Abstract:
With the use of a selectable fluid path assembly, the recovery and cleaning of the liquid path line is possible. Selecting the primary use path permits a syringe assembly to be filled with fluid in a positive pressure supplied fluid system. When the secondary fluid path is selected, the fluid in the line can be reversed and with negative pressure pulled back through the line up to the pump motor and moved back into the bottle. With air following the liquid a bubble can be detected and stop the fluid reversal. With the use of a selectable fluid path assembly, the prevention of contamination of the remaining liquid in the bottle can be prevent through proper use of the fluid recovery system.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the priority benefit of U.S. provisional application No. 61/209,755 filed on Mar. 11, 2009, the contents of which are hereby incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates to syringe injection systems and methods of recovery of fluids from syringe injection systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is often desirable to treat large numbers of individuals or animals with a substance, such as a medication or other material, with speed, efficiency, accuracy, and accurate maintenance of records. As an example, the livestock industry requires routine vaccinating, medicating and/or treating of cattle or livestock. Failure to properly treat the animals can result in significant losses to the rancher or feedlot owner or other party responsible for the livestock. Typically, the livestock is segregated into groups according to general size and weight. It is common upon arrival at the processing station for cattle to be vaccinated for viral respiratory disease, implanted with a growth stimulant, and treated for internal and external parasites. In high stress situations, antibiotics are sometimes administered simultaneously with vaccinations. 
         [0004]    To assist in vaccination large numbers of animals, able syringe injections systems have been developed that allow a syringe to be filled by a pump from a fill bottle, where the dose loaded into the syringe can be effectively controlled and varied as needed to tailor the injections by animal weight. Such a syringe system does not require the cumbersome filling of the syringe from a separate fluid container, allows for repeated injections, using precisely predetermined but differing dosages, and are capable of operating in a wide range of environments. One such syringe system is shown in U.S. Pat. No. 7,056,307, hereby incorporated by reference As shown in  FIG. 1 , a syringe system will include a fill or reservoir bottle  2 , a syringe  10 , a highly accurate reversible motor  4  and pump  4  combination, and various fluid lines between the components. The system unit pump  4  is a valveless, substantially viscosity-independent pump. The pump  4  used in the system is manufactured by Fluid Metering, Inc. (“FMI”) of Syosset, N.Y., Models STH and STQ. To the extent necessary to understand the features and construction of the pump  4  manufactured by FMI, Applicant hereby incorporates by reference U.S. Pat. Nos. 5,279,210; 5,246,354; 5,044,889; 5,020,980; 5,015,157; and 4,941,809. A complete FMI pump cycle includes a ½ cycle of gather fluid from the reservoir lines, and a second ½ cycle of pumping the gathered fluid out the fluid line  6  (that is, the pump is not continuously pumping fluids as would, for instance, and impeller type pump). However, instead of use of a reversible motor/pump, two pumps may be used, (one pumping to the syringe, one pumping from the syringe), and a switch employed to select the desired pump. 
         [0005]    Animal medicine injection dispensing systems used expensive medications which are wasted when the remaining amount left in the line is not used for medicating. Often, the fluid bottle is removed from the system, and materials remaining in the fluid lines and syringe are wasted, disposed of by dispensing the materials out through the dispensing tip, or in some cases, dispense back into the bottle for later use. This is poor practice, as the dispensing tip could be contaminated and returning materials through the tip could contaminate the remaining volume in the bottle. A system is needed to easily recover fluids in a syringe system without the possibility of contamination. 
       SUMMARY OF THE INVENTION 
       [0006]    The fluid recovery system includes two fluid paths, a first path that preferably terminates in a check valve or other one way valve, though it could open to directly to the atmosphere, and a second part that terminates into the syringe, such as at a syringe valve body. The system also includes a switch that allows the fluid line from the pump to be switched between the two paths. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a block diagram of representation of a basic syringe system. 
           [0008]      FIG. 2  is one embodiment of a syringe that may be used in the syringe system. 
           [0009]      FIG. 3   a  is a cross section side view of a plunger embodiment of the fluid recovery system in direct path mode. 
           [0010]      FIG. 3   b  is a cross section side view of a plunger embodiment of the fluid recovery system in vent path mode. 
           [0011]      FIG. 4   a  is a detail cross section side view of a first plunger embodiment of the fluid recovery system in direct path mode. 
           [0012]      FIG. 4   b  is a detail cross section side view of a first plunger embodiment of the fluid recovery system in vent path mode. 
           [0013]      FIG. 5   a  is a cross section side view of a second plunger embodiment of the fluid recovery system in direct path mode. 
           [0014]      FIG. 5   b  is a cross section side view of a second plunger embodiment of the fluid recovery system in vent path mode. 
           [0015]      FIG. 6   a  is a detail cross section side view of a rotatable embodiment of the fluid recovery system in direct path mode. 
           [0016]      FIG. 6   b  is a detail cross section side view of a rotatable embodiment of the fluid recovery system in vent path mode. 
           [0017]      FIG. 7   a  is a cross section side view of a rotatable embodiment of the fluid recovery system in direct path mode. 
           [0018]      FIG. 7   b  is a cross section side view of a rotatable embodiment of the fluid recovery system in vent path mode. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The invention will be described within a syringe system, where a syringed is filled by operation of a reversible pump, such as described in U.S. Pat. No. 7,056,307 or 6,989,000, both of which are incorporated by reference. A basic system is shown in  FIG. 1 . As shown in  FIG. 1 , a syringe system will include a fill or reservoir bottle  2 , a pump  4  and motor  5 , various fluid lines between the components and a syringe  100  shown in  FIG. 2 . Fluid is pumped from the reservoir bottle  2  to the syringe  100  (shown in  FIG. 2 ) and enters the syringe at a syringe inlet  111  which controls the flow of fluids within the syringe  100 . 
         [0020]    A schematic of one syringe embodiment is shown in  FIG. 2 . As shown, the syringe  100  is a includes a syringe body  110  having a front grip  120  and rear grip  130 , with one of the grips movable with respect to the other (here the rear grip  130  is movable with respect to an integral front grip  120 ). The two gripped syringe is preferred, but not required (e.g., the plunger could be separately operated). The syringe  100  includes a dispensing tip  115  to which a needle may be attached. The syringe body  110  includes a hollow barrel chamber  109  with a shaft plunger  140  slidable in the interior of barrel chamber  109 . By squeezing the two grips, the shaft plunger  140  is forced into the barrel chamber  109  to discharge fluids stored in the barrel chamber  109  through the dispensing tip  107 , and ultimately, to an injection needle (not shown) attached to the dispensing tip  107 . Most pump finable syringes include a valve body  160  having internal valves to control fluid movement within the syringe  100 , such as the valve bodies depicted in U.S. Pat. No. 6,989,000. For purposes of the fluid recovery system, there are not preferred syringe valve systems. Fluids enter the syringe through the syringe inlet  111 , here shown as being on the valve body  160 . 
         [0021]    To this base syringe injection system is added a fluid recovery system  20 . In the embodiment shown in  FIG. 2 , the recovery system is located at the input of the fluid line  6  to the syringe  100  (that is, at the syringe inlet). As shown, the recovery system is shown attached to a syringe valve body  160 , however, the fluid recovery system  20  could be placed anywhere on the fluid line  6 . It is preferred to attach the recovery system directly to the syringe  100 , to provide for the efficient recovery of fluids, later described. In the embodiment shown in  FIGS. 3   a  &amp;  3   b , the system includes a path body  21  and a fluid switch  22 . Path body  21  is a block (such as inert plastic, stainless, aluminum) having two channels or fluid paths therethrough: a direct path  30 , and a vent path  40 . Both paths have an inlet  41  and  31  respectfully, and outlets  42  and  32  respectfully. Vent path  40  contains in a check valve  45  or other means to removably seal vent path (such as an insertable plug, threaded cover, etc). As shown, the check valve  45  is positioned near the vent path outlet  42 . Vent path may simply open to the atmosphere, but this is not preferred. An air filter  47  may also be positioned in the vent path  40 , or at the vent path outlet  42 . Also a cap or cover is preferably used to cover the terminal end of the vent path when not in use. 
         [0022]    As shown in  FIGS. 4   a  &amp;  4   b , fluid switch  22  is a housing  23  having a slidable plunger  24  positioned therein. Fluid line  6  is coupled to the switch housing  23  (such as with a quick connect joint) at connect  27 . Two hollow tubes or channels are fixedly positioned on the plunger  24 : a direct switch channel  25  and a vent switch channel  26 , each having inlets and outlets (the paths may be channels drilled through the plunger, or tubes attached to the plunger) By sliding the plunger  24  between a first position (shown in  FIGS. 3   a  &amp;  4   a ) to a second position (shown in  FIGS. 3   b  &amp;  4   b ), the operator can choose to connect either the direct switch channel  25 , or vent switch channel  26 , to the fluid line  6 . 
         [0023]    In the plunger position shown in  FIG. 3   a , the switch position fluidly connects direct switch channel  25  between fluid line  6  and direct path  30 , while blocking the vent path inlet  41 . In this position, the direct path outlet  32  is sealingly aligned with the syringe inlet  11  (here shown on the valve body  160 ), and direct path inlet is sealingly aligned with direct switch channel  25 . In the plunger position shown in  FIG. 3   b , vent switch channel  26  is fluidly connected between fluid line  6  and the vent path  40 , while the direct path inlet  31  is blocked, thereby connecting fluid line  6 , through the vent path  40  and check valve  45  (if so equipped), to the atmosphere. 
         [0024]    In a second embodiment shown in  FIGS. 5   a  &amp;  5   b , the recovery system is located at the input of the fluid line  6  to the syringe  100  (that is, at the syringe inlet). As shown, the recovery system is shown attached to a syringe valve body  160 . This embodiment uses a type of fluid switch  22  that is a rotatable fluid switch. One embodiment of a rotatable fluid switch is shown in  FIGS. 5   a  &amp;  5   b . In this embodiment, the switch body  22  is rotatably attached within the path body  21 . Rotation may be in a vertical plane (e.g. in a plane parallel to the plane containing syringe handles), or a horizontal plane (e.g. in a plane perpendicular to the plane containing syringe handles) or even an intermediary plane. If rotation occurs in a vertical plane, as shown in  FIGS. 5   a,    5   b ,  6   a  and  6   b , it is preferred that the lower surface of the path body  21  and the upper surface of the fluid switch housing  22  be curved to accommodate a seal between the two bodies (see detail of  FIG. 5   a ). 
         [0025]    Within the rotatable fluid switch housing  22  is a single fluid path or fluid channel  52 . The fluid switch housing  22  is rotatable between two positions, a first position connecting the single path outlet  51  to the direct path inlet  31  (see  FIG. 5   a ), and a second position, connecting the single path outlet  51  to the vent path inlet  41  (see  FIG. 5   b ). The fluid line  6  remains connected to the single path inlet  53 , and hence moves with the rotation of the fluid switch housing  22 . 
         [0026]    If rotation occurs in a horizontal plane, as shown in  FIGS. 7   a  &amp;  7   b , a rotatable disk  49 , rotating around a pivot point  48 , is rotatable between two positions, a first position connecting a single disk fluid channel outlet  46  to the direct path inlet  31  (see  FIG. 7   a ), and a second position, connecting the single disk fluid channel outlet  46  to the vent path inlet  41  (see  FIG. 7   b ). The fluid line  6  remains connected to the single disk fluid channel outlet  46 , and hence moves with the rotation of the rotatable disk  49 . 
         [0027]    Other embodiments of a plunger type switch are may also be utilized. For instance, the plunger may carry a single tube  50 , where the tube inlet remains connected to the fluid line  6 , and the tube outlet is movable by operation of the plunger between the vent path  40  and direct path  30 . In this configuration, that portion of the tube  50  near the tube inlet must bend or flex between the two positions, and for this reason, is not preferred—the flexing or bending of the tube  50  creates a potential fracture point in the flexible tube. An alternative arrangement using a single channel  50  in the switch housing that avoids the need for flexing can be achieved by allowing the switch housing  22  to be slidable with respect to the path body  21 . In this embodiment (not shown), the input fluid line  6  remains connected to the inlet of the channel  50 , and the switch housing  22  acts as a plunger, slidable between a first position (connecting the single path  50  outlet to the vent path inlet  41  and blocking the direct path inlet), and a second position (connecting the single path  50  outlet to the direct path inlet  31 , and blocking the vent path inlet). 
       Fluid Recovery Operation 
       [0028]    The fluid recovery system thus has two operator selected operating positions: a first fill position, fluidly connecting the fluid line  6 , through the recovery system (direct path), to the inlet of the syringe, and a second recovery position that fluidly connects the fluid line  6 , through the recovery system (vent path), to a vent and the atmosphere. When the fill position is selected, the pump  4  and motor  5  should be placed in the normal mode, pumping fluids from the reservoir bottle  2  through the pump  4  to the flow control system, and then to the syringe. When the recovery position is selected, the motor  5  pump  4  should be in reverse mode, pumping fluids from the fluid line  6 , through the pump  4 , back to an up-righted reservoir bottle  2   a . In the recovery position, the fluid line  6  is connected to the atmosphere via the vent path  40  in the fluid recovery system, so no back pressure will be created when pumping from the syringe. 
         [0029]    In all full fluid line recovery operations, it is preferred that reservoir bottle  2   a  be up-righted (See  FIG. 1   b ) to prevent the build up of pressure in the reservoir bottle  2   a , which could result in fluid being pushed out the bottle vent. Additionally, shown in the fluid line to the reservoir bottle  2  is a bubble detector  105 , such as a Lifeguard ultrasonic air bubble detector from MOOG, Inc. of Stuttgart, Germany). 
         [0030]    During partial fluid line recovery operations, which can occur during the syringe fill operation, fluid is extracted from the reservoir bottle  2  by the motor  5  pump  4 , as the fluid level goes down, air will be pulled into the fluid line where the bubble detector  105  can be tied to a motor control to send a command to shut off the motor and prompt the operator (to replace the empty bottle with a replacement bottle) when bubbles are detected in the fluid line. After a fluid bottle is replaced the motor can be controlled to run in reverse to push the air out of the line between the sensor and the reservoir bottle  2 , then back to forward to pull liquid into the line replacing the air, this will insure that there will be no air in the fluid line that could end up in the syringe, causing the incorrect volume to be dispensed.