Abstract:
An arrangement for introducing a liquid into the body of a patient or for withdrawing a liquid from the body of a patient, including a first structural part carrying a cannula for positioning in the body of the patient, and a second structural part with a connection port for detachably coupling a conduit for supplying or withdrawing a liquid, wherein the first and second structural parts are connected, can be rotated relative to each another and in relative rotational positions form a channel for introducing a liquid from the conduit to the cannula or for withdrawing a liquid from the cannula to the conduit, and whereby movement of the conduit for coupling and uncoupling is transverse to the longitudinal axis of the cannula.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/CH2007/000074, filed on Feb. 13, 2007, which claims priority to Swiss Application No. 911/06, filed on Jun. 7, 2006, the entire contents of both of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to devices for infusing, delivering, administering, injecting or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to an arrangement for introducing a liquid into the body of a patient or for withdrawing a liquid from the body of a patient and use of the arrangement for subcutaneous supplying of a liquid medicament into the body of a patient. 
     In those patients who have an ongoing need for medicaments or therapeutic agents to be administered by direct supply to the body tissue or the blood stream, or in whom body fluid samples for monitoring certain parameters, such as e.g. blood sugar, need to be taken from the body over a longer period, it is meaningful to undertake supply of the medicament or withdrawal of the body fluid via a cannula introduced at a suitable site into the body and remaining there over a longer period. 
     For example, these days, in many patients with type I and type II diabetes, the required quantity of insulin is supplied to the body continuously or at short intervals. This may be accomplished, in many instances, using a cannula inserted through the skin into the subcutaneous tissue of the patient, which is part of an arrangement attached to the body of the patient and often designated as an “infusion set.” The insulin supplied is controlled by an automated insulin pump. The connection between insulin pump and infusion set is made by a flexible supply conduit which is coupled detachably to the infusion set by a connector. Since the infusion set is worn practically permanently on the body, good wearer comfort is important. For this reason, the infusion set is built as flat as possible, including with a supply conduit connected, and the freedom of movement of the patient is impaired to the least extent possible. In addition, it is important that the coupling and uncoupling of the supply conduit can be done easily and securely and operating errors are excluded as early as possible by the constructive configuration of the infusion set. Similar marginal conditions and requirements will emerge when body fluid samples are taken from the body of a patient over a longer period. 
     Documents WO 02/070037 A2, DE 299 05 068 U1, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 disclose infusion devices in which the supply conduit with an adapter part in an axial direction of the cannula can be set on the part of the device bearing the cannula and can be removed again from the latter in the opposite direction. The cannula in the infusion devices disclosed in WO 02/070037 A2, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 are provided for substantially vertical insertion into the body of the patient, whereby the supply conduit is led away from the adapter part in a direction vertical to the direction of setting. The device disclosed in DE 299 05 068 U1 is provided for inserting into the body of a patient at a flat angle, whereby the supply conduit is led away from the adapter part in the direction of setting. After being set on the part bearing the cannula, the adapter part in the devices according to WO 02/070037 A2, DE 299 05 068 U1, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 is rotatable relative to the part bearing the cannula, while in the device disclosed in WO 2004/026375 A1 it is latched in rotatory alignment selected for setting on with respect to the part bearing the cannula. 
     A disadvantage of known devices is that the adapter for uncoupling the supply conduit from the infusion set in the axial direction of the cannula is removed from the infusion set, whereby there is a not insubstantial danger that the cannula may be withdrawn from the injection site unnoticed fully or partially, resulting in no delivery or inadequate delivery of liquid medicament into the tissue. 
     A further disadvantage of the infusion devices disclosed in WO 02/070037 A2, U.S. Pat. No. 6,923,791 B2, WO 2005/049117 A2, US 2005/0101910 A1 and WO 2004/026375 A1 is that, in the applied state with the supply conduit coupled, they have a relatively high structure. An added disadvantage of the device disclosed in DE 299 05 068 U1 is that after application of the part bearing the cannula on the body of a patient there is no further possibility of altering the direction in which the supply conduit leads away from the infusion device. 
     SUMMARY 
     An object of the present invention, therefore, is to provide an arrangement for introducing a liquid into the body of a patient or for withdrawing a liquid from the body of a patient, which does not have the disadvantages of the prior art or at least partially avoids these. 
     In one embodiment, the present invention comprises an arrangement for introducing a liquid into the body of a patient or for withdrawing a liquid from the body of a patient, including a first structural part carrying a cannula for positioning in the body of the patient, and a second structural part with a connection port for detachably coupling a conduit for supplying or withdrawing a liquid, wherein the first and second structural parts are connected, can be rotated relative to each another and, in relative rotational positions, form a channel for introducing a liquid from the conduit to the cannula or for withdrawing a liquid from the cannula to the conduit, and wherein movement of the conduit for coupling and uncoupling is transverse to the longitudinal axis of the cannula. 
     In one embodiment, the present invention comprises an arrangement for introducing a liquid to the body of a patient or for withdrawing a liquid from the body of a patient, comprising a first structural part with a cannula protruding from this for arrangement in the body of the patient; a second structural part with a connection port for detachable coupling of a corresponding connector of a conduit for supplying or withdrawing a liquid, wherein the first structural part and the second structural part are configured and connected to one another such that they are inseparable and can be rotated relative to one another and in every relative position form a channel for introducing a liquid from the connection port to the cannula or for withdrawing a liquid from the cannula to the connection port, and wherein the connection port of the second structural part is designed such that the coupling and uncoupling of a corresponding connector takes place in each case in a direction transverse to the longitudinal axis of the cannula. 
     In one embodiment, the present invention comprises an arrangement for introducing a liquid into the body of a patient or respectively for withdrawing a liquid from the body of a patient comprising a first structural part which bears a projecting cannula provided for positioning in the body of a patient after it is inserted in through the skin. The arrangement of the present invention further comprises a second structural part which forms a connection port for detachable coupling of a corresponding connector of a conduit for delivering or withdrawing a liquid. “Corresponding” connector is understood here as a connecting element adapted to complement the connection port, such that the connection port and the connector together form a secure and repeatedly detachable and reconnectable coupling site for the liquid conduit in the form of a matching plug and socket connection. The first structural part and the second structural part of the inventive arrangement are configured and connected to one another such that they are inseparable and can be rotated about an axis of rotation relative to one another. The first and the second structural part, in each relative position which they can take up relative to one another, form a channel sealed to the outside between the connection port and the cannula, via which a liquid can be delivered from the connection port to the cannula or from the cannula to the connection port. The connection port is in this case configured and associated with the second structural part such that the coupling and uncoupling of a corresponding connector of a conduit is possible exclusively in a direction transverse to the longitudinal axis of the cannula. 
     The present invention enables manufacture of arrangements for introducing a liquid into the body of a patient or respectively for withdrawing a liquid from the body of a patient which offer a high degree of wearer comfort along with good security against operating errors. 
     In one preferred embodiment of the arrangement of the present invention, the connection port of the second structural part of the arrangement is configured such that the coupling and uncoupling of a corresponding connector in each case must take place vertically to the longitudinal axis of the cannula. This provides maximal security against unintentional withdrawal of the cannula when the connector is being uncoupled. 
     In yet another preferred embodiment of the arrangement of the present invention, the first and the second structural part can be rotated relative to one another about an axis of rotation extending parallel to the longitudinal axis of the cannula. Thus, a simple construction can be realized, e.g. whenever the cannula is provided for vertical insertion into a body, which may be preferred. 
     In yet another preferred embodiment of the arrangement in accordance with the present invention, the cannula projects vertically or non-vertically from a substantially even or flat outside surface of the first structural part, whereby in both cases the first and the second structural part can be rotated relative to one another about an axis of rotation standing vertically to the outside surface. The advantage of this is that the rotation plane of the second structural part on completion of application of the arrangement extends parallel to the body surface, so that a substantially identical application situation arises from every rotatory relative position between the first and the second structural part. 
     In yet another preferred embodiment of the arrangement in accordance with the present invention, the first and the second structural part can be rotated through 360°, e.g. endlessly rotatably about one another, or can be rotated by less than 360° to one another, i.e. not endlessly rotatably about one another. Depending on the application or intended use, one or the other variant can be advantageous, whereby the first-mentioned variant has the advantage that the second structural part can be arranged in every position and that with first and second structural parts endlessly rotatable about one another and corresponding configuration of the arrangement, rotation of the second structural part can occur in any other relative position in any direction of rotation. An advantage of the latter variant, for example, is that unwanted “coiling” of the conduit is not possible with use as intended connected to the arrangement as a result of repeated rotation of the second structural part relative to the first structural part. 
     In yet another preferred embodiment, the connection between the first and the second structural part is configured such that a specific torque must be overcome for counterrotation of both structural parts relative to one another, e.g. a torque in the range between 0.01 and 0.05 Nm or in the range between 0.01 and 0.1 Nm. In some preferred embodiments, a pre-tensed elastic structural part is available to generate the torque to be overcome, which produces friction between the first and the second structural part. Exemplary suitable structural parts are a pre-tensed elastic seal, such as an O-ring seal, and/or a ratchet arrangement. 
     The advantage of such embodiments is that unnecessary rotating, caused e.g. by a change in position of the person wearing the arrangement with respect to the direction of gravity, of both structural parts relative to one another can be prevented, whereby the previously mentioned danger of “coiling” of a liquid conduit coupled to the arrangement is reduced. Retrieval of the connection port after momentary uncoupling of the connector of the connection conduit from the arrangement is also improved, since the second structural part, in the absence of forces bearing thereon, remains in the position assumed during uncoupling relative to the first structural part. 
     In yet another preferred embodiment, an arrangement in accordance with the present invention comprises a detent means, e.g., a latch or lock, configured for releasably preventing or overriding the twisting capacity (or turning or rotation) of the first and second structural part relative to one another by latching them in a specific position relative to one another. 
     In some preferred embodiments, the detent means is configured such that the first and the second structural part are latched automatically in a position relative to one another. This may be the case if, for example, no corresponding connector of a conduit is coupled to the connection port of the second structural part. In some embodiments, both structural parts are latched during uncoupling of the connector. In some embodiments, the latching can be cancelled by coupling of a corresponding connector to the connection port, e.g. by a latching element of the latching device being moved by the connector into a non-latched position. Such configuration guarantees easy retrieval of the connection port following momentary uncoupling of the connector from the arrangement, since the second structural part remains in its relative position assumed during uncoupling. 
     In some preferred embodiments, the detent means is configured such that the first and second structural part are latched or are being latched in a position relative to one another if a corresponding connector of a conduit is coupled or is being coupled to the connection port of the second structural part. Such latching can be cancelled by uncoupling of the connector from the connection port so that there is no latching when the connector is uncoupled. This variant can be advantageous in the event where a selected relative position is to be adhered to in the normal case, e.g. for preventing coiling of the conduit. 
     In some preferred embodiments, the detent means is configured such that it can be activated and/or deactivated via one or more actuation elements, and, in some embodiments, it may be preferred that the detent means are latched without actuation of the actuation elements. Because of this there is easy retrieval of the connection port following momentary uncoupling of the connector from the arrangement and “coiling” of the coupled conduit is securely prevented. According to one preferred subvariant of the present invention, the detent means can be selectively activated or deactivated via the actuation elements such that, in each state, twisting between the first and the second structural part can be permitted or prohibited. 
     In embodiments of the arrangement fitted with detent means, the detent means is configured such that latching can take place positively in discrete positions or frictionally in any position. Depending on use and configuration, one or the other of these variants may be preferred. 
     In yet another preferred embodiment of the arrangement of the present invention, the cannula is designed as a flexible cannula, wherein it is penetrated by a guide needle removable after application by insertion to enable insertion into the tissue of a patient in its cannula channel. Such so-called soft cannulas are well-suited for remaining longer in the subcutaneous tissue of a patient, since they cause almost no irritations in the vicinity of the injection site. 
     In yet another preferred embodiment of the arrangement of the present invention, the outside surface of the first structural part from which the cannula protrudes extends bears an adhesive layer advantageously formed by plaster for fastening the first structural part by adhesion on the skin of a patient. The adhesive layer is covered by a protective film which is removed shortly prior to application or use of the arrangement. Such an adhesive layer allows the arrangement to be attached securely and comfortably on the skin of the patient during application. 
     In yet another preferred embodiment, the arrangement additionally comprises a connector for coupling a conduit for delivering or for withdrawing a liquid. 
     One aspect of the present invention relates to use of the arrangement of the present invention for subcutaneous supplying of a liquid medicament, e.g. for subcutaneous supplying of insulin, into the body of a patient. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a perspective plan view of an embodiment of an arrangement in accordance with the present invention with a supply conduit connected; 
         FIG. 2  is a perspective plan view of the embodiment of  FIG. 1  with the supply conduit removed; 
         FIG. 3  is a vertical section transverse to the longitudinal direction of the supply conduit through part of the embodiment illustrated in  FIG. 1 ; 
         FIG. 4  is an illustration as per  FIG. 3  of the embodiment of  FIG. 2 ; 
         FIG. 5  is a plan view of the embodiment of  FIG. 1 ; 
         FIG. 6  is a perspective view of the second structural part of the embodiment of  FIG. 1  providing the connection port; 
         FIG. 7  is a perspective plan view of another embodiment of an arrangement of the present invention in the applied state with a supply conduit connected; 
         FIG. 8  is a perspective plan view of the embodiment of  FIG. 7  without the supply conduit; 
         FIG. 9  is a vertical section in the longitudinal direction of the supply conduit through the embodiment illustrated in  FIG. 7 ; 
         FIG. 10  is an illustration as per  FIG. 9  of the embodiment of  FIG. 8 ; 
         FIG. 11  is a vertical section through the embodiment illustrated in  FIG. 7  in a protective housing; 
         FIG. 12  is a vertical section through the embodiment illustrated in  FIG. 7  directly prior to application or use; 
         FIG. 13  is a perspective plan view of another embodiment of an arrangement in accordance with the present invention in the applied state with a supply conduit connected; 
         FIG. 14  is a side elevation of the embodiment of  FIG. 13 , including of the connecting device of the supply conduit; 
         FIG. 15  is a vertical section in the longitudinal direction of the supply conduit through the embodiment illustrated in  FIG. 13 ; 
         FIG. 16  is a perspective plan view of another embodiment of an arrangement in accordance with the present invention in the applied state with a connected supply conduit; 
         FIG. 17  is a perspective plan view of the embodiment of  FIG. 16  without the supply conduit; 
         FIG. 18  is a vertical section in the longitudinal direction of the supply conduit through the embodiment illustrated in  FIG. 16 ; 
         FIG. 19  is a perspective plan view of another embodiment of the present invention in the applied state with a connected supply conduit; 
         FIG. 20  is a vertical section in the longitudinal direction of the supply conduit through the embodiment illustrated in  FIG. 19 ; 
         FIG. 21  is a perspective plan view of another embodiment of the present invention in the applied state; 
         FIG. 22  is a plan view of the embodiment of  FIG. 21 ; 
         FIG. 23  is a side elevation of the embodiment of  FIG. 21 ; 
         FIG. 24  is a vertical section transverse to the direction of coupling of the supply conduit through the embodiment illustrated in  FIG. 21 ; and 
         FIG. 25  is a perspective view of the first structural part of the embodiment of  FIG. 21 , including part of the detent means. 
     
    
    
     DETAILED DESCRIPTION 
     With regard to fastening, mounting, attaching or connecting components of the present invention, unless specifically described 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 the invention and/or its components may be selected from appropriate materials such as metal, metallic alloys, ceramics, plastics, etc. 
     A first preferred embodiment of the inventive arrangement of the present invention (which, in addition to being termed an arrangement, also may be thought of and/or referred to as a system, device, infusion apparatus, infusion set or system) is illustrated in  FIGS. 1 and 2  in a perspective plan view, in  FIGS. 3 and 4  selectively in the longitudinal section and in  FIG. 5  in plan view. This embodiment, in the form of an infusion set, is shown with a coupled supply conduit for an infusion liquid ( FIGS. 1 ,  3  and  5 ) and also without the supply conduit ( FIGS. 2 and 4 ). The infusion set comprises a first structural part  1 , which bears or carries on its underside a vertically projecting cannula (not shown). The underside of the first structural part  1  is formed by plaster  12 , the adhesive surface of which is covered by protective plaster paper  13 . A second structural part  3  is inseparably connected to the first structural part  1 , and can be rotated about a vertical axis of rotation R which runs or extends in the longitudinal axis of the cannula. The second structural part  3  forms a connection port  4  for the connector  5  of the supply conduit  6  and cooperates with the first structural part  1  such that the structural parts, in every rotatory relative position which they can assume relative to one another, form a channel sealed to the exterior (not shown) for delivering the infusion liquid from the connection port  4  to the cannula. For the inner structure of the infusion set (not shown here), e.g. with respect to the way in which the channel is formed between the cannula and the connection port  4  by the first  1  and the second structural part  3  and how the cannula is connected to the first structural part  1 , reference is also made to the following embodiments, in which structures are shown in detail and are also suited for this first preferred embodiment. 
     With reference to  FIGS. 3 ,  4  and  6 , the second structural part  3  has on the topside of its outermost radial periphery upwardly aligned teeth  14 . In the absence of a corresponding connector  5  for coupling the supply conduit  6  to the connection port  4 , the teeth  14  engage resiliently in corresponding, opposing teeth  15  under the effect of a spring force generated by the second structural part  3 . When the supply conduit is not connected, the spring force overrides the twisting capacity of both structural parts  1 ,  3  relative to one another (see  FIG. 4 ). If the supply conduit  6  with its connector  5  is coupled to the connection port  4  of the second structural part  3 , in that the retaining arms  16  of the connector are moved towards one another, e.g. by exerting pressure with the thumb and index finger, under elastic deformation of the same, the connector  5  is set on the connection port  4  at the same time in a direction vertical to the axis of rotation R of both structural parts  1 ,  3  or respectively to the longitudinal axis of the cannula. If the retaining arms  16  are then released again, whereby they are moved away again from one another and come up against stop cams  17  on the second structural part  3  under spring preload, the second structural part  3  is bulged or urged downwardly by the spring force of the retaining arms  16  in the vicinity of its external radial periphery, whereby its teeth  14  disengage from the teeth  15  of the first structural part  1  and the structural parts  1 ,  3  can be rotated against one another. At the same time, when viewed in the direction of coupling of the connector  5 , the retaining arms  16  catch behind the stop cams  17 , making unintentional withdrawal of the connector  5  from the connection port  4  impossible. If the connector  5  is uncoupled from the infusion set by renewed compression of its retaining arms  16  and simultaneous motion of the same against the direction of coupling, the second structural part  3  bulges, is urged or moves upwardly again in the vicinity of its external radial periphery until its teeth  14  engage resiliently in the teeth  15  of the first structural part  1 , thus latching both structural parts  1 ,  3  in the position assumed. 
       FIGS. 7 to 10  show, in perspective plan views and in longitudinal sections, a second embodiment of the inventive arrangement of the present invention in the form of an applied infusion set, and specifically with coupled supply conduit ( FIGS. 7 and 9 ) and without a supply conduit ( FIGS. 8 and 10 ). The infusion set again has a first structural part  1  which bears on its underside a vertically projecting cannula  2  made of flexible material. Arranged on the topside of the first structural part  1  is a second structural part  3  which forms a connection port  4  for coupling a corresponding connector  5  of a supply conduit  6  for infusion liquid. The first  1  and the second structural part  3  are inseparable and are connected together rotatably relative to one another about a vertical axis of rotation R, whereby the axis of rotation R is identical to the longitudinal axis of the cannula  2 . In each rotatory relative position which they can take up relative to one another, the first and second parts form a liquid-tight channel  7  for delivering infusion liquid from the connection port  4  to the cannula  2 . As is evident from  FIGS. 9 and 10 , the channel  7  on the connection port side is delimited or defined in part by a first septum  18  which acts as liquid-tight coupling of the supply conduit  6 , in that it is pierced through during coupling of the connector  5  by a delivery cannula (not shown here, however see  FIGS. 15 and 18  of the following exemplary embodiments) arranged in the former. 
     Liquid-tight transition between the first  1  and the second structural part  3  is effected by a second septum  19  provided by the first structural part  1  and penetrated by a cannula extension  20  of the second structural part  3 , extending in the axis of rotation R of the structural parts  1 ,  3 . As is evident from  FIGS. 11 and 12 , which show vertical sections through the arrangement illustrated in  FIG. 7 , prior to application the arrangement may be in a special protective housing  23   a ,  23   b , and the channel  7  is blocked or sealed directly opposite the inlet aperture of the cannula  2  and in straight-line extension of the cannula channel by another septum  21  which forms part of the topside of the second structural part  3  and is penetrated in the original state by a guide needle  11 . This guide needle  11  supports the cannula  2  during application of the infusion set by inserting the cannula  2  into the body of a patient and after application is withdrawn using a reset element  22  arranged at its external end from the cannula channel and the other septum  21  and removed from the infusion set. 
     The protective housing  23   a ,  23   b  is formed from two housing halves  23   a ,  23   b  which, based on the original situation illustrated in  FIG. 11 , in which the infusion set is marketed and in which it is arranged protected inside the housing  23   a ,  23   b , can be telescoped. The first structural part  1  of this embodiment is formed by a circular plate element  26  and a central body  27  bearing the cannula  2  and connected to the second structural part  3 , whereby the plate element  26  and the central body  27  are configured to pivot relative to one another. Both housing halves  23   a ,  23   b  have guides, via which, during telescoping of the same, the central body  27  is pivoted with the second structural part  3  arranged thereon and the cannula  2  pierced through by the guide needle  11 , until the cannula  2  pierced through by the guide needle  11  projects at a right angle from the housing  23   a ,  23   b  and from the plate element  26 . In this situation, which is illustrated in  FIG. 12 , both the two housing halves  23   a ,  23   b  and also the plate element  26  and the central body  27  snap in undetachably to one another and the housing  23   a ,  23   b  forms a grip for a user which is grasped for application of the infusion set and by which the guide needle  11  is withdrawn with the reset element  22  from the cannula  2  and the other septum  21  and removed from the infusion set. 
     As is further evident from  FIGS. 7 to 10 , the plate element  26  of the first structural part  1  has on the peripheral delimiting of its topside upward aligned teeth  15 , in which a projection formed on the underside of a locking rocker  24  formed by the second structural part  3  engages in the absence of a corresponding connector  5  for coupling the supply conduit  6  to the connection port  4  of the second structural part  3 . Thus, the twisting capacity or motion of both structural parts  1 ,  3  to one another when the supply conduit  6  is not connected is overridden or prevented (see  FIGS. 8 and 10 ). If the supply conduit  6  with its connector  5  is coupled to the connection port  4  of the second structural part  3  by the connector  5  being set on the connection port  4  in a direction vertical to the axis of rotation R of both structural parts  1 ,  3  or respectively to the longitudinal axis of the cannula  2 , whereby its retaining arms  16  latch behind an assigned retainer cam  25  such that unintentional removal of the connector  5  from the connection port  4  is rendered impossible, the locking rocker  24  is deflected by the connector  5 . The projection formed on its underside thereby disengages from the teeth  15  of the first structural part  1  and the structural parts  1 ,  3  can be rotated against one another. If the connector  5  is removed again, for which the retaining arms  16  have to be moved toward one by exertion of pressure by the thumb and index finger for disengaging from the retainer cams  25 , while the connector  5  is removed against the direction of coupling from the infusion set, the locking rocker  24  tips supported by spring force back into its previous start position and latches both structural parts  1 ,  3  in the rotatory position relative to one another. 
       FIGS. 13 to 15  show a third embodiment of an inventive arrangement in accordance with the present invention in the form of an applied infusion set with connected supply conduit, viewed in perspective plan view ( FIG. 13 ), in side elevation from the direction of connection of the supply conduit ( FIG. 14 ) and in the vertical section in the longitudinal direction of the supply conduit ( FIG. 15 ). As is evident from the figures, the infusion set has a first structural part  1 , which is formed substantially by a circular plate element  26  and a central body  27  which bears the cannula  2 . In the upper region the central body  27  is enclosed by a second structural part  3  in the peripheral sense, which forms a connection port  4  for coupling a corresponding connector  5  of a supply conduit  6  for infusion liquid. The first  1  and the second structural part  3  are inseparable and are connected to one another rotatably relative to one another about a vertical axis of rotation R, whereby the axis of rotation R is identical to the longitudinal axis of the cannula  2 . 
     In each rotatory relative position which they can take up relative to one another, the first  1  and the second structural part  3  form a liquid-tight channel  7  for delivering infusion liquid from the connection port  4  to the cannula  2 . As is evident from  FIG. 15  the channel  7  is delimited on the connection port side by a first septum  18  which acts as liquid-tight coupling of the supply conduit  6 , in that it is pierced through by a delivery cannula  28  arranged therein when the connector  5  is coupled. The liquid-tight transition between the first  1  and the second structural part  3  is effected by two O-rings  31  spaced apart from one another in the longitudinal direction of the cannula  2 , which are borne or carried by the central body  27 . Between these O-rings  31  the central body  27  has a peripheral groove  29  which is connected via a radial bore  30  to the cannula entry. The channel  7  is delimited directly opposite the inlet aperture of the cannula  2  and in straight-line extension of the cannula channel by another septum  21  which forms part of the topside of the central body  27  of the first structural part  1  and in the original state is penetrated by a guide needle (not shown here). This guide needle supports the cannula  2  when inserted into the body of a patient and after application is withdrawn from the cannula channel and the septum  21  and removed from the infusion set. 
     Referring to  FIG. 13 , the plate element  26  of the first structural part  1  has on its topside six identical, trough-like depressions  32  arranged evenly spaced generally peripherally, whereof the surface contour has a constant profile cross-section when viewed in a radial direction. As is evident from  FIG. 14 , the assigned connector  5  of the supply conduit  6  has on its underside a corresponding countercontour and is guided on the connection port  4  of the second structural part  3  such that it can be set on the connection port  4  and then latches the structural parts  1 ,  3  in a relative position. The connection port  4  is located in the middle above one of the depressions  32 , in that it engages with the countercontour of its underside in the respective depression  32 . In this embodiment, the first  1  and the second structural part  3  can be latched in six different rotatory positions relative to one another, whereby coupling of the connector  5  to the connection port  4  is possible only in one of these relative positions, inevitably resulting in latching of the structural parts  1 ,  3  in the relative position. Here, too, the connector  5  has retaining arms  16 , with which it snaps in behind retainer cams (not shown) when being set on the connection port  4 , preventing unintentional removal of the connector  5  from the connection port  4 . The arms have to be moved toward one another for uncoupling the connector  5  from the infusion set by exertion of pressure by the thumb and index finger, so that the connector  5  can be removed against the direction of coupling. As previously described, if the connector  5  is again removed from the infusion set both structural parts  1 ,  3  can be rotated again relative to one another. 
       FIGS. 16 to 18  show a fourth embodiment in accordance with the present invention in the form of an applied infusion set. The set is shown in perspective plan view with a connected supply conduit ( FIG. 16 ), in perspective plan view without the supply conduit ( FIG. 17 ) and in the vertical section in the longitudinal direction of the connected supply conduit ( FIG. 18 ). The infusion set shown here has a similar construction as that previously described, however with the difference that here the plate element  26  is designed in one piece with the central body  27  and on its topside, instead of the six large depressions along its peripheral limit, it has a multiplicity of identical small depressions  32 , arranged evenly spaced in the peripheral sense, resulting in the vicinity of the edge having a corrugated surface contour. Likewise in contrast to the previous embodiment, the second structural part  3  here has a spring-elastic latching arm  33 , which, when the supply conduit  6  is not connected to a detent projection  34  formed on its underside, rests on the corrugated surface contour of the plate element  26  and thus together with the latter forms a ratchet mechanism, the effect of which is that a specific force must be applied to rotate the second structural part  3  relative to the first structural part  1  and that these structural parts  1 ,  3  in each case assume discrete positions relative to one another. 
     If a corresponding connector  5  is set on the connection port  4  of the second structural part  3 , as shown in  FIGS. 16 and 18 , the latching arm  33  is prevented by the connector  5  from deviating upward and the first  1  and the second structural part  3  are latched in their relative position. In this embodiment, the first  1  and the second structural part  3  can therefore be latched in a multiplicity of discrete positions relative to one another, whereby coupling of the connector  5  to the connection port  4  is possible only in one of these relative positions, inevitably resulting in latching of the structural parts  1 ,  3  in the relative position. When the connector  5  is disconnected, the first  1  and the second structural part  3  can be rotated against one another against a force defined by the previously described ratchet mechanism, whereby they assume discrete positions relative to one another after a torsional force has been overcome. Here, too, the connector  5  has retaining arms  16 , with which it snaps in behind retainer cams  25  when set on the connection port  4 , rendering unintentional removal of the connector  5  from the connection port  4  impossible. The arms have to be moved toward one another to uncouple the connector  5  from the infusion set, so that the connector  5  can be removed against the direction of coupling. The remaining construction of this embodiment, with respect to the structural design of the seals  18 ,  21 ,  31  and the channel  7 , corresponds substantially to the previous embodiment. Those elements not described explicitly here, though provided with reference numerals, have the same function as the structural parts with corresponding reference numerals in the previously described designs. 
       FIGS. 19 and 20  show a fifth embodiment of the present invention in the form of an applied infusion set. The set is shown in perspective plan view with a connected supply conduit ( FIG. 19 ) and in the vertical section in the longitudinal direction of the connected supply conduit ( FIG. 20 ). The infusion set shown here is identical to that previously described, with the difference that here the latching arm  33  is arranged at a peripheral position opposite the connection port and, as a result, can also rebound when the supply conduit  6  is connected. In this embodiment, the second structural part  3  can accordingly always be rotated against the force defined by the ratchet mechanism relative to the first structural part  1 , both when the connector  5  is coupled and also when the connector  5  is removed, whereby the structural parts  1 ,  3  then assume positions relative to one another. Those elements not described explicitly here, though provided with reference numerals, have the same function as the structural parts with corresponding reference numerals in the previously described design. 
       FIGS. 21 to 24  show another embodiment of the present invention in the form of an applied infusion set with a connected supply conduit. The set is shown in perspective plan view ( FIG. 21 ), in plan view ( FIG. 22 ), in side elevation ( FIG. 23 ) and in vertical section in the longitudinal direction of the connected supply conduit ( FIG. 24 ). The inner construction of this embodiment with respect to the structural configuration of the seals  8 ,  18  and  21  of the channel  7  corresponds substantially to the second embodiment discussed with reference to  FIGS. 7 to 10 . 
     As is evident from  FIGS. 21 to 24  the infusion set again has a first structural part  1 , which on its underside bears a vertically projecting cannula  2  made of flexible material. On the topside of the first structural part  1  a second structural part  3  is arranged, and forms a connection port  4  for coupling a corresponding connector  5  of a supply conduit  6  for infusion liquid. The first  1  and the second structural part  3  are inseparably connected to one another and can be rotated relative to one another about a vertical axis of rotation R, whereby the axis of rotation R is identical to the longitudinal axis of the cannula  2 . In each rotatory relative position which they can assume relative to one another, the first and second parts form a liquid-tight channel  7  for delivering infusion liquid from the connection port  4  to the cannula  2 . Here, too, the channel  7  is delimited or defined in part on the connection port side by a first septum  18  which serves as liquid-tight coupling of the supply conduit  6 , in that it is pierced through during coupling of the connector  5  by a delivery cannula  28  arranged therein. The liquid-tight transition between the first  1  and the second structural part  3  is effected by a rubber seal  8  under compressive stress, which is penetrated by a connection journal  9  of the second structural part  3 , extending in the axis of rotation R of the structural parts  1 ,  3  and which has in its center a bore forming part of the channel  7 . Directly opposite the inlet aperture of the bore of the journal  9  and in straight-line extension of the cannula channel the channel  7  is delimited by another septum  21  which forms part of the topside of the second structural part  3  and in the original state is penetrated by a guide needle (not shown). This guide needle supports the cannula  2  in application of the infusion set by insertion of the cannula  2  into the body of a patient and after application is withdrawn from the cannula channel and the other septum  21  by a reset element arranged on its external end and is removed from the infusion set. 
       FIG. 25  shows a perspective view of the first structural part  1  together with an actuating element  10  of a latching device. The first structural part  1  is formed from a plate element  26 , which has circular, radially inwardly directed inner cogging  15 , and a central body  27  which in the center of the plate element  26  projects upwardly therefrom. Arranged between the first  1  and the second structural part  3  in a peripheral position, lying opposite the connection port  4 , is the actuating element  10 , which is guided radially in the second structural part  3  and is pressed radially outwardly with a spring tab  35  formed by the second structural part  3  with spring preload. Thus, it engages with corresponding counter-cogging (not shown) formed by the latter in the inner cogging  15  of the first structural part  1 , thereby preventing rotating of both structural parts  1 ,  3  in the illustrated situation. If a compressive force is exerted on the actuating element  10  inwardly in a radial direction, then it shifts against the spring force of the spring tab  35  radially inwardly, whereby the counter-cogging of the actuating element  10  is disengaged from the inner cogging  15  and twisting of the second structural part  3  relative to the first structural part  1  becomes possible, independently of whether or not a connector  5  is coupled to the connection port  4 . If the actuating element  10  is released it is again moved radially outwardly by the spring tab  35  until the counter-cogging of the actuating element  10  engages in the inner cogging  15  of the first structural part  1  and latches both structural parts  1 ,  3  in the rotatory relative position. Here also the latching is carried out at discrete positions. 
     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 provide the best illustration of 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.