Abstract:
A fluid aspiration device is provided having a syringe, a disposal reservoir and a disposal fluid passageway. The syringe has a variable-volume fluid chamber and an aspiration fluid passageway between the fluid chamber and a region of the body containing a fluid for aspiration. An aspiration valve is positioned in the aspiration fluid passageway. The disposal fluid passageway is between the fluid chamber and disposal reservoir and has a disposal valve positioned therein. The fluid is aspirated by expanding the variable volume of the fluid chamber to draw the fluid through the open aspiration valve into the fluid chamber. The aspiration valve is closed and the variable volume of the fluid chamber is contracted to open the disposal valve and displace the fluid into the disposal reservoir. When aspiration is terminated, the fluid aspiration device is maintained intact and the intact device including the fluid is disposed.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates generally to fluid aspiration, and more particularly to a device for aspiration of fluid from the body, sanitary disposal of the fluid, and optional collection of a fluid sample.  
       BACKGROUND OF THE INVENTION  
       [0002]     Localized accumulation of excess bodily fluid in an internal region of the body frequently occurs as a result of injury, infection, surgical trauma, or some other type of damage or disorder in that internal region of the body. It is generally desirable from a medical treatment standpoint to remove such excess accumulated bodily fluid from the body to reduce swelling and pain and to promote healing. Aspiration is a procedure for removing excess accumulated bodily fluid, which employs suction to draw the bodily fluid from the body. Aspiration procedures are commonly performed on joints. Aspiration of a joint is more specifically termed arthrocentesis. A syringe is the instrument of choice for performing arthrocentesis due to its simplicity and effectiveness.  
         [0003]     In practice, the health care provider first preps the patient then inserts the needle of the syringe into the afflicted joint. The plunger of the syringe is manually pulled backward, displacing the plunger within the barrel of the syringe to create a suction. The suction draws the accumulated bodily fluid from the joint into the barrel of the syringe. When the barrel is filled, the health care provider withdraws the needle from the patient and disposes the aspirated bodily fluid in a sanitary manner, for example, by emptying the aspirated bodily fluid from the syringe into a disposal reservoir. It is oftentimes also desirable to retain samples of the aspirated bodily fluid for future diagnostic purposes.  
         [0004]     With the existence and increased awareness of many blood-borne pathogens, the handling, sampling and disposal of medical waste, such as aspirated bodily fluids, has become more strictly regulated and correspondingly more costly and more problematic. U.S. Pat. No. 5,038,938 teaches a reservoir for disposing bodily fluids resulting from an arthrocentesis procedure in a relatively safe and regulatory compliant manner.  
         [0005]     The present invention recognizes a continuing need for arthrocentesis devices, and more generally fluid aspiration devices, which enable effective performance of aspiration procedures and which further provide a safe and effective means for handling, sampling, and disposing the resulting aspirated bodily fluids. Accordingly, it is an object of the present invention to provide a fluid aspiration device, which enables effective performance of an aspiration procedure. More particularly, it is an object of the present invention to provide a fluid aspiration device, which is a safe and effective means for handling the resulting aspirated bodily fluid. It is another object of the present invention to provide a fluid aspiration device, which is a safe and effective means for disposing of the resulting aspirated bodily fluid. It is still another object of the present invention to provide a fluid aspiration device, which is a safe and effective means for sampling the resulting aspirated bodily fluid.  
         [0006]     These objects and others are accomplished in accordance with the invention described hereafter.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is a fluid aspiration device. The fluid aspiration device includes a syringe which has an aspiration intake and a fluid chamber. An aspiration valve is positioned in an aspiration fluid passageway between the aspiration intake and the fluid chamber. The fluid aspiration device also preferably includes fluid-tight connections between the aspiration intake and the aspiration valve and between the aspiration valve and the fluid chamber.  
         [0008]     The aspiration valve has an open aspiration position and a closed disposal position. The aspiration valve is preferably biased in the closed disposal position and transitions from the closed disposal position to the open aspiration position in response to fluid pressure directed from the aspiration intake to the fluid chamber.  
         [0009]     The fluid aspiration device further includes a disposal reservoir, a disposal fluid passageway between the fluid chamber and the disposal reservoir, and a disposal valve positioned in the disposal fluid passageway. The fluid aspiration device also preferably includes a junction fitting, a reservoir connector, and fluid-tight connections between the disposal valve and the disposal reservoir. The disposal fluid passageway preferably comprises a disposal line, the junction fitting and the reservoir connector in series.  
         [0010]     The disposal valve has an open disposal position and a closed aspiration position. The disposal valve is preferably biased in the closed aspiration position and transitions from the closed aspiration position to the open disposal position in response to fluid pressure directed from the fluid chamber to the disposal reservoir. The disposal and aspiration valves are preferably mounted in a valve assembly, which is included in the syringe, in series between the aspiration intake and the fluid chamber.  
         [0011]     In accordance with a specific embodiment of the present fluid aspiration device, a sampling outlet, a sampling fluid passageway, and a sampling valve are additionally included. The sampling fluid passageway is between the disposal reservoir and the sampling outlet. The sampling fluid passageway preferably comprises a sampling line, the junction fitting and the reservoir connector in series. The fluid aspiration device also preferably includes fluid-tight connections between the disposal reservoir and the sampling outlet. The syringe, disposal reservoir, disposal fluid passageway, sampling outlet, and sampling fluid passageway are preferably in fluid isolation from the external environment of the fluid aspiration device.  
         [0012]     The sampling valve is positioned in the sampling fluid passageway and has an open sampling position and a closed non-sampling position. The sampling valve prevents fluid communication between the disposal reservoir and the sampling outlet in the closed non-sampling position and enables fluid communication between the disposal reservoir and the sampling outlet in the open sampling position.  
         [0013]     The present invention is also a method for aspirating a fluid from a region of a body of a patient. The method provides a fluid aspiration device. The fluid aspiration device includes a syringe, an aspiration valve, a disposal reservoir, a disposal fluid passageway, and a disposal valve. The syringe has an aspiration intake, a fluid chamber with a variable volume, and an aspiration fluid passageway between the fluid chamber and the region of the body containing the fluid. The aspiration valve is positioned in the aspiration fluid passageway. The aspiration valve has an open aspiration position and a closed disposal position and the aspiration valve is fluid pressure actuated. The disposal fluid passageway is between the fluid chamber and the disposal reservoir. The disposal valve is positioned in the disposal fluid passageway. The disposal valve has an open disposal position and a closed aspiration position and the disposal valve is fluid pressure actuated. The fluid aspiration device is preferably maintained in fluid isolation from an external environment of the fluid aspiration device during practice of the present aspiration method.  
         [0014]     The method proceeds by inserting the aspiration intake into the region of the body. The variable volume of the fluid chamber is expanded to create a suction in the fluid chamber and the fluid is drawn in an aspiration direction from the region of the body through the aspiration passageway in response to the suction. The aspiration valve is transitioned to the open aspiration position in response to fluid pressure in the aspiration direction and the fluid is further drawn through the aspiration valve in the open aspiration position into the fluid chamber in response to the suction.  
         [0015]     The aspiration valve is then transitioned to the closed disposal position and the variable volume of the fluid chamber is contracted to displace the fluid from the fluid chamber into the disposal passageway in a disposal direction. The disposal valve is transitioned to the open disposal position in response to fluid pressure in the disposal direction and the fluid is displaced through the disposal valve in the open disposal position into the disposal reservoir in response to the contraction. The disposal valve is preferably transitioned thereafter to the closed aspiration position.  
         [0016]     The sum of the above-recited method steps following insertion of the aspiration intake comprise an operating cycle of the fluid aspiration device. The present aspiration method may additionally include repeating the operating cycle one or more times. The method may also further include removing the aspiration intake from the region of the body after completing displacement of the fluid into the disposal reservoir in one of the operating cycles. The fluid aspiration device is maintained intact thereafter with the fluid retained therein and the intact fluid aspiration device including the fluid is disposed.  
         [0017]     In accordance with a specific embodiment of the present aspiration method, the provided a fluid aspiration device further includes a sampling outlet, a sampling fluid passageway, and a sampling valve. The sampling fluid passageway is between the disposal reservoir and the sampling outlet. The sampling valve is positioned in the sampling fluid passageway. The sampling valve has an open sampling position and a closed non-sampling position. The sampling valve prevents fluid communication between the disposal reservoir and the sampling outlet in the closed non-sampling position and enables fluid communication between the disposal reservoir and the sampling outlet in the open sampling position.  
         [0018]     The method further comprises placing a sampling container in fluid communication with the sampling outlet. The sampling valve is transitioned from the closed non-sampling position to the open sampling position and the fluid is conveyed from the disposal reservoir to the sampling container.  
         [0019]     The present invention will be further understood from the drawings and the following detailed description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective view of a fluid aspiration device of the present invention.  
         [0021]      FIG. 2  is a cross sectional view of a syringe of the fluid aspiration device of  FIG. 1  in a fluid withdrawal mode of operation.  
         [0022]      FIG. 3  is a cross sectional view of the syringe of the fluid aspiration device of  FIG. 1  in a fluid disposal mode of operation. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0023]     Referring to  FIG. 1 , an embodiment of a fluid aspiration device of the present invention is shown and generally designated  10 . The fluid aspiration device  10  comprises a syringe  12 , a disposal reservoir  14  and a disposal line  16  providing selective fluid communication between the syringe  12  and the disposal reservoir  14  in a manner described hereafter. The syringe  12  includes an aspiration intake  18 , a valve assembly  20 , a barrel  22  and a plunger  24 , wherein the valve assembly  20  is positioned in series between the aspiration intake  18  and the barrel  22 .  
         [0024]     The aspiration intake  18  is preferably a conventional hollow syringe needle fabricated from a rigid metal and having an open front end  26 , an open back end  28 , and a continuous fluid passageway (not shown) extending therethrough. The front end  26  is a sharpened tip and the back end  28  is fixably attached in a fluid-tight manner to an aspiration intake coupler  30   a , such as a releasable plastic male Luer lock fitting shown herein. The aspiration intake coupler  30   a  has a continuous fluid passageway extending therethrough, which is in fluid communication with the continuous fluid passageway of the aspiration intake  18  via the open back end  28  of the aspiration intake  18 .  
         [0025]     The valve assembly  20  has in series a front end  32 , a mid-section  34 , and a back end  36 . An aspiration intake coupler  30   b , such as a releasable plastic female Luer lock fitting shown herein, is also provided on the front end  32  of the valve assembly  20 . The aspiration intake coupler  30   b  has a continuous fluid passageway extending therethrough into the valve assembly  20 . The back end  28  of the aspiration intake  18  is releasably mounted to the front end  26  of the valve assembly  20  in a fluid-tight manner by means of the aspiration intake couplers  30   a ,  30   b . The continuous fluid passageways of the aspiration intake couplers  30   a ,  30   b  are in fluid communication with one another as well as with the aspiration intake  18  and the valve assembly  20 . Although not shown, it is within the scope of the present invention and the purview of the skilled artisan to substitute alternate conventional releasably connecting or fixably connecting aspiration intake couplers for the male and female Luer lock fittings  30   a ,  30   b  shown herein.  
         [0026]     The barrel  22  has in series a front end  38  with a narrow opening  39  formed therein, a widened open interior  40 , and an open back end  42 . The back end  42  also has a barrel finger grip  44  integral therewith. A barrel coupler  46   a , such as a releasable plastic female Luer lock fitting shown herein, is provided on the front end  38  of the barrel  22  which is in fluid communication with the interior  40  of the barrel  22  via the narrow opening  39  in the front end  38  of the barrel  22 . The barrel coupler  46   a  has a continuous fluid passageway extending therethrough. A barrel coupler  46   b , such as a releasable plastic male Luer lock fitting shown herein, is also provided on the back end  36  of the valve assembly  20 . The barrel coupler  46   b  has a continuous fluid passageway extending therethrough into the valve assembly  20 . The back end  36  of the valve assembly  20  is releasably mounted to the front end  38  of the barrel  22  in a fluid-tight manner by means of the barrel couplers  46   a ,  46   b , wherein the continuous fluid passageways of the barrel couplers  46   a ,  46   b  are in fluid communication with one another as well as with the opening  39  and the valve assembly  20 . Although not shown, it is within the scope of the present invention and the purview of the skilled artisan to substitute alternate conventional releasably connecting or fixably connecting barrel couplers for the male and female Luer lock fittings  46   a ,  46   b  shown herein.  
         [0027]     The plunger  24  has in series an internal front end  48 , a mid-section  50 , and an external back end  52 . The internal front end  48  has a plunger seal  54  mounted thereon and the external back end  52  has a plunger finger grip  56  integral with the plunger  24 . A portion of the plunger  24 , including the plunger seal  54 , the internal front end  48  and a portion of the mid-section  50 , is positioned at all times within the interior  40  of the barrel  22 . The plunger  24  is slidably displaceable within the interior  40 , but is not fully removable therefrom. Backward displacement of the plunger  24  within the interior  40  of the barrel  22  is limited by means of corresponding plunger stops  58   a ,  58   b  to prevent the plunger  24  from exiting the interior  40  of the barrel  22  via the open back end  42 . The plunger stop  58   a  is mounted in the interior  40  of the barrel  22  proximal to the open back end  42  and engages the plunger stop  58   b  mounted on the internal front end  48  of the plunger  24  when the plunger  24  is withdrawn to its maximum extent from the interior  40  of the barrel  22  (i.e., maximum plunger withdrawal position) in a manner described hereafter. Forward displacement of the plunger  24  is limited by engagement of the plunger seal  54  with a front wall  60  of the barrel  22  when the plunger  24  is depressed to its maximum extent into the interior  40  of the barrel  22  (i.e., maximum plunger depression position) in a manner described hereafter.  
         [0028]     Slidable displacement of the plunger  24  between the maximum plunger withdrawal and depression positions defines a variable-volume fluid chamber  62  within the interior  40  of the barrel  22 . The variable-volume fluid chamber  62  is bounded by the plunger seal  54  at the internal front end  48  of the plunger  24 , the front wall  60  of the barrel  22 , and side walls  64  of the barrel  22 . The actual volume of the variable-volume fluid chamber  62  ranges from essentially zero when the plunger  24  is at its maximum depression position (i.e., minimum depression volume) to approximately 20 cc, for example, when the plunger  24  is at its maximum withdrawal position (i.e., maximum withdrawal volume). A plurality of graduations (not shown) are preferably distributed along the length of the side walls  64  of the barrel  22  to enable the user to determine the volume of the variable-volume fluid chamber  62  at any position of the plunger  24 . The user correlates the position of the plunger seal  54  with the specific adjacent graduation at a given time to fix the volume of the variable-volume fluid chamber  62  at that time.  
         [0029]     The barrel  22  and plunger  24  are preferably fabricated from a disposable material, such as a relatively rigid or semi-rigid plastic. The barrel  22  is also preferably transparent or translucent. The plunger seal  54  is preferably fabricated from a relatively more pliant elastomeric material. The plunger seal  54  functions as a barrier to fluid flow from the variable-volume fluid chamber  62  past the plunger seal  54  into the interior  40  of the barrel  22  on the opposite side of the plunger seal  54  from the variable-volume fluid chamber  62 .  
         [0030]     The valve assembly  20  is a housing for an aspiration valve  66  and a disposal valve  68 . The valve assembly  20  is preferably fabricated from a disposable material, such as a rigid plastic, and has an integral construction or is assembled from a plurality of separate components. The aspiration valve  66  is positioned in an aspiration valve chamber  70  having an aspiration inlet opening  72  and an aspiration outlet opening  74 . The disposal valve  68  is correspondingly positioned in a disposal valve chamber  76  having a disposal outlet opening  78 . The aspiration and disposal valve chambers  70 ,  76  share a common disposal opening  80  which is positioned between the aspiration valve chamber  70  and the disposal valve chamber  76  and provides fluid communication therebetween.  
         [0031]     The aspiration inlet opening  72  is positioned adjacent to the aspiration intake coupler  30   b  and provides fluid communication between the continuous fluid passageway of the aspiration intake  18  and the aspiration valve chamber  70  via the back end  28  of the aspiration intake  18  and the continuous fluid passageways of the aspiration intake couplers  30   a ,  30   b . The aspiration outlet opening  74  is positioned adjacent to the barrel coupler  46   b  and provides fluid communication between the aspiration valve chamber  70  and the variable-volume fluid chamber  62  via the narrow opening  39  at the front end  38  of the barrel  22  and the continuous fluid passageways of the barrel couplers  46   a ,  46   b.    
         [0032]     The valve assembly  20  is further provided with a disposal line coupler  82 , which is shown herein as an integral nipple positioned on the mid-section  34  of the valve assembly  20 . The disposal line coupler  82  is cross-sectionally sized in correspondence with the disposal line  16  for close-fitting fluid-tight insertion and retention in an open first end  84  of the disposal line  16 . The disposal line coupler  82  has a continuous fluid passageway extending therethrough in fluid communication with the disposal outlet opening  78 , which is positioned adjacent to the disposal line coupler  82 . Accordingly, the disposal outlet opening  78  provides fluid communication between the disposal valve chamber  76  and the disposal reservoir  14  via the disposal line coupler  82  and the disposal line  16 .  
         [0033]     The aspiration valve  66  is a pressure-actuated one-way valve having a duckbill configuration. The aspiration valve  66  is biased in a closed disposal position with the paired duckbill flaps engaging one another as shown in  FIG. 1  when no fluid pressure is applied to the aspiration valve  66 . The aspiration valve  66  is transitioned to an open aspiration position with the paired duckbill flaps spread apart from one another as shown and described hereafter by applying a sufficient fluid pressure to the aspiration valve  66  in an aspiration direction (i.e., in a direction from the aspiration inlet opening  72  toward the aspiration and disposal valves  66 ,  68 ) to overcome the biasing force of the aspiration valve  66 . The aspiration valve  66  returns to the closed disposal position when the fluid pressure to the aspiration valve  66  is either removed, decreased to a level below the biasing force of the aspiration valve  66 , or applied in a disposal direction counter to the aspiration direction (i.e., in a direction from the aspiration outlet opening  74  toward the aspiration and disposal valves  66 ,  68 ).  
         [0034]     The disposal valve  68  is similarly a pressure-actuated one-way valve having a duckbill configuration. The disposal valve  68  is biased in a closed aspiration position with the paired duckbill flaps engaging one another as shown in  FIG. 1  when no fluid pressure is applied to the disposal valve  68 . The disposal valve  68  is transitioned to an open disposal position with the paired duckbill flaps spread apart from one another as shown and described hereafter by applying a sufficient fluid pressure to the disposal valve  68  in the disposal direction to overcome the biasing force of the disposal valve  68 . The disposal valve  68  returns to the closed aspiration position when the fluid pressure to the disposal valve  68  is either removed, decreased to a level below the biasing force of the disposal valve  68 , or applied in the aspiration direction.  
         [0035]     Although not shown, it is within the scope of the present invention and the purview of the skilled artisan to substitute alternate conventional valves for either or both of the one-way duckbill aspiration and disposal valves  66 ,  68  shown herein. The primary requirement of the alternate aspiration valve is that it permits flow in the aspiration direction, while preventing or substantially limiting flow in the disposal direction. Conversely, the primary requirement of the alternate disposal valve is that it permits flow in the disposal direction, while preventing or substantially limiting flow in the aspiration direction.  
         [0036]     It is further within the scope of the present invention and the purview of the skilled artisan to modify the valve assembly  20  shown herein. For example, the aspiration and disposal valves  66 ,  68  may be repositioned in a single valve chamber of a modified valve assembly rather than in separate valve chambers  70 ,  76  of the valve assembly  20 . Any number of other readily apparent structural modifications of the valve assembly  20 , which do not obviate the desired function of the valve assembly  20  described below, are likewise within the scope of the present invention.  
         [0037]     As recited above, the open first end  84  of the disposal line  16  receives the disposal line coupler  82  in fluid-tight engagement therewith. The disposal line  16  extends from the open first end  84  to an open second end  86  of the disposal line  16 . An exemplary length of the disposal line  16  may be on the order of about 6 to 18 inches or more. The disposal line  16  is preferably fabricated from a clear flexible compressible plastic tubing having an inside diameter on the order of about ______. A continuous lumen (not shown) extends through the disposal line  16  from the first end  84  to the second end  86  of the disposal line  16 , thereby providing a continuous fluid passageway between the first and second ends  84 ,  86 .  
         [0038]     A junction fitting  88  is provided downstream of the disposal line  16 . The junction fitting  88  has an open disposal inlet port  90  and an open disposal outlet port  91 , which are in fluid communication with one another via a common within the junction fitting  88 . The second end  86  of the disposal line  16  is received into the disposal inlet port  90  and is attached in a fluid-tight manner thereto, providing a continuous fluid passageway between the disposal line  16  and the junction fitting  88 . A relatively short reservoir connector  92  is received into the disposal outlet port  91  and is attached in a fluid-tight manner thereto. The reservoir connector  92  has a continuous fluid passageway extending therethrough, which is in fluid communication with the disposal outlet port  91 . The reservoir connector  92  is preferably fabricated from the same or similar material as the material of the disposal line  16  and is cross-sectionally sized in correspondence with the disposal line  16  and the disposal outlet port  91 .  
         [0039]     The disposal reservoir  14  is a closed fluid-tight container having a volumetric capacity greater than the maximum withdrawal volume of the variable-volume fluid chamber  62  and preferably many times greater than the maximum withdrawal volume. An exemplary volumetric capacity of the disposal reservoir  14  is on the order of about 300 cc. The disposal reservoir  14  is preferably a flexible, fluid-tight, transparent or translucent, plastic bladder  93  and a peripheral tab  94  integral with the bladder  94 , but in fluid isolation therefrom. The tab  94  has a plurality of cutouts  95  formed therein, which enable the practitioner to hang the disposal reservoir  14  from a hook or stand in the manner of an IV bag. A plurality of graduations (not shown) are preferably distributed along the height of the bladder  93  to enable the user to determine the volume of fluid in the disposal reservoir  14  at a given time. The disposal reservoir  14  is provided with a single open reservoir port  96 , which is cross-sectionally sized in correspondence with the reservoir connector  92 . The reservoir port  96  and the reservoir connector  92  are connected in a fluid-tight manner to provide a continuous fluid passageway between the reservoir connector  92  and the disposal reservoir  14 .  
         [0040]     The fluid aspiration device  10  may optionally include a sampling assembly generally designated  97  and described hereafter. In accordance with this embodiment as shown herein, the junction fitting  88  is configured as a “Y” fitting, which includes an open sampling port  98  in addition to the disposal inlet and outlet ports  90 ,  91 . The sampling port  98  is in fluid communication with the disposal inlet and outlet ports  90 ,  91  via the junction fitting common. An open first end  102  of a relatively short sampling line  100  is received into the sampling port  98  and is attached in a fluid-tight manner thereto, providing a continuous fluid passageway between the sampling line  100  and the reservoir connector  92  via the disposal outlet port  91 , junction fitting common, and sampling port  98 . The sampling line  100  is preferably fabricated from the same tubing as the disposal line  16 . As such, the sampling line  100  has a lumen which provides a continuous fluid passageway extending therethrough to an open second end  104  of the sampling line  100 .  
         [0041]     A sampling outlet coupler  105   a , such as a releasable plastic female Luer lock fitting shown herein, is fixably attached in a fluid-tight manner to the open second end  104  of the sampling line  100 . The sampling outlet coupler  105   a  has a continuous fluid passageway extending therethrough. A sampling outlet coupler plug  106 , such as a releasable plastic male Luer lock plug shown herein, is provided, which is selectively releasably engagable with the sampling outlet coupler  105   a . When the sampling outlet coupler plug  106  is placed in engagement with the sampling outlet coupler  105   a , the sampling outlet coupler plug  106  prevents fluid flow out the sampling outlet coupler  105   a  via the open second end  104  of the sampling line  100 .  
         [0042]     The sampling assembly  97  further includes a sample transfer unit  107  comprising a sampling outlet  108  and a sampling guide  110 . The sampling outlet  108  is a conventional hollow needle fabricated from a rigid metal and having an open front end  112 , an open back end  114 , and a continuous fluid passageway extending therethrough. The sampling guide  110  has in series a front end  116  with a narrow guide port  118  extending therefrom, a widened open interior  120 , and an open back end  122 . The back end  122  also has a retainer finger grip  124  integral with the sampling guide  110 . The sampling guide  110  is preferably fabricated from the same or similar material as the barrel  22  and plunger  24 .  
         [0043]     The sampling outlet  108  is concentrically, fixably mounted in the guide port  118  of the sampling guide  110  in a fluid-tight manner such that no fluid flow is permitted between the inside wall of the guide port  118  and the outside wall of the sampling outlet  108 . The open back end  114  of the sampling outlet  108  extends concentrically into the interior  120  of the sampling guide  110  and the open front end  112  of the sampling outlet  108  extends out of the sampling guide  110  in the opposite direction. An elastomeric self-resealing sampling outlet seal (not shown) in the form of a sheath is preferably positioned over the back end  114  of the sampling outlet  108  in the interior  120  of the sampling guide  110 .  
         [0044]     A sampling outlet coupler  105   b , such as a releasable plastic male Luer lock fitting shown herein, is fixably attached to the end of the guide port  118  opposite the sampling guide  110 . The sampling outlet coupler  105   b  has a continuous fluid passageway extending therethrough, in which the open front end  112  of the sampling outlet  108  is concentrically positioned. Accordingly, the back end  114  of the sampling outlet  108  is in fluid communication with the continuous fluid passageway of the sampling outlet coupler  105   b  via the open front end  112  and continuous passageway of the sampling outlet  108 .  
         [0045]     The sample transfer unit  107  is selectively releasably mountable to the sampling line  100  in a fluid-tight manner by means of the sampling outlet couplers  105   a ,  105   b . When the sample transfer unit  107  is mounted to the sampling line  100 , the continuous fluid passageways of the sampling outlet couplers  105   a ,  105   b  are in fluid communication with one another as well as with the sampling line  100  and the sampling outlet  108 . Although not shown, it is within the scope of the present invention and the purview of the skilled artisan to substitute alternate conventional releasably connecting or fixably connecting sampling outlet couplers for the male and female Luer lock fittings  105   a ,  105   b  shown herein.  
         [0046]     The back end  122  and interior  120  of the sampling guide  110  are preferably cross-sectionally sized to receive a sampling container  126 . The sampling container  126  is preferably an evacuated glass test tube  128  sealed at its open end  130  with an elastomeric puncturable and self-resealing stopper  132 . During a fluid sampling sequence, the sealed open end  130  of the sampling container  126  is inserted into the back end  122  of the sampling guide  110  until the stopper  132  engages a front wall  134  of the sampling guide  110 . With the sampling container  126  so positioned, the sampling outlet seal is displaced to expose the open back end  114  of the sampling outlet  108 , which punctures the stopper  132  and extends into the test tube  128  in a manner described hereafter.  
         [0047]     A manual sampling valve  138  is provided in the sampling line  100 . The sampling valve  138  is a rigid or semi-rigid plastic rectangular plate having an asymmetrical slot  140  cut therethrough. The slot  140  has a narrow segment  142  and a wide segment  144  at opposite ends of the slot  140 . The sampling valve  138  is enabled by threading the sampling line  100  through the slot  140 . In particular, when the sampling line  100  is manually slid into the narrow segment  142  of the slot  140 , the sampling valve  138  is in a closed non-sampling position. As such, the width of the narrow segment  142  is sufficiently narrow that the side edges of the narrow segment  140  pinch the sampling line  100  closed, thereby preventing fluid flow through the sampling line  100  past the sampling valve  138  in either direction. Conversely, when the sampling line  100  is manually slid into the wide segment  144  of the slot  140 , the sampling valve  138  is transitioned to an open sampling position. As such, the width of the wide segment  144  is sufficiently wide that the side edges of the wide segment  144  do not significantly crimp the sampling line  100 , thereby permitting fluid flow through the sampling line  100  past the sampling valve  138  in either direction.  
         [0048]     Although not shown, it is within the scope of the present invention and the purview of the skilled artisan to substitute alternate conventional valves for the manual sampling valve  138  shown herein. The primary requirement of the alternate valve is that it permits flow in a direction from the disposal reservoir  14  to the sampling outlet  108  when in the open sampling position and prevents flow in the direction from the disposal reservoir  14  to the sampling outlet  108  when in the closed non-sampling position.  
         [0049]     It is understood that the sampling assembly  97 , which includes components  98 - 144  of the fluid aspiration device  10  recited above, is optional insofar as it is within the scope of the present invention to omit the sampling assembly in its entirety from the fluid aspiration device of the present invention. The resulting fluid aspiration device having the sampling components omitted retains a fluid aspiration function, but lacks a fluid sampling function as described hereafter.  
       Method of Operation  
       [0050]     A method of operating the fluid aspiration device  10  is described hereafter with continuing reference to  FIG. 1  and additional reference to  FIGS. 2 and 3 , wherein components in  FIGS. 2 and 3 , which are common to  FIG. 1 , are designated by the same reference character. The present operating method is generally characterized as a method for removing undesirable bodily fluid from an internal region of the body and subsequently disposing and/or sampling the removed fluid using the fluid aspiration device  10  described above. The operating method is specifically applicable to the removal of a fluid mixture of blood and joint fluid (specifically termed synovial fluid) from a joint, such as the knee, where the fluid mixture has undesirably accumulated by reason of injury, infection, surgical trauma, or some other type of joint damage or disorder. The fluid aspiration device  10  is used in accordance with this specific operating embodiment as an arthrocentesis device.  
         [0051]     A number of preparatory steps are preferably performed before initiating the present operating method. In particular, the patient is preferably prepped by cleaning and sterilizing the skin external to a selected internal region of the body (not shown) from which the bodily fluid is to be removed. Patient prepping may also include injection of a local anesthesia into the selected internal region of the body. Preparatory steps further include ensuring that all fluid-tight connections for the components of the fluid aspiration device  10  are properly secured, that the plunger  24  is at the maximum plunger depression position in the barrel  22  of the syringe  12 , that the sampling valve  138  is in the closed non-sampling position, and that the sampling outlet coupler plug  106  is placed in engagement with the sampling outlet coupler  105   a . The practitioner then inserts the sharpened front end  26  of the aspiration intake  18  through the skin into the selected internal region of the body and ensures that the aspiration intake  18  is securely in place.  
         [0052]     Referring initially to  FIGS. 1 and 2 , the present operating method commences with an aspiration sequence, wherein the practitioner grasps the barrel finger grip  44  and plunger finger grip  56  in each hand and manually pulls backward in the aspiration direction on the plunger finger grip  56  integral with the external back end  52  of the plunger  24  as shown by the directional arrow  146  in  FIG. 2 . Pulling backward in the aspiration direction on the plunger finger grip  56  correspondingly slidably displaces the plunger seal  54  backward in the aspiration direction through the interior  40  of the barrel  22  and expands the variable-volume fluid chamber  62 . Expansion of the variable-volume fluid chamber  62  creates a vacuum therein. The resulting suction force maintains the disposal valve  68  in the closed aspiration position. The suction force also draws the bodily fluid from the selected internal region of the body through an aspiration fluid passageway including the aspiration intake  18 , aspiration intake couplers  30   a ,  30   b , and aspiration inlet opening  72  into contact with the aspiration valve  66  within the aspiration valve chamber  70 . The aspiration valve  66 , which is initially biased in the closed disposal position, responds to the fluid pressure of the bodily fluid in the aspiration direction by transitioning to the open aspiration position. The open aspiration valve  66  enables the bodily fluid to continue through the aspiration fluid passageway further including the aspiration valve chamber  70 , aspiration outlet opening  74 , barrel couplers  46   a ,  46   b , and narrow front end opening  49  of the barrel  22  into the variable-volume fluid chamber  62  as shown by the flow arrows  148 .  
         [0053]     The practitioner continues backward manual displacement of the plunger  24  in the aspiration direction through the interior  40  of the barrel  22  until the plunger stops  58   a ,  58   b  engage one another at the maximum plunger withdrawal position. The variable-volume fluid chamber  62  correspondingly reaches its maximum withdrawal volume and is filled to capacity with the bodily fluid removed from the selected internal region of the body. At this point the aspiration sequence of the present operating method is completed.  
         [0054]     Referring to  FIGS. 1 and 3 , the operating method continues with the disposal sequence, wherein the practitioner grasps the barrel finger grip  44  and plunger finger grip  56  in each hand and manually pushes the plunger finger grip  56  forward in the disposal direction as shown by the directional arrow  150  in  FIG. 3 . Pushing the plunger finger grip  56  forward in the disposal direction correspondingly slidably displaces the plunger seal  54  forward in the disposal direction through the interior  40  of the barrel  22  and contracts the variable-volume fluid chamber  62 . Contraction of the variable-volume fluid chamber  62  displaces a portion of bodily fluid residing therein, termed the aspirate, forward in the disposal direction from the variable-volume fluid chamber  62  through a disposal fluid passageway including the narrow front end opening  49 , barrel couplers  46   a ,  46   b , aspiration outlet opening  74 , and aspiration valve chamber  70  into contact with the aspiration valve  66  within the aspiration valve chamber  70 . The aspiration valve  66 , which is biased back to the closed disposal position after completion of the aspiration sequence, remains in the closed disposal position during the disposal sequence in response to the fluid pressure of the bodily fluid being displaced in the disposal direction. The closed aspiration valve  66  diverts the bodily fluid through the common disposal opening  80  into the disposal valve chamber  76  where the bodily fluid contacts the disposal valve  68 . The closed aspiration valve  66  also prevents backflow of the bodily fluid through the aspiration intake  18  into the selected internal region of the body during the disposal sequence and from the aspiration intake  18  even after termination of operation described below.  
         [0055]     The disposal valve  68  is initially in the closed aspiration position, but responds to the fluid pressure of the bodily fluid in the disposal direction by transitioning to the open disposal position. The open disposal valve  68  enables the bodily fluid to continue through the disposal fluid passageway further including the disposal valve chamber  76 , disposal outlet opening  78 , disposal line coupler  82 , first end  84  of the disposal line  16 , and lumen of the disposal line  16  as shown by the flow arrows  152 . Although not shown in  FIG. 3 , displacement of the bodily fluid continues from the lumen of the disposal line  16  through the disposal fluid passageway further including the second end  86  of the disposal line  16 , disposal inlet port  90 , junction fitting common, disposal outlet port  91 , reservoir connector  92  and reservoir port  96  into the disposal reservoir  14 .  
         [0056]     The practitioner continues forward manual displacement of the plunger  24  in the disposal direction through the interior  40  of the barrel  22  until the plunger seal  54  engages the front wall  60  of the barrel  22  at the maximum plunger depression position. The variable-volume fluid chamber  62  correspondingly reaches its minimum depression volume and is essentially free of any bodily fluid. At this point the disposal sequence of the present operating method is completed. A first operating cycle of the present operating method is likewise completed, which consists of the first aspiration sequence followed in series by the first disposal sequence. One or more additional operating cycles may be performed repetitively thereafter. It is noted that the disposal valve  68  is in the closed aspiration position during succeeding aspiration sequences in response to the suction force in the variable-volume fluid chamber  62  and the fluid pressure in the aspiration direction caused by the bodily fluid residing in the disposal reservoir and line  14 ,  16 . The closed disposal valve  68  retains the bodily fluid in the disposal reservoir and line  14 ,  16  and prevents backflow of the bodily fluid into the syringe  12  during the aspiration sequences and even after termination of operation described below.  
         [0057]     Operation of the fluid aspiration device  10  preferably continues until the disposal reservoir  14  is filled to capacity, all of the bodily fluid has been removed from the selected internal region of the body, or the practitioner no longer desires to remove additional bodily fluid from the selected internal region of the body. At this point operation of the fluid aspiration device  10  is terminated and the aspiration intake  18  is withdrawn from the selected internal region of the body out through the skin. It is apparent that the one-way valves  66 ,  68  and fluid-tight connections of the fluid aspiration device  10  prevent any undesirable leakage of bodily fluid from the device  10  during and after termination of operation. Accordingly, the intact fluid aspiration device  10  is in a condition for proper sanitary disposal in its entirety without any further handling of the device  10  upon termination of operation and withdrawal of the aspiration intake  18  from the patient. Sanitary disposal of the intact fluid aspiration device  10  correspondingly effectuates sanitary disposal of the bodily fluid residing therein.  
         [0058]     A sampling sequence may optionally be performed at any time that sufficient bodily fluid resides in the fluid aspiration device  10  to reach the sampling container  126  positioned in the sampling guide  110 . The sampling sequence is preferably performed when the disposal reservoir  14  is relatively full after termination of operation, but before disposal of the fluid aspiration device  10 , or during operation of the fluid aspiration device  10 , but preferably not during performance of an aspiration sequence. In accordance with the sampling sequence, the practitioner disengages the sampling outlet coupler plug  106  from the sampling outlet coupler  105   a  and connects the sampling outlet couplers  105   a ,  105   b  together. The practitioner then inserts the end  130  of the evacuated sampling container  126  into the interior  120  of the sampling guide  110  via the open back end  122 . The practitioner displaces the sampling container  126  against the front wall  134  of the sampling guide  110 , thereby pealing the sampling outlet seal away from the open back end  114  of the sampling outlet  108  and pushing the back end  114  through the stopper  132  into the evacuated test tube  128 .  
         [0059]     Once the sampling container  126  is securely in place in the sample transfer unit  107 , the sampling valve  138  is manually transitioned from the closed non-sampling position to the open sampling position by manually sliding the sampling line  100  from the narrow segment  142  of the slot  140  in the sampling valve  138  into the wide segment  144  of the slot  140 , thereby enabling fluid flow through the sampling line  100  past the sampling valve  138 . Opening the sampling valve  138  provides fluid communication between the disposal reservoir  14  and the sampling container  126 . Accordingly, the vacuum in the sampling container  126  draws a sample of bodily fluid from the disposal reservoir  14  through a sampling fluid passageway including the reservoir port  96 , disposal outlet port  91 , junction fitting common, sampling port  102 , sampling line  100 , sampling valve  138 , sampling outlet couplers  105   a ,  105   b , and sampling outlet  108  into the sampling container  126  when the sampling valve  138  is transitioned to the open position.  
         [0060]     Once the sampling container  126  is filled with the sample of bodily fluid, the sampling valve  138  is transitioned back to the closed non-sampling position and the sampling container  126  is withdrawn from the sample transfer unit  107  via the open back end  122  of the sampling guide  110 . Both the sampling outlet seal and the elastomeric stopper  132  are self-resealing once the sampling container  126  is removed from the sample transfer unit  107 . The sampling outlet coupler plug  106  is also replaced in engagement with the sampling outlet coupler  105   a . As a result, essentially no bodily fluid leaks from the fluid aspiration device  10  via the sampling assembly  97  at any time before, during or after the sampling sequence. In addition, the fluid-filled sampling container  126  can be stored or transported for subsequent analysis of the fluid sample without leakage of the sample from the sampling container  126 .  
         [0061]     An advantageous feature of the fluid aspiration device  10  is that the device  10  enables aspiration, disposal and optional sampling of bodily fluids without ever requiring the practitioner to handle the bodily fluids outside of the fluid aspiration device  10  and to risk unsafe contact therewith. The fluid passageways of the fluid aspiration device  10  remain closed to the external environment of the device  10  at all times during and after operation of the device  10  to minimize or eliminate the possibility of any bodily fluids escaping into the external environment and posing a contamination risk. It is noted that the term “external environment of the device  10 ” as used herein is not intended to include the body of the patient to which the device  10  is applied.  
         [0062]     While the forgoing preferred embodiments of the invention have been described and shown, it is understood that alternatives and modifications, such as those suggested and others, may be made thereto and fall within the scope of the invention.