Abstract:
A system for handling and testing fluids and gases such as, for example, blood samples, includes a tube in cooperation with at least one input port and at least one pressure source mounted in a novel arrangement to enable precise, accurate, and relatively spill-proof handling of fluids and gases to perform mixing and visual inspection and other tests. After testing, various components may be easily disassembled and discarded. A method of operation includes energizing the pressure source, in the form of a flexible bulb, to draw blood from a standard blood tube into a measuring tube according to a preferred embodiment of the invention said system in order to visually inspect sediment or red blood cell settling level after a predetermined time in order to test for certain blood characteristics.

Description:
RELATED APPLICATION  
       [0001]    This application relates to and claims priority from U.S. PROVISIONAL APPLICATION No. 60/308,408 filed on Jul. 26, 2001. 
     
    
     
       TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention relates to fluid handling systems and related methods and, more particularly, to systems and methods for sampling, mixing, measuring or testing fluids, especially in a laboratory setting. One specific use for which the invention is particularly well-suited is the measurement of the amount of relatively dense particles within a liquid sample.  
         BACKGROUND OF THE INVENTION  
         [0003]    While the present invention has broad utility and is suitable for a variety or uses with a variety of different substances, the preferred embodiments described herein are particularly well-suited for use in handling and testing blood samples. By way of example, and not intended to be limiting, the present invention is described herein with respect to blood sampling, handling and testing.  
           [0004]    Various blood tests require removing the stopper or cap from a blood containing tube and then removing a portion of sample, diluting and mixing with a reagent, and placing into a readout instrument. These tests are either special tests which are not performed automatically or tests that require manual manipulation of the plasma, serum, or whole blood. Typically these tests are for chemistry, immunology, and hematology analysis.  
           [0005]    The present invention is adaptable to a number of blood tests. One test which is particularly adaptable to is the “Erythrocyte Sedimentation Rate” (ESR) test. There are several methods for performing this test but the most common and preferred primary method is the “Westergren Method” 
           [0006]    A blood sample which has been diluted by 20% with anti coagulant is put into a 200 mm long by 2.5 mm inside diameter rigid tube. This tube is placed vertically on a stand, then the interface of plasma and red cells is measured after one hour in millimeters of settling of red cells. Normal samples range between 0 and 15 mm of settling. Abnormals can settle over 100 mm in one hour.  
           [0007]    The rate of erythrocyte sedimentation has long been known to be increased by the presence of acute phase proteins, especially fibrinogen, alpha-2 macroglobulin and, to a lesser extent, immunoglobulins. Some serum proteins, notably albumin, have also been reported to decrease erythrocyte sedimentation. These serum proteins appear to act by reducing (or, for albumin, increasing) the electrostatic forces between red cells, allowing rouleaux to form. This aggregation allows the red cells to sediment through the plasma more quickly. The ESR is therefore increased by conditions that increase the concentration of acute phase proteins in the plasma, such as acute inflammation, fever and infections. The use of the ESR in diagnosis and monitoring of temporal arteritis and polymyalgia rheumatica is particularly well defined. Symptoms of many acute phase reactions can be non-specific (general malaise or musculoskeletal complaints), and performance of the ESR can aid in distinguishing inflammatory causes from other possible causes of these symptoms. The ESR is less useful as a general screening for wellness in the absence of symptoms, although this use is not uncommon. Long term conditions, such as autoimmune diseases (rheumatoid arthritis) or cancer can also increase the ESR, and so the ESR is often used to help diagnose and monitor disease activity and response to treatment in these conditions.  
           [0008]    When performing the ESR test, typically the laboratory technician does the following:  
           [0009]    1. Takes the sample tube off a rocker mixer and removes the sample tube cap.  
           [0010]    2. Using a disposable pipette aspirates out enough sample (approx. 1.5 ml) and dispenses it into a plastic vial until it reaches a fill mark near the top of the vial. Note: there are two types of vials. One is empty and the other has sodium citrate reagent.  
           [0011]    3. The vial is then capped and mixed.  
           [0012]    4. The Westergren tube (W.T.) is pushed into the vial (the vial&#39;s inside diameter is the same as the outside diameter of the W. T). The sample rises up the W. T. and is adjusted to the zero mark near the top of the tube by adjusting the tube up or down.  
           [0013]    5. Places the tube on a holding rack.  
           [0014]    6. Recaps the blood sample.  
           [0015]    7. Reads ESR by eye one hour later.  
           [0016]    8. Disposes of the vial, W.T., and pipette.  
           [0017]    During this procedure blood samples commonly contaminate safety gloves from the top of the open sample tube or from the sample cap. The samples also commonly contaminate the outside of the sample tubes. The contaminant is spread around the laboratory via gloves to benches, computers, etc. The disposables often leak into the waste containers. At times samples leak out of the vial while filing the W. T. As a result, all samples must be treated as if the patient&#39;s sample is contaminated.  
         OBJECTS OF THE PRESENT INVENTION  
         [0018]    One object of the present invention is to eliminate the potential for contamination hazards.  
           [0019]    Another object of this invention is to provide a new means for sampling directly from the sample tube without the need to remove the stopper or cap.  
           [0020]    Another object of this invention is to provide means to proceed or follow the sample through the same conduit with reagent and/or air for dilution and mixing.  
         SUMMARY OF THE INVENITON  
         [0021]    A system for handling fluids and gases such as, for example, blood samples, comprises a tube in cooperation with at least one input port and at least one pressure source mounted in a novel arrangement to enable precise, accurate, and relatively spill-proof handling of fluids and gases to perform mixing and visual inspection and other tests. After testing, various components may be easily disassembled and discarded. A method of operation includes energizing the pressure source, in the form of a flexible bulb, to draw blood from a standard blood tube into a measuring tube according to a preferred embodiment of the invention said system in order to visually inspect sediment or red blood cell settling level after a predetermined time in order to test for certain blood characteristics. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    [0022]FIG. 1 is a schematic side view of a pipette with port and pressure bulb assembled according to a first embodiment of the present invention.  
         [0023]    [0023]FIG. 2 is a detailed, partial, schematic side view of a first end of the pipette shown in FIG. 1.  
         [0024]    [0024]FIG. 3 is a schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack according to a first embodiment of the present invention.  
         [0025]    [0025]FIG. 4 is a detailed, partial, schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack and having a sample tube holder secured thereto according to a first embodiment of the present invention.  
         [0026]    [0026]FIG. 5 is a detailed, partial, schematic front view of the sample tube holder, with a cut off section of the sample inlet tube, according to a first embodiment of the present invention.  
         [0027]    [0027]FIG. 6 is a detailed, partial, schematic top view of the sample tube holder of FIG. 5.  
         [0028]    [0028]FIG. 7 is a schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack and having a sample tube connected in fluid cooperation therewith according to a first embodiment of the present invention.  
         [0029]    [0029]FIG. 8 is a schematic as in FIG. 7, having the sample tube removed and the fluid contents of the sample tube of FIG. 7 being now transferred into the pipette of FIG. 8.  
         [0030]    [0030]FIG. 9 is a schematic side view of a pipette with two ports and pressure bulb assembled according to a second embodiment of the present invention.  
         [0031]    [0031]FIG. 10 is a detailed, partial, schematic side view of a first end of the pipette shown in FIG. 9.  
         [0032]    [0032]FIG. 11 is a schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack according to a second embodiment of the present invention.  
         [0033]    [0033]FIG. 12 is a schematic front view of the system as shown in FIG. 11.  
         [0034]    [0034]FIG. 13 is a schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack according to a second embodiment of the present invention.  
         [0035]    [0035]FIG. 14 is a schematic side view of a pipette with port and pressure bulb assembled and secured within a holder rack and having a sample tube connected in fluid cooperation therewith according to a second embodiment of the present invention.  
         [0036]    [0036]FIG. 15 is a schematic of the system shown in FIG. 14, further showing sample fluid partially drawn into a mixing chamber according to a second embodiment of the present invention.  
         [0037]    FIGS.  16 - 20  are schematic views of the system shown in FIG. 15 having the sample tube removed and fluid/air in various states of mixing in a mixing chamber.  
         [0038]    [0038]FIG. 21 is a schematic of the system shown in FIG. 14, further showing sample fluid drawn into a pipette according to a second embodiment of the present invention.  
         [0039]    [0039]FIG. 22 is a schematic side view of a pipette with two ports, two pressure bulbs and a mixing chamber assembled according to a third embodiment of the present invention.  
         [0040]    [0040]FIG. 23 is a schematic side view of a holder assembly according to a third embodiment of the present invention.  
         [0041]    [0041]FIG. 24 is a schematic side view of the pipette assembly of FIG. 22 positioned in the holder assembly according to FIG. 23.  
         [0042]    [0042]FIG. 25 is a schematic side view according to FIG. 24 and having a sample tube held therein in fluid communication.  
         [0043]    FIGS.  26 - 28  are schematic views of the system shown in FIG. 25 having the sample tube removed and fluid/air in various states of mixing in a mixing chamber.  
         [0044]    [0044]FIG. 29 is a schematic as in FIG. 22 having fluid contained in a mixing chamber.  
         [0045]    [0045]FIG. 30 is a schematic side view of a pipette with three ports and a mixing chamber assembled according to a fourth embodiment of the present invention.  
         [0046]    [0046]FIG. 31 is a schematic side view of a holder assembly according to FIG. 30 held in a holder assembly according to a fourth embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0047]    In a first embodiment, the invention is described relative to performing a modified Westergren Erythrocyte Sedimentation Rate Test.  
       Method A  
       [0048]    Samples are collected with sodium citrate reagent within the sample tube prior to collecting sample.  
         [0049]    [0049]FIG. 1 shows a side view of the 200 mm long by 1.0 mm inside diameter rigid tube  10  with a sampling tab  12  on the upper inlet end and a flexible pipette bulb  14  on the lower end.  
         [0050]    [0050]FIG. 2 shows the sampling end in detail. The stopper piercing tip  16  is sealed. The sample inlet port  18  is shown on the upper side of the inlet tube  20 . A flexible silicone tube/sleeve  22  surrounds the sample inlet port  18 . This sleeve  22  covers the entire inlet tube and terminates on the top of the sampling tab  12 .  
         [0051]    [0051]FIG. 3 shows a side view of the modified ESR tube  10  connected to a holding rack  24 . The holding rack  24  has a slot  26  to hold the sampling tab  12  in place. This rack  24  also has a sample tube holder  28 . The drawing shows that a technician has placed the ESR tube  10  on the holding rack  24  and has “charged” the aspiration pipette  14  by squeezing the pipette bulb  14 . As the bulb  14  is squeezed the air pressure opens the silicone sleeve  22  and the air is released through the sample inlet port  18 . The flexible silicone tube  22  returns and again seals the sample inlet port  18 .  
         [0052]    [0052]FIG. 4 shows a detailed side view of the sample tube holder  28  which is permanently mounted to the ESR tube  10  Rack/Base stand  24 . This Rack/Base stand  24  will have multiple positions, each position will also have a sample tube holder  28 . The drawing also shows a partial upper section of the ESR tube  10 . Of particular importance are the springs  30  mounted in the bottom of the sample tube holder. Several of these springs  30  surround the sample inlet tube  20 .  
         [0053]    The purpose of these springs  30  is to assist in the removal of the sample tube  32 . With no assistance, the sample inlet tube  20  will resist the sample tube stopper  34  removal, which poses the risk of suddenly popping off the stopper  34  in an uncontrolled manner as the technician removes the sample tube  32 .  
         [0054]    The technician will now insert the mixed sample tube  32  (See FIG. 7) pushing slightly until the stopper  34  bottoms out against the compressed springs  30 . Also while inserting the sample tube  32  the flexible silicone tube  22  will be pushed down below the sample tube stopper  34 . The sample inlet port  18  is now open to the sample which is pulled by vacuum in the flexible pipette  14  through the ESR tube  10  until it reaches the bottom of the ESR tube  10 . Then the technician removes the sample tube  32  (See FIG. 8). The flexible silicone sleeve  22  will spring back up sealing off the sample inlet port  18 , preventing further flow. This filling process will take several seconds. The ESR result is read one hour later.  
         [0055]    There are various methods using various lengths and inside diameters, some on specific angles. Some of these methods are measured earlier, twenty minutes or so. Although the Westergren method is described herein, this system is adaptable to other methods.  
         [0056]    [0056]FIG. 8 also shows a manual tubing pincher  11  mounted on the base stand  24  positioned below the 200 millimeter position of the ESR tube  10 . This may be desirable to prevent red blood cells from settling beyond the ESR tube  10  bottom, towards the sampling pipette  14 . Also shown is a flexible section of conduit  15  prior to the sampling pipette  14 . Following the filling of the ESR tube  10  the Technician would push the flexible section conduit  15  down into the tubing pincher  11 . If the overall instrument is further automated, a programmed pinch valve would be used.  
         [0057]    Shown in FIG. 4 is the riser tube  36  which has several purposes. First, it allows room for the ESR tube  10  to be in front for easy readability.  2 . Also, because it is a one-piece, molded rigid tube, the 0 mm mark  38  can be easily located precisely at the sample inlet port  18  height. This will prevent plasma and/or red cells from settling in the 200 mm measurement path.  3 . This riser tube  36  section can also be calibrated in millimeters and be at some ideal angle for the technician to read an earlier ESR to screen stat samples. It is well known that the red cells will settle faster when the ESR tube  10  is on an angle. Essentially, the plasma can flow more easily upwards as the red cells settle off the upper inside wall of the riser tube  36 .  
         [0058]    [0058]FIG. 5 shows an expanded front view of the sample tube holder  28 , with a cut off section of the sample inlet tube  20 . Part of the holding rack  24  is slotted to hold the sampling tab  12  in place and part of the upper sample tube holder  28  is slotted for the sample inlet tube  20  to fit into position. The depth of the sampling tab slot  26  is such that the inlet tube  20  will be centered in the sample tube holder  28 .  
         [0059]    Looking at FIG. 7 note that the flexible pipette bulb  14  is “nearly” back to its original round configuration. The volume of this pipette  14  is selected so as to control the flow of sample so that the ESR tube  10  is filled in several seconds.  
         [0060]    Following the final readout the technician will remove the ESR tube  10  and discard it. Sample is contained via the silicone tubing sleeve  22  and the otherwise closed ESR tube  10 .  
       Method B  
       [0061]    Many laboratories prefer to perform the ESR test using whole blood collected in tubes without sodium citrate diluent. Therefore, the technician must dilute the sample by 20% using sodium citrate reagent. Commonly they use an available method having a vial with liquid sodium citrate. The technician adds the whole blood sample to a line near the top of the vial. The sample is mixed and then the Westergren tube is pushed into it. At this point the technician follows the same steps as described above using a blood sample collected with the sodium citrate in the sample tube.  
         [0062]    The present invention enables handling of these whole blood samples with dilution of the sample by 20% with sodium citrate.  
         [0063]    [0063]FIG. 9 shows the same ESR tube  10  but the sampling tab  12  has two inputs. The vertical input  20  is identical to Method A, the horizontal input  40  is for the reagent addition and air addition. The air is for assuring accurate dilution and to mix the sample and reagent. The reagent inlet tube  40  also has a silicone (or other elastic) tube  42  that seals off the tube before and after use.  
         [0064]    Between the two chambers there is a mark  46  inscribed, this mark is used to insure the proper volume of sample is aspirated. After the technician “charges” the flexible pipette  14  at the lower end of the ESR tube  10 , at anytime thereafter he can aspirate a blood sample. As soon as the sample is inserted into the sample inlet tube  20  blood will begin flowing. The technician will remove the sample tube  32  when the sample reaches the mark  46 . The time is several seconds for this filling to complete.  
         [0065]    [0065]FIG. 10 shows the detail of the sampling tab  12 . This tab  12  will fit into the sample tube holder  28  as shown in FIGS. 11 and 12. The sampling inlet tube  20  is identical to ESR method A. The reagent/air inlet tube  40  and tip  48  will slide through a hole  66  in the rear of the Rack/Base stand  24 . There is a hard rubber seal  50  that the tip  48  and inlet tube  40  fit through. As the reagent/air inlet tube  40  is pushed into the base stand holder  24  the silicone tubing sleeve  42  will slide back and stay against the outside or front side of the base stand  24 . The sample tube  20 , silicone tubing sleeve  22  and reagent/air tubing sleeve  42  will rebound covering the inlet port  18  when the sample tube  32  is removed and port  52  when the sampling tab  12  is removed. The reagent/air inlet tube  40  is now open to a flexible tube  54  with an inside diameter larger than the outside diameter of the reagent/air inlet tube  40 . This flexible tube  54  seals tightly around the hard rubber seal  50 .  
         [0066]    [0066]FIG. 11 shows a pinch valve  56  that seals off the path near the tip  48  of the reagent/air inlet tube  40 . The leading end of this flexible tubing  54  where the reagent/air inlet port  52  is contained, is only air when a new ESR tube is installed. This pinch valve  56  prevents flow entering the sample inlet tube  20  during sample aspiration.  
         [0067]    [0067]FIG. 12 is a front view and shows a notch  26  on the base stand  24  for the sampling tab  12  to slide into and a notch  26  in the front of the sample tube holder  28  for the sample inlet tube  20  to fit. When the sampling tab is fully inserted the sample inlet tube  20  will be centered inside the sample tube holder  28 .  
         [0068]    [0068]FIG. 13 shows the ESR tube  10  mounted to the “multiple” (only one position is shown) ESR sample tube holder  24 . Also shown in FIG. 13 is a programmable air pump  58 . Although other pumps can be used, a peristaltic pump seems ideal. The air flow and the reagent can be independently programmed.  
         [0069]    This pump supplies all positions on the multi tube rack. Each position on the multi tube ESR rack  24  will have its own pinch valve  56 .  
         [0070]    [0070]FIG. 14 shows the technician has “charged” the flexible pipette  14  and has inserted the sample tube  32 . At the same time the pinch valve  56  remains closed and the pump  58  is off.  
         [0071]    Immediately following the insertion of the sample tube  32  the sample will begin to flow. Several seconds later, as shown in FIG. 15, the sample will reach the mark  46  between the dual chambers  44 . The technician then removes the sample tube  32 . At that time the flow of the sample stops since the sample port  18  is sealed off. This is shown in FIG. 16.  
         [0072]    As seen in FIG. 17 the technician now pushes a button switch  60  which activates the pinch valve  56  to open it and starts the pumping profile for reagent and air addition. This pumping profile will also take several seconds. The volume of the sample trapped in the lower dilution/mixing chamber is approximately 1000 microliter.  
         [0073]    The reagent and air flow start pumping simultaneously. As the reagent and air flows into the reagent inlet tube  40  the flexible pipette  14  will insure this flow proceeds into the dilution/mixing chambers  44 . Also, shown in FIG. 17 are air bubble segments  62  formed in the flowing stream. These bubble segments  62  will insure all blood sample is pushed into the dilution/mixing chambers  44 . They will also act as mixing devices as they float up through the dilution/mixing chambers  44 .  
         [0074]    Near the end of the reagent/air pumping profile the programmed reagent pumping will stop and the air pumping will continue. As shown in FIG. 18, this will empty the conduit  64  between the pump  58  and the dilution/mixing chambers  44  and also create more air bubbles  62  to form and float up into the dilution/mixing chambers  44  for mixing. Then air pumping stops. This pumping profile takes several seconds. The volume of reagent pumped is approximately 250 microliters for a dilution of 4 parts sample and  1  part reagent.  
         [0075]    Referring to FIG. 19, upon completion of the pumping profile the technician will flip over the dilution/mixing chambers  44  180 degrees using their finger. The flexible pivot conduits  68  are shown in this drawing. This action will both create further mixing as the bubbles  62  rise back up through the dilution/mixing chambers  44  and create a direct path of the mixed sample/diluent solution to the ESR tube  10 . FIG. 20 shows the air bubbles  62  have risen to the top of the “now” upper chamber  44 . The technician will again push the button switch  60  which will both open the pinch valve  56  and start the air pump  58  which will cause air to flow through the reagent/air input tube  40  and allow the flexible pipette  14  to pull the mixed sample/reagent, filling the ESR tube  10 . Then the pinch valve  56  will close again and the air pump  58  will stop as shown in FIG. 21. The ESR test will now begin. The technician will read the results one hour later, then discards the one piece ESR tube  10 . It is obvious that the flipping over of the dilution/mixing chambers  44  can be automated mechanically. The invention drawing&#39;s starting with FIG. 22 and ending with FIG. 29 shows a method of performing other blood tests or chemical tests which will improve hazardous material handling in the laboratory.  
         [0076]    [0076]FIG. 22 shows a one piece disposable test device  94 , mostly rigid series of conduits, chambers  72  and  74 , sampling pipette  76 , and sampling tab  12 . The reagent/air pipette  78  and the sample pipette  76  are flexible bulbs which act as suction pumps after being charged by the Technician squeezing them closed. The sampling tab  12  is exactly like the one shown in more detail in FIG. 10. Two other flexible conduits  80  and  81  are short sections before the two pipettes  76  and  78 . The thickness of the conduit walls are shown to be very thin. Actually the wall thickness may be significantly thicker. It is designed to mix  10  microliters of sample with  200  microliters of reagent for a dilution of 1 to 20. “Point A” is the intersection where sample and reagent will combine. “Point B” is shown at the intersection below the chamber  72 . The volume of the conduit  98  between these points is exactly  10  microliters. The volume of the lower chamber  72  is exactly  200  microliters. Also shown is a “mark”  82  between the two chambers  72  and  74 .  
         [0077]    [0077]FIG. 23 shows a reagent/air pump  58 , flexible tubing  54 , pinch valve  56 , sample tube holder  28 , rack/base stand  96 , calorimeter  84  with optical filter  86  and light source  88  and tubing pinchers  90  and  92 . The pump conduits for air and reagent flexible tubing  54  and pinch valve  56  are shown near actual size. The tubing pinchers  90  and  92  are near actual size and are mounted to the rack/base stand  96 .  
         [0078]    [0078]FIG. 24 shows the Technician has placed the test device  94  shown in FIG. 22 into position for testing. The sampling tab  12  and sample tube holder  28  are the same as shown in more detail in FIGS.  9 - 12 . The upper, or reagent/air tubing pincher  92  is actually mounted on the rack/base stand  96  as shown in FIG. 23. It is also drawn up higher in FIGS.  24 - 28  only to reduce the drawing complexity.  
         [0079]    In the first step before placing the disposable device  94  in position, the Technician will squeeze the reagent/air pipette  78  and sample pipette  76  to “charge” them. Then the technician will push the disposable device  94  into position and will push the flexible tubing  80  and  81  down into the tubing pinchers  90  and  92 .  
         [0080]    As the pipettes  76  and  78  are “charged” they will create air pressure which will escape by pushing open the silicone sleeves  22  and  42  which surround the sample inlet port  18  and the reagent/air inlet port  52 . As shown in FIG. 25 the Technician then pushes a sample tube  32  down into the sample tube holder  28 , releases the flexible tubing  80  in front of the sample pipette  76  from the tubing pincher  90 .  
         [0081]    Referring to FIG. 26, when the sample flow has reached the sample pipette  76  the technician will again push the flexible tubing  80  down into the sample pincher  90 , sealing off all conduits, chambers and pipettes. The Technician then removes the sample tube  32 . Referring to FIG. 27, the Technician now removes the flexible tubing  81  from the reagent/air pincher  92  and pushes the pump profile switch  60 . The pinch valve  56  opens and the pumping profile begins. Air bubbles  104  are injected into the flowing reagent stream. This flowing stream displaces the trapped sample between Points A and B as shown in FIG. 22. This flowing stream proceeds to fill the lower mixing, dilution and measurement chamber  72 . As the bubbles  104  float up through this chamber  72  they mix the sample and reagent. The reagent profile pump  58  will pump approximately 200 microliters and then stop. The air profile pump  58  will continue pumping and displacing all reagent within the conduit  98  path into the lower chamber  72  to fully mix the sample and reagent. The conduit entry port  100  leading into the bottom chamber  72  may need to be off-set to one side to insure complete mixing with certain tests. Also, the upper chamber  74  may need to be larger to accept more air bubbles.  
         [0082]    [0082]FIG. 28 shows a completed test. Although some tests can be measured by the colorimeter immediately, other tests will need more reaction time or heat to be complete. Delay time will be provided before measurement. The colorimeter  84  base  102  can be a heater for those tests needing heat to complete a reaction.  
         [0083]    [0083]FIG. 29 illustrates the one piece disposable test device  94  with sample, air and reagent entrapped.  
         [0084]    [0084]FIG. 30 shows a modified test device  106  having an additional tab  112 . This tab  112  is identical to the sampling tab  12  shown in the prior drawings FIGS. 1 and 2. It has a inlet tube  120  with a silicone sleeve  122  and inlet port  118 .  
         [0085]    This tab  112  is for an alternate vacuum source to pull sample, air and reagent through the conduits.  
         [0086]    [0086]FIG. 31 shows the alternate vacuum source  126  which is a common vacuum sampling tube  126  with a rubber stopper  128 . This vacuum tube  126  replaces the sampling pipette  76  and reagent/air pipette  78  shown in FIGS. 22 through 29. FIG. 31 also shows a second tube holder  108  mounted to the rack base stand  114 . This tube holder  108  is identical to the sample tube holder  28  shown in FIG. 3,4 and  5 , except it has a tube keeper  124  that keeps the vacuum tube  126  in place during operation. This tube keeper  124  will adjust vertically to accept various length vacuum tubes  126  and pivot horizontally to permit the Technician to install and remove the vacuum tube  126 . This vacuum tube  126  offers higher vacuum pressure and more vacuum capacitance. Also, multiple tests may be performed with a single vacuum tube  126 . The Technician places the test device  106  in position on the instrument then pushes the flexible conduits  80  and  81  down into the tubing pinchers  90  and  92 . The Technician then pushes the vacuum tube  126  down into the vacuum tube holder  108  and moves the tube keeper  124  in place to hold the vacuum tube  126  in place. The Technician then continues the instrument operation as discribed earlier. Following completion of the test the Technician will remove the vacuum tube  126 . The tubing pinchers  90  and  92  can be replaced with programed automatic pinch valves to further automate the tests. This alternate vacuum source can also be used for the ESR test described earlier.  
         [0087]    While the preferred embodiments have been herein disclosed, it is understood and acknowledged that variation can be made without departing from the scope of the invention as claimed.