Infusion system

Abstract

An infusion system of this type for use in pain therapy, comprising a catheter with a proximal end, a distal end, at least one lumen extending longitudinally between the proximal end and the distal end, and with several outlets, wherein the several outlets are each fluid-conductingly connected to the at least one lumen, and wherein the several outlets each extend radially through a catheter wall of the catheter and are spaced proximodistal apart from each other, is known.According to the invention, the multiple outlets have at least one first outlet and at least one second outlet, wherein the first outlet is open for the delivery of an analgesic regardless of the fluid pressure prevailing in the lumen, and wherein the second outlet is configured for the fluid pressure-dependent delivery of the analgesic and can be switched between an open state, in which the second outlet is open for the delivery of the analgesic, and a closed state, in which the second outlet is closed, depending on the fluid pressure prevailing within the lumen. Use in pain therapy.

Description

The invention relates to an infusion system for use in pain therapy, comprising a catheter having a proximal end, a distal end, at least one lumen elongated between the proximal end and the distal end, and having a plurality of outlets, wherein the plurality of outlets are each fluidly connected to the at least one lumen, and wherein the plurality of outlets each extend radially through a catheter wall of the catheter and are proximodally spaced apart from one another.Such an infusion system is generally known in the field of medical technology and is used in pain therapy for the delivery of a pain killer. In order to be able to dispense the analgesic in a distributed manner at a plurality of locations, the catheter has a plurality of outlets arranged spaced apart from one another in a proximodial manner. The positioning of the outlets specifies the local distribution of the analgesic.It is an object of the invention to provide an infusion system of the type mentioned at the beginning which enables improved pain therapy.This object is achieved in that the plurality of outlets have at least one first outlet and at least one second outlet, wherein the first outlet is opened for the delivery of an analgesic independently of a fluid pressure prevailing in the lumen, and wherein the second outlet is configured for the fluid-pressure-dependent delivery of the analgesic and is transferable between an opening state, in which the second outlet is opened for the delivery of the analgesic, and a closing state, in which the second outlet is closed, depending on the fluid pressure prevailing within the lumen. The solution according to the invention allows a pressure-dependent control of the release of the analgesic through the at least second outlet. Since the plurality of outlets and thus the at least one first outlet and the at least one second outlet are spaced apart from one another in a proximodstal manner, i.e. along the longitudinal axis of the catheter, the position of the analgesic release can be influenced thereby. The invention is based on the consideration that a painkilling agent delivery controllable over the length of the catheter can be advantageous from a medical point of view. The solution according to the invention allows such control by being able to control the painkilling agent delivery through the at least one second outlet depending on the fluid pressure prevailing in the at least one lumen. For this purpose, the at least one second outlet is configured for fluid pressure-dependent dispensing of the pain killer. In one configuration, the at least one second outlet is specially designed for this purpose, for example in the form of a slot or the like. In a further embodiment, a valve for pressure-dependent control is assigned to the at least one second outlet. In contrast to the at least one second outlet, the at least one first outlet is not controllable, in particular is always open. The at least one second outlet is closed, in particular completely, in the closed state. In one configuration, the at least one second outlet is not completely closed in the closed state, so that pain killer delivery takes place at a reduced flow rate compared to the open state. Preferably, the at least one second outlet is configured such that a flow rate discharged through the at least one second outlet in the open state corresponds to a flow rate through the at least one first outlet.In one embodiment of the invention, the second outlet is formed by a slit in the catheter wall, wherein the catheter wall is elastically flexible at least in the region of the slit, wherein the slit is closed at a first fluid pressure, and wherein the slit is opened at a higher second fluid pressure as a result of an elastic deformation of the catheter wall caused by the second fluid pressure. By forming the second outlet as a slit, the fluid pressure-induced controllability is achieved with particularly simple means. The slit extends radially from an inner side of the catheter wall facing the lumen to an outer side of the catheter wall facing the environment. Due to the elastically flexible design of the catheter wall at least in the region of the slot, the slot can open and close as a result of an elastic deformation of the catheter wall caused by fluid pressure. When the first fluid pressure is applied, the slit is closed and the catheter wall is substantially not deformed in the region of the slit. If the second fluid pressure is present, which is higher than the first fluid pressure, the catheter wall is elastically deformed in the region of the slit, whereby the latter opens and allows the pain killer to be discharged through the slit. In one embodiment, the slot is straight and elongated throughout, for example in the proximodstal longitudinal direction of the catheter or transversely to the longitudinal direction, in particular in the circumferential direction. In a further embodiment, the slot is curved and elongated. In a further embodiment, the slot has a plurality of differently oriented slot sections connected to one another. By selecting the length and / or shape of the slit and the elastic properties of the catheter wall in the region of the slit, the opening and closing behavior can be adapted to different requirements with simple means. Due to the elastic design of the catheter wall at least in the region of the slit, the latter automatically returns from the open to the closed state when the fluid pressure is reduced.In a further embodiment of the invention, the slit is longitudinally proximodally extended and, in the open state, widened in the circumferential direction of the catheter wall. Preferably, the slot is straight and elongated throughout. By the proximodally elongated orientation of the slot, an improved opening and closing behavior can be achieved depending on the prevailing fluid pressure. This in particular in comparison with a fundamentally conceivable alignment of the slot in the circumferential direction of the catheter wall.In a further embodiment of the invention, the slit is introduced into the catheter wall in a U-shaped manner in the radial viewing direction and bounds a wall section which, in the open state, is extended radially outwards relative to the remaining catheter wall. The wall section functions in the manner of an elastic flap or also flap. When the first fluid pressure is applied, the wall section is flush with the remaining catheter wall, whereby the slot is closed. If the higher second fluid pressure is present, the wall section is extended radially outwards as a result of the action of pressure, as a result of which the slot is opened. Due to the elastically flexible design of the catheter wall at least in the region of the slot, the wall section returns to the closed state upon a reduction of the pressure starting from the opening self-function.In a further embodiment of the invention, a valve is assigned to the second outlet, wherein the valve is configured for fluid pressure-dependent opening and closing, wherein the valve is closed at a first fluid pressure and is opened at a higher second fluid pressure. The valve may be of any suitable design for the present purpose. The valve opens and closes automatically in dependence on the fluid pressure, for example in the manner of a nonreturn valve.In a further embodiment of the invention, the valve is arranged upstream of the second outlet. For example, the valve can be arranged in the lumen or a branch of the lumen assigned to the second outlet. In a further embodiment, the valve is arranged downstream of the second outlet.In a further embodiment of the invention, the at least one first outlet is arranged proximodally, in particular centrally, between at least two second outlets. The two second outlets are thus arranged on both sides of the at least one first outlet with respect to the longitudinal axis of the catheter. In this context, a peripheral arrangement of the at least two second outlets can also be referred to. This configuration allows control of pain relieving in a peripheral area. In contrast, the discharge takes place in the region of the first outlet between the at least two second outlets independently of the prevailing fluid pressure, in particular continuously. In an alternative embodiment, the at least one second outlet is arranged proximodstalally, in particular centrally, between the at least two first outlets. In this embodiment, there is a release of pain medium which is invariable peripherally as a function of the fluid pressure, whereas in a central region between the two first outlets, there can be a fluid-pressure-controlled release through the at least one second outlet.In a further embodiment of the invention, a group having a plurality of, in particular exactly three, first outlets is arranged proximodally, in particular centrally, between two groups each having a plurality of, in particular exactly three, second outlets. By arranging them in groups with a plurality of first or second outlets in each case, the local distribution of the analgesic release can be controlled in an improved manner. In an alternative embodiment, a group having a plurality of, in particular exactly three, second outlets is arranged proximodally, in particular centrally, between two groups each having a plurality of, in particular exactly three, second outlets.In a further embodiment of the invention, a conveying device and a control device are provided, wherein the conveying device is connected in a fluid-conducting manner to the at least one lumen of the catheter and is configured for conveying the pain medium through the at least one lumen with different fluid pressures, and wherein the control device is connected to the conveying device and is configured for controlling the fluid pressure and thus for opening and / or closing the at least one second outlet. The conveying device can have any design suitable for the present purpose. For example, the delivery device can be a piston, peristaltic or elastomer pump, wherein other designs are naturally also conceivable and possible. The control device is configured to control the conveying device, wherein in particular a control of the fluid pressure is provided. By controlling the fluid pressure, the at least one second outlet of the catheter can be opened and / or closed by means of the control device. The opening and / or closing of the at least one second outlet controlled in this way allows a particularly simple local adaptation of the analgesic release.Further advantages and features of the invention are evident from the claims and from the following description of preferred exemplary embodiments of the invention, which are illustrated on the basis of the drawings. FIG. 1 shows a schematic view of an embodiment of an infusion system according to the invention with a catheter, a conveying device and a control device, FIGS. 2, 3 show a section of the catheter in the radial direction in the region of a second outlet, wherein the second outlet assumes a closed state (FIG. 2 ) and an open state (FIG. 3 ) as a function of a fluid pressure, FIGS. 4, 5 show the region of the catheter shown in FIGS. 2 and 3 with an alternative configuration of the second outlet in the closed state (FIG. 4 ) and in the open state (FIG. 5 ), wherein FIG. 5 shows a longitudinal section with a radial viewing direction rotated through 90°, and FIG. 6 shows a functional diagram for illustrating a further embodiment.Referring to Figure 1, an infusion system 1 is provided for use in pain therapy and includes a catheter 100, a delivery device 200 and a control device 300. The conveying device 200 and / or the control device 300 are optional and not present in all embodiments.Catheter 100, which may also be referred to as a pain catheter, has a proximal end 101, a distal end 102, at least one lumen 103, and a plurality of outlets A.The proximal end 101 and the distal end 102 are proximodally spaced apart from each other. Catheter 100 is axially elongated between proximal end 101 and distal end 102. The straight longitudinal extension shown in FIG. 1 throughout and the shape shown are to be understood as schematically simplified and purely exemplary.Lumen 103 is elongated between proximal end 101 and distal end 102. In embodiments not shown in the figures, the catheter has a plurality of lumens.The plurality of outlets A serve for the delivery of an analgesic S. The analgesic S is conveyable by means of the conveying device 200, which is connected in a fluid-conducting manner, not shown, to the proximal end 101, into the lumen 103 and from there through the outlets A. The outlets A are each connected to the lumen 103 in a fluid-conducting manner. In an embodiment not shown in the figures, different outlets are connected to different lumens of the catheter in a fluid-conducting manner. Furthermore, the outlets A in the present case each extend radially through a catheter wall 106 of the catheter 100 and are spaced apart proximodally from one another. In other words, the outlets A are distributed in the longitudinal direction of the catheter 100. This distributed arrangement of the outlets A enables a locally distributed delivery of the analgesic S.The arrangement of the plurality of outlets A, which is shown in FIG. 1 and is distributed over the length of the catheter 100, and the number thereof are to be understood as purely exemplary. In embodiments not shown in the figures, a different number and / or arrangement of the plurality of outlets is provided. In the simplest case, the catheter 100 has exactly two outlets.The plurality of outlets A include at least one first outlet 104 and at least one second outlet 105.In the embodiment shown, there are a plurality of first outlets 104 and a plurality of second outlets 105. For simplified description, reference is made below only to a / the first outlet 104 and a / the second outlet 105. The statements made with regard to the (one) first outlet 104 also apply analogously to the further first outlets. The statements made with regard to the (one) second outlet 105 also apply analogously to the further second outlets.In the embodiment shown, the first outlet 104 is always open, as a result of which permanent dispensing of the pain killer S can take place through the first outlet 104.The second outlet 105 is configured for controlled delivery of the pain killer S. For this purpose, the second outlet 105 is transferable between an open state and a closed state depending on a fluid pressure P prevailing within the lumen 103. In the open state, the second outlet 105 is opened for discharging the pain killer S. In the closing state, the second outlet 105 is closed. In the embodiment shown, the second outlet is completely closed in the closed state, so that no or at least no practically relevant dispensing of the pain killer S can take place. In an embodiment not shown in the figures, the second outlet is partially and / or incompletely closed in the closed state, so that the analgesic S can be discharged at a flow rate that is reduced compared to the open state.By opening and closing the second outlet 105 depending on the fluid pressure P, the delivery of the analgesic S can be controlled locally. In the closed state of the second outlet 105, the discharge takes place only through the first outlet 104. In the open state of the second outlet 105, the pain killer is discharged through the first outlet 104 and through the second outlet 105.The fluid pressure P is generated by the conveying device 200 and controlled by the control device 300. By controlling the fluid pressure P, a control of the local pain killer release is accordingly effected indirectly.The conveying device 200 and the control device 300 are schematically illustrated in FIG. 1. The conveying device 200 is connected to a source of the pain medium S, not shown in detail. The conveyor 200 may be of any suitable construction for the present purpose. For example, the conveying device 200 can be designed as a piston pump, peristaltic pump or elastomer pump.In the embodiment shown, there is a group G 1 with a plurality of first outlets 104. In addition, two groups G 2, G 2' each having a plurality of second outlets 105 are present. In the embodiment shown, the groups G 1, G 2, G 2' each have exactly three first outlets 104 and exactly three second outlets 105, respectively. In an embodiment not shown in the figures, different numbers are provided therefrom. The group G1 with the first outlets 104 is arranged proximodally between the two groups G2, G2' with the second outlets 105. This arrangement is central in the present case, so that it is also possible to speak of a central group G1 and two peripheral groups G2, G2'. The embodiment shown in Figure 1 allows control of the peripheral analgesic delivery, whereas the analgesic delivery in the central region of the group G1 is not controllable depending on the fluid pressure.FIGS. 2 to 6 show variants of different configurations of the second outlet 105. The illustrated designs each allow fluid pressure dependent control of the second outlet 105 between the open and close states. The configurations shown in Figures 2 to 6 may be present alternatively or in combination. For example, the second outlets 105 of the group G2may have a different configuration than the plurality of second outlets 105 of the group G2'.In the variant shown in FIGS. 2 and 3, the second outlet 105 is formed by a slot 107. The catheter wall 105 is elastically flexible at least in the region of the slot 107. If a first fluid pressure P 1 is present within the lumen 103, the slot 107 is closed (FIG. 2 ), i.e. the second outlet 105 assumes the closed state. If a second fluid pressure P 2 that is higher than the first fluid pressure P 1 is present within the lumen 103, the slot 107 is opened as a result of an elastic deformation of the catheter wall 106 caused by the second fluid pressure P 2 (see FIG. 3 ). If the fluid pressure falls off from the second fluid pressure P2, the slit 107 closes automatically as a result of the elastic properties of the catheter wall 106.In the present case, the catheter wall 106 is made of an elastic plastic. Any plastic suitable for the present purpose having elastic properties and suitability for medical applications is suitable. Such plastics are known to the skilled person.In the variant shown in FIGS. 2 and 3, the slot 107 is longitudinally extended in a proximodstal manner. The longitudinal extension is straight and parallel to the longitudinal axis of the catheter 100. The slot 107 is continuously straight longitudinally extended between a slot proximal end 1071 and a slot distal end 1072. In the radial direction, the slot extends starting from an inner side (without reference sign) of the catheter wall 106 facing the lumen 103 to an outer side (without reference sign) of the catheter wall 106 facing the environment. In the open state (FIG. 3 ), the slot 107 is widened in the circumferential direction of the catheter wall 106. In this expanded state, inner surfaces 1073, 1074 of the slot 107 which are opposite one another in the circumferential direction are lifted from one another, as a result of which the outlet 105 is released. In the closed state (FIG. 2 ), the inner surfaces 1073, 1074 lie on top of one another in a fluid-tight manner, i.e. the second outlet 105 is closed.In the variant shown in FIGS. 4 and 5, the slot 107 ais introduced into the catheter wall 106 in a U-shaped manner in the radial viewing direction of FIG. 4. The U-shaped slot 107a borders a wall portion 111a of the catheter wall 106. The wall section 111 ais in the open state (FIG. 5 ) extended or opened radially outwards relative to the remaining catheter wall 106. As a result, the second outlet 105 is released. In the closed state (FIG. 4 ), the wall section 111 ais substantially flush with the remaining catheter wall 106, so that the second outlet 105 is closed. The wall portion 111a forms a type of flap or flap which is elastically movable relative to the surrounding catheter wall 106 depending on the prevailing fluid pressure. When the second fluid pressure P2 is applied, the wall portion 111a elastically springs outward to release the second outlet 105. When the fluid pressure is lowered from the second fluid pressure P 2, the wall portion 111 asprings back to the closed state automatically due to the elastic properties of the catheter wall 106.In the variant shown in FIGS. 4 and 5, the slot 107 aincludes a first slot section 108 a, a second slot section 109 aand a third slot section 110 a. The first slot portion 108 aand the second slot portion 109 aare each proximodally elongated and spaced apart from one another in the circumferential direction. In the present case, the first slot section 108 aand the second slot section 109 aare parallel. In addition, the first slot portion 108 aand the second slot portion 109 aare of equal length. The third slot section 110 ais elongated in the circumferential direction and is arranged at a distal end of the two slot sections 108 a, 109 a, respectively. The third slot portion 110 aconnects a distal end (not numbered) of the first slot portion 108 ato a distal end (not numbered) of the second slot portion 109 a. At an end of the first slot section 108 aand of the second slot section 109 a, which end is opposite the third slot section 110 a, the wall section 111 a, which is bordered by the U-shaped slot 107 a, is connected to the remaining catheter wall 106 a. This connection forms an elastic solid joint or elastic hinge, wherein the imaginary joint axis is oriented parallel to the circumferential direction of the catheter wall 106.In the variant shown in FIG. 6, a valve 112 is assigned to the second outlet 105. In FIG. 6, the second outlet 105 and the valve 112 are schematically shown in simplified form. The valve 112 is configured for fluid pressure-dependent opening and closing when the first fluid pressure P 1 is applied and opened when the second fluid pressure P 2 is applied. The valve 112 may also be referred to as a two-way valve. The valve 112 may be of any suitable design for the present purpose and may be upstream or downstream of the second outlet 105. It is conceivable for the valve 112 itself to form or comprise the second outlet 105.

Claims

An infusion system (1) for use in pain therapy, comprising a catheter (100) having a proximal end (101), a distal end (102), at least one lumen (103) elongated between the proximal end (101) and the distal end (102), and having a plurality of outlets (A), wherein the plurality of outlets (A) are each fluidly connected to the at least one lumen (103), and wherein the plurality of outlets (A) each extend radially through a catheter wall (106) of the catheter (100) and are proximodally spaced apart from one another, characterized in that the plurality of outlets (A) comprise at least one first outlet (104) and at least one second outlet (105), wherein the first outlet (104) is open for the delivery of an analgesic (S) independently of a fluid pressure (P) prevailing in the lumen (103), and wherein the second outlet (105) is configured for the fluid-pressure-dependent delivery of the analgesic (S) and is transferable between an open state, in which the second outlet (105) is open for the delivery of the analgesic (S), and a closed state, in which the second outlet (105) is closed, depending on the fluid pressure (P) prevailing within the lumen (103).Infusion system (1) according to claim 1, characterised in that the second outlet (105) is formed by a slit (107, 107a) in the catheter wall (106), wherein the catheter wall (106) is elastically flexible at least in the region of the slit (107, 107a), wherein the slit (107, 107a) is closed at a first fluid pressure (P1), and wherein the slit (107, 107a) is opened at a higher second fluid pressure (P2) as a result of an elastic deformation of the catheter wall (106) caused by the second fluid pressure (P2).Infusion system (1) according to claim 2, characterised in that the slot (107) extends longitudinally proximodally and, in the open state, is widened in the circumferential direction of the catheter wall (106).Infusion system (1) according to claim 2, characterised in that the slot (107a) is introduced into the catheter wall (106) in a U-shaped manner in the radial viewing direction and borders a wall section (111a) of the catheter wall (106), which wall section in the open state is extended radially outwards relative to the remaining catheter wall (106).Infusion system (1) according to claim 1, characterised in that a valve (112) is associated with the second outlet (105), wherein the valve (112) is configured for fluid pressure-dependent opening and closing, and wherein the valve (112) is closed at a first fluid pressure (P1) and opened at a higher second fluid pressure (P2).Infusion system (1) according to claim 5, characterised in that the valve (112) is arranged upstream of the second outlet (105).Infusion system (1) according to one of the preceding claims, characterized in that the at least one first outlet (104) is arranged proximodally, in particular centrally, between at least two second outlets (105) or vice versa.Infusion system (1) according to claim 7, characterised in that a group (G1) with several, in particular exactly three, first outlets (104) is arranged proximodally, in particular centrally, between two groups (G2, G2') with in each case several, in particular exactly three, second outlets (105) or vice versa.Infusion system (1) according to one of the preceding claims, characterized in that a conveying device (200) and a control device (300) are present, wherein the conveying device (200) is connected in a fluid-conducting manner to the at least one lumen (103) of the catheter (100) and is configured for conveying the pain medium (S) through the at least one lumen (103) with different fluid pressures (P1, P2), and wherein the control device (300) is connected to the conveying device (200) and is configured for controlling the fluid pressure (P, P1, P2) and thus for opening and / or closing the at least one second outlet (105).

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