Abstract:
A tube clamp is disclosed for optional opening and closing of tubes such as infusion tubes, an infusion pump, an infusion tube set and the combination thereof, the tube clamp comprising means for opening or closing the tube clamp which interacts with a part of the infusion pump which is a lever for locking and unlocking a door in the pump, wherein an automatic opening and closing of the tube clamp can be realized without a relative movement of the tube clamp and the tube.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   The application is a continuation of prior filed U.S. application Ser. No. 10/117,317 filed Apr. 5, 2002 now abandoned, which is a continuation of prior filed copending PCT International application no. PCT/DE00/03282, filed Sep. 20, 2000, which designated the United States and on which priority is claimed under 35 U.S.C. §120 and which claims the priority of German Patent Application, Serial No. 199 47 973.9, filed Oct. 5, 1999, pursuant to 35 U.S.C. 119(a)-(d). 

   BACKGROUND OF THE INVENTION 
   The invention relates, in general, to a combination of an infusion pump with an infusion tube set wherein a tube is guided through a tube clamp for selectively closing and opening of tubes, for example infusion tubes, and in particular to a tube clamp essentially shaped as a shackle of U-shaped configuration with rigid legs, whose inner surface have projections configured with cooperating pinching edges and a flexible web by means of which the legs may be spread apart into a diverging position; with the first leg terminating in a flexible deflectable spring latch configured to point in a direction of the second leg and formed with an inner ledge surface for engagement of a free end of the second leg when the legs are squeezed together, and wherein the web and the spring latch are provided with openings for guiding the infusion tube therethrough. 
   The invention relates also to an infusion pump with a door that can be locked and unlocked for selective insertion and removal of a tube which has been placed in the tube clamp, and wherein the tube clamp can be selectively opened or locked, or respectively may be engaged in a locked position. 
   The invention also relates to an infusion tube set with a tube guided through the tube clamp for selectively opening and closing the tube. 
   A tube clamp of the type as described in the foregoing paragraphs is for example known from EP 0637 456 A1. In an open position, such tube clamps are resting loosely at the tube, thereby not obstructing the flow in the tube. When the legs of the clamp are pressed together until the spring latch engages, the clamp retains the locked position, in which the tube is being firmly pinched together. The locked position is easily unlocked with one hand, whereby the spring latch with the cam for engagement outside is bent back, thereby releasing the leg that has been locked in. 
   Tube clamps of this type are used also in infusion sets as afore-described. 
   From U.S. Pat. No. 5,817,116, a device is known for use in a medical application where removal of a tube, especially a fast removal of the device from the patient can be realized, for example during an earthquake or in a fire. By means of the device, a medical tube, which is connected to the patient, can be pinched-off at two points, so that the tube can be cut between the two pinch-off points. 
   In EP 0767 691 B1 an infusion set is described, showing slidable locking means, which are disposed with an opening for the tube. It is provided that, in a first position, the tube is guided through an area of the opening with sufficiently large dimension so as to allow the flow of the infusion matter through the tube, and in a second position the tube penetrates through an area of the opening with dimension substantially smaller than the tube diameter, so that the tube is thereby closed in liquid tight manner. A latch and an engaging hook are provided, which are disposed in such a manner, that the locking means are sliding from the first to the second position when opening the infusion set and upon closing it, from the second to the first position. 
   A drawback of this embodiment is that the tube and the locking means are moving relative to one another, which can lead to an unwanted jamming of the tube. In addition, there is the drawback that this relative movement causes wear and tear on the tube. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the invention a tube clamp is provided, wherein automatic locking and opening of the tube clamp can be realized without the relative movement between the tube clamp and the tube. As a further aspect a suitable infusion pump and an infusion tube set with an integrated tube clamp is provided. 
   These aspects and others is realized in accordance with the invention by providing an improved combination of an infusion pump and an infusion tube set wherein a tube is guided through a tube clamp which is designed to obviate the afore-stated shortcomings and drawbacks and which is configured for closing the tube when the tube clamp is engaged in a locked position; wherein the infusion pump is provided with an actuating member for cooperative engagement with a part of the tube clamp for closing or opening the tube clamp, and an infusion tube set wherein the tube is guided through the tube clamp for a selective opening and closing of the tube; and wherein the tube clamp comprises a shackle of generally U-shaped configuration, said shackle having first and second rigid legs provided with inside projections interacting with one another as pinch-off edges, and a flexible web interconnecting the legs and spreading the legs into a diverging position, said first leg terminating in a flexible spring latch which is configured to point in a direction of the second leg and formed with an undercut to define an inner ledge surface for engagement of a free end of the second leg, when the legs are squeezed together, and wherein the web and the spring latch are provided with openings for guiding the tube therethrough; the tube having actuating means responsive to a force exerted by the actuating member of the infusion pump for moving the second leg into engagement with the ledge surface of the spring latch to thereby clamp the tube in conjunction with the pinch-off edges. 
   In accordance with the invention the tube clamp is provided with means for closing the tube clamp and means for opening the tube clamp in such a manner, that by means of a force exerted by an actuating member upon the tube clamp opening or locking of the tube clamp is realized. 
   In accordance with another aspect of the invention, it is provided that the means for closing the tube clamp is configured as an element disposed at the tube clamp, on which a part of the pump can impart a vertical force upon the second leg of the tube clamp. 
   In accordance with one embodiment of the invention it is provided, that the means for closing the tube clamp is configured with an arched portion at the outer surface of the second leg, from which at least one part of a lever of the infusion pump is able to perform a roll-off motion. 
   It is an aspect of the present invention that the lever which is already present for locking and unlocking the door can also be used for opening and closing the tube. Through suitable adaptation of the tube clamp, a cooperative interaction of the tube clamp with the lever can be realized. 
   When opening the door, the lever carries out a rocking motion so that during this motion the end of the lever can roll off the arched portion at the outside of the second leg of the tube clamp and thereby brought into locked position. When locking the door, the process is reversed. 
   Advantageously, the arched portion has a toothed surface for interacting with a complementary tooth surface of the rocking lever to thereby prevent a slipping between the means which are disposed at the leg of the tube clamp for engagement with the lever and the lever itself. 
   It is within the scope of the invention, that the tube, which is placed in the tube clamp, is clamped liquid proof by means of the cooperative engagement with the closing means and the lever. 
   In another aspect of the invention, the tube clamp is latched through the co-operative engagement of the closing means of the tube clamp with the lever. 
   It is also within the scope of the invention, that the means for opening the tube clamp at the spring latch are configured as an element for cooperative engagement with at least one part of the rocking lever of the infusion pump, whereby the spring latch is being pushed away from the second leg. 
   Also within the scope of the invention, is an infusion pump with an infusion tube set, wherein the infusion pump is provided with a door activated for closing and opening by a lever, for inserting or removing a tube, which tube is guided through a tube clamp for selectively opening or closing the tube, respectively for the tube clamp being in a locked position, and wherein the infusion pump is provided with an actuating member by which a force is exerted upon the tube clamp whereby locking of the tube clamp is realized. 
   Within the scope of the invention is also the use of an infusion tube set, wherein a tube is guided through a tube clamp, by means of which the tube may be selectively opened or closed, respectively the tube clamp can be engaged in a locked position in an infusion pump. 
   One of the advantages of the invention is that it utilized the rocking lever already available, opening and closing of the tube can be realized in coordination with the locking respectively, the unlocking of the door without the need for a relative movement between the tube clamp and the tube. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which: 
     In the following paragraphs, the invention is described in connection with exemplary embodiments. It is shown in: 
       FIG. 1  a tube clamp according to the invention; 
       FIG. 2   a - 2   d  the locking of the tube clamp according to the invention by means of a lever; 
       FIG. 3   a - 3   c  further embodiments of a tube clamp according to the invention shown in a side view, in a sectional view and a top plan view; 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. 
   Turning now to the drawing, and in particular to  FIG. 1 , there is shown a tube clamp  1  that has a first leg  2  and a second leg  3  with their respective inner surfaces configured as projections  4 ,  5  which are acting as cooperating pinching edges and which are connected by means of a bending-elastic web  6  by which the legs  2 ,  3  can be brought in diverging position and spread apart. 
   A bending-elastic spring latch  7 , which serves to keep the tube clamp  1  in the locked position, is connected to the free end of the first leg and is curved in the direction of the second leg and disposed with an inward pointing lug  8 , which the free end of the second leg engages in a locking position when the legs  2 ,  3  are pressed together. The web  6  and the spring latch  7  are provided with openings  9 ,  10  for guiding the tube therethrough. The second leg is provided at its outer surface with means  11  for locking the tube clamp which is configured as an arched portion that corresponds in the present example with the shape of the lever and upon which the end  14  of the lever  12  can roll off. 
     FIGS. 2   a - 2   d  illustrate the cooperation of lever  12  and the means  11  for locking the tube clamp and the means  16  for opening the clamp. In its starting position (according to  FIG. 2   a ) the shoulder  15  of lever  12  is resting on the element  16  of tube clamp  1  configured with a step for resting the shoulder  15 , and wherein element  16  is disposed approximately perpendicular to spring latch  7 , and the tube  13  extends through tube clamp  1  without any particular pressure exerted by the projections  4 ,  5  onto the tube  13 . The liquid can circulate within tube  13 . 
   Starting from the positions shown in  FIG. 2   a,  the lever  12  starts its rotational motion and exerts pressure upon the means  11  through end  14 , for co-operating with lever  12 , as shown the arched portion  11 . The projections  4 ,  5  are beginning to pinch the tube  13 . 
   As seen in  FIG. 2   b,  tube  13  has been pressed together firmly by means of the end  14  of lever  12 , so that the tube is pinched liquid tight. Due to the roll off motion of the end  14  of lever  12  upon camber  11 , the second leg  3  of the tube clamp  1  is being moved towards the spring latch  7  and pressed downwardly. Simultaneously, the web  6  is resiliently restored into its starting position because the shoulder  15  of lever  12  no longer presses upon element  16 . 
     FIG. 2   c  shows the moment where the second leg  3  engages in the projection  8  of spring latch  7 , after the lever  12  has been further rotated. 
   As is shown in  FIG. 2   d,  after locking the tube clamp  1 , the lever  12  can be lifted. 
   Due to considerations of storage, as a rule, the tube set will be distributed with the tube clamp in open position. Prior to application, the user will close the tube clamp and inserts the tube set into the pump. The pump must now be ready to open the tube clamp. Opening of tube clamp  1  takes place in reverse order to the one shown in  FIGS. 2   a - 2   d.  When opening, a force is applied approximately parallel to spring latch  7  upon the step of element  16  whereby a torque is created which leads to the expansion of the tube clamp. 
   It should be noted, that instead of step  16  any other element can be provided at tube clamp  1  for cooperation with lever  12 , so long as by this cooperation the spring latch  7  can be pushed away by the second leg of the tube clamp. Likewise when closing the tube clamp, it is important that the pressure is being exerted in vertical direction upon the second leg  3  of the tube clamp. 
   As is illustrated from  FIGS. 3   a  to  3   c,  the tube clamp according to the invention can be so configured, that in lieu of the element  16  configured as a stepped shoulder, an inclined surface is provided upon which the end of the second leg moves along before engaging under the cam  8  of spring latch  7 . In this embodiment the counter part  15  on the infusion pump side is in contact only with the upper portion of the stepped shoulder of element  16 . By means of effecting a force approximately parallel to the spring latch  7  upon the upper portion of element  16 , a torque is created which leads to the expansion of the tube clamp. 
   It may be desirable that a small slip is created during the roll off motion of the lever  12  from the means  11 , respectively  16  when closing, respectively opening the tube clamp. This can be realized for example by the cooperating surfaces of the lever and the means  11  respectively  16  by providing a friction-increasing layer, or by arranging for corresponding teeth between them. 
   With a tube clamp that is automatically operated through the infusion pump it is advantageous to provide means for detection of a tube clamp in the pump, for example by an optical scanning system or an electrical scanning system (e.g. by using an electrical conducting plastic for the tube clamp. 
   While the invention has been illustrated and described as embodied in a tube clamp and infusion pump set, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. 
   What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents.