Abstract:
The liquid transfer apparatus includes a liquid storage drum, a liquid transfer structure on said storage drum and a transfer container positionable on the liquid transfer structure. The liquid transfer structure includes a pump, a level sensor and a riser hose member. The riser hose member has one end in the drum and another end in communication with the pump. The pump and the level sensor remove a desired amount of the liquid from the storage drum through the riser hose member into the transfer container. The riser hose member includes a rigid riser tube inserted into said drum, a free end of the riser tube resting on or adjacent a bottom surface of the drum, allowing the drum to be completely emptied of the liquid.

Description:
[0001]    This application claims the priority of application for U.S. Letters Patent Serial No. 60/460,898, filed Apr. 7, 2003 entitled LIQUID TRANSFER SYSTEM FOR DIALYSIS CHEMICALS. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to a system for transferring the liquid chemicals used during dialysis from storage drums to a dialysis machine.  
         BACKGROUND OF THE INVENTION  
         [0003]    The major role of the kidneys is to remove waste products and excess fluid from the body through urine. They also regulate the body&#39;s salt, potassium, and acid content, and they produce hormones, including erythropoietin, which stimulates the production of red blood cells. When the kidneys&#39; ability to remove and regulate water and chemicals is seriously impaired, waste products and excess fluid build up in the body, causing swelling and other symptoms. Dialysis is one way of replacing the critical function of failing kidneys, thereby sustaining life. Through dialysis, the blood is cleaned and filtered, ridding the body of harmful waste products and extra salts and fluids.  
           [0004]    There are two types of dialysis: hemodialysis and peritoneal dialysis. In hemodiaylsis blood is passed through an artificial kidney called a dialyzer, outside the body. Peritoneal dialysis uses a filtering process similar to hemodialysis but uses a person&#39;s own peritoneal lining in the abdomen to do the filtering.  
           [0005]    During hemodialysis the dialyzer includes a selectively permeable membrane which allows toxic fluids and waste to pass through. The fluid used to clean the blood is called dialysate. By controlling the chemicals in the dialysate, the dialysis machine controls the transfer of solutes according to the doctor&#39;s prescription. Dialysis machines control the chemicals in the dialysate by mixing dialysis fluid concentrates, which are strong versions of the chemicals, acetate or sodium bicarbonate plus other acid based solutions, with purified water.  
           [0006]    Traditionally, such dialysis chemicals come in 55-gallon drums. To transfer the chemicals from the drum to the dialysis machine, a transfer jug is filled from the drum through one of the bungholes in the top of the drum using an inserted tube and a hand or electric pump. The jug is placed on the dialysis machine and the solution is drawn into the machine as needed.  
           [0007]    This traditional transfer process has several disadvantages. If distracted while filling the bucket, overflow and spillage can occur. The chemicals can eat flooring, even concrete. Also, the drum spigot is typically not at the drum&#39;s lowest point, but is spaced up from the bottom of the drum. Thus, a drum is not generally completely emptied. Residual chemicals are left in the bottom of the drum. This traditional method is messy, corrosive and inefficient.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view of the liquid transfer system for dialysis chemicals in accordance with the present invention shown mounted to the lid of a drum containing such chemicals;  
         [0009]    [0009]FIG. 2 is a front view of the liquid transfer system shown in FIG. 1 but with the riser assembly thereof removed from the drum for clarity and showing the transfer container in hidden lines;  
         [0010]    [0010]FIG. 3 is a vertical sectional view taken along line  3 - 3  of FIG. 2;  
         [0011]    [0011]FIG. 4 is a vertical sectional view taken along line  4 - 4  of FIG. 2; and  
         [0012]    [0012]FIG. 5 is an electrical schematic diagram of the transfer system in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0013]    A liquid transfer system  10  for dialysis chemicals in accordance with the present invention is shown in FIG. 1. The dialysis chemicals are stored in the drum  12  and are pumped from the drum to a transfer container  14  for ultimate deposit in a dialysis machine (not shown). The transfer container is shown in broken lines in FIGS. 2 and 4.  
         [0014]    Drums, such as drum  12 , in which dialysis chemicals are typically stored have approximately a 55-gallon capacity and include a circular top lid  16  and two diametrically spaced bungholes  18  and  18   a.  The liquid transfer system  10  is mounted to the top lid  16  of the drum  12 . The system  10  includes a specially configured body member  20 , a conventional riser hose assembly  22 , an electrically operated pump  24  (FIG. 3) and a level sensor  26 .  
         [0015]    The body member  20  includes a support shelf  30 , which rests across the drum&#39;s lid  16 . Specifically, as seen in FIG. 1, support shelf  30  has two grooves  32  formed in the bottom surface of the shelf  30 , one groove being formed adjacent each end of the shelf for receiving opposed edges of the top lid  16 . The body member  20  further includes a box-like housing  34  which is secured to and extends upwardly from one end of the support shelf  30  and a wing  50  which extends horizontally from the housing  34  and upwardly from the shelf  30 . The pump  24  and level sensor  26  are mounted in the housing  34 .  
         [0016]    The housing  34  includes an inner wall  36 , an outer wall  38  and a front wall  40 . The inner wall  36  has a square recessed portion  42  within which the level sensor  26  extends. Wing  50  extends outwardly from the rear end of the inner wall  36  as may be appreciated from FIGS. 1 and 4, and has an inverted U-shaped upper portion that presents a depending front lip  51 .  
         [0017]    The rear wall  41  of housing  34  (FIG. 3) has apertures through which a supply hose  56  and a power cord  46  can extend. A pair of switch buttons  65  (start) and  68  (stop) are mounted on the front wall  40 . The wing  50  and adjacent inner wall  36  cooperate to present a recessed area in which the transfer container  14  rests to hold it in position on the support shelf  30  adjacent the level sensor  26  and beneath an outlet spigot  52  that extends through inner wall  36  at its upper rear corner and downwardly behind lip  51 .  
         [0018]    As best shown in FIG. 2, the riser assembly  22  includes a riser tube  54 , the hose  56  and connection tubing  63 . The tube  54  is preferably formed of rigid plastic for insertion in the drum  12  through the bunghole  18   a.  The free end of the tube  54  extends to the bottom surface of the drum  12 . A threaded cap  60  mounted to the opposite upper end of the tube  54  screws into bunghole  18   a  to secure the tube  54  in the drum  12 .  
         [0019]    The hose  56  is preferably formed of flexible tubing unitarily and integrally connected to the tube  54 . The hose  56  extends from just above the threaded cap  60  through the rear wall  41  of the housing  34  and is secured to the intake of pump  24  by an elbow  62 . The connection tubing  63  communicates the pump  24  with the spigot  52  (FIG. 3).  
         [0020]    The riser assembly  22  typically includes a manual diaphragm pump  58 , which is not used with the present invention. It is secured to the end of the tube  54  opposite the free end thereof and just above the connection with hose  56 .  
         [0021]    The pump  24  is preferably a conventional self-priming, diaphragm, automatic demand pump. In particular, the pump  24  may comprise a positive displacement three-chamber diaphragm pump provided with a check valve  64  that closes when the pump is not in operation to prevent reverse flow and maintain the liquid level in the hose  56 . One suitable pump is the 2088 Series Diaphragm Pump, Model No. 2088-594-154, manufactured and sold by SHURflo® Pump Manufacturing Company. Of course, any suitable electrically controlled pump may be used.  
         [0022]    A level sensor  26  is electrically connected to the pump  24  to control flow as will be discussed. Level sensor  26  is preferably a capacitance proximity switch which senses liquid levels through a tank wall. Such a sensor  26  has the ability to respond to a liquid level that it “sees” through a plastic container wall. Other types of level sensors may alternatively be used. The sensor  26  is mounted in the recessed portion  42  of the inner wall  36  of the box-like housing  34  at a level spaced above the support shelf  30  at the desired height. One such capacitance proximity switch is sold by Levelite under product No. GAL100100.  
         [0023]    To assemble the liquid transfer system  10  as shown in FIG. 1, the bunghole  18   a  is opened in the lid  16  of drum  12  containing dialysis chemicals. The riser tube  54  of the assembly  22  is inserted through the bunghole  18   a  into the drum  12 . The length of the tube  54  corresponds to the height of the drum  12  so that when installed, the bottom of the tube  54  is immediately adjacent or rests on the bottom of the drum  12 . This allows the drum  12  to be completely emptied of chemicals. The tube  54  is secured in the bunghole  18   a  by the threaded cap  60 .  
         [0024]    The body member  20  is placed over the top lid  16  of the drum  12  with the grooves  32  receiving and engaging the edge of the top lid  16 . Now, a plastic liquid transfer container  14  can be placed on top of the support shelf  30  such that it is held in place by the wing  50  of the body member  20 , immediately adjacent the sensor  26  and with the mouth of the container  14  immediately beneath the outlet spigot  52 , as shown in FIGS. 2 and 4.  
         [0025]    Once the container  14  is properly positioned as illustrated and described above, it can be filled with the liquid chemicals contained in the drum  12 . The pump  24  and sensor  26  are activated by depressing start button  65 . The desired amount of liquid chemicals are pumped from the drum  12 , through tube  54 , hose  56 , tubing  63  and spigot  52  and into the container  14 . When the liquid chemicals reach the level at which the sensor  26  is mounted, the sensor  26  deactivates the pump  24  and immediately stops the flow of any liquid into the container  14 , which may then be removed. If the user desires that the container be only partially filled, the stop button  68  may be depressed at the desired level.  
         [0026]    The electrical operation and interaction of the pump  24  and sensor  26  are shown in the schematic diagram of FIG. 5. The system  10  may be operated from any available electrical power source such as the AC source  70  illustrated. When not operating or deactivated, the “start” switch responsive to push button  65  is open as shown. Momentarily depressing push button  65  closes a circuit from source  70  through the closed contacts of the “start” switch, the liquid sensor  26  and the coil of a relay  72 . When the relay  72  pulls in, it closes two normally open contacts  74  and  76  to latch the relay through the now-closed contact  74  and maintain the relay energized. This completes a power circuit via line  78  through parallel-connected pump  24  and check valve  64  to closed contact  76  and line  80 , thereby completing the circuit from source  70 . Accordingly, pump  24  is activated and check valve  64  opens to deliver liquid through spigot  52  to container  14 . When the liquid reaches the level of the sensor  26 , the proximity switch opens and relay  72  drops out, thereby terminating operation of the pump  24  and closing the check valve  64 . If the user desires that the container be only partially filled, or wishes for any reason to override the automatic system and terminate operation of the pump  24 , the push button  68  associated with the normally closed “stop” switch may be momentarily pressed to de-energize the coil of relay  72  and open the contacts  74  and  76 .  
         [0027]    After the container  14  has been filled to the desired level, it can be removed from the support shelf  30 , transferred to and the liquid therefrom placed at the dialysis machine. Container  14  is refilled as required. Accordingly, the liquid transfer system provides an efficient, clean and safe method of rapidly transferring liquid dialysis chemicals to the dialysis machine.  
         [0028]    It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable equivalents thereof.