Sterile sampling methods and apparatus

Abstract

An apparatus and method that allow multiple samples of a liquid in a primary container (here called a ‘pouch’) to be taken with minimal danger of contaminating the liquid in the container during the sampling process are disclosed. In an embodiment, a closed sterile sight chamber is connected with the pouch in a sterile manner to allow fluid to flow into the chamber while at the same time allowing air within the chamber to be displaced through a bacterial filter to atmosphere. The connection between the sight chamber and the pouch is then terminated (severed or closed), isolating the pouch from the sampling apparatus. Only then are samples of liquid withdrawn from the sight chamber, while allowing air to flow into the chamber through the bacterial filter.

1 . Apparatus for providing at least one sample of a liquid contained in a pouch while mitigating the danger of contaminating the liquid in the pouch, the apparatus comprising:
 the pouch;   a closed sterile rigid sight chamber, having:
 an inlet; 
 an outlet adapted to permit substantially all of said liquid in the chamber to flow from the chamber in one or more samples under the action of gravity, and 
 a filtered vent in fluid connection with the sight chamber adapted to permit flow of displaced air from the chamber during flow of liquid into the chamber and adapted to permit flow of air into the chamber during flow of liquid from the chamber, said filtered vent being adapted to block the flow of airborne particles including bacteria into the chamber, 
   and   a flexible inlet tube having first and second ends, said first end being in fluid connection with said inlet, and said second end being in fluid connection with said pouch;   a tube clamp mounted on the inlet tube remote from the second end and operable to close the inlet tube;   wherein:   
       said tube clamp is operable to regulate liquid flow through said inlet tube to the chamber and operable to block the inlet tube. 
     
     
         2 . Apparatus of  claim 1  wherein said inlet tube is closed at a first location intermediate the first and second ends. 
     
     
         3 . Apparatus of  claim 1  wherein the inlet tube is closed at a first location intermediate the first and second ends by a frangible barrier. 
     
     
         4 . Apparatus of  claim 1  wherein the inlet tube is closed at a first location intermediate the first and second ends by said tube clamp. 
     
     
         5 . Apparatus according to  claim 1  wherein:
 said sight chamber is tubular and transparent and has an upper end and a lower end, and 
 said at least one inlet is located at the upper end and the outlet is located at the lower end. 
 
     
     
         6 . Apparatus according to  claim 1  wherein:
 said sight chamber is tubular and transparent and has an upper end and a lower end; 
 said at least one inlet is located at the upper end and the outlet is located at the lower end; 
 said vent is located at the upper end; 
 said sight chamber is marked with graduations to indicate the volume of liquid therein, the uppermost of the graduations being below the said at least one inlet and said vent. 
 
     
     
         7 . Apparatus according to  claim 1  including a sample port connected to said outlet, for dispensing liquid in the chamber into at least one sample phial in a substantially sterile manner. 
     
     
         8 . Apparatus according to  claim 7  wherein said sample port is joined to the outlet at the lower end of the sight chamber in a rigid manner so that the sight chamber can be supported substantially upright by a user holding the sample port in one hand while inserting a phial into said open end of the sample port with the other hand. 
     
     
         9 . Apparatus according to  claim 7  wherein
 said sample port has an internal diameter adapted to receive a first sample phial having an external diameter approximating the said internal diameter of the sample port, 
 a tubular spacer is provided having an internal diameter adapted to receive a second sample phial having an external diameter substantially smaller than the external diameter of said first sample phial, 
 said spacer being adapted to be slidingly received within the sample port, and said spacer having a lower end, 
 means for clipping the spacer into the sample port when it is received therein, 
 opposed tabs on the lower end of the spacer adapted to extend radially outwards from the opening of the sample port when the spacer is inserted therein, and 
 said tabs are adapted to be gripped between a thumb and finger of a user for insertion of the spacer into the sample port so that neither said thumb nor said finger enter the sample port during insertion of the spacer into the sample port. 
 
     
     
         10 . Apparatus according to  claim 7  including:
 a port cap mounted for rotation about an axis to the open end of the sample port, and 
 said port cap is movable to a closed position to close said open end and 
 said port cap includes releasable locking means adapted to hold it in the said closed position, and said locking means comprises a first radially extending tab on the open end of the sample port and a second radially extending tab on the port cap, said tabs being adapted to engage one another when the port cap is in said closed position. 
 
     
     
         11 . The apparatus of  claim 1  wherein the vent has an opening to the environment and a hinged cap is mounted adjacent the opening, the cap movable between a closed position in which it blocks the opening and an open position in which the opening is unblocked and positions therebetween in which the opening is partially blocked. 
     
     
         12 . A method for providing at least one sample of liquid from an amount of said liquid contained in a pouch while mitigating the danger of contaminating the liquid in the pouch, the method comprising the steps of:
 providing an assembly of the pouch, a transparent rigid sight chamber, a flexible inlet tube interconnecting the pouch and sight chamber and a tube clamp,
 the sight chamber having a vent fitted with a bacterial filter through which air can flow to and from the chamber, an inlet and an outlet; 
 said flexible inlet tube having first and second ends, said first end being in fluid connection with said chamber, and a second end in fluid communication with the pouch, 
 said inlet tube being closed at a first location intermediate the first and second ends, 
 the tube clamp mounted on the inlet tube remote from the second end and operable to close the inlet tube; 
   opening the inlet tube at the first location to permit flow of liquid from the pouch and said inlet;   allowing a minor quantity of the liquid in the pouch to flow into the chamber from the pouch through said inlet while venting displaced air from the chamber through the vent,   immediately after said quantity of liquid has flowed into the chamber, closing said tube clamp to clamp the inlet tube closed to prevent fluid flow into or out of the chamber via said inlet and to initially isolate all of said quantity of liquid mixture that has flowed into the chamber in the chamber, and then   immediately after closing the inlet tube, withdrawing at least one sample of the liquid from the chamber into at least one sample phial through said outlet while allowing air to enter the chamber via the vent to replace the liquid withdrawn,   said liquid flowing into said at least one sample phial under the action of gravity or a vacuum in said at least one sample phial,   said at least one sample having the same composition as the liquid in the pouch.   
     
     
         13 . The method of  claim 12  wherein the inlet tube is closed at the first location by the tube clamp and the step of opening the inlet tube at the first location includes opening the tube clamp. 
     
     
         14 . The method of  claim 12  wherein the inlet tube is closed at the first location by a frangible barrier and the step of opening the inlet tube at the first location includes breaking the frangible barrier. 
     
     
         15 . A method of  claim 12  including terminating the connection between the pouch and the chamber after closing the inlet tube and before withdrawing at least one sample of the liquid from the chamber into at least one sample phial. 
     
     
         16 . A method of  claim 15  wherein terminating the connection is effected by heat-sealing the inlet tube on the pouch side of the tube clamp. 
     
     
         17 . The method of  claim 12  including providing a cup-like sample port, having an open end and a tubular peripheral wall connected to the outlet of the chamber, said sample port having an internal diameter adapted to receive a first sample phial having an external diameter approximating the said internal diameter of the sample port. 
     
     
         18 . The method of  claim 17  including inserting at least one first sample phial into the sample port. 
     
     
         19 . The method of  claim 18  including the steps of:
 inserting a tubular spacer into said sample port, said tubular spacer having an internal diameter adapted to receive a second sample phial having an external diameter substantially smaller than the external diameter of said first sample phial, the spacer effecting guidance of the phial within the sample port, and 
 inserting said second sample phial into the spacer and sample port and withdrawing a sample of the liquid from the chamber into said second phial. 
 
     
     
         20 . The method of  claim 12  wherein:
 said sight chamber is tubular and transparent and has an upper end and a lower end; 
 said at least one inlet is located at the upper end and the outlet is located at the lower end; 
 said vent is located at the upper end; 
 said sight chamber is marked with graduations to indicate the volume of liquid therein, the uppermost of the graduations being below the said at least one inlet and said vent, and 
 
       said method includes maintaining the sight chamber substantially vertical with the upper end above the lower end and filling said minor quantity of the liquid to one of the graduations, thereby maintaining an air gap between the liquid in the sight chamber and the inlet during said step of allowing a minor quantity of the liquid in the pouch to flow into the chamber. 
     
     
         21 . The method of  claim 20  including maintaining the sight chamber substantially vertical with the upper end above the lower end whilst withdrawing said at least one sample. 
     
     
         22 . The method of  claim 12  wherein the vent has an opening to the environment and including the step of:
 restricting said vent by partially covering the opening to restrict flow of air from the chamber when liquid is flowing into the chamber so as to limit the rate of fluid flow and to thereby facilitate the termination of the connection between the pouch and the chamber when a desired amount of liquid has flowed into the chamber. 
 
     
     
         23 . The method of  claim 12  wherein the sight chamber is marked with graduations to indicate the volume of liquid therein and wherein the vent has an opening to the environment and wherein the method includes the step of:
 restricting said vent by partially covering the opening to restrict flow of air into the chamber when one of said samples is being withdrawn so as to slow the rate of withdrawal of liquid from the chamber thereby facilitating termination of said withdrawing step when a predetermined volume of liquid has been withdrawn from the chamber into the sample phial, as indicated by reference to said graduations of the chamber. 
 
     
     
         24 . The method of  claim 12  wherein the liquid is blood, blood serum or blood platelets. 
     
     
         25 . A method for providing at least one sample of liquid from an amount of said liquid contained in a pouch while mitigating the danger of contaminating the liquid in the pouch, the method comprising the steps of:
 establishing a sterile fluid connection between the pouch and a sterile transparent rigid sight chamber, the sight chamber having:
 a vent fitted with a bacterial filter through which air can flow to and from the chamber; 
 an inlet including:
 a flexible inlet tube having first and second ends, said first end being in fluid connection with said chamber, and 
 a tube clamp mounted on the inlet tube remote from the second end and operable to close the inlet tube, 
 said inlet tube being closed at a first location intermediate the first and second ends; 
 
 and 
 an outlet, 
   by establishing a sterile fluid connection between the pouch and said inlet;   allowing a minor quantity of the liquid in the pouch to flow into the chamber from the pouch through said inlet while venting displaced air from the chamber through the vent,   immediately after said quantity of liquid has flowed into the chamber,
 closing said tube clamp to clamp the inlet tube closed to close the inlet to prevent fluid flow into or out of the chamber via said inlet and to initially isolate all of said quantity of liquid mixture that has flowed into the chamber in the chamber, and then 
 terminating the connection between the pouch and the chamber, and 
   immediately after terminating the connection, withdrawing at least one sample of the liquid from the chamber into at least one sample phial through said outlet while allowing air to enter the chamber via the vent to replace the liquid withdrawn,   said liquid flowing into said at least one sample phial under the action of gravity or a vacuum in said at least one sample phial,   said at least one sample having the same composition as the liquid in the pouch, and   wherein the pouch has a sealed flexible thermoplastic outlet tube, and wherein   said step of establishing sterile fluid connection between the pouch and said chamber is performed by:
 sterile-docking said inlet tube with said outlet tube to provide a sterile fluid connection therebetween at a location between the second end and the first location, and 
 then opening the inlet tube at the first location to permit flow of liquid from the pouch to the chamber, and 
   said steps of closing the inlet and then terminating the connection is effected by first clamping the inlet tube with the tube clamp to block further flow of liquid into the chamber and then heat-sealing the outlet tube from the pouch on the pouch side of the tube clamp.   
     
     
         26 . The method of  claim 25  wherein the inlet tube is closed at the first location by the tube clamp and the step of opening the inlet tube at the first location includes opening the tube clamp. 
     
     
         27 . The method of  claim 25  wherein the inlet tube is closed at the first location by a frangible barrier and the step of opening the inlet tube at the first location includes breaking the frangible barrier. 
     
     
         28 . Apparatus for providing at least one sample of a liquid contained in a pouch while mitigating the danger of contaminating the liquid in the pouch, the apparatus comprising:
 a closed sterile rigid sight chamber, having:   an inlet adapted for substantially sterile connection with the pouch to permit liquid to flow from the pouch to the chamber and adapted for effecting termination of said liquid flow so as to isolate the liquid in the pouch from the liquid in the chamber, said inlet including:
 a flexible inlet tube having first and second ends, said first end being in fluid connection with said chamber, and 
 a tube clamp mounted on the inlet tube remote from the second end and operable to close the inlet tube, 
 said inlet tube being closed at a first location intermediate the first and second ends; 
   and   an outlet adapted to permit substantially all of said liquid in the chamber to flow from the chamber in one or more samples under the action of gravity, and   a filtered vent in fluid connection with the sight chamber adapted to permit flow of displaced air from the chamber during flow of liquid into the chamber and adapted to permit flow of air into the chamber during flow of liquid from the chamber, said filtered vent being adapted to block the flow of airborne particles including bacteria into the chamber, wherein:   
       said second end is closed, 
       said inlet tube is adapted for sterile-docking to effect sterile connection to a flexible thermoplastic outlet tube extending from and in fluid communication with the pouch, and 
       said tube clamp is operable to regulate liquid flow through said inlet tube to the chamber when the inlet tube is sterile-docked to the outlet tube of the pouch and operable to block the inlet tube when the inlet tube is disconnected from the outlet tube. 
     
     
         29 . Apparatus of  claim 28  wherein the inlet tube is closed at the first location by the tube clamp. 
     
     
         30 . Apparatus of  claim 28  wherein the inlet tube is closed at the first location by a frangible barrier. 
     
     
         31 . Apparatus according to  claim 28  wherein said inlet tube includes at least one marking positioned between the second end and the first location indicative of a preferred area for sterile docking. 
     
     
         32 . Apparatus according to  claim 28  wherein:
 said sight chamber is tubular and transparent and has an upper end and a lower end; 
 said at least one inlet is located at the upper end and the outlet is located at the lower end; 
 said vent is located at the upper end; 
 said sight chamber is marked with graduations to indicate the volume of liquid therein, the uppermost of the graduations being below the said at least one inlet and said vent. 
 
     
     
         33 . The method of  claim 25  wherein the liquid is blood, blood serum or blood platelets. 
     
     
         34 . The method of  claim 25  wherein:
 said sight chamber is tubular and transparent and has an upper end and a lower end; 
 said at least one inlet is located at the upper end and the outlet is located at the lower end; 
 said vent is located at the upper end; 
 said sight chamber is marked with graduations to indicate the volume of liquid therein, the uppermost of the graduations being below the said at least one inlet and said vent; 
 
       said method includes maintaining the sight chamber substantially vertical with the upper end above the lower end and filling said minor quantity of the liquid to one of the graduations, thereby maintaining an air gap between the liquid in the sight chamber and the inlet during said step of allowing a minor quantity of the liquid in the pouch to flow into the chamber, and 
       maintaining the sight chamber substantially vertical with the upper end above the lower end whilst withdrawing said at least one sample.