Abstract:
The invention concerns an arrangement to couple an intravenous hose having a roller clamp with an infusion pump. A hose clamp has clamping surfaces in the form of legs which can move relative one another about a hinge, the legs being enveloped on their outside by a biased clamping spring, and the device is formed by an expander rib that is fastened on the inside of the door and can be brought into engagement with the legs of the hose clamp so to produce the open position after closing the door to expand the legs. The housing has a receiver, into which the hose clamp can be snapped, and that a locking device is present in the housing that prevents the closing of the door if the hose clamp is not inserted into the receiver and permits the closing of the door when the hose clamp is fully inserted.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention concerns an arrangement for coupling an intravenous hose having a roller clamp with an infusion pump with a housing to deliver a medicinal solution to a patient. 
         [0003]    2. Description of the Related Art 
         [0004]    An arrangement for coupling an intravenous hose with an infusion pump is known from EP 238 227 B1. This, however, requires a clamping part with a drop-shaped opening, through which the hose passes and is moved back and forth in this drop-shaped opening by a device between the open and closed position. In addition, a locking device has to be provided on the pump to place the clamping part with the pump initially in the closed position. In the case of this prior known device the intravenous hose has to be first threaded through the drop-shaped opening, for which purpose the hose has to be released at one end of the infusion set. The intravenous hose can also be inserted into the housing of the infusion pump without the hose clamp and following this the door of housing can be closed. A person may have the impression that this arrangement is ready for operation, thus resulting in improper operation. 
         [0005]    The provides the operators, such as carers, nurses and doctors with a system or an arrangement, or to improve the arrangement mentioned in the introduction in such a manner, that an uncontrolled delivery of infusion solutions of any kind to the patient will be ruled out. In other words, improper operations by the operating personnel should be prevented as far as possible. 
         [0006]    According to the invention, the arrangement mentioned in the introduction will be achieved by that the hose clamp has clamping surfaces in the form of legs which can move relative one another about a hinge, the legs being enveloped on their outside by a biased clamping spring, and that the device is formed by an expander rib that is fastened on the inside of the door and can be brought into engagement with the legs of the hose clamp so that to produce the open position after closing the door to expand the legs, and that the housing has a receiver, into which the hose clamp can be snapped, and that a locking device is present in the housing that prevents the closing of the door if the hose clamp is not inserted into the receiver and permits the closing of the door when the hose clamp is fully inserted. 
         [0007]    The arrangement according to the invention has also a simple construction and therefore can be produced economically, while it also ensures the exclusion of risk potential caused by improper operation. 
         [0008]    In the following a preferred embodiment is explained in detail based on the drawing so that to achieve a better understanding of the invention. It has to be clarified, however, that the invention is not limited to this embodiment. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention provides an arrangement for coupling an intravenous hose having a roller clamp with an infusion pump with a housing to deliver a medicinal solution to a patient, comprising: 
         [0010]    a hose clamp that can be coupled with the intravenous hose and can be displaced between an open position, in which the medicinal solution can flow through the hose, and a closed position, in which the hose is closed by the hose clamp, 
         [0011]    a device mounted on the door or lid of the housing, that can be engaged with the hose clamp to bring it to the open position from the closed position, wherein 
         [0012]    the hose clamp has clamping surfaces in the form of legs which can move relative one another about a hinge, the legs being enveloped on their outside by a biased clamping spring, 
         [0013]    wherein the device is formed by an expander rib that is fastened on the inside of the door and can be brought into engagement with the legs of the hose clamp so that to produce the open position after closing the door to expand the legs, 
         [0014]    wherein the housing has a receiver, into which the hose clamp can be snapped, 
         [0015]    and wherein a locking device is present in the housing that prevents the closing of the door if the hose clamp is not inserted into the receiver and permits the closing of the door when the hose clamp is fully inserted. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective illustration of the arrangement according to the invention. 
           [0017]      FIG. 1A  is a perspective illustration of the arrangement according to the invention, with the door of the infusion pump open prior to starting up. 
           [0018]      FIG. 1B  is a schematic perspective illustration of a detail of  FIG. 1 , enlarged. 
           [0019]      FIG. 2  is a further schematic perspective illustration of a detail of  FIG. 1 , enlarged. 
           [0020]      FIG. 3  is a further schematic perspective illustration of the receiver with the locking slide, in a detail from the interior of the pump. 
           [0021]      FIG. 4  is a further schematic perspective illustration of the spring-loaded locking slide. 
           [0022]      FIG. 5  is a schematic detailed view, similar to  FIG. 2 , but with the hose clamp locked in the receiver, with the door opened. 
           [0023]      FIG. 5A  is a further schematic perspective view in detail, wherein parts are removed and the door is swung upward, while the locking slide does not yet lie on the stop rib. 
           [0024]      FIG. 5B  is a schematic view, similar to  FIG. 5A , but with the door closed and the legs of the hose clamp are spread apart by the expander rib, so that the hose can be flown through freely. 
           [0025]      FIG. 5C  is a further schematic perspective illustration in a detail, wherein the door is illustrated partly cut away during the opening process. 
           [0026]      FIG. 6  is a perspective illustration of the arrangement according to the invention with the hose inserted without hose clamp, so that the door is not fully closed. 
           [0027]      FIG. 6A  is a schematic perspective illustration in detail with partly cut away door, that due to locking slide, pressing against the stop, is not closed. 
           [0028]      FIG. 7  is a schematic perspective illustration of a portion of the pump housing with safety magnets. 
           [0029]      FIG. 8  is a schematic perspective illustration of the hose clamp according to the invention with a steel bending spring. 
           [0030]      FIG. 9  is a schematic perspective illustration of the receiver or the insert module with printed circuit board and sensor. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    The overall arrangement according to the invention is designated in  FIG. 1  by  10 . It comprises the usual infusion set  8  with a drip chamber  9  having an insertion mandrel, that is inserted into an infusion flask  6  containing the medicinal solution, and a hose clamp  11  for the hose  12  and an infusion pump  14 , provided in a housing. 
         [0032]    When using volumetric infusion pumps  14 , the roller clamp  11  has only the function to clamp the hose  12  after the infusion has been prepared (connection of the infusion set with the infusion flask, filling and venting the set), so that to prevent the outflow of the fluid until the hose  12  is secured in the drive of the pump  14 . After placing the hose  12  into the pump and closing the door  13  of the pump, the hose  12  is clamped by the combination of the peristaltic drive and the pressure plate  17 . The roller clamp  11  of the infusion set is subsequently opened, and the system or the arrangement  10  is checked to see whether the pump  14  totally clamps the hose  12 . 
         [0033]    Thus during the feeding operation of the pump  14  the roller clamp  11  is fully open. If during the operation of the pump  14  a person opens the door  13  of the pump without previously closing the roller clamp  11 , will bring with it the danger that the infusion fluid will reach the patient without any control. To prevent this, the pump  14  according to the invention is provided with a so called anti-free-flow hose clamp  16 . In this case after opening the door  13  of the pump a closing device closes the intravenous hose off to prevent the flow. 
         [0034]    Following this the user has to close the roller clamp  11  before the hose  12  is removed from the pump  14 . 
         [0035]    As mentioned in the introduction, this is where the potential danger of some existing arrangements and systems become obvious, since the hose  12 , after its removal from the pump  14 , is continued to be closed off only when the user, as already described, had already closed the roller clamp  11  on the infusion set  8 . However, if the user has not closed the clamp  11  and the infusion set  8  is removed from the pump  14 , the infusion solution will flow uncontrolled to the patient. Thus the patient is exposed to considerable danger due to an error in the operation of the infusion set and the pump  14 . 
         [0036]    To start up the arrangement  10  according to the invention the following steps have to be carried out: 
         [0037]    1. Preparation of the infusion set  8 : 
         [0038]    The roller clamp  11  is closed. 
         [0039]    The drip chamber  9  is inserted into the infusion flask  6 . 
         [0040]    The drip chamber  9  is filled. 
         [0041]    The roller clamp  11  is opened and the infusion set is vented. 
         [0042]    The roller clamp  11  is closed. 
         [0043]    2. Door  13  of the pump is opened. 
         [0044]    3. The intravenous hose  12  is placed horizontally into the pump  14  (see  FIGS. 1A and 1B ). The hose clamp  16  is placed into the receiver  15  provided for this purpose in the pump. Prior to placing the hose clamp  16  into the receiver  15  of the pump  14 , the clamp  16  is opened, i.e. at this stage the hose  12  is clamped only by the closed roller clamp  11 , however, the hose clamp  16  is still open and consequently its position on the hose  12  can be changed along the hose. 
         [0045]    With the clamp  16  not being inserted, the locking device of the pump  14 , constructed as a locking slide  20 , is biased by a spring  23  against a bottom stop, that presses the pump  14  (see  FIGS. 2 and 3 ). 
         [0046]    By inserting the hose clamp  16  into the receiver  15  of the pump  14  the locking slide  20  is pressed upwards in the direction of the arrow and retains this position (see  FIGS. 5 and 5A ). At the same time the hose  12  is secured in the pump  14  and the hose clamp  16  is pushed to the back of the receiver  15 . Due to this the hose clamp  16  is shifted in that region over the hose  12 , in which the hose clamp  16  clamps the hose  12 . 
         [0047]    The closing of the door  13  of the pump is shown in  FIGS. 5A and 5B . The door  13  of the pump can be closed only when the hose clamp  16  is inserted into the receiver and thus the locking slide  20  is pushed into its top position. 
         [0048]      FIG. 5A  shows that the door  13  can be closed now, since it is no longer blocked by the locking slide  20  abutting against the stop  25 . 
         [0049]    4. To operate the pump  14  it is necessary to open the hose clamp  16 , because when the door  13  is closed the hose  12  is unclamped between a fixture  17  in the form of a pressure plate of the door  13  of the pump and the peristaltic drive, what is achieved by that after fully closing the door  13  of the pump the hose clamp  16  will be opened by an expander rib  18  situated in the door  13 , as this is indicated by arrows (see  FIGS. 5A and 5B ). 
         [0050]    5. After closing the door  13  of the pump the roller clamp  11  on the infusion set  8  can be opened and the set can be checked by the peristaltis of the pump  14  (the infusion solution must not flow) with regard to a total unclamping of the hose  12 . The pump  14  can be started up. 
         [0051]    To properly terminate the operation of the pump  14  the following procedure is carried out: 
         [0052]    1. The roller clamp  11  is closed. 
         [0053]    2. The door  13  of the pump is opened. 
         [0054]    By opening the door  13  of the pump the hose clamp  16  is automatically closed, because the expander rib  18  of the door  13  no longer will keep the clamp  16  open. Thus the hose clamp  16  will clamp the hose  12  again automatically due to the pressure of the steel spring  21  mounted on the hose clamp  16 , as this is indicated by the arrows in  FIG. 5C . 
         [0055]    3. The hose  12  with the hose clamp  16  is removed from the pump  14 . 
         [0056]    4. After opening the door  13  the hose  12  with the clamp  16  and the spring  21  can be removed from the pump  14 . The hose clamp  16  with the spring  21  is removed from the receiver  15 , whereby the locking slide  20  is pushed back to its initial position by the spring ( FIG. 2 ). 
         [0057]    Thus, when properly operated, the arrangement  10  according to the invention with the infusion pump  14  is secured against an uncontrolled flow or so called “free flow” of the infusion solution to the patient by the manually closed roller clamp  11  on the one hand and by the automatic clamping of the hose clamp  16  on the other. 
         [0058]    The operation of the infusion pump  14  can be incorrectly terminated by various means. 
         [0059]    If, for example, door  13  of the pump is opened without the operator previously manually closing the roller clamp  11  on the infusion set  8 , the hose clamp  16 , as described above, closes the hose  12  also automatically. 
         [0060]    A further possible cause of maloperation is the starting up of the infusion pump  14  without the hose clamp  16 . The decisive improvement of the arrangement  10  according to the invention is that the infusion pump  14  cannot be operated without the hose clamp  16  with the spring  21  being inserted. This will be ensured by that the door  13  of the pump cannot be fully closed (see  FIGS. 6 and 6A ) if the hose clamp  16  with the spring  21  had not been inserted into the receiver  15 . 
         [0061]    If the hose clamping unit  16 / 21  is not inserted into the receiver  15 , the locking slide  20  is pressed by the spring to the bottom end position (cf. arrow in  FIG. 2 ). The door  13  cannot be closed because the stop rib  25  on the door  13  is exactly in the position of the locking slide  20  without the hose clamp  16  being inserted (see  FIG. 6A ). 
         [0062]    Since the door  13  of the pump cannot be closed, the pump  14  cannot be operated. Thus an unintended flow of the infusion solution to the patient is not possible, because the operator cannot close the door  13  of the pump, and consequently will not open the roller clamp  11 , closed after the preparation of the infusion, either. 
         [0063]    Because the pump  14  must not be stored with the door  13  open, the door is held by two magnets in a position, wherein the stop rib abuts against the locking slide  20 . While one of the magnets  29 ,  30  is provided in the bottom corner of the housing, the other is secured in the edge region of the door, as this is illustrated in  FIG. 7 . 
         [0064]    Moreover, the hose clamp  16  of the embodiment, that as clamping surfaces has legs  19  that can move relative one another about a hinge  17 , is asymmetric and is enveloped on the outside surfaces of the legs by a clamping spring  21  (see  FIG. 8 ). By virtue of this the operator cannot insert the infusion set  8  incorrectly reversed, i.e. against the direction of pumping. 
         [0065]    In an advantageous manner as additional safety a printed circuit board  27  with a sensor  28  is mounted on the receiver  15 , that can also be described as an insertion module (cf.  FIG. 9 , in which the receiver is illustrated on its own). The sensor  28  detects via the steel spring  21  on the hose clamp  16 , whether the clamping unit  16 / 21  had been inserted into the receiver  15 . The pump  14  can be started up only when the sensor  28  emits the signal “hose clamp  16  inserted”.