates the specimen sample site without the tip of the needle coming out of the site and leaking the vacuum. Specimens pass into the tip and side scoop  82  openings of the needle  22  under vacuum as the device is moved, and specimens are drawn into the channel  72  of the hub  24  where they will pass through the side opening  74  and from there fall down into the collection well  64 . Specimens will continue to pile up in the collection well  64 , and when sufficient specimens for analysis have been collected (which can be checked visually through the transparent hub) and before the needle  22  is removed from the site, the turn lever  52  is again turned ¼ turn so that the valve  26  is once again closed. This will disrupt the vacuum in the needle  22 . The collection well  64  is large enough to accumulate a diagnostically sufficient quantity of specimens without reaching the height of the side opening  74 . The collected specimens are thus spaced from the path back to the needle  22 . This, and the fact that the specimens would have to travel sideways relative to the needle  22  (thus without the assistance of gravity) to pass through the lateral segment  76 , prevents loss of specimen into the syringe barrel and by reflux back into and through the needle.  
         [0052]     Following the procedure, the anti-reflux head can be separated from the rest of the FNAB device  20  by uncoupling the hub  24  from the collar  54  by holding grips  60 . The wide mouth  58  of the hub  24  allows access to the collected sample material with conventional gripping instruments, such as forceps or micropipette tips, which can be used to transfer a controlled amount of specimens into a test tube or vial or onto a microscope slide or other examination area. When the FNAB device  20  includes the sheath stand  90 , the head can be placed needle first into the sheath stand  90  so that the hub  24  rests securely in the retainer cup  92 . If some or all of the collected specimens are to be stored rather than processed immediately, the lid  100  can be secured onto the mouth  58  of the hub  24 .  
         [0053]      FIGS. 9-14  illustrate an alternate embodiment of the device in which the anti-reflux head has a different needle and hub configuration to accomplish the functional one-way valve arrangement through which the specimens are deposited into the collection well. In this embodiment like components will be referred to herein using like reference numerals albeit with the suffix “A” attached.  
         [0054]     Here, the FNAB device  20 A includes a needle  22 A mounted to a hub  24 A which is connected to a coupler  25 A attached to a valve  26 A and mounted at the end of a syringe  28 A. Although shown in the drawings of slightly different configuration, the syringe  28 A in this embodiment can be identical to that previously described, including a standard type barrel  30 A and sliding piston  36 A. The narrow end of the syringe  28 A receives a tubular extension  42 A of one part  27 A of the valve  26 A, which has another longitudinal extension  44 A and a lateral T-section  46 A housing a valve body section  48 A with an axial opening  50 A. As above, the valve body  48 A is rotated about its lateral axis by a turn lever  52 A to open and close the valve  26 A. Here, the extension  44 A is connected to coupler part  53 A that includes a wide collar  54 A having ridges about its periphery for gripping. In this embodiment, the collar  54 A has male threads  55  that engage the exterior of the hub  24 A, and two gaskets or seals  57  and  59  can be disposed between the hub  24 A and the collar  54 A to prevent leakage.  
         [0055]     Like before, the hub  24 A is large and has a wide mouth  58 A sized to fit just inside the collar  54 A and forming the opening to a collection well  64 A, having a floor  66 A. The hub  24 A also defines a narrowed end  68 A with an opening  70 A that opens at the bottom of the collection well  64 A. As mentioned, the principal distinguishing feature of this embodiment is the arrangement of the needle and hub defining the pathway for the specimens into the collection well  64 A. Rather than an internal passageway in the hub  24 A, the needle  22 A is formed with a unique hooked or C-shaped proximal end  78 A, some of which preferably follows the contour of the collection well  64 A to better stabilize the needle  22 A. The proximal end  78 A defines a lateral segment  76 A ending in a side opening  74 A. The proximal end  78 A is at the end of a straight shaft of the needle  22 A that fits through the narrow hub opening  70 A. As before, the needle  22 A is hollow from the proximal end  78 A to a pointed tip  80 A, however, here two side scoops  82 A are located a short distance up the shaft from the tip  80 A. As shown in  FIG. 12 , the scoops  82 A are preferably oblong, however, they may be of any other suitable configuration, such as circular, as shown in  FIG. 13 . Scoops  82 A of these configuration provide on the order of three times the cutting surface of the needle tip opening and thereby increase the yield of specimens significantly on each pass.  
         [0056]     Thus, in this embodiment the needle  22 A defines the entire passageway for the specimens to reach the collection well  64 A. This alternate configuration retains the same type of anti-reflux one way flow by depositing the specimens through the side opening  74 A, which is spaced from the well floor  66  near the mouth  58 A. And, as before the collection well  64 A has an anti-coagulant coating and the outside of the needle has an anti-friction coating. As shown in  FIG. 14 , this embodiment of the device can also include a sheath stand  90 A for covering the needle  22 A and supporting the FNAB device  20 A upright. Here, the sheath stand  90 A has a long, narrow retainer cup  92 A that receives the hub  24 A and the needle  22 A and is supported by a wide flat base  94 A.  
         [0057]      FIG. 15  shows the head of another alternate embodiment of the inventive FNAB device  20 B, which is similar to the last described embodiment, having a needle  22 B with a hooked proximal end  78 B and a separate hub  24 B defining a collection well  64 B with a floor  66 B spaced from a side opening  74 B of a lateral segment  76 B. In this embodiment, a separate collection vial  53 B can be assembled with the hub  24 B. The collection vial  53 B defines an interior volume  110  into which the specimens can be transferred and enclosed by a cap  112  with a seal  114 . The vial  53 B can be used in standard laboratory centrifuges.  
         [0058]      FIG. 16  shows the head of yet another alternate embodiment of the inventive FNAB device  20 C, which is similar to the first embodiment, in which a straight needle  22 C and is connected to a separate hub  24 C having a C-shaped channel  72 C with a lateral segment  76 C and side opening  74 C opening to a collection well  64 C with a floor  66 C spaced from the side opening  74 C. In this embodiment, the needle  22 C is a conventional, straight hypodermic needle with a standard female Luer connection end  116  which removably snaps onto the narrow neck of the hub  24 C configured in a standard male Luer connection. The Luer connection can be a locking or slip type connection, the locking type being preferred. This allows the FNAB device  20 C to accept standard needles with standard connections. Since no special needle is required, the device can be made and used even more cost effectively and operated even more intuitively. The anti-reflux and high yield characteristics of the FNAB device are retained by the configuration of the hub  24 C.  
         [0059]     The inventors of the present invention have conducted empirical studies establishing the efficacy of the device and method described herein. One comparative study was conducted using the second described embodiment of the FNAB device shown in  FIGS. 9 and 10 . The study included taking five trial biopsies using this FNAB device and five trial biopsies using a conventional syringe and hypodermic needle. Each set of five trial biopsies were performed four times so that there were 20 samples for the new FNAB device and the conventional device. All of the biopsies were taken from cattle liver and using the same number of probes to a generally uniform depth. The trials using the conventional device yielded between about 17 and 30 μL of tissue, while those using the FNAB of the present invention yielded between about 70 and 100 μL of tissue. Cell blocks were formed from the yield from each of the ten trial biopsies and cytology smears were conducted for each trial. The cytology smears were observed without any type of image enhancement, yet significantly improved cellularity and tissue density was apparent for each trial using the new FNAB device when compared to the trials from the conventional device. It was observed that the smears from specimens obtained with the new FNAB device had cells covering at least 20-50% and in some cases more than 50% of the smear field, compared to those from the conventional device which covered less than 20% of the field with cells and in some cases had only a few cells scattered across the field. The study thus supports the position that the new FNAB device provides consistently higher yields of sample tissue, on the order of 300 to 500 percent, and affords physicians a consistently improved cytology diagnosis procedure.  
         [0060]     Illustrative embodiments of the present invention have been described above in detail. However, the invention should not be limited to the described embodiments since many modifications and variations to the preferred embodiments, apparent to those skilled in the art, will be within the spirit and scope of the invention. Therefore, to ascertain the full scope of the invention, the following claims should be referenced.