Abstract:
The invention relates to a diagnostic medical device, and in particular to a blood cell analyzer which by manual or automatic operation withdraws and analyzes a minimal amount of blood that is stored in open or sealed vials. The analyzer includes a manually operated self cleaning sampling device for open vials and an automated self cleaning sampling device for sealed vials fitted with a pierceable cap.

Description:
This application is a continuation of Ser. No. 09/029,905, filed Apr. 23, 1998, now U.S. Pat. No. 6,126,903, which is a 371 of PCT/US97/00645 filed Nov. 14, 1997, and claims benefit of provisional application 60/030,841, filed Nov. 15, 1996. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a diagnostic medical device, and in particular to a blood cell analyzer which by manual or automatic operation withdraws and analyzes a minimal amount of blood that is stored in open or sealed vials with pierceable caps. 
     BACKGROUND OF THE INVENTION 
     Blood sample analysis systems are known in which the operator must position and hold in place tubes or vials of the samples to be analyzed. The systems include needles which pierce a closure on a sample tube to provide communication between blood in the sample tube and the system. Such prior art systems expose operators to the risk of contamination and infection from blood samples, as well as the risk of being cut by broken glass or other shattered materials. In addition, the prior art systems can only accept a limited number of sizes of tubes or vials. 
     It is desired to have a safer, more flexible means for positioning and holding blood sample tubes and vials during the cap piercing operation. Specifically, it is desired to have a holding and piercing apparatus which is “hands off” during the piercing operation, so as to prevent exposure of the operator to contamination from the blood in the vial being penetrated. It is also desired to improve the safety of such an apparatus by incorporating a safety interlock system. It is also desired to make it easier to insert and remove tubes or vials from the holder. It also is desired to have more flexibility to analyze samples from many sizes of vials or tubes (e.g., from 10.25×64 mm to 16×100 mm). 
     SUMMARY OF THE INVENTION 
     The present invention is a blood cell analyzer which by manual or automatic operation withdraws and analyzes a minimal amount of blood that is stored in open or sealed vials. The analyzer includes a manually operated self cleaning sampling device for open vials and an automated self cleaning sampling device for sealed vials fitted with a pierceable cap. The analyzer further includes a red blood cell counter, white blood cell counter, hemoglobin detector, valving system, and electronic controller. The blood cell analyzer further includes features for precisely measuring and mixing whole blood or prediluted blood with diluent as needed in order to analyze the blood sample 
     The present invention includes an apparatus for holding vials of varying sizes sealed with pierceable caps and for piercing the caps of the vials. The apparatus comprises a frame, holder, plate, cup, needle, driver, and an interlocking safety switch. 
     The frame has upper and lower ends. The holder is adjustably mounted on the upper end of the frame and is adapted to receive and hold the outer surface of a vial opposite the pierceable cap which seals the vial. The plate, which has an aperture in it, is mounted on the frame below the holder. 
     A cup is mounted on the top of the plate. The bottom of the cup has an aperture aligned with the aperture in the plate. The cup is adapted to receive the pierceable cap which seals the vial. 
     The needle is adapted to pierce the pierceable cap of the vial and to communicate with the contents of the vial. The needle is extendable and retractable through the apertures in the plate and the cup. 
     A driver, such as an electric motor, which extends and retracts the needle, is interlocked with the holder by a safety switch. The driver cannot extend the needle through the aperture in the cup whenever a vial is not held by the holder. 
     The apparatus may also include a needle cartridge assembly below the plate. The needle cartridge assembly has a lower end, a body, and an upper end, the top of which has an aperture aligned with the aperture in the plate. The body of the needle cartridge assembly contains the needle and a biasing means for engaging the needle and biasing the needle away from the pierceable cap of the vial. The biasing means may be a compression spring, such as a coil spring. 
     The apparatus may also include a rinse system for cleaning the needle. The needle cartridge assembly is connected to a rinse passage for selectively communicating a rinse fluid to the needle. The needle may be contained in a chamber within the needle cartridge assembly. The chamber is connected to the rinse passage, through which the rinse fluid is injected in one direction into the chamber, and from which the rinse fluid is withdrawn in another direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the accompanying drawings. The drawings show one embodiment of the invention as presently preferred. However, it should be understood that the invention is not limited to the precise arrangements and instrumentality shown in the drawings. 
     FIG. 1 shows a front view of blood cell analyzer having a vial holder and cap piercer device according to the present invention. 
     FIG. 2 is an isometric view of a vial holder and cap piercer according to the present invention. 
     FIG. 2A is a schematic diagram of the electric controls of the vial holder and cap piercer device of FIG.  2 . 
     FIG. 3 illustrates various types and sizes of vials sealed with pierceable caps. 
     FIG. 4 is an isometric view of a vial holder and cap piercer device illustrating several features of the present invention, including the frame, holder, plate, and driver motor. 
     FIG. 5A illustrates a bevel shaped tongue portion of a holder and a recess for receiving and holding a vial according to the present invention. 
     FIG. 5B illustrates a bevel shaped tongue portion of a holder and a recess holding a vial according to the present invention. 
     FIGS. 6A illustrate a top view of a plate illustrating keyed openings with bayonet ramps according to the present invention. 
     FIGS. 6B illustrate a side view of the plate illustrated in FIG.  6 A. 
     FIG. 7A illustrates a cup with locking device according to the present invention. 
     FIG. 7B illustrates a bottom view of the cup shown in FIG.  7 A. 
     FIG. 8A illustrates a needle and hub assembly according to the present invention in a retracted position. 
     FIG. 8B illustrates the front portion of the needle and hub assembly shown in FIG.  8 A. 
     FIG. 9A illustrates a needle and hub assembly according to the present invention in an extended position. 
     FIG. 9B illustrates the front portion of the needle and hub assembly shown in FIG.  9 A. 
     FIG. 10 illustrates eccentric positioning of a needle cartridge assembly according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, where like elements are identified by like numerals, there is shown in FIG. 1 a blood cell analyzer  10  having a vial holder and cap piercer device  11  according to a preferred embodiment of the present invention. 
     FIG. 2 shows a preferred embodiment of the variable size vial holder and cap piercer  11 . This apparatus comprises a frame  12 , an adjustable holder  14 , a top plate  16 , a cup  18 , an extendable and retractable needle  20 , and a driver  22  for extending and retracting the needle  20 . A multi-lobe cam  22   a  with associated position switches  24  is used to detect needle position. In addition, a safety switch  24   a  is used for interlocking the driver with the holder  14  so that the driver  22  cannot extend the needle  20  when a vial  23  is not fully engaged in and held by the holder  14 . 
     In one aspect of the invention, an important feature is provided where the closed end of the vial  23  opposite the capped end trips the safety switch  24   a , and that the tongue  34  alone can not enable the needle  20  to extend. 
     The frame  12  in the preferred embodiment includes two ways  26 , which are upright members mounted on a base  28 . The ways  26  are connected at the top plate  16  by a block  30 . The holder  14  is adjustably mounted on the upper end of the frame  12 . The cup  18  and the holder  14  is designed to receive and hold a vial  23 , also referred to as a tube, such as those shown in FIG.  3 . The tubes shown in FIG. 3 range in size from 10.5×64 mm to 16×100 mm. The tubes are sealed with caps  25  which are typically are made of a pierceable material, such as rubber or plastic. The holder  14  is designed to receive and hold the outer surface of a vial or tube  23  opposite the pierceable cap  25  which seals the vial or tube when the cap  25  is seated in the cup  18 . 
     In the preferred embodiment, the holder  14  is an over center spring loaded mechanism of the configuration shown in FIG.  4 . The holder  14  includes a U-shaped clamp  32  adjustably mounted to the frame  12  and an oblong-shaped tongue  34  mounted between two arms  33  of the clamp  32 . The tongue  34  is retained in the clamp  32  by a pin  36  which extends across the width of the clamp  32 . The tongue  34  has a beveled surface  35  and pivots about the axis of the pin  36 . A spring  38  on one side of the holder  14  biases the tongue  34  in either the closed or open position as shown in FIG.  2  and FIG.  4 . The capped end of the vial  23  is inserted into the cup  18  as the vial  23  is pivoted into contact with the tongue  34 . The vial  23  is held into position as the tongue  34  pivots into its open and closed position as shown in FIGS. 5A and 5B. The vial  23  is removed from the holder  14  by reversing this process. 
     As shown in FIG. 5A, the underside of the tongue  34  has a recess  31 , also referred to as an indentation, for receiving and holding the outer surface of a vial  23  opposite the pierceable cap  25  which seals the vial  23 . When the surface of a vial contacts the beveled surface  35  of the tongue  34 , the tongue  34  rotates or flips into the open position as shown in FIG.  5 A. Further movement of the vial  23  into the holder causes contact to be made with the recessed  31  portion of the tongue  34 . As the vial  23  is pivoted further into the holder  11  the tongue  34  in turn moves into the closed position as shown in FIG.  5 B. 
     In the preferred embodiment, an adjustable handle  40  is mounted on one arm of the U-shaped clamp  32  opposite the spring  38 . The adjustable handle  40  is used to reposition the holder  14 , which can be moved higher or lower on the frame  12  to adjust for different sizes of tubes or vials. In addition, the adjustable handle  40  may be spring loaded. When the holder  14  is moved to the desired position, it is locked in place. In the preferred embodiment, the adjustable handle  40  lifts and adjusts to 18 detent positions in 360°, so that the angle can be positioned for operator convenience. 
     Referring to FIGS. 4 and 5, a plate  16  is mounted on the frame  12  and below the holder  14 . In the preferred embodiment, the plate  16  has a keyed opening  42  with bayonet ramps  43  which are shown in FIG.  6 . The keyed opening  42  in plate  16  is for receiving the cup  18  which is shown in detail in FIGS. 7A and 7B. The opening  42  engages the cup&#39;s  18  locking device  44  which is typically located at the bottom of cup  18 . The locking device  44  is inserted in the keyed opening  42  and rotated so that the ramped edges  45  of the locking device  44  lock with the bayonet ramps  43  of the keyed opening  42  of plate  16 . 
     Rotation of the cup  18  in the opposite direction unlocks the locking device  44  allowing removal of the cup  18 . Different size cups  18  may be mounted on the plate  16  for receiving the pierceable caps  25  on vials  23  like those shown in FIG.  3 . It has been found that two different cup sizes are adequate to handle the range of tube sizes shown in FIG.  3 . In one aspect, a cup  18  may be used to accept standard size tubes under a 3 milliliter volume, and another cup may be used to accept standard size tubes that are 3 milliliter in volume or greater. The cup  18  has a tapered shape which helps guide a tube or vial into position when placed in the holder  14 . In the preferred embodiment, the cup  18  is made of a clear glass-smooth injection molded polycarbonate or acrylic. As shown in FIG. 7B, the bottom of the cup  18  has a small aperture aligned with the hole in plate  16  that allows the needle  20  to pierce the cap  25  of a vial. 
     In the invention includes a needle cartridge assembly  48  as shown in FIG.  8 A. The needle cartridge assembly  48  includes a needle  20 , and a needle cartridge body  53  with a stepped nosepiece  47  and a needle cartridge assembly  48 . The needle  20  is attached to a hub assembly  46  that moves within the needle cartridge assembly  48 . The needle  20  is extendable and retractable through apertures  41 ,  42  which are located in the top plate  16  and the cup  18  respectively. Referring to FIG. 9A, the needle  20  may be extended to pierce the cap  25  of the vial  23  that is held by the holder  14 . The needle  20  is extended so that the needle  20  may communicate with the contents of the vial  23 . 
     As shown in FIGS. 8A and 9A, the needle hub assembly  46  is mounted within a needle cartridge assembly  48  which is positioned below plate  16 . The needle cartridge assembly  48  has a lower end  51 , a body  53 , and an upper end  47 , the top of which has an aperture  49  aligned with the aperture  42  in plate  16 . The body  53  of the needle cartridge assembly  48  contains the needle  20  and a biasing means  50  for engaging the needle  20 . The biasing means  50  applies a bias to the needle  20  retracting it away from the pierceable cap  25  of the vial  23 . In addition, needle cartridge assembly  48  can be removable from the holder  14 . 
     As a safety feature, the biasing means  50  will retract the needle into the needle cartridge assembly  48  whenever the cartridge assembly  48  is removed from the holder  14 . In one aspect of the invention, the biasing means  50  may be a coil compression spring. 
     In one aspect of the invention as shown in FIG. 10, the needle  20  is positioned concentrically with respect to the needle cartridge assembly  48 , but eccentrically with respect to the center longitudinal axis of the vial  23  and its cap  25 . As an example, in FIG. 9B the nosepiece  47  is shown to be made eccentric with needle cartridge assembly  48 . This design allows the needle  20  to extend and retract eccentrically with respect to the center axis of the cap  25 . This feature prevents the pierceable caps  25  of the vials  23  to be pierced in the same location, typically the center of the vial&#39;s cap  25  when multiple samples are taken from the same vial. After the cap  23  has been pierced and a sample drawn the needle  20  is retracted. 
     In order to extract a precise amount of sample a circuit is formed by the sample which is conductive, the needle  20  which is conductive, and a second electrode (not shown) located at a fixed distance from the needle in and along a confined path formed by the sample as it is drawn from the vial  23 . The sample may be drawn through a non-conductive tube made of plastic or rubber. As the sample is drawn from the vial  23  through the needle  20  the sample comes in contact with the second electrode to form a closed circuit between the conductive needle and the other second electrode. The closed conductive path is used to indicate that a precise amount of sample has been drawn. 
     In one example, a current can be applied to the needle through pin  56  and carried by the fluid to the electrode down stream. When the current reaches the electrode it can be used to indicate that a sufficient amount of fluid has been drawn and/or that the needle  20  should be withdrawn. As the needle  20  is withdrawn its outer surface is cleaned by a squeegee effect produced by the material of pierceable cap  23  which is typically made of rubber or plastic. 
     Referring to FIGS. 8B and 9B, a rinse system is used to clean the inside of the needle  20 . In the preferred embodiment, the needle cartridge assembly  48  is connected to a rinse passage  52  for selectively communicating a rinse fluid to the needle  20 . The needle  20  may be contained in a chamber within the needle cartridge assembly  48 . The chamber is connected to the rinse passage  52  through which the rinse fluid is injected in one direction into the chamber, and from which the rinse fluid is withdrawn in another direction. A first pump (not shown) is used to inject the rinse fluid through the rinse passage  52 . A second (not shown) pump is used to withdraw the rinse fluid. 
     Referring to FIG. 4, movement of the needle  20  is controlled by a driver  22  which causes the needle  20  to extend and retract. In a preferred embodiment the driver  22  includes an electric motor  21 . The motor  21  has a shaft that is connected to a scotch yoke mechanism  54 , which translates rotary motion to linear motion. Needle  20  rides on a pin  56  connected to the scotch yoke mechanism  54  causing the needle  20  to move up or down during operation. Movement of the needle  20  is controlled by electric circuitry illustrated in FIG.  2 A. Switches  24  are used to control the piercing and retracting strokes of the needle  20 . 
     For example, to indicate needle position, one switch is open when the needle  20  is fully retracted, while another switch is open when the needle  20  is fully extended. A safety switch  24   a  interlocks the driver  22  with holder  14 . When the tongue  34  of the holder  14  is in the open position, safety switch  24   a  is open, and needle  20  cannot be extended through the aperture in cup  18 . When a vial or tube is placed in holder  14  and the tongue  34  moves to the closed position, switch  24   a  closes, allowing driver  22  to extend the needle  20  to pierce the pierceable cap of the vial. 
     Prior to running samples, the operator should adjust the height of the holder  14  to fit the size of the vials to be tested. The operator loosens the clamp handle  40 , allowing the holder  14  to slide on the ways  26  and moves the holder  14  upward or downward. A vial is then placed in the cup  18  (cap end down). The opposite end of the vial is positioned in the holder  14  until the interlock switch  24   a  is tripped. The spring applying a bias off the center axis of the tongue  34  keeps it in either an open or closed position in the holder  14 . 
     After inserting the cap end of a vial or tube in the cup  18 , the operator pivots the opposite end of the vial or tube into the holder  14 . When the tongue  34  is in the open position, the tube or vial first contacts the beveled front of the tongue  34  and kicks it open. With the tongue  34  in the open position the capped end of the vial  23  enters and is engaged by the conical-shaped pocket area of cup  18 , and with a pivoting motion is further inserted to close the holder  14 . As the closed uncapped end of the vial moves into the recessed portion of the tongue  34  of the holder  14 , it trips the recessed interlock switch  24   a , which enables the electric motor drive  22  to function. The vial seats securely and stays in position until the needle  20  is fully retracted. The operator may then remove the vial from the holder  14 . If an attempt is made to remove the vial  23  from the holder  14  when the cap  25  is being pierced, the interlocking switch  24   a  will disable the motor drive  22  to prevent injury to the operator by unintended movement of the needle  20 . 
     The present invention may be embodied in other variant forms where the variation does not substantially differentiate from the essential novelty and uniqueness revealed in the foregoing disclosure. Reference should therefore be made to the appendant claims rather than the foregoing specification, as indicating the scope of the invention. It should be understood that many modifications, variations and changes may be made without departing from the spirit and scope of the invention as defined in the claims.