with regard to fastening , mounting , attaching or connecting components of the present invention , unless specifically described as otherwise , conventional mechanical fasteners and methods may be used . other appropriate fastening or attachment methods include adhesives , welding and soldering , the latter particularly with regard to the electrical system of the invention , if any . in embodiments with electrical features or components , suitable electrical components and circuitry , wires , wireless components , chips , boards , microprocessors , inputs , outputs , displays , control components , etc . may be used . generally , unless otherwise indicated , the materials for making embodiments of the invention and / or components thereof may be selected from appropriate materials such as metal , metallic alloys , ceramics , plastics , etc . unless otherwise indicated specifically or by context , positional terms ( e . g ., up , down , front , rear , distal , proximal , etc .) are descriptive not limiting . same reference numbers are used to denote same parts or components . fig1 shows a first embodiment of a blocking valve 2 which is formed on a catheter 1 , directly on or in the flexible catheter tube and in the vicinity of the outlet point of a pump ( not shown ). the blocking valve 2 is configured such that it blocks or prevents flow when an interior pressure of the flexible tube or a pressure of the medium being guided in the flexible tube 1 is 0 . 1 bar or less , and opens at higher pressures and allows a flow through the flow region 1 b of the catheter 1 . the first embodiment of the catheter 1 shown can , for example , be obtained by reshaping the catheter or flexible tube in the region of the valve 2 by a thermal reshaping method , wherein the annular or tubular cross - section of the catheter 1 is reshaped in the region of the valve 2 into a flat flexible tube , as shown in the sectional view in fig1 a , such that the wall halves 1 a of the catheter 1 abut each other and can thus prevent a flow when a low interior pressure is being applied . if the pressure of the medium being guided in the catheter 1 rises above a predetermined minimum pressure of , for example 0 . 1 bar , the inner wall 1 c of the catheter is pushed open and the valve 2 is opened , such that a flow through the catheter 1 is possible . as can be seen from fig1 a and 1b , the valve 2 can be fitted with a clip 3 which is formed as a u - shaped spring element and comprises pressing pieces 3 a and 3 b . the clip 3 is arranged around the catheter 1 and can bias the catheter halves and therefore the inner walls 1 c of the catheter against each other via its clamping force . by using the clip 3 , it is possible to set a defined blocking force or blocking pressure . the greater the force with which the clip 3 presses the catheter walls 1 c onto each other , the greater the minimum pressure of the medium which has to be applied to enable a flow through the catheter 1 . if such a catheter 1 , comprising one or more valves 2 successively arranged in the longitudinal direction of the catheter 1 , is connected to an administering device , for example an infusion pump , the catheter 1 is connected to a reservoir 4 for a substance or medium to be administered . usually , a stopper 5 is inserted into the reservoir 4 or an ampoule 4 by an infusion pump , such that the interior pressure in the ampoule 4 is increased and a substance contained in the ampoule 4 is dispensed from a dispensing opening 4 a of the ampoule 4 . this causes a rise in pressure in the connected catheter 1 , which ensures that the catheter walls 1 a , which are biased against each other , are pushed open and that a desired amount of the substance , such as for example insulin , can thus be dispensed to a patient . as soon as the desired amount of the substance has been administered , and the stopper 5 of the reservoir 4 is at rest again , the valve 2 closes due to the force of the clip 3 which presses the catheter 1 together again , automatically . the opening pressure for the valve 2 is thus set or defined by the biasing force of the clip 3 . fig2 shows a second embodiment of a catheter 1 in accordance with the present invention , comprising two valves 2 . the two valves 2 are arranged in two zones spaced apart from each other in the longitudinal direction of the catheter 1 , i . e along the length of the catheter , and comprise catheter walls 1 a which are respectively biased against each other , wherein one catheter wall 1 a of a first side , shown on the left in fig2 a , is biased toward the second side ( in the drawing , downwardly ), such that the inner walls 1 a of the catheter abut each other and prevent a flow of a medium when a predetermined minimum pressure is not being applied . in the region of the second valve , shown on the right , the bias relative to the first valve is reversed , i . e . the opposing second side is biased toward the first side , such that the desired valve blocking effect occurs . each bias of a catheter wall 1 a can thus be regarded as an aperture . if a number of apertures are arranged in series , the overall difference in pressure is divided into stage differences in pressure , such that the drop in pressure per valve zone can be reduced . reducing the overall difference in pressure is advantageous , since the closing force per valve zone can then be reduced and the functional reliability of the overall valve , formed from a number of valve zones , can thus be increased . in accordance with another embodiment of the present invention , a valve function using a catheter 1 can be achieved by moving the catheter 1 into a sharply bent region using a defined path - force element ( spring ). when the pressure rises , for example between 0 . 5 and 0 . 8 bar , the catheter 1 is released from the sharply bent region and so releases the flow . fig3 schematically shows an ampoule 4 comprising a stopper 5 which can be shifted within it in the direction of the arrow and using which a substance contained in the ampoule 4 can be dispensed from a dispensing opening 4 a to the catheter 1 connected to the ampoule 4 . if , for example , the difference in height between the lower and upper end of the catheter 1 measured one metre , then a partial vacuum of 0 . 1 bar would be applied at the upper end of the catheter 1 , which could cause a substance to be unintentionally dispensed from the ampoule 4 in an uncontrolled manner , solely due to the hydrostatic pressure generated by the column of fluid in the catheter 1 . it is therefore advantageous , in some embodiments , to arrange a valve in the upper region of the catheter , since a partial vacuum of 0 . 1 bar in relation to a relative exterior pressure of 0 bar causes the catheter walls 1 a to be automatically pressed together . if the catheter walls 1 a are elastic , the partial vacuum in the upper catheter portion can therefore be utilized such that in the event of a hydrostatic pressure distribution in the catheter , the valve is automatically closed . if the above - described catheter 1 in accordance with the present invention is used , then it is possible to prevent a substance from being unintentionally dispensed from the ampoule 4 through the catheter 1 . in some embodiments , a number of sharply bent regions 1 d can also be successively arranged , as shown in fig4 , wherein a catheter or flexible tube 1 is accommodated in a clamping piece or clip 3 which can consist of an upper part 3 c of the clamping piece and a lower part 3 d of the clamping piece , which can be connected to each other . the catheter 1 is inserted into the catheter guides , which are , for example , formed by a number of mutually parallel partition walls 3 e , such that the catheter 1 is held meandering , or snaking or winding , in the clamping piece 3 , wherein linear regions of the catheter 1 are parallel to each other , separated by the wall pieces 3 e , wherein a sharply bent region 1 d is provided in each region in which the catheter 1 transitions from one guide , formed by two adjacent wall pieces 3 e , to the next guide . fig4 shows the open - catheter state , in which the sharply bent regions 1 d are open , due to an applied pressure of , for example , more than 0 . 7 bar , and so enable a flow of a medium through the catheter 1 . if a pressure below 0 . 7 bar is being applied , the catheter 1 is deformed in the region of the sharp bends 1 d , such that a medium is prevented from passing through the catheter 1 . the clamping piece 3 can , for example , be formed to be rigid , such that when the pressure of the medium being guided in the catheter 1 rises above 0 . 7 bar , a flow is enabled solely by the deformation of the catheter 1 . alternatively , the clamping piece 3 can also be formed to be elastic or flexible , such that when the pressure of the medium being guided in the catheter 1 rises , the clamping piece 3 is deformed or expanded and so releases the flow for the fluid being guided in the catheter 1 . although the clamping piece 3 could in principle be formed in one piece , in some preferred embodiments it is formed — to more easily insert the catheter 1 — from two partial pieces 3 c and 3 d which can be placed onto each other or connected to each other , after the catheter 1 has been inserted into the clamping piece 3 d in the manner shown in fig4 , such that the catheter 1 exhibits a number of successive sharply bent regions 1 d on two opposing sides of the clamping piece 3 . fig5 a shows another embodiment of a blocking mechanism for a catheter 1 , wherein a catheter blocking valve can be both integrated into the catheter 1 and formed as a separate valve piece which can be inserted between two catheter pieces 1 . in the embodiment shown in fig5 a , a valve base body 4 made from a thermoplastic elastomer ( tpe ) can be seen which is formed in the shape of a disc or plate and is flat . the body 4 has been inserted between two catheter pieces 1 , wherein the body 4 has been placed onto the catheter pieces 1 in the region of a fusing zone 4 a and connected or fused to the catheter pieces 1 , so as to be an integrated part of the catheter . a sealing or covering element 4 b , in the form of a film which is likewise formed from a thermoplastic elastomer , is placed onto the valve base body 4 and can be formed double - layered and from a different material than the valve base body 4 . the film 4 b is connected to the valve base body 4 in the region of a fusing zone 4 c . a bent clip 3 formed from spring steel may be slid or placed onto the valve base body 4 connected to the film 4 b , in a similar way to the embodiment described with respect to fig1 . the clip comprises two mutually opposing pressure surfaces 3 f and 3 g , such that the upper pressure surface 3 f can press onto the film 4 b and the lower surface 3 g can press onto the lower side of the valve base body 4 . fig5 c is a top view onto the clip 3 which is shown in a lateral view in fig5 b . if a pressure of , for example , less than 0 . 7 bar is being applied to the medium being transported in the catheter 1 , then the film 4 b is pressed into the valve base body 4 or the valve base body 4 is pressed together with the film 4 b , such that a flow of a medium cannot occur . if the pressure of the medium rises above 0 . 7 bar , then the clip 3 is pressed or urged apart by the pressure of the medium , i . e . the pressure surfaces 3 f and 3 g are urged away from each other enabling a flow of the medium . the blocking pressure of the valve shown in fig5 can be altered by the configuration of the clip 3 , and / or by its manufacture , deformation and material constants or processing , such that the valve can also open at a lower pressure of , for example , 0 . 1 bar or 0 . 2 bar or at a higher pressure of , for example , 1 bar or above . embodiments of the present invention , including preferred embodiments , have been presented for the purpose of illustration and description . they are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed . the embodiments were chosen and described to illustrate the principles of the invention and the practical application thereof , and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated . all such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly , legally , and equitably entitled .
a catheter for connecting an administering device to an administering needle , the catheter including a catheter wall , a flow region limited by the catheter wall , and at least one catheter portion at which at least one partial piece of the catheter wall abuts at least one other partial piece of the catheter wall to releaseably block or obstruct the flow of a medium through the catheter , wherein the flow is unblocked or opened when the medium exhibits a pressure above a predetermined blocking pressure .