DE102021115847A1 - puncture device - Google Patents

Abstract

The invention relates to a puncturing device for puncturing a hollow body using a puncture needle, the puncturing device having at least one tubular outer shell in which the puncture needle can be guided in a longitudinally displaceable manner, the outer shell being set up to, after a puncture has been carried out, a shell of the hollow body to be punctured via at least one Part of its length to be pushed through the opening created by the puncture needle through the shell of the hollow body to be punctured and to stay there for a period of time.

Description

The invention relates to a puncturing device for puncturing a hollow body using a puncture needle, the puncturing device having at least one tubular outer shell in which the puncture needle can be guided in a longitudinally displaceable manner, the outer shell being set up to, after a puncture has been carried out, a shell of the hollow body to be punctured via at least one Part of its length to be pushed through the opening created by the puncture needle through the shell of the hollow body to be punctured and to stay there for a period of time.

Such a puncturing device is also referred to below as a puncturing system or, particularly when it relates to the medical field, as an indwelling vein cannula. The tubular outer shell or “outer shell” for short is also referred to below as a venous catheter. The hollow body to be punctured can be a hollow body of a living being or a hollow body of an object. As far as the puncturing device relates to the medical field, the hollow body can be, for example, a blood vessel such as a vein or artery.

The terms "puncture" and "puncture" are to be understood in the medical sense. Puncture is the insertion of a puncture needle into the hollow body in such a way that the puncture needle penetrates the shell of the hollow body to be punctured.

Sections of parts of the puncturing device close to the hollow body are considered to be those parts which, from the user's point of view, are arranged at the far (distal) end of the puncturing device and thus in the vicinity of the punctured hollow body. Accordingly, sections remote from the hollow body are arranged at the end of the puncturing device that is proximal from the user's point of view, i. h further away from the punctured hollow body. In connection with medical applications of the puncture device, the terms close to the veins or close to the patient are also used synonymously with the term close to the hollow body, and also far from the veins and away from the patient for the term far from the hollow body.

A puncture-proof IV catheter is made of PCT/ EP2019/057097 famous.

An improved puncture system in the sense of a general puncture system is to be created. In principle, it is also possible with the improved intravenous cannula to advantageously puncture all body cavities and interbody spaces and all anatomical and diseased structures that are to be punctured and to insert a catheter into them.

In principle, components of the improved indwelling cannula can also be combined with all known puncture and catheter systems or used as independent products.

The term “in-dwelling cannula” will be retained in the following, but has a broader meaning in the sense of a general puncture system with which not only veins can be punctured. In the following, the terms “vein” and “veins” basically include all blood vessels and, very generally, all body cavities and spaces between the bodies and all anatomical and pathological structures that are to be punctured and provided with a catheter.

For example, the trachea, pleural space, abdomen, stomach, intestines, renal pelvis, bladder, liquor space and bones can also be punctured with the IV catheter. In addition, pathological structures such as abscesses can be punctured in and on the patient. In addition, arterial blood vessels can advantageously be punctured.

In the following, the term "patient" includes all living beings of all ages and genders. Likewise, applications in technical areas and in and on all objects and structures, e.g. in and on reservoirs, containers, cavities, expandable materials and in and on pump, hose, tube and port systems, are explicitly possible.

If the word "or" is used in the following, possible alternatives are shown, but combinations of the characteristics or characteristics separated by "or" are also explicitly possible.

In the following, "close to the veins" can usually be equated with "close to the patient" and "away from the veins" with "close to the user". Components close to the vein tend to be inside the patient and components distant from the vein tend to be outside of the patient. This does not always have to be the case, but it is intended to further clarify the terms. The additions are usually self-explanatory and the context is crucial.

All of the components described can be used one or more times on an indwelling cannula or also independently of such an indwelling cannula on/in other products or completely independently. Various features of different components can also be freely combined and features of certain components can also be used on other components without this being explicitly mentioned. In principle, all components and features can be used inside and outside of a patient.

Special cross-sectional areas of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the outer shell and/or another part of the puncturing device has one or more flow channels running predominantly or completely in the longitudinal direction of the puncturing device, through which a fluid flowing through the punctured hollow body can flow along the outer shell and/or the other part of the puncture device can flow past. Such a flow channel can be formed, for example, by a trough or groove-like indentation, for example a groove, on the outside of the outer shell or a channel in the wall of the outer shell. The flow channel can also vary over its length partly as a recess and partly as a channel in the wall of the outer shell. The flow channel does not have to be present over the entire length of the outer shell. For example, the flow channel can be arranged exclusively or predominantly in the section of the outer shell designed to remain in the hollow body. This applies to one, several or all flow channels. The flow channels of the outer shell can in particular run predominantly or completely in the longitudinal direction of the outer shell.

The cross-sectional area of the venous catheter can be a circle or an ellipse. One side of this circle or ellipse can have at least one flat, indentation or protuberance. As a result, the venous catheter can also be optimally adapted to veins that do not have a purely circular cross-sectional area. The venous catheter can be made of a thermoplastic material, e.g. a plastic material, over part of its length, most or all of its length, which has the property that it no longer maintains a special shape of the venous catheter at body temperature, so that the venous catheter adapts optimally to the Shape of the vein can adjust. The wall of the venous catheter can thus rest against the vein wall. The venous catheter can thus keep the lumen of the vein open for a fluid flow via the venous catheter when such a fluid is applied via the venous catheter. If this is no longer applied via the venous catheter, the venous catheter collapses due to its pronounced thermoplastic properties and thus closes itself. This has the advantage that no fluid, e.g. blood, can then escape from the patient via the venous catheter.

The venous catheter can also have at least one channel/groove-shaped recess on its outside. This indentation may be, for example, a longitudinal indentation. As a result, a fluid flow can be achieved next to the venous catheter even when the venous catheter is in the vein. In this way, e.g. drainage problems in the vein can be prevented with an inserted venous catheter. In the area of arterial vascular puncture, this can be of particular relevance for preventing circulatory disorders. The same applies if the actual lumen of the venous catheter is misplaced or blocked, e.g. by coagulated blood. In the area of the indentation, the venous catheter can consist entirely or partially of at least one material or be coated with one that has antimicrobial and/or anticoagulant properties. This prevents the accumulation of germs and/or blood clots in this area. At least one material can also be used in this area which has particularly favorable fluid-conducting properties and does little damage to the corpuscular components of the blood when it comes into contact with blood.

The indentation does not have to be the entire length of the venous catheter. Thus, the indentation can advantageously not be formed away from the veins in the area of the transition from the venous catheter to the other components of the indwelling venous cannula and/or where the venous catheter leads through the skin and the subcutaneous tissue of the patient. This means that there is no entry point for germs in this area, since the skin and subcutaneous tissue can wrap themselves completely around the venous catheter. The indentation can also end in front of the tip of the venous catheter near the vein so that it can be designed without edges ( 2 , 3 ). The indentation can also result from the venous catheter consisting at least partially, for example on its outside, of at least one resorbable material which has the complementary shape of the indentation and initially at least partially fills the indentation. If this material is now resorbed in the patient, for example when it comes into contact with blood or when it comes into contact with other fluids, the depression is formed. This resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Resorbable polymers, composites, bioceramic materials or biodegradable metals can also be used. The material can also be a combination of several absorbable materials.

It is also conceivable that, instead of the indentation, there is at least one longitudinal channel in the wall of the venous catheter, which channel branches off from the actual lumen of the venous catheter is bordering. This channel can begin far from the vein via a recess in the wall of the venous catheter and end close to the vein via a recess which is located directly in the area of the tip of the venous catheter or somewhat distant from it in the wall of the venous catheter ( 4 until 6 ). This allows at least one additional fluid flow in the venous catheter.

Combinations of the above-mentioned groove-shaped indentations and channels are possible.

An expansion body for fixing the position of the venous catheter in the punctured part of the body can be arranged on the venous catheter of the venous indwelling cannula. Such an expansion body can be designed, for example, as an inflatable sleeve, a so-called cuff, which is arranged, for example, on the outside of the venous catheter. In an advantageous development, this expansion body can now also have at least one trough/groove-shaped depression as described above, which is also retained in the expanded state in order to enable a fluid flow around the expansion body. It is also conceivable that the expansion body also contains at least one channel as described above in the expanded state, so that a fluid flow through the expansion body is possible. This channel can be kept open by a circular structure that at least partially surrounds it and forms the wall.

A venous catheter as described above can also be used independently of an indwelling venous cannula, e.g. in a longer design with a larger diameter as a tube of a device for carrying out extracorporeal membrane oxygenation (ECMO).

The cross-sectional area of the venous catheter can also be designed with at least one tooth in a manner similar to that of an externally toothed gear wheel. The gear can be 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24, 25,26,27,28,29,30 or more than 30 teeth. Alternatively or additionally, the cross-sectional area of the venous catheter can also have an internally toothed gear wheel with the number of teeth just mentioned. It is also conceivable that at least one further lumen located in the venous catheter has external teeth and the venous catheter itself has internal teeth.

The design of the cross-sectional area of the venous catheter as a semicircle, semiellipse, arc or ring is also possible, as is at least one flattening, depression or protuberance on each side of these geometric figures/shapes (hereinafter referred to as “shapes”). Groove-like shapes can also be present.

It is also possible for the inner and/or outer cross-sectional area to be in the form of a rectangle, square, cross, parallelogram, rhombus, triangle, pentagon, hexagon, octagon or, quite generally, a polygon. Frame-like, cloverleaf or crescent-like shapes are also conceivable.

The venous catheter can have the shape of a cylinder, cone, cuboid or even a prismatic shape. A pyramid-like design is also possible. The venous catheter can also have a wing profile, more precisely a wing profile.

It is possible that both the inside and the outside of the venous catheter each have at least one of the above shapes or are further developed with structures that have at least one of the above shapes. The outside and inside of the venous catheter can also differ in these properties. For example, it is conceivable that the outside of the venous catheter adapts flexibly to the shape of the vein, but the inside of the venous catheter has rather rigid properties that also keep the lumen of the venous catheter open, e.g. against external pressure. These rigid properties can be achieved by a special shape of the inside of the venous catheter, e.g. by an oval shape, but also by using special materials, in particular metals, metal alloys and hard plastic materials. These rigid properties can also be created by a spiral, wavy or net-shaped surface on the inside of the venous catheter. A combination with transverse, longitudinal or diagonal structures is conceivable, these can also provide the desired rigidity on their own.

All of the above and other geometric shapes can be freely combined. Different sections of the venous catheter can also have different cross-sectional areas or shapes.

These can change due to special properties, e.g. thermoplastic properties, if the venous catheter is exposed to other environmental conditions, e.g. body temperature. These can also change if the venous catheter is subjected to a certain amount of internal or external pressure. It is therefore conceivable, for example, that a universal blood vessel catheter will be created which can be used under conditions of low blood pressure, e.g. in veins, but also under conditions of high blood pressure, e.g. in arteries and near the heart.

The combination of different shapes can also be used to delimit several lumens within the venous catheter. For example, the venous catheter can have at least one lumen which has a circular cross-sectional area and another which has an elliptical or rectangular cross-sectional area. The cross-sectional area can be optimized for specific properties of different fluids.

barb-like structures

According to an advantageous embodiment of the invention, it is provided that barb-like structures are present on the outside of the outer shell, which make it difficult or prevent the puncture device inserted into the hollow body to be pulled out. As a result, the puncturing device is secured against accidentally sliding out of the punctured hollow body.

Structures that represent or resemble barbs can also be attached to the outside of the venous catheter. These can, for example, be designed to be foldable or extendable. For example, these can also be activated by a fluid, gas or vapor flow. For example, these can also be activated by a blood flow, which can be pulsatile or non-pulsatile/continuous.

These structures can thus make it more difficult or prevent the venous catheter from being pulled out or slipping out of the vein. The venous catheter can also be designed similar to a dowel. It is conceivable that structures located on the outside, e.g. elongated structures, move away from the outside of the venous catheter when heated to body temperature, e.g. protrude from the venous catheter. These structures can also experience an increase in volume when warmed to body temperature. Likewise, these structures can also be designed to absorb fluids and thus experience an increase in volume when they come into contact with fluids, e.g. blood, vapors or gases. This allows the venous catheter to stabilize itself in the vein.

The venous catheter can also be designed like a telescopic tube, e.g. a telescopic round tube, and its length can be adjusted. This can consist of 2,3,4,5,6,7,8,9,10 or more than 10 elements that can be slid into one another, e.g. rings, with different inside and outside diameters.

What is written in this paragraph can also apply to puncture needles and to catheters and tubes in general. These can have the above-mentioned properties and can be advantageously further developed as just described.

Special design of the venous catheter with an internal capillary system

According to an advantageous embodiment of the invention, it is provided that the outer shell has an arrangement of a large number of elongated cavities which extend at least predominantly in the longitudinal direction of the outer shell, with the cavities being able to be in the form of capillaries in particular.

The venous catheter can also consist of a system of elongated cavities, e.g. capillaries, which can have very thin walls. The capillaries can also be designed as glass capillaries. These can, for example, have an outer diameter of between 0.01 and 2.5 millimeters, preferably between 0.05 and 0.5 millimeters. However, smaller or larger outside diameters are also conceivable. The wall thickness/thickness (hereinafter only “wall thickness”) can be, for example, between 0.002 and 0.25 millimeters, preferably between 0.01 and 0.05 millimeters. However, smaller or larger wall thicknesses are also conceivable.

With a venous catheter designed in this way, capillary forces can have an advantageous effect. Advantageously, for example, a venous catheter designed in this way can also be wetted with other fluids or substances, e.g. anticoagulant or antimicrobial substances.

The elongate cavities described above may also be formed from other materials such as plastics materials or metals or metal alloys. They can be electrically conductive and, for example, also act as sensors. A heating or cooling of a fluid flowing through is conceivable, cocurrent and countercurrent principles can be applied. The walls of the elongate cavities can only be permeable to certain substances over part, most or all of their length. For example, they can be semipermeable or enable other diffusion processes. It is also conceivable that fluids flowing in the venous catheter are freed from harmful substances and thus, for example, detoxification takes place.

At least three-layer structure of the indwelling cannula

According to an advantageous embodiment of the invention it is provided that the puncturing device has a further tubular structure between tween the outer shell and the puncture needle is arranged.

An at least three-layer construction of the indwelling cannula is thus possible. At least one further tubular/cylindrical structure, which can also be designed as a hose or catheter, can be located between the puncture needle lying on the inside and the venous catheter lying on the outside. This central structure can also have a different shape and, for example, have the cross-sectional areas mentioned above. The central structure is arranged to be longitudinally displaceable and/or rotatable about its own longitudinal axis relative to an internal puncture needle and/or relative to the external venous catheter.

The wall of this central structure can be formed from at least one layer and partially, predominantly or completely surround the puncture needle located inside or another catheter located inside. The wall of the central structure can preferably be formed from at least two or three layers, at least one of which has at least partially puncture-resistant properties. The layer with these properties can consist, for example, at least in part of a metal, a metal alloy or of aramid/aramid fibers. The central structure can thus provide puncture protection for at least one external catheter against the tip of the puncture needle.

Likewise, the central structure can also be semicircular or trough-shaped. In such a design, it only partially surrounds the internal puncture needle. In a preferred embodiment, it surrounds the surface of the puncture needle over part or its entire length in a semicircle or trough shape by at least 5% or 10%, in other preferred embodiments by at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%.

In addition to an embodiment with a smooth or knobbed surface, the central structure can also be spiral-shaped and provide a wavy surface. It can also be provided with a sealing coating, in particular a PTFE coating, and additionally reinforced with other structures or elements, e.g. by structures running transversely, longitudinally or diagonally.

The middle structure can have a significantly reduced wall thickness compared to an external venous catheter. Thus the wall thickness can be less than 90%, in advantageous embodiments even less than 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% or 5%.

The central structure can also be in the form of a conventional guide wire, e.g. without a core, through which the puncture needle is guided in a longitudinally displaceable manner. In such a case, the external venous catheter can be dispensed with. This creates a system consisting of an internal puncture needle and an external guide wire, which is used to place a guide wire in a target structure, e.g. in a vein.

lotus effect

According to an advantageous embodiment of the invention, the outside of the puncture needle and/or the inside of the outer sheath has a surface layer made of a material with increased lubricity compared to the other material of the puncture needle and/or the outer sheath. For example, this can provide a type of lotus effect on the outside of the puncture needle and/or the inside of the outer shell.

The outside of the puncture needle can consist of a particularly slippery material or be coated with such a material. Alternatively or additionally, the inside of the venous catheter can consist of such a material or be coated with such a material. In particular, this can also involve a material, a coating and/or surface structures which alone or in combination with one another cause a lotus effect. As a result, hydrophobic properties up to super hydrophobicity can be achieved. Corresponding surface structures can in particular have a nub, and at least one layer of wax can also advantageously be used. The corresponding surfaces of the puncture needle and the venous catheter can thereby succumb to self-cleaning properties. All other components and surfaces of the venous catheter can also be designed in the manner just mentioned. Advantageous effects on the flow resistance inside the venous catheter are conceivable.

Friction-reducing properties between puncture needle and venous catheter

According to an advantageous embodiment of the invention, it is provided that there is a friction-reducing additional substance, in particular a substance containing oil or fat, on the outside of the puncture needle and/or the inside of the outer casing.

It is also possible that there is at least one oily or greasy or similar substance between the puncture needle and the venous catheter Frictional resistance between the two is reduced. This can also have antimicrobial or anticoagulant properties. In order for this substance to remain in the space between the puncture needle and the venous catheter, this space can advantageously be further developed with a closing element near the vein and away from the vein. This terminating element can, for example, be designed in such a way that it partially or completely surrounds the puncture needle, eg circularly, and this is passed through a recess in the terminating element in a longitudinally displaceable manner and/or rotatable about the longitudinal axis.

It is also conceivable that at least one terminating element is mounted in the venous catheter so that it can be displaced longitudinally. This can be connected to an actuating element, through which the position of the closing element can be adjusted by a user. If the puncture needle now has a structure or a shape that increases the outer diameter of the puncture needle at least over a partial length of the same, the puncture needle can no longer pass through the end element over this partial length. Thus, the length over which the puncture needle tip projects beyond the venous catheter near the vein can be variably adjusted within certain limits.

A terminating element described above can form a wavy surface and/or also be formed in the form of a spring and/or spiral. A closing element described above can consist of a plastic, but also of a metal or a metal alloy. So that the closing element is impermeable to gas, vapor and/or fluid, it can also be coated or encased with at least one other material. The use of PTFE is conceivable here.

Hollow guide wire as a venous catheter

According to an advantageous embodiment of the invention, it is provided that at least the part of the outer shell that is designed to remain in the hollow body, over its entire length or the majority of its length, in which the puncture needle can be guided in a longitudinally displaceable manner, has a spirally wound, hollow inside has guide wire. A hollow space is thus present within the spiral structure, through which a puncture needle, for example, can be passed.

It is also proposed that at least the part of the venous catheter that is designed to remain in the patient consists of a guide wire over its entire length or the majority of its length, in which the puncture needle can be moved longitudinally, from which the inner core is removed has been. It is therefore hollow on the inside and consists of a spiral structure. This can also be designed as a flat wire. This helical structure can be covered on the inside, outside or immediately by a gas, vapor and/or fluid impermeable layer. This layer can be a PTFE layer, for example, or another material.

Puncture needle (tip) made of resorbable material and with other properties

According to an advantageous embodiment of the invention, it is provided that the section of the puncture needle close to the hollow body is blunt and/or consists of a bioresorbable material and/or some area of the puncture needle consists of a bioresorbable material or is coated with it and/or at least a part the outer shell consists of or is coated with a bioresorbable material. Such a bioresorbable material has the advantage that it dissolves in the body of a living being after a certain time due to the substances present there. Insofar as resorbable materials are mentioned below, this also includes bioresorbable materials.

It is thus possible for the section of the puncture needle close to the vein to be blunt rather than pointed. For example, it can also be in the form of a stamp. If made blunt, it may have further applications in solid or even softer tissues such as the brain, where a sharp puncture needle is unnecessary for penetrating the tissue and could result in injury.

In principle, the puncture needle can be hollow or non-hollow on the inside. If it is not hollow, punching out of the tissue and thus possible displacement of tissue into deeper anatomical structures can be avoided. The puncture needle can also be designed with an internal core or other reinforcing but also flexible structures or materials. It can also contain an internal stylet, which itself is hollow or non-hollow on the inside.

Preferably, the tip of the puncture needle close to the vein can also consist of an absorbable/dissolvable (hereinafter only “absorbable”) material or be coated with such a material.

This resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Similarly, absorbable Polymers, composites, bioceramics or biodegradable metals can be used. The material can also be a combination of several resorbable materials and also contain or be coated with at least one antimicrobial or anticoagulant or otherwise effective or biologically active substance.

In the event of contact with blood or other fluids, the shape of the puncture needle tip can change, e.g. the tip of the puncture needle close to the vein can be partially or completely resorbed. Depending on the material used, this process can happen very quickly, e.g. within 1 second, within 30 seconds or within 1 minute or 2 or 5 minutes. However, this process can also be slower, e.g. at least 1 hour, at least 1 day, at least 1 week, at least 1 month, at least 3 or 6 months or at least 1 year.

It is also conceivable that the tip of the puncture needle close to the vein consists only partially of at least one resorbable material or is coated with such a material. As a result, the tip can assume a desired shape when it comes into contact with blood or other fluids and, for example, the type of cut can also change. This can occur in that the resorbable material releases a material lying beneath and adjacent, which has a different shape than the resorbable material. The material released in this way can also be resorbable, e.g. also more slowly resorbable, or non-resorbable.

In concrete terms, it is conceivable that the puncture needle tip is formed by at least one resorbable material with a sharp cut. If this material is resorbed in the patient, e.g. in the event of contact with blood or other fluids, the puncture needle tip can become blunt if a structure is exposed which, e.g. is designed without a sharp cut and is cut straight and consists of at least one non-resorbable material material exists. This can result in a puncture needle whose tip close to the vein defuses itself, e.g. if it comes into contact with blood, and thus can no longer unintentionally pierce the posterior wall of the vein, for example. Another advantage is that patient and user can no longer be endangered when removing the now blunt puncture needle from the body and an additional safety device, e.g. a puncture protection, is no longer required.

It is also conceivable that a material is used which undergoes a change, e.g. a change in shape, as a result of a gas, vapor or fluid flow. For example, the shape change can be brought about by such a current in such a way that the current removes at least one molecular layer, for example, and is advantageously also transported away directly with the current.

In this context, it is conceivable that at the end of the venous catheter and/or at another component of the venous catheter, e.g. an extension element, which can be at least partially hollow, there is an element which intermittently or continuously at least over a certain Gas, steam or fluid flow generated. This current can advantageously be directed in the direction of the vein. However, an element is also conceivable which generates a negative pressure and thus a flow away from the vein, ie in the direction of the user. As a result, the shape and/or cut of the puncture needle can be modified as it is advanced into the vein.

It is also conceivable that a structure exposed by resorption of another material is designed in the same or similar way to a button cannula. The end of this cannula close to the vein can be rounded or widened, for example.

It is also conceivable that the opening at the puncture needle tip and/or the lumen of the puncture needle can be kept partially or completely open by at least one resorbable material. If this material is now resorbed, e.g. through contact with blood or through contact with other fluids, the opening of the puncture needle tip or the lumen of the puncture needle is closed. This can be relevant, for example, if it is not desired to administer fluids or medication to a blood vessel, but it cannot be ruled out that the puncture needle will reach a blood vessel.

The effect just described can be achieved, for example, by using at least one resorbable material to form struts which partially or completely keep the opening at the puncture needle tip and/or the lumen of the puncture needle open, but no longer in the event of resorption.

It is also conceivable that the puncture needle is reinforced on the inside and/or outside of its wall with an absorbable material that keeps the wall in a position in which the opening at the puncture needle tip and/or the lumen of the puncture needle is partially or completely open are.

In an advantageous embodiment, at least part of the puncture needle consists of elastic material.

However, it is also conceivable that the diameter of the opening of the puncture needle tip and/or the lumen of the puncture needle is/is narrowed by at least one resorbable material and the opening and/or lumen experience/experiences an increase in their inner diameter as a result of the absorption of the material. This can be particularly relevant if punching effects are to be avoided. By filling the lumen of the venous catheter with an absorbable material during the puncture, components that are in the puncture canal can be prevented from being carried over into the vein or into deeper tissue layers. If such an effect is desired, it is advantageous if at least one resorbable material predominantly narrows or completely closes the lumen of the puncture needle in its original state. If the material is resorbed through contact with fluids, for example through contact with blood and/or also with contact with fluids introduced from the outside, an uninterrupted flow of fluids through the puncture needle can then take place, for example.

This can also be relevant for other applications, e.g. for applications in the spinal and epidural space. It is therefore proposed that puncture needles, which are used in these applications, are advantageously further developed in the manner just described. The resorbable material used can, for example, also be dissolved when it comes into contact with liquor.

It is also particularly advantageous to use a material which only dissolves when it comes into contact with liquor, but not when it comes into contact with blood. In this way, an unintentional intravascular administration/injection of fluids and also e.g. medication can be avoided, since the lumen of the puncture needle remains closed when it comes into contact with blood and is therefore in a position in a blood vessel, e.g. in a vein. A catheter, which is possibly to be inserted through the interior of the puncture needle, cannot then be accidentally inserted into a blood vessel. Thus, for example, an unwanted catheter position in a blood vessel can be avoided.

The puncture needle can also consist of a lattice, mesh, honeycomb, labyrinth or pore-like structure, which can contain at least one non-absorbable material and/or at least one absorbable material. Combinations of all the structures mentioned are conceivable.

The puncture needle can also be reinforced with other structures/elements, e.g. with structures running transversely, longitudinally or diagonally, which can contain at least one non-absorbable material and/or at least one absorbable material. Combinations of all the structures mentioned are conceivable.

At least one resorbable material can be embedded in the gaps in these structures. Such a structure can also fill the interior of a hollow puncture needle. A metal can be used as the non-resorbable material, also in the form of a metal alloy, or a plastic or natural material. For example, carbon fiber-reinforced laminate materials, polymers or Teflon come into consideration as plastic materials, also in combination with one another. Aramids can also be used. The resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Resorbable polymers, composites, bioceramic materials or biodegradable metals can also be used. The material can also be a combination of several resorbable materials and also contain or be coated with at least one antimicrobial or anticoagulant or otherwise effective or biologically active substance.

Through contact with blood or through contact with other fluids, the resorbable material can dissolve and structures consisting of at least one non-resorbable material can remain. As a result, the puncture needle and/or the interior of the puncture needle can/can develop other properties, e.g. also filter-like properties. Because the dissolution of the resorbable material changes the flow properties, a filter-like structure is created that can adapt to the environmental conditions (e.g. changes in humidity) through changes in permeability.

Conventional filter systems can also be integrated directly into the interior of the puncture needle. This also applies to swellable materials, e.g. for elastomers or for materials that consist to a certain extent or mainly of fibers of plant origin and can have different strengths.

The puncture needle can advantageously be of lightweight construction. Lightweight materials can be used. In particular, lightweight metallic materials such as titanium, high-strength steels, aluminum and magnesium can also be used. Plastics and fiber-plastic composites can also be used.

The puncture needle can partially, predominantly or completely consist of at least one material or be coated with such a material, which with the help of ultrasound in particular is clearly visible. It is also conceivable that the puncture needle contains at least one channel in its wall, which is filled with a fluid, gas or steam. A substance that is particularly visible with ultrasound can be used for this, but air, for example, can also be used. This channel can be a channel that runs longitudinally over part of the length, most of the length, or the entire length of the puncture needle and is designed to be impermeable to fluid, gas, and vapor to its surroundings. However, the channel can also be designed to run transversely or diagonally and partially, predominantly or completely surround the circumference of the puncture needle in the sense of a ring-shaped structure. This structure can be arranged several times on the puncture needle. In this case, the structures can be spaced at equal or different distances from each other. The distances between these structures can change, in particular towards the puncture needle tip. In an advantageous embodiment, the distances to the puncture needle tip decrease, so the structures are closer together. In this way, in particular, the position of the puncture needle tip can be easily determined with the aid of ultrasound.

All other sections of the puncture needle can partially, predominantly or fully exhibit the properties just mentioned.

A puncture needle as described above can also be used independently of venous cannulas.

A venous catheter or another catheter or hose can also be designed as described above and have the properties described above.

Other aspects of the absorbable venous catheter

Venous catheters and/or puncture needles can also consist of at least one material that can be absorbed/dissolved in the patient, e.g. through contact with blood or other fluids, gases or vapors, over the entire length or a partial length, or be coated with at least one such material. The resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Resorbable polymers, composites, bioceramic materials or biodegradable metals can also be used. The material can also be a combination of several resorbable materials and also contain or be coated with at least one antimicrobial or anticoagulant or otherwise effective or biologically active substance. It is conceivable that all components of the IV catheter consist of a dissolvable material or are coated with such a material.

An absorbable material that is initially present can give the venous catheter and/or puncture needle a certain degree of hardness, and such a material can also be used to make the tip close to the vein hard so that it can be easily advanced into the vein. When it comes into contact with blood, the material is resorbed, i.e. dissolved in the blood. As a result, less hard or less pointed structures can be released. For example, a venous catheter can be made hard before it is inserted into the patient and in particular before it is inserted into the vein, and then become soft. A puncture needle can be pointed when it is inserted into the patient and the vein and then become blunt.

Puncture needle with absorbable external thread

According to an advantageous embodiment of the invention, it is provided that the puncture needle has an external thread and/or the outer sleeve has an internal thread. The external thread and the internal thread can be matched to one another in terms of size and pitch, so that the component with the internal thread can be rotated in the component with the external thread like a screw.

It is also possible for the puncture needle to be developed with an external thread made of at least one resorbable material. The venous catheter can then be provided with a matching internal thread made of at least one resorbable material. It is also possible that only non-resorbable materials are used. The puncture needle and/or the venous catheter can then be turned/screwed precisely into the vein.

The resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Resorbable polymers, composites, bioceramic materials or biodegradable metals can also be used. The material can also be a combination of several resorbable materials and also contain or be coated with at least one antimicrobial or anticoagulant or otherwise effective or biologically active substance.

After the puncture needle has been screwed in/screwed into the vein alone or together with the venous catheter, resorbable materials are resorbed through contact with blood or through contact with other fluids. Thus arise how a smooth-walled puncture needle and a smooth-walled venous catheter.

A puncture needle as described above can also be used independently of venous cannulas.

Resorbable Guide Wire

According to an advantageous embodiment of the invention, it is provided that the puncture device has a guide wire that can be guided through the outer sheath or through the puncture needle, the guide wire being partially, predominantly or completely formed from at least one bioresorbable material.

A conventional guide wire can be inserted into the puncture needle or the venous catheter. This can be partially, predominantly or completely made of at least one resorbable material. The materials mentioned above can be used by way of example. The guide wire according to the invention is then at least partially resorbed and can therefore possibly be left in the body. If the guide wire is forgotten or parts of it shear off, this can no longer cause serious complications if the appropriate material is selected.

The puncture needle can be rotated around its own longitudinal axis with a spring mechanism

According to an advantageous embodiment of the invention, it is provided that the puncture needle can be rotated about the longitudinal axis relative to the outer casing, the puncture device having holding elements by which the rotatability of the puncture needle is restricted or eliminated at least in certain longitudinal displacement positions of the puncture needle relative to the outer casing.

According to an advantageous embodiment of the invention, it is provided that the puncture device has at least one restoring spring, by which the puncture needle is held by spring force in a longitudinal displacement position in which the rotatability of the puncture needle is restricted or eliminated.

It is conceivable that there is a spring at the end of the indwelling cannula that is far from the vein, which in a relaxed (longer) state holds the puncture needle in such a longitudinal position that the puncture needle can be held in place by holding or travel-limiting elements which are on the puncture needle itself and on at least one other components of the IV catheter are attached, is prevented from rotating about the longitudinal axis. The holding or path-limiting elements can be designed, for example, as indentations, grooves or projections. If the puncture needle is now actively pushed with pressure against at least one other component of the venous cannula in the longitudinal direction in the direction of the vein, the spring is compressed. The holding or travel-limiting elements of the puncture needle and the at least one other component of the venous cannula then no longer block the rotational movement of the puncture needle about the longitudinal axis, since they no longer snap into or wedge into one another, for example. The puncture needle can now be rotated around its own axis in the longitudinal direction. If the pressure on the puncture needle is released, the spring relaxes and the puncture needle moves passively in the direction of the user (away from the vein). The holding or path-limiting elements now again prevent a rotary movement of the puncture needle about its own longitudinal axis in the manner described above. This can be used, for example, to create a kind of “child safety device”.

The venous catheter of the venous indwelling cannula can also be rotated as just described. This can have the advantage that, for example, components of the venous catheter that are displaced/blocked by anatomical structures, e.g. entry or exit holes, can be rotated/moved away from the obstructing/blocking structures without having to move or remove the entire venous catheter.

For this purpose, the venous catheter can be mounted in or on the venous indwelling cannula so that it can be rotated about its own longitudinal axis. Likewise, the venous catheter can transition into a structure with a larger inner or outer diameter at its portion remote from the vein.

This can also be mounted such that it can rotate about its own longitudinal axis in relation to at least one component of the venous catheter. This structure can be moved longitudinally. It is also conceivable that a further structure, which is independent of the venous catheter and has a larger inner and outer diameter, is located in the area in which the venous catheter merges into the body of the venous indwelling cannula. This corresponds to the area of the fastening elements 5 and the holding elements 8. This structure can reduce or completely prevent the ability of the venous catheter to rotate about the longitudinal axis.

• - Ein Expansionskörper, der zur Fixierung der einzelnen Schichten in das Punktionssystem eingebracht wird, wobei durch Expansion des Expansionskörpers die innenliegenden Schichten gegen die außenliegenden Schichten gedrückt und damit fixiert werden.
  • - Ein Bügelsystem, wobei durch Umklappen eines außerhalb des Punktionssystems befindlichen Bügels durch Druck die einzelnen Schichten gegeneinander fixiert werden.
  • - Eine Schraube, die über eine entsprechende Bohrung in das Punktionssystem eingebracht ist, wobei die Schraube durch Drehen die unterschiedlichen Lagen durch Druck gegeneinander fixiert.
  • - Eine Beschichtung der einzelnen Schichten des Punktionssystems kann dafür eingerichtet sein, dass die Längsverschieblichkeit im Gegensatz zum herkömmlichen System eingeschränkt ist.
  • - Es ist auch möglich, dass die einzelnen Schichten z.B. durch Einkerbungen ineinander einrastbar sind.
  • - Die einzelnen Schichten können dadurch ineinander verkeilbar sein, dass sie einen nicht kreisrunden oder an einzelnen Stellen erhöhten Durchmesser besitzen und somit durch Drehung oder Vor- und Zurückziehen der einzelnen Schichten gegeneinander zumindest eine teilweise Fixierung erfolgt.
  • - Das Klemmelement kann derartig ausgebildet sein, dass es in einer unberührten Position, z.B. durch einen Federmechanismus, alle Schichten gegeneinander fixiert. Durch Druck oder Zug am Klemmelement wird die Fixierung der Schichten aufgehoben und die Feder gespannt. Erfährt das Klemmelement keinen Druck oder Zug, so kehrt es aufgrund des Federmechanismus in seine Ausgangsposition zurück und fixiert alle Schichten gegeneinander. Diese Ausführung des Klemmelements hat den Vorteil, dass das Klemmelement z.B. mit nur einem Finger bedienbar ist.

By providing a clamping element, the individual layers of the puncture system can be partially or completely against each other be fixed in order to be able to ensure a safe position of the puncture system. The clamping element can be designed as a kind of collet with a conically slotted sleeve and a union nut, the individual layers being pressed into the inner cone of the sleeve and thus clamped by tightening the union nut. However, the following alternatives are also conceivable:

• - An expansion body that is introduced into the puncture system to fix the individual layers, the inner layers being pressed against the outer layers and thus fixed by expansion of the expansion body.
  • - A bracket system in which the individual layers are fixed to one another by pressure by folding over a bracket located outside of the puncture system.
  • - A screw, which is introduced into the puncture system via a corresponding hole, the screw fixing the different positions against one another by turning them.
  • - A coating of the individual layers of the puncture system can be set up so that the longitudinal mobility is limited in contrast to the conventional system.
  • - It is also possible that the individual layers can be snapped into one another, for example by means of indentations.
  • The individual layers can be wedged into one another in that they have a non-circular diameter or a diameter that is increased at individual points, and thus at least partial fixation occurs by rotating or pulling the individual layers against one another.
  • - The clamping element can be designed in such a way that it fixes all layers against one another in an untouched position, for example by a spring mechanism. By pressing or pulling on the clamping element, the fixation of the layers is released and the spring is tensioned. If the clamping element does not experience any pressure or tension, it returns to its original position due to the spring mechanism and fixes all layers against one another. This design of the clamping element has the advantage that the clamping element can be operated with just one finger, for example.

The described functions of the fixing element can be regulated and repeated, so that great flexibility of the fixing element is guaranteed. In particular, the fixing element should also ensure that the puncture system can be adapted to individual living beings and their individual anatomy or to the anatomy of different body regions. The presumed subcutaneous depth of the structure to be punctured can be taken into account before the start of the puncture process, in that the free length of the pointed portion of the puncture needle protruding from the inner tubular body towards the living being to be punctured can be limited. This also reduces the risk of anatomically deeper structures being accidentally punctured, especially by an inexperienced user. This represents an essential safety aspect of the new puncture system.

The puncture needle and venous catheter can also be connected to one another in such a way that they can only be rotated together/in combination. It is conceivable that at least one friction-increasing material is located on the outside of the puncture needle and/or on the inside of the venous catheter in order to achieve this effect.

Puncture needles and/or venous catheters can preferably be adjusted to a circular dimension of 45°, 90°, 135°, 180°, 225°, 270°, 315° or 360° (angles in degrees based on a circular dimension of 360 degrees (360° )).

The angle information can be marked on a component of the indwelling cannula for the user so that, for example, the current angle of the puncture needle or the venous catheter can be read. Here, for example, circular or semi-circular markings with different line widths and, for example, colored markings in the traffic light colors "green", "yellow" and red are conceivable.

Marker detectable with an imaging device

According to an advantageous embodiment of the invention, it is provided that at least one component of the puncturing device, in particular the outer shell, has at least one marker that can be detected with an imaging examination device. There can also be several markers, either on the same component or on different components of the puncture device. The markers can be of the same type or different markers that can be detected by different types of imaging examination devices. For example, there can be at least one marker that can be detected by an ultrasound examination device and/or at least one marker that can be detected by computed tomography and/or at least one marker that can be detected by magnetic resonance tomography. In an advantageous embodiment, the at least one marker is located in an area of the puncturing device which is set up for insertion into the hollow body to be punctured, ie in the area close to the hollow body.

According to an advantageous embodiment of the invention, it is provided that at least one component of the puncturing device, in particular the outer shell, has at least one cavity that is or can be filled with air or another substance that can be detected with an imaging examination device. Such a cavity can function, for example, as at least one marker in the sense described above. The at least one cavity can be completely hermetically sealed from the outside environment or have at least one opening to the environment, for example to the outside of the outer shell. In an advantageous embodiment, the at least one opening is located in a region of the puncturing device that is not designed for insertion into the hollow body to be punctured, i. H. in the area far from the hollow body.

Addition to puncture resistance

It is proposed that at least the part of the venous catheter that is designed to remain in the patient is made of a puncture-proof material over part of its length, its entire length or the majority of its length, in which the puncture needle can be moved longitudinally, or with a coated with such puncture-resistant material.

Complementary aspect to the puncture-resistant hollow Seldinqer wire

With a significantly lengthened venous catheter, which is designed in the sense of a hollow, puncture-proof Seldinger wire, a puncture needle can in principle be brought to any part of the body without any risk of injury to the anatomical structures that are passed on the way to the target structure. Such a significantly lengthened venous catheter can also be used independently of an indwelling venous cannula. For example, it can have a length of at least 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, but also up to 2000 mm. All lengths between these dimensions are conceivable.

If this venous catheter or hollow wire is designed to be impermeable to fluids, e.g. with a corresponding coating or sheathing, which can be made of PTFE, for example, then it can also be used as an aspiration element. With this aspiration element, for example, blood clots or other foreign bodies can be sucked out of any anatomical structures that can be reached with the aspiration element and removed from the anatomical structures. For example, blood clots can be recovered from blood vessels close to the brain, heart and extremities. Another aspiration element, e.g. a syringe, can be connected to the portion of the hollow Seldinger wire that is formed in this way that is remote from the vein, e.g. via a correspondingly formed connector. Connection to a precisely controllable aspiration element is also conceivable.

One aspect of the invention therefore also relates to the design of the puncturing device in the form of a hollow spiral-shaped wire with a fluid-impermeable coating, which is designed to be extra long, for example at least 1000 mm. This hollow helical wire may have a connector at the end distal to the patient for connecting a suction device, for example a syringe, motorized suction device or similar device. In this way, for example, a coronary suction device can be created. This relatively long hollow helical wire may be provided, for example, in a coiled condition and/or covered with a sterile sheath.

Self-closing of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the outer shell has a fluid-permeable lattice, mesh or pore-like structure with fine openings that can be closed by blood components flowing through during operation of the puncture device. Such an outer shell with fine openings initially, i.e. in the state of manufacture, allows fluids, in particular blood, to flow through. Certain blood components that accumulate in the gaps in the structure then automatically close the openings, so that the outer shell then becomes impermeable to fluids.

This can also be accompanied by increased resistance to pressure.

In its original state, the venous catheter can also consist of a fluid-permeable lattice, mesh or pore-like structure, which can also be further developed by other structures, e.g. structures running horizontally, diagonally or vertically. After the catheter has been inserted, blood components can accumulate in the gaps in these structures, as a result of which the venous catheter is designed to be impermeable to fluids. This creates a venous catheter that develops biological properties and can be left in the vein for longer or permanently.

Electrically isolating elements on the venous cannula

According to an advantageous embodiment of the invention, it is provided that at least parts of the puncturing device have electrically insulating elements and/or electrically conductive elements that form electrically conductive connections from one part of the puncturing device to another part of the puncturing device.

It is also conceivable that the indwelling cannula contains insulating, e.g. electrically insulating, elements or materials which, for example, can prevent the build-up of heat that occurs on the indwelling cannula due to external influences. For example, these elements or materials may surround a sensor that may be attached to the venous catheter. These elements or materials can, for example, also surround a spiral or wave-shaped structure and be embedded in the venous catheter with it or form the venous catheter with it.

Electrically conductive elements on the IV catheter

The entire venous cannula can be partially or completely made of at least one electrically conductive material or be coated with such a material. It is also conceivable that a longitudinal structure, e.g. in the form of a strip, can run on or in the venous catheter, which is electrically conductive.

The electrically conductive material can be, for example, a metal or a metal alloy. The following materials can be used as examples: gold, silver, copper, brass, tungsten, aluminum, lead, stainless steel, iron, zinc, chromium, stainless steel, beryllium, platinum, nickel, titanium. Carbon/graphite can also be used.

Other versions of the venous end of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the outer shell has a larger outer diameter in the area close to the hollow body than in the area remote from the hollow body.

The venous catheter can be surrounded by a stamp-shaped/cylindrical structure over part of its length, most of its length or its entire length, against which it can also be longitudinally displaceable. This structure can experience a significant increase in its outer diameter in the direction of the vein and thus stabilize the puncture needle and venous catheter when inserted through the skin and into the vein. When inserting the puncture needle and the venous catheter, this structure can shift towards the user on the venous catheter because it cannot pass through the skin. It can also have telescopic properties. Likewise, puncture needle and venous catheter can be mounted such that they can be displaced, tilted and/or rotated in different directions in relation to this structure.

The venous catheter can be surrounded in the stamp-shaped/cylindrical structure by a further semicircular or circular structure, against which it can be mounted in a longitudinally displaceable and/or rotatable manner. It can also be surrounded by a bag-like structure. This structure surrounding the venous catheter can keep the venous catheter sterile and, for example, also contain an antimicrobial, anticoagulant and/or friction-reducing substance.

Increase in volume of the venous catheter

According to an advantageous embodiment of the invention, it is provided that at least one area of the outer shell has a material that swells as a result of contact with a fluid. Such an intumescent material may be, for example, an intumescent material such as a hydrogel. Insofar as a fluid is named in this application, this includes both liquid and gaseous and vaporous media.

Likewise, the venous catheter can partially consist of at least one material or be coated with such a material, which experiences an increase in volume through contact with blood or quite generally through contact with fluids, gases or vapors or through at least one chemical reaction. For example, polymers, layered silicates, bentonite or composite materials containing natural fibers can be used. Proteins, fats or superabsorbents can also be used.

It is also possible that the venous catheter consists at least partially of a material or is coated with a material over part of its length, most of its length or its entire length, which experiences an increase in volume through contact with blood or quite generally through contact with fluids.

If this material is on the outside of the venous catheter, the venous catheter fixes its position in the vein itself by increasing its outer diameter, especially if another solid material on the inside of the venous catheter only allows the venous catheter to increase in volume outwards. Is the volume-increasing material out against the inside of the venous catheter and if there is a solid material on the outside that prevents the increase in volume to the outside, the inner diameter of the venous catheter is reduced, which means that it closes itself.

Enlargement of the inner diameter of the venous catheter through blood contact

Parts or layers of the catheter can also consist of a material which is resorbable, e.g. This material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. This soluble material can form any layer of the venous catheter. For example, when it forms the inner layer of the venous catheter, the inner diameter of the venous catheter increases through contact with blood.

Limited longitudinal mobility of the puncture needle

According to an advantageous embodiment of the invention, it is provided that the puncture device has an automatic blocking mechanism which prevents the puncture needle from being advanced to the end near the hollow body if the puncture needle has been withdrawn more than a predetermined amount from the end near the hollow body.

In order to prevent the puncture needle from being advanced again into the vein after the puncture needle has already been withdrawn from the vein, a mechanism can be formed on the puncture needle which prevents this. This mechanism can be located anywhere on the puncture needle, but in an advantageous further development it can be located at a point which is on the half of the puncture needle which faces the user (farthest from the vein) in relation to the longitudinal extent of the same. In a further advantageous development, this point is formed in the last third, last quarter or last fifth of the puncture needle close to the user.

Such a mechanism is important, since renewed advancement of the puncture needle in the direction of the vein can also result in components of the venous catheter being sheared off by the tip of the puncture needle.

The mechanism can be designed in such a way that there is at least one ramp-shaped structure on the puncture needle. This structure can be located on the surface of the puncture needle or embedded in a recess of the puncture needle. The ramp-shaped structure can contain at least one spring-shaped and/or spiral-shaped structure and/or be connected to such a structure.

If the puncture needle is in its original maximum venous position before and during the puncturing process, the structure just described is surrounded by the venous catheter or other hollow elements/components of the venous indwelling cannula, which lengthen the venous catheter in the direction of the user in the longitudinal direction. The structure can therefore not rise above the level of the surface of the puncture needle. The spring connected to the structure remains compressed.

If, on the other hand, the structure leaves the venous catheter or the other hollow elements/components of the venous indwelling cannula, relaxation of the spring causes the structure to rise above the level of the puncture needle.

This happens to such an extent that the puncture needle can no longer be advanced in the direction of the vein without further intervention, since the structure no longer fits into the venous catheter or the other hollow elements/components of the indwelling cannula.

Instead of the ramp-shaped structure, a button-shaped or stamp-shaped structure can also be used.

It is also conceivable that a curved structure without a spring mechanism is used. This can also have the properties of a bimetal and, for example, stand out from the surface of the puncture needle due to body heat by increasing its curvature.

General material properties

• - Biokompatible Metalle und Polymere, Biopolymere
• - Biokompatible Kunststoffe, explizit für die medizinische Anwendung
• - Formgedächtnis-Legierungen, z.B. Nitinol (Nickel-Titan-Legierung)
• - Kupfer, Zink, Aluminium, Eisen, Wolfram, Mangan, Silizium, Magnesium, Cobalt, Gold, Silber, Bronze, Platinum, Palladium
• - Messing
• - Edelstahl, Stahllegierung, insbesondere auch rostfrei
• - Ungebrannte Steine
• - Funktionspolymere oder intelligente Polymere, z.B. Formgedächtnispolymere und thermoresponsive Polymere
• - Keramische Werkstoffe, auch Biokeramiken, textile Faserkeramiken
• - Silikon oder Silikonelastomere
• - Chrom
• - Thermoplaste
• - Duroplaste
• - Elastomere, thermoplastische Elastomere (TPE), TPE-A
• - Polyimide
• - Polyolefine
• - Harze und Kunstharze
• - Kautschuk, auch Spezialkautschuk, auch EDPM
• - Gummi
• - Latex
• - Aramide, Aramidfasern, Para- und Meta-Aramidfasern
• - Pappe
• - Natürliche Fasern
• - Mineralische Fasern
• - Faserverbundwerkstoffe, faser- und textilverstärkte Verbunde
• - Kohlenstofffasern, die auch Verbundwerkstoffe verstärken können
• - Technische Textilien
• - Urethane, Polyurethane, auch thermoplastische Polyurethane (TPU)
• - Polyester (PES)
• - Polyvinylchlorid (PVC)- und latexfreie Materialien
• - Sand, z.B. Quarzsand
• - Holz
• - Basalt
• - Fluorpolymere
• - Polyurethanelastomere
• - Thermoplastische Hochleistungskunststoffe
• - Polystyrol (PS), auch expandiertes PS
• - Polyamid (PA)
• - Polycarbonate (PC)
• - Perfluoralkoxy-Polymere (PFA)
• - Polysulfon (PSU)
• - Polyetherblockamid (PEBA)
• - Polyetheretherketon (PEEK)
• - Polyoxymethylene (POM)
• - Polyphenylensulfon (PPSU)
• - Polypropylen (PP)
• - Polyethylen (PE), auch LDPE, HDPE
• - Polyetherimid (PEI)
• - Polyethylenterephthalat (PET), Dacron
• - Polyvinylidenfluorid, Polyvinylidendifluorid (PVDF)
• - Fluorethylenpropylen (FEP)
• - Polyphenylensulfid (PPS)
• - Polyphthalamide (PPA)
• - Acrylnitril-Butadien-Styrol (ABS)
• - Methylmethacrylat-Acrylnitrilbutadienstyrol (MABS)
• - Ethylenvinylacetat (EVA), EVAC
• - Elastan
• - Melamin-Formaldehyd-Harz (MF)
• - Polyesterharz
• - Phosphorylcholin
• - Nylon
• - Teflon
• - Bentonit
• - Glas, Fiberglas, glasfaserverstärkter Kunststoff
• - UV-Klebstoff
• - PTFE, expandiertes PTFE, poröses PTFE, Polytetraflon^®-PTFE
• - ETFE
• - Parylene
• - Aminoplaste
• - Kohlenhydrate, Zucker
• - Proteine
• - Fette
• - Carbon
• - Wolle
• - Mylar^®, Kapton^®, Nomex^®, Kevlar^®
• - Vlies, Vliesstoff
• - Chitin

The indwelling cannula can be advantageously developed individually or in combination with the following materials or classes of materials, materials, elements, etc. (hereinafter referred to as “materials”). The materials listed are not arranged systematically and describe both material and functional properties. Overlaps, in particular between material and functional descriptions, but also in the terms themselves, are possible. It is also explicitly possible that all components of the IV catheter are made of the following materials or contain them, individually or in combination with one another:

• - Biocompatible metals and polymers, biopolymers
• - Biocompatible plastics, explicitly for medical use
• - Shape memory alloys, e.g. Nitinol (nickel-titanium alloy)
• - Copper, Zinc, Aluminum, Iron, Tungsten, Manganese, Silicon, Magnesium, Cobalt, Gold, Silver, Bronze, Platinum, Palladium
• - Brass
• - Stainless steel, steel alloy, especially rust-free
• - Unfired stones
• - Functional polymers or smart polymers, eg shape memory polymers and thermoresponsive polymers
• - Ceramic materials, including bioceramics, textile fiber ceramics
• - Silicone or silicone elastomers
• - chrome
• - thermoplastics
• - thermosets
• - Elastomers, thermoplastic elastomers (TPE), TPE-A
• - polyimides
• - Polyolefins
• - Resins and synthetic resins
• - Rubber, also special rubber, also EDPM
• - rubber
• - latex
• - Aramids, aramid fibres, para- and meta-aramid fibres
• - cardboard
• - Natural fibers
• - Mineral fibers
• - Fiber composites, fiber and textile reinforced composites
• - Carbon fibres, which can also reinforce composite materials
• - Technical Textiles
• - Urethanes, polyurethanes, also thermoplastic polyurethanes (TPU)
• - Polyester (PES)
• - Polyvinyl chloride (PVC) and latex free materials
• - Sand, eg quartz sand
• - Wood
• - basalt
• - Fluoropolymers
• - Polyurethane elastomers
• - Thermoplastic high-performance plastics
• - Polystyrene (PS), also expanded PS
• - Polyamide (PA)
• - Polycarbonate (PC)
• - Perfluoroalkoxy polymers (PFA)
• - Polysulfone (PSU)
• - Polyether block amide (PEBA)
• - Polyetheretherketone (PEEK)
• - Polyoxymethylene (POM)
• - Polyphenylene sulfone (PPSU)
• - Polypropylene (PP)
• - Polyethylene (PE), also LDPE, HDPE
• - Polyetherimide (PEI)
• - Polyethylene terephthalate (PET), Dacron
• - Polyvinylidene fluoride, polyvinylidene difluoride (PVDF)
• - Fluoroethylene propylene (FEP)
• - Polyphenylene sulfide (PPS)
• - Polyphthalamides (PPA)
• - Acrylonitrile Butadiene Styrene (ABS)
• - Methyl methacrylate acrylonitrile butadiene styrene (MABS)
• - Ethylene Vinyl Acetate (EVA), EVAC
• - Spandex
• - Melamine formaldehyde resin (MF)
• - Polyester resin
• - phosphorylcholine
• - Nylon
• - Teflon
• - Bentonite
• - Glass, fiberglass, fiberglass reinforced plastic
• - UV adhesive
• - PTFE, expanded PTFE, porous PTFE, Polytetraflon ^® -PTFE
• - ETFE
• - Parylene
• - Aminoplasts
• - Carbohydrates, sugars
• - Proteins
• - Fats
• - Carbon
• - Wool
• - ^Mylar® , ^Kapton® , ^Nomex® , ^Kevlar®
• - fleece, non-woven fabric
• - chitin

The venous catheter can contain at least one spiral and/or corrugated structure, which consists of at least one of the materials just mentioned and/or is coated with at least one such material and/or is partially, predominantly or completely surrounded by at least one such material.

The use of composite materials and layered composites is explicitly possible, hemocompatibility and anti-adhesive behavior is advantageous for all materials used. Resistance to sterilization and resistance to breakage are also advantageous. Materials with thermoplastic properties can advantageously be used and also those that are visible in X-rays. UV resistance and high resistance to the effects of chemicals are desirable.

The materials can advantageously be combined in such a way that the entire venous cannula or venous catheter is designed to be puncture, kink and cut-resistant as in PCT/ EP2019/057097 prescribed. Fabric inserts can also be used.

The use of fibers and biodegradable materials is also possible. Foils and laminates can also be used.

Likewise, resorbable/dissolvable or drug- or material/substance-releasing materials can be used. For example, it is possible for materials to release, contain or be coated with antimicrobial, anti-inflammatory, chemotherapeutic or local anesthetic substances. This also applies, for example, to substances with an antithrombogenic effect, such as heparin, which can prevent the formation of blood clots on and near the venous catheter.

Surface structure and chemistry of the surface can be optimized. A hydrophilic or hydrophobic coating may be advantageous. A super- or ultra-hydrophobic surface can also be used advantageously. The plasma coating process can be used for production. It is also conceivable that the surface of components of the indwelling cannula, e.g. the surface of the puncture needle or the venous catheter, is partially, predominantly or completely provided with polymer brushes.

The above-mentioned materials can also be used locally on the venous catheter. For example, it is conceivable that a different material is used at the end of the venous catheter that is immediately close to the vein than at the area further away from the vein. For example, the tip of the venous catheter can be made of a softer material with thermoplastic properties. However, the tip of the venous catheter can also be deliberately made of a harder material in order to make it easier to advance into the vein.

In addition, materials can be connected by technical processes or merge into one another at one or more points of the venous cannula. For example, it may be possible to connect or fuse a spiral spring at the end of the venous catheter that is immediately close to the vein to a material that surrounds it, is on the inside or on the outside. Such a connection or fusion can take place in the area of the entire venous catheter. This can prevent the spiral spring from being broken. Materials with a suitable toughness can advantageously be used here.

Materials that expand at body temperature or swell in the vicinity of a fluid, that is to say increase in volume, can also be advantageously used. For example, bentonite can be used. Such an effect can be used, for example, at the end of the venous catheter close to the vein: When inserting the venous catheter, it is relatively sharp-edged at the end close to the vein and lies snugly against the puncture needle. When the venous catheter is placed in the vein as intended, it now swells at the end close to the vein and can thus cause less damage to the vein wall. It is also possible that the venous catheter can swell over a further part or over the entire length. It is also possible that the puncture needle can swell as just described and thus change its properties, e.g. defused itself and is no longer sharp at the end near the vein. Hydrogels can be used.

It is also possible to attach other structures, e.g. coil-like structures.

The use of several layers of different materials, which form the wall of the venous catheter, for example, is explicitly possible. These layers can be firmly attached to each other or be mutually displaceable. Different states of aggregation of materials can exist in the wall of the venous catheter.

When using suitable materials, the indwelling cannula or components of it can be adapted by the user to the individual course or the individual anatomical characteristics of the vein, e.g. by bending, before being inserted into a patient.

A refinement of the layers or surfaces mentioned in the last paragraph is explicitly possible.

Materials or surface coatings can have fluorescent properties. Materials or surface coatings can also discolour or change in general due to metabolic activities, e.g. due to the metabolic activities of germs, e.g. bacteria. However, a discoloration or change due to the patient's own metabolic activities is also conceivable. For example, the length of time an indwelling cannula or a venous catheter has been in place can be determined and monitored.

The integrity can also be checked in this way. It is conceivable that the material properties of the venous catheter may change if it is left in place for a longer period of time or if there are material defects, e.g. breaks or tears in the venous catheter. For example, the electrical conductivity can change. If a current is applied via a conductive venous catheter, it can be determined whether the venous catheter is damaged. It is also conceivable that the venous catheter changes properties that make it less, more or differently visible in an ultrasound or X-ray image. In the present text, this always includes representation using other imaging methods such as computed tomography and magnetic resonance tomography.

In this way, a regular material check can be carried out, especially in the case of venous catheters/venous indwelling cannulas that have been in the patient for a longer period of time. The length of stay can also be controlled in this way. It can also be particularly relevant if the venous catheter has properties that make it less, more or differently visible in an X-ray or ultrasound control in the event of germ contamination. For example, it can be determined whether a venous catheter is the cause of blood poisoning (sepsis). In this way, potentially unnecessary catheter changes can also be avoided.

Electrically charged materials can also be used advantageously. It is conceivable that the venous catheter is electrically charged, e.g. positively charged, due to special material properties on the outside and thus automatically repels or moves away from the rather negatively charged vein inner wall (intima). Potential injuries to the vein wall can now be avoided through reduced mechanical irritation. The venous catheter can also be supplied with a low current or a low voltage from the outside, so that this effect is enhanced or only made possible with sufficient intensity.

Nanoparticles can also be used.

All of the above materials can also be used on all sections, parts and components of the IV catheter that are set up to remain outside the patient.

The entire venous cannula or components of it can be designed in a lightweight construction.

Specific use as a pleural catheter

According to an advantageous embodiment of the invention, it is provided that the puncturing device is designed as a pleural catheter. It is advantageous if the puncturing device or at least the outer shell is designed to be puncture-proof and/or kink-proof. Puncture resistance can be achieved, for example, by an appropriate puncture-resistant coating or by designing it as a spiral-shaped hollow wire. The helical hollow wire can be wound very densely. In an advantageous embodiment, the windings of the spiral-shaped hollow wire lie directly against one another without any spacing. In a further advantageous embodiment, the windings are spaced apart from one another by a maximum of 0.1 millimeters, a maximum of 0.5 millimeters, a maximum of 1 millimeter or a maximum of 2 millimeters, it being possible for the distance between the windings to vary. In order to continue to make the spiral-shaped hollow wire puncture-proof, at least one other puncture-proof material can be located between the windings. The puncture resistance of the material refers to a possible puncture of the pleural catheter by the puncture needle, which is to be prevented by the puncture-proof material. The puncture-resistant material can be a metal, also in the form of a metal alloy, or a correspondingly puncture-resistant plastic or natural material. For example, carbon fiber reinforced laminate materials, polymers and/or Teflon come into consideration as plastic materials, also in combination with one another. Aramids can also be used.

The puncture safety ensures that no parts of the puncture device can be punctured or sheared off by a conventional puncture needle being passed through. The kink safety ensures that the puncture device does not accidentally kink when used as intended.

When designed as a pleural catheter, the catheter system is designed so that it can be used to puncture the pleural space, eg in the case of pathological accumulations of gases, vapors or fluids in the pleural space (eg pneumothorax, hemothorax, pleural effusion). These can then be evacuated from the pleural space with the help of the catheter system. In this application, too, a puncture needle (in this application a pleural puncture needle) is guided through a catheter surrounding it (in this application a pleural catheter). The catheter can here as in this patent application and as in PCT/ EP2019/057097 described be trained.

It is advantageous if the pleural catheter has a stitch length of at least 50 mm, e.g. 80 mm, 85 mm, 90 mm and a maximum of 140 mm. However, the pleural catheter can also have stitch lengths of up to 160, 180, 200 or 600 mm. The pleural puncture needle and pleural catheter and the entire catheter system as a whole are significantly longer. The stitch length of the pleural catheter is the length that corresponds to the length of the pleural catheter in the patient. This can be used for special patient groups, e.g. in children, can also be less than 50 mm. All lengths are conceivable. The outer diameter of the pleural catheter can be 2-5 millimeters, in an advantageous embodiment 3-4 millimeters. The inner diameter of the pleural catheter can be 1-4 millimeters, in an advantageous embodiment 1.5-3 millimeters. All sizes are conceivable.

All of the configurations/properties just mentioned can also be used in and on a general puncture system, e.g. also an indwelling cannula.

More applications

In an advantageous training/further development, the venous cannula is a catheter system for the invasive measurement of the arterial blood pressure.

In an advantageous training/further development, the venous cannula is a universal blood vessel catheter system which can be used for all blood vessels. In this case, the catheter system can be provided with a marking system that includes the elements/colors “blue” and “red” that can be set alternatively. "Blue" stands for a venous position, "red" for an arterial position of the catheter in the corresponding vessel.

In an advantageous training/further development, the venous cannula is a catheter system for puncturing the trachea.

In an advantageous training/further development, the venous cannula is a catheter system for puncturing the urinary bladder.

In an advantageous training/further development, the venous cannula is a catheter system for puncturing the gastrointestinal tract and/or the abdominal cavity.

In an advantageous training/development, the venous cannula is a catheter system for puncturing reservoirs, pump, hose, tube and port systems.

In an advantageous training/further development, the indwelling vein cannula is a catheter system for use in the field of interventional radiology.

In an advantageous training/further development, the indwelling vein cannula is a catheter system for use in the field of interventional cardiology.

In an advantageous training/further development, the venous cannula is a catheter system for use in the field of emergency, disaster, tactical and military medicine.

thumb piece

The indwelling cannula can have at least one holding and/or connecting element (hereinafter only “holding element”) for easier application to a patient, the holding element having a complementary shape or a negative contour of a human thumb or a human fingertip. As a result, the venous cannula can be further developed in an ergonomically advantageous manner for the user.

In particular, the holding element can also be bent/curved. For example, it can be convex in the direction of the vein and concave in the direction of the user. However, it is also possible for it to be concave in the direction of the vein and convex in the direction of the user. It is also conceivable that only the side facing the user is bent/curved and the side facing away from the user is straight. Likewise, the side facing the user can have at least one indentation, flattening and/or groove be able to accommodate a user's finger, fingertip and/or fingernail.

In such a case, the one-handed operation of the indwelling cannula can be facilitated since a finger, e.g. the index finger, of the user can safely push the connection element and the venous catheter connected thereto in the direction of the vein. The holding element can, but does not have to, be designed in such a way that an aspiration element such as a syringe can be connected. For example, it can also be in the form of a cylinder, stamp or plate or also in the form of a polygon and only the side facing the user as described above.

The holding element can also be attached to the other components of the indwelling cannula so that it can be rotated partially or completely.

The connection element can also be attached to the other components of the intravenous cannula so that it can be tilted partially or completely to one, two or more sides.

The connection element can also be attached to the other components of the intravenous cannula so that it can be displaced partially or completely in the longitudinal direction.

The connection element can consist of at least one material on its upper side or be coated with one that is characterized by increased frictional resistance. For example, the surface structure can have a corrugation or be nubbed. It can also have adhesive or adhesive properties and/or be provided with a removable protective film.

A plastic deformability of the holding element can also be provided. In addition, the deformable material can be partially or completely detachable from the other components of the indwelling cannula.

Likewise, the connection element can contain a coupling element. This can be used to separably connect it to the other components of the intravenous cannula. This coupling element can also be designed in the form of a plug connection. Likewise, the connection element can be separably or inseparably connected to a second connection element. It is also conceivable that the connection element is also only partially designed in the manner just mentioned, in particular in the direction of the user.

The above-mentioned developments have the advantage that the venous cannula no longer has to be touched in the vicinity of the venous catheter, which reduces the risk of contamination with germs.

It is also conceivable for the connection element to have a flat running inner channel, which connects to the venous catheter at a flat angle. As a result, the height of the connecting element can be reduced. It is then possible to place an aspiration element at an acute angle, relative to the longitudinal axis of the venous catheter, via the connection element on the venous indwelling cannula. An infusion line, for example, can also be attached to the indwelling cannula at the acute angle just described. A further hollow extension element through which a fluid can flow can then be dispensed with. The acute angle has the advantage, for example, that no holding and/or aspiration element protrudes steeply upwards from the indwelling vein cannula. The acute angle also has the further advantage, for example, that an aspiration element and/or an infusion line do not have to be connected to the indwelling cannula directly in the vicinity of the skin, which can cause contamination of the connection point with germs.

The connecting element can have an internal and/or external thread and be compatible, for example, with the connecting elements of aspiration elements and/or infusion lines, which can also contain thread-like structures.

Venous catheter removable layers/hollow structure

According to an advantageous embodiment of the invention, it is provided that the outer shell is multi-layered with one or more removable layers.

The venous catheter can also be constructed with one or more removable layers. If these are removed, the inner diameter or lumen of the venous catheter increases. In this way, layers of the venous catheter that are colonized with germs or provided with blood clots can be easily removed. However, it is also possible that layers can be introduced from the outside in this way and the venous catheter can thus be supplemented with further layers. A hollow structure can also be used, which can be inserted into the venous catheter and changed regularly. This can be adapted to the respective inner diameter and the geometric shape of the venous catheter or adapt to it. However, the hollow structure can also form a geometric structure which is different from that of the venous catheter. The hollow structure can consist of at least one layer hen. This at least one layer can have antithrombogenic, antimicrobial and/or puncture-resistant properties. The hollow structure can also have a spiral or wavy surface and be further developed with a sealing coating, for example a PTFE coating.

Further training of the venous catheter

It is also conceivable that the venous catheter contains structures similar to fish scales or roof tiles, which are arranged, for example, in an overlapping or superimposed manner.

The venous catheter can also be designed similar to a commercially available shower hose, as well as a braided hose. The venous catheter can advantageously be further developed using various types of braiding. For example, various spiral braids are conceivable here, which can be made of stainless steel or another metal or metal alloy. Flat braids, core-sheath or packing braids, possibly in modified forms, are also conceivable. However, the braids can also consist of any other material, in particular of a puncture-proof and cut-resistant material, or be coated with such a material. It is also conceivable to construct the venous catheter with a metal mesh, an expanded mesh or expanded metal.

The venous catheter can also have a honeycomb, lattice or pore-like structure. It can also be designed with multi-dimensional fabric structures.

The venous catheter can also be reinforced with longitudinal structures. These can be arranged over part of the length, the majority or the entire length of the venous catheter or only in the area of the portion of the venous catheter close to the vein. These longitudinal structures can, for example, promote the advancement of the venous catheter into the vein during the insertion process and stabilize the rather flexible venous catheter in such a way that it is not pressed against the vein wall by the blood flow.

The venous catheter can also be designed as a shrink tube or be covered with one. This can be a PTFE hose. The venous catheter can also be designed as a multi-layer tube.

The venous catheter can be a rubber hose or a rubber tube.

Three-way tap/filter

The indwelling cannula can already contain at least one integrated three-way stopcock or a multi-way stopcock system, which can be separably or inseparably connected to the indwelling cannula. In particular, it can be inseparably connected to a hollow extension element adjoining the venous catheter in the direction of the user. The three-way valve can also be designed as a three-way valve with a hose. At least one filter element can be separably or inseparably connected to at least one component of the venous catheter, in particular also to the hollow extension element.

Further developments of the spiral/wavy structure

According to an advantageous embodiment of the invention, it is provided that the wall of the outer shell has at least two spiral or wavy structures, in particular a spiral or wavy structure directed toward the inside of the outer shell and a spiral or wavy structure toward the outside of the outer shell.

The wall of the venous catheter can also be formed by an at least double spiral or wavy structure or there can be at least two spiral or wavy structures in the wall of the venous catheter.

These can be inseparably connected to each other, but also have no connection with each other due to the construction. In the latter case, they can be movable in relation to one another, e.g. displaceable in the longitudinal direction, or can be turned/rotated in relation to one another. This has the advantage that the venous catheter retains its flexibility and can thus adapt to the course of the vein, but it is nevertheless made more robust/rigid.

In particular, it is also conceivable that a second spiral or wave-shaped structure is embedded in the depressions of a first one and/or engages in them. In this case, the structures can be movable relative to one another, but their mobility relative to one another can also be limited by at least one material and/or a coating that increases the frictional resistance. The relative mobility can also be restricted in such a way that there are further connections or structures between the two spiral or wave-shaped structures, e.g. microstructures or nanostructures.

A combination of at least one spiral or wave-like structure and at least one braid-like structure is also conceivable. A wavy medium surface is characterized by alternating diameters of the venous catheter, at least in cross section along the longitudinal axis of the venous catheter. A waveform can consist of a sine, square, triangular and/or sawtooth wave, for example.

The outer diameter of at least one spiral structure can vary over the length of the venous catheter. In particular, the outer diameter can decrease in the direction of the vein. However, it is also conceivable that the outer diameter in areas of the venous catheter that are subject to particularly high mechanical loads, e.g. where the venous catheter is connected to other components of the indwelling cannula and/or guided through the patient's skin after installation, is larger than in other areas. A corresponding design of the spiral structure over a length of 1-20 millimeters, in particular also 2-10 millimeters, can be advantageous here. The outer diameter can be increased at least 1.5 times, but also at least doubled.

In combination with a variation in the density of the windings, a venous catheter that is flexible, but at the same time also more robust and adapted to different conditions, e.g. anatomical conditions, can be created.

The spiral or wave-shaped structure can consist of nitinol (nickel-titanium alloy), stainless steel, aramide and/or at least one hard plastic material over its partial length, predominant length or total length, or can have a corresponding coating.

The spiral or wavy structure can consist of magnesium materials over its partial length, predominant length or total length or have a corresponding magnesium-containing coating. This allows the structure to acquire resorbable properties. In particular, longitudinal, transverse or diagonal structures that stabilize the venous catheter during its insertion into the vein can also contain magnesium. After the venous catheter has been inserted into the patient, these can then be resorbed, e.g. through the bloodstream.

This creates a venous catheter that is stiff when inserted into the vein and then becomes increasingly softer. Alternatively or additionally, the venous catheter can be coated on the inside and/or outside with a corresponding material, in addition to, but also independently of, the use of a spiral or wave-shaped structure. However, if one is used, it can also be completely surrounded by at least one material that contains magnesium.

However, it is also conceivable that all other components of the venous catheter and the venous indwelling cannula consist at least partially of magnesium materials or have a corresponding coating that contains magnesium.

A helical structure may be made of at least one material that expands at body temperature compared to room temperature. As a result, a denser winding and thus a change in the flexibility of the spiral structure can be achieved when it is heated to body temperature, e.g. when the venous catheter is placed in the vein. A venous catheter containing the helical structure can then, for example, become stiffer after being inserted into the vein. The material can, for example, be a metal, also in the form of a metal alloy. Specifically, the material can be aluminum. Generally speaking, any material listed in the General Material Properties section above can be used.

The same effect can be achieved if at least one material is used which has swelling and/or hygroscopic properties. The material may be or include, for example, bentonite, hydrogel or starch.

It is also conceivable that the windings of the helical structure are hollow on the inside over a partial length, most or the entire length of the helical structure. A fluid or a gas/vapor can be located in this cavity, which expands with increasing ambient temperatures, e.g. again with an increase from room to body temperature. The cavity can be connected to at least one channel, to which in turn an aspiration element can be connected selectively via a connector, for example. The cavity of the spiral structure can thus be filled with a fluid, gas or vapor by a user, for example with the aid of an aspiration element. Likewise, this can in turn be evacuated from the cavity. Advantageously, a valve-like element can also be used, which prevents the fluid, gas or vapor from being able to flow out of the cavity via the channel without the aspiration element being placed on the connector.

However, it is also conceivable for the windings of the spiral structure to be developed with a plurality of cavities which are separated from one another by structures and therefore do not communicate with one another. In such a case, these non-communicating cavities may be connected to different channels, to which again so that an aspiration element can be connected selectively via a connector, for example. Valve-like elements can advantageously be used as just described.

The spiral structure can consist of at least one material which has elastic properties. Thus, the spiral structure can expand or contract, that is, its volume can also change independently of the existing ambient temperature, depending on whether or not it is filled with a fluid, gas, or vapor, as just described.

Depending on the filling quantity, the volume of the spiral structure can be precisely controlled. This can directly affect the properties of the venous catheter.

A helical structure formed in this way can be located in the wall of a venous catheter and can be delimited inwardly from the lumen of the venous catheter by a non-elastic layer. Thus, when a fluid, gas or vapor is supplied, the outside diameter of the venous catheter will increase without the diameter of the lumen changing.

A spiral structure formed in this way can be located in the wall of a venous catheter and can also be delimited to the outside by a non-elastic layer from other structures of the venous catheter or the vein itself. Thus, when a fluid, gas or vapor is supplied, the diameter of the lumen will decrease without the outer diameter of the venous catheter increasing.

This creates a venous catheter that can be optimally adapted to the individual course of the vein and a vein diameter that increases in the direction of the heart, for example.

A venous catheter developed as described above can also be used independently of an indwelling cannula as a hose for other applications. For example, it can be used as a hose for other catheter systems or as a ventilation hose, e.g. also as an endotracheal tube. A puncture needle can also have the properties just mentioned.

Special design of the venous catheter in the mechanically stressed skin area

According to an advantageous embodiment of the invention, it is provided that the outer shell has one or more reinforcement elements in one or more areas that are exposed to increased mechanical stress. Such reinforcement elements can be designed, for example, as support structures.

An accordion-shaped, spiral or wave-shaped design of the venous catheter is also conceivable only at the points of particular mechanical stress, e.g. where the venous catheter is at skin level and merges into other components of the venous indwelling cannula away from the vein. A special design of the venous catheter over a distance of 1-20 millimeters, in particular over 2-10 millimeters, can be advantageous here. It can also be reinforced with other structures or elements over this length only. Over this length, the venous catheter can also be reinforced with additional layers or a protective sleeve, for example. This can surround the venous catheter over a partial length in the shape of a trough, a semicircle or a circle. The venous catheter can be inseparably connected to this protective sleeve. It is also conceivable, however, for the venous catheter to be guided in this in a longitudinally displaceable and/or rotatable/rotatable manner. The protective sleeve can prevent potential material damage to the venous catheter, e.g. breaking.

It is also possible to form a very flexible connection in the area just mentioned. An additional connector can thus be used. A fluid-conducting element can also be used, which continues in the direction of the vein into the venous catheter and can be rotated or angled. It can be rotated or bent freely in all directions. Such a fluid-conducting element can also be designed in the manner of a joint, e.g.

In the area just mentioned, the venous catheter can also be guided through a joint-like structure, e.g. The venous catheter can be guided through this structure on the inside and be partially or completely surrounded by the structure.

The venous catheter can also be splinted by a structure lying on its outside, which can lie partially, predominantly or completely on it, so that it does not kink. The external structure can in particular be embodied in the form of a trough, semi-circle or circle and also be part of an articulated structure as described above or be combined with one.

Connection elements can also be connected to the other components of the indwelling cannula via the articulated structures described above. A fluid-conducting structure can be passed internally through these structures.

Adjustable flexibility of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the puncturing device has at least one adjusting element with which the flexibility of at least one area of the outer shell can be adjusted by the user.

In the wall of the venous catheter, i.e. the outer shell, a tubular structure can be embedded in a cavity, which can be longitudinally displaceable relative to the other wall components and rotatable/rotatable about the longitudinal axis of the venous catheter. The cavity can be closed in the direction of the vein and open in the direction of the user. The tubular structure, which may not be completely circular but may also be semi-circular, for example, may protrude beyond the venous catheter in the longitudinal direction. In particular, it can protrude in the longitudinal direction beyond the venous catheter and an extension element located in the direction of the user, in which or whose wall it can be located as just described. This allows the structure to be controlled in its position by a user.

Flexibility and rigidity of the venous catheter in the blood vessel can be individually varied by the user. This is particularly relevant when the venous catheter has not yet reached its final position in the vein. This creates a new group of catheter systems.

If the tubular structure is also designed to be puncture-proof, movements of the venous catheter in relation to the puncture needle in all directions are also possible multiple times in relation to one another, without the venous catheter being able to be damaged in the process. The tubular structure may be formed of at least one puncture resistant material or coated with at least one such puncture resistant material. The puncture resistance of the material refers to a possible puncture of the venous catheter by the puncture needle, which is to be prevented by the puncture-proof material. The puncture-resistant material can be a metal, also in the form of a metal alloy, or a correspondingly puncture-resistant plastic or natural material. For example, carbon fiber reinforced laminate materials, polymers and/or Teflon come into consideration as plastic materials, also in combination with one another. Aramids can also be used.

Due to the above-mentioned properties of the indwelling cannula, it may also be possible to initially leave a puncture needle that has been withdrawn in the venous catheter in the venous catheter in order to puncture a deeper structure at a later point in time, for example. A puncture needle pulled back sufficiently far into the venous catheter is surrounded by the external puncture-proof venous catheter and cannot damage surrounding structures.

Applicator on the venous part of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the puncturing device has an applicator at the end near the hollow body for the application of a substance in the area of the puncture point of the puncture needle on the hollow body. The applicator can, for example, be designed as a liquid-tight hollow body, e.g. as a bag, which is filled with an antimicrobial liquid or some other fluid. The antimicrobial liquid can be, for example, an alcoholic, iodinated or other disinfecting liquid. The fluid may have anti-friction, antimicrobial, local anesthetic, and/or anticoagulant properties, for example. For example, the applicator can also contain a cooling medium, for example cooling liquid and/or ice, in order to cool the area of the puncture point of the puncture needle. As a result, the use of the puncturing device in living beings can be designed to be painless. In particular, the applicator can be designed in such a way that it cannot penetrate the shell of the hollow body to be punctured, i.e. it should not be too pointed in the area close to the hollow body, but rather blunt.

There may be another structure, i.e. the applicator, which partially or completely surrounds the venous catheter and/or the introducer needle prior to insertion into the patient. This structure can be a closed hollow body that is longitudinally displaceable relative to the venous catheter. For example, it can be cylindrical with a round or ellipsoidal cross-sectional area, also in the form of a rod, a nozzle or a tube. It can also be cuboid. It can also be further developed, e.g. in the form of an applicator, sponge, foam or gel ring, a bag or a capsule. It can also be disk-, rim- or ramp-like.

The structure can also be designed in such a way that at least part of the hollow body is located in front of the puncture needle tip in the longitudinal direction. It is then advantageous if the hollow body is surrounded by a wall which is formed by the Puncture needle tip can be punctured. This wall can also be a membrane. If there is a fluid in the hollow body, the puncture needle and venous catheter are wetted with this before being inserted into the vein. The fluid may have anti-friction, antimicrobial, local anesthetic, and/or anticoagulant properties, for example.

A structure that is located in front of the puncture needle tip before the venous cannula is used also has the advantage that it provides puncture protection for the patient and the user until it is placed on the patient's skin.

In an advantageous development, the outer diameter of a structure surrounding the venous catheter is at least 1.5 times as large as the outer diameter of the venous catheter. In a further advantageous development, the outer diameter is at least twice as large as the outer diameter of the indwelling cannula. In further advantageous developments, the outer diameter of the structure is at least 3 times, at least 4 times, at least 5 times and at least 6 times as large as the outer diameter of the indwelling vein cannula.

The structure surrounding the venous catheter can taper towards the end near the hollow body, e.g. taper at an angle of at least 30 degrees, 45 degrees, 60 degrees, 75 degrees or 90 degrees, starting from a 360 degree system. The angle refers to the angle measurement between two external oblique dilation surfaces of the structure and not to the central axis of the structure.

This means that the structure cannot penetrate through the skin when the puncture needle and the venous catheter are inserted. Due to its longitudinal mobility, the venous catheter is wetted with the above-mentioned fluid over most or its entire length. After the wetting process, the structure can either remain on the venous catheter and at least partially protectively surround it, e.g. in the area of the transition into other components of the venous catheter. The structure can be a kind of "sleeve" that is first "in front" of the venous catheter, then "slips back" on it when the venous catheter is inserted (and thereby wets it) and then protectively surrounds the area where the venous catheter enters the skin (minimization of the risk of infection).

However, it is also conceivable that the structure can be removed from the venous catheter and, for example, is designed so that it can be split or torn off.

The structure can also be provided with an adhesive or adhesive surface in order to stabilize the venous cannula during the puncture on the skin.

It is also conceivable that the puncture needle and/or venous catheter have already been passed through the above-mentioned structure even before the puncture process has started.

The structure can therefore partially or completely enclose the puncture needle and/or venous catheter. The wall of the cavity of the structure can be attached to the puncture needle and/or the venous catheter in a longitudinally displaceable and fluid-tight manner.

It is also conceivable that the cavity of the structure is at least partially surrounded by at least one further cavity, which is delimited from the first cavity by an additional wall. Likewise, at least one further cavity can be adjacent to the first one and also be delimited from it by a wall. The venous catheter can thus be wetted by different fluids, which can be used on the venous catheter in a compatible manner, but must be stored separately from one another before use.

It is also conceivable that there is urea in one cavity and water in the other cavity. Other substances that are used in commercial instant cold packs can also be used. In this way, the puncture needle and/or the venous catheter can be cooled before and during introduction into the patient, the puncture needle and/or venous catheter can thus be introduced into the anatomical structures with little pain.

A capillary, pore and/or honeycomb structure, e.g. in the form of a sponge, can also be located in the cavities, which has direct contact with the venous catheter and is used both for wetting the venous catheter with a fluid and for mechanical wetting cleaning and/or drying of the venous catheter. It is also conceivable that at least one cavity of the applicator can be filled with a fluid from the outside, e.g. also through a bacterial filter. The above-mentioned structure can then ensure that the cavity is filled evenly with a fluid and that the fluid is continuously released onto the venous catheter.

Training of the venous catheter as a pigtail catheter

According to an advantageous embodiment of the invention, it is provided that the puncture device device has a mechanism by which the outer shell can be converted into a spiral shape by a relative movement with respect to the puncture needle. The outer shell can initially have a non-spiral shape, for example an elongate, rectilinear shape. The puncture needle can be guided through an outer shell designed in this way. By withdrawing the puncture needle relative to the outer casing and/or advancing the outer casing relative to the puncture needle, the outer casing can be converted into the spiral shape.

The venous catheter can also be designed with a curl at the end immediately close to the vein. In contrast to the pigtail catheters used in medicine, the catheter is not initially stretched by an inserted guide wire, but by the inserted puncture needle. As soon as the venous catheter is advanced over the tip of the puncture needle in the direction of the vein or the puncture needle is withdrawn from the venous catheter, it changes from a straight course to a curled or at least curved one. The venous catheter can be made of silicone or polyurethane, for example, but can also contain at least one shape-memory alloy, e.g. nickel-titanium or nickel-titanium-copper. Combinations of copper, aluminum, nickel and zinc are also conceivable. The formation with at least one shape memory alloy can also only exist in the area of the venous catheter which is intended to transition into a curled or at least curved course. This area of the venous catheter can also contain a spiral or wavy structure. However, it is also possible that a spiral or wave-shaped structure is no longer present in this area of the venous catheter, but forms the area of the venous catheter that remains straight.

Recesses/openings can be arranged over the entire length of the venous catheter, but preferably also at the point at which the angling or bending of the venous catheter is at its maximum. As a result, liquids to be infused, for example, continue to flow in the direction away from the venous catheter into the blood vessel.

An indwelling vein cannula developed in this way can be used in particular in the field of urology, but also for pneumothorax drainage, in particular in the case of premature babies/newborns.

Communication of lumen within the venous catheter

According to an advantageous embodiment of the invention, it is provided that the outer shell has a multi-lumen design, with two or more lumens being able to be connected to one another via one or more openings. Such different lumens are normally separated from each other. However, such openings may allow localized fluid communication between two or more lumens.

If the indwelling cannula is designed with at least two lumens, the separation between the lumens can be partially or predominantly eliminated, particularly within the venous catheter. This can be done by recesses made in the structures separating the lumens. These recesses can, for example, have a circular or ellipsoidal structure and can also be provided with flap-like structures which only allow the fluid to flow in one direction. In addition, elements that perform the function of overflow valves can be located in the recesses.

The recesses can also have filter-like structures which only allow specific fluid components to pass through the recesses. In addition, it is conceivable that at least one lumen within the venous catheter partially or completely merges into another. A lumen can also end blindly and represent a kind of dead end or reservoir, e.g. for a drug. The blind ending lumen can also contain at least one sensor.

It is also conceivable that the structures that separate the lumens from one another within the venous catheter contain elements that can be adjusted from the outside, via which it is possible to influence whether the fluids in the initially separated lumens can communicate with one another. This can also be done in such a way that at least two lumens within the venous catheter can be rotated about the longitudinal axis or displaced in the longitudinal direction and contain recesses that are complementary to one another. If these recesses are brought one over the other by corresponding movements, the fluids can communicate between the different lumens; otherwise the fluids are strictly separated from each other.

It is also possible at any time to connect at least one further lumen within the venous catheter to a lumen and thus to increase the flow rate if necessary, if this is decisive and not the presence of at least a second separate lumen.

The separate lumens may be separated from one another by at least one wall having a spiral/wavy or mesh, mesh, or lattice-like surface and further formed with a sealing coating, eg, a PTFE coating. A combination with transverse, Longitudinally or diagonally running structures are conceivable; these alone can ensure the desired stability of the lumen wall. In an advantageous development, the above-mentioned recesses are surrounded by structures, for example ring-shaped structures, which can also be designed as wire structures, which stabilize the shape of the recesses and keep them open.

A venous catheter designed in this way can also be used independently of an indwelling venous cannula, e.g. as a midline catheter, central venous catheter (CVC) or dialysis catheter

Automatic advancement mechanism of the venous catheter

According to an advantageous embodiment of the invention, it is provided that the puncture device has an automatic feed mechanism, by which, depending on at least one external condition, an automatic feed of the outer shell into the punctured hollow body is generated through the opening created by the puncture needle.

A mechanism can exist here that ensures that when the patient's blood flows backwards through the puncture needle or the venous catheter during the puncture process, the venous catheter is automatically advanced in the direction of the vein over the puncture needle. For example, the mechanism may be or include a spring mechanism.

It is conceivable that the spring mechanism is triggered by the heat of a fluid flowing back through the venous catheter in the direction of the user, e.g. blood, but also by the heat of a gas or steam. A fluid-conducting component of the intravenous cannula, e.g. the venous catheter itself or a hollow extension element adjoining the venous catheter in the direction of the user, or the chamber 7 can be made of a bimetal or contain one.

This bimetal can be coupled to a travel limiting element, which is in contact with a travel limiting element of the venous catheter and prevents the venous catheter from advancing in the direction of the vein when it is not heated.

If a heated fluid, e.g. blood, flows near the bimetal, it bends. It can bend in such a way that the travel-limiting element of the bimetal is moved away from the travel-limiting element of the venous catheter.

If the venous catheter has the natural tendency to be advanced in the direction of the vein due to a spring coupled to it, this is precisely the effect that occurs. Depending on the preload of the spring, the feed is slower or faster. The speed of the feed can also be changed or completely prevented by another manual actuating element.

With a slow advance, fragile veins, for example, can be gently punctured. Another advantage is that an indwelling cannula designed with the mechanisms just described can be operated with one hand. In addition, unwanted movements of the venous cannula by the user are largely suppressed. He can concentrate fully on stabilizing the indwelling cannula on the patient. This minimizes the risk that the necessary components of the venous cannula, in particular the puncture needle tip and the venous catheter, will dislocate from the vein again during the puncture process, since less manipulation of the venous cannula has to be carried out in this critical phase.

Instead of the bimetal mentioned above, at least one material that undergoes a change in volume, e.g.

It is also conceivable that a tensioned spring is held under tension and thus in its position by at least one structure, which consists of at least one resorbable material. This spring can, for example, be located between the puncture needle and the venous catheter and connect them to one another. However, this spring can also be connected only to the puncture needle or only to the venous catheter. However, it is also conceivable that the spring is not firmly connected to the puncture needle or the venous catheter in a section of the indwelling cannula that is further from the vein and can push either the puncture needle or the venous catheter in the direction of the vein when there is a change in status.

If blood or another fluid flows into the venous catheter, the resorbable structure is dissolved and the spring experiences a change of state, e.g. an increase in length. The spring now ensures that the venous catheter is advanced in the direction of the vein.

When blood flows back through components of the indwelling cannula, a flap, valve or bracket mechanism can also be activated, which ensures that the force is redirected in this way or is controlled so that the venous catheter is advanced in the longitudinal direction via the puncture needle in the direction of the vein. This can also be relevant, for example, when puncturing arteries, in which the pressure is higher than in veins.

However, it is also possible for the puncture needle itself to be pushed away from the vein in the direction of the user in the longitudinal direction by blood flowing back into the puncture needle and/or the venous catheter. For this purpose, the puncture needle inside, where it is hollow, ie has its lumen, can advantageously be further developed with flap-, wing- or valve-like or other elements that increase the flow resistance. These can also be adjustable in the sense that they are projected into the lumen by the blood flowing back into the puncture needle, i.e. they are moved away from the wall of the lumen. Normally, the external venous catheter is advanced into the vein via the internal puncture needle. Here, the venous cannula is often operated with two hands and there is an unavoidable "jerking" of the venous cannula. This "jerking" can cause the venous catheter to slip out of the vein and endanger the success of the puncture, especially in small veins. This can be avoided by the configuration of the puncture device described above.

If a flow of blood from the vein hits these structures, the puncture needle is pushed away from the vein in the direction of the user if the user does not hold onto it. So that he does not have to do this when inserting the venous cannula into the patient, further fastening and holding elements can advantageously be attached to or on the venous cannula.

In principle, these elements can also be located on the outside of the puncture needle or on the inside of the venous catheter surrounding the puncture needle. In the latter case, it can be advantageous if they interact with other elements on the outside of the puncture needle.

Venous catheters or puncture needles can also be passively flushed into the vein by the bloodstream. It can be advantageous here if these are then not connected to other components of the intravenous cannula. It is also conceivable that a potentially existing negative venous pressure in some veins leads to the venous catheter also being pulled longitudinally into the vein. The advantage is that if the venous catheter is intended to be in a venous location, it can no longer be accidentally introduced into an artery, since the pressure there is higher.

A flood can also be triggered when the PCT/ EP2019/057097 described hollow extension element is flowed through by the patient's blood. It is possible that this blood flow is accelerated by a vacuum element. A vacuum effect can be used for this.

Prevention of contamination of the intravenous cannula when connecting a syringe or infusion line

According to an advantageous embodiment of the invention, it is provided that the puncturing device has a contamination protection device for protecting the end of the puncturing device remote from the hollow body from contamination. In this way, in particular, connections for connecting further elements, e.g. hoses, to the puncture device can be protected from contamination. For example, the contamination protection device may have an external protective structure.

When connecting an aspiration element or other elements through which fluids or medication can be administered, contamination of the indwelling cannula with germs, e.g. through the user's hand or the patient's skin, in the area of the fluid-conducting elements (hereinafter only " Element”) on the chamber 7 and/or the connecting element 9 can be prevented.

This can be solved in such a way that a fluid-conducting, e.g. cylindrical, element which is distant from the vein and which is located outside of the patient is partially or completely surrounded by at least one further protective structure. In the longitudinal direction, this outer protective structure protrudes beyond the fluid-conducting element in the direction of the aspiration element. In an advantageous embodiment, the outer protective structure projects beyond the fluid-conducting element in the longitudinal direction by 1-5 millimeters, but it can also project beyond the fluid-conducting element by 6-10 millimeters or more than 10 mm in the longitudinal direction. The fluid-conducting element can also be designed, for example, in the form of a three-way cock.

The fluid-conducting element can be passed through the outer protective structure in a longitudinally displaceable manner. Likewise, only the outer protective structure can be applied to the fluid-conducting element in a longitudinally displaceable manner or enclose it partially or completely.

The fluid-conducting element can be passed through the outer protective structure so as to be rotatable about the longitudinal axis. Likewise, only the outer protective structure can be applied to the fluid-conducting element such that it can rotate about the longitudinal axis, or can enclose it partially or completely.

However, a differently designed double structure made up of a fluid-conducting element and an outer protective structure is also conceivable. In this way, different geometric shapes can be combined with regard to the respective inside or outside diameters or the cross-sectional areas. Also conceivable are ramp-shaped structures or structures that ensure a targeted and reversible wedging of the fluid-conducting element with the outer protective structure. Snapping into each other or a click-clip mechanism is also conceivable.

Thread-like structures can also be formed on the outside of the fluid-conducting element and/or the inside of the outer protective structure, which can engage in one another or basically act on one another. Friction-increasing, tacky, or knurled structures may be present on the outside of the outer protective structure to allow a user to safely operate the outer protective structure without slipping.

Likewise, the fluid-conducting element can be rotated about the longitudinal axis relative to the outer protective structure without any significant longitudinal displacement by forming straight groove-shaped recesses on the outside of the fluid-conducting element with respect to the transverse axis, into which elevations on the inside of the outer protective structure engage. Alternatively, these straight groove-shaped recesses can also be formed on the inside of the protective outer structure and the elevations just described can also be formed on the outside of the fluid-conducting element.

At least one path-limiting element may be mounted on the fluid-conducting element or the outer protective structure, or both. The travel-limiting elements can intermesh or act on one another in a different way. These path-limiting elements can influence the displacement of the fluid-conducting element or of the outer protective structure individually or in relation to one another in the longitudinal direction, in particular reduce it, enable it to a certain point or make it impossible. They can also be designed in such a way that they influence, in particular reduce, enable up to a certain point or make impossible a rotational movement about the longitudinal axis.

A spring may be located between the fluid-conducting element and the outer protective structure. In a longer (less dense) state, this can ensure that the outer protective structure projects beyond the fluid-conducting element in the direction of the user in the longitudinal direction. If the spring is now compressed by active action, the outer protective structure is also displaced in the direction of the vein and thus no longer protrudes beyond the end of the fluid-conducting element that is remote from the vein. This allows another suitable element to be connected to the fluid-conducting element. If this is now removed, the end of the fluid-conducting element which is remote from the vein is again protected, since the outer protective structure once again protrudes in the longitudinal direction. The spring can also be located between the outer protective structure and the distal end of the chamber of the IV catheter.

It is also conceivable that the location of, for example, an aspiration element, an infusion line, a three-way stopcock or another element of a stopcock bank, which comes into contact with the end remote from the vein, is designed in a similar or identical manner to that just described. In order to enable a connection to the end of the fluid-conducting element of the intravenous cannula configured in this way that is remote from the vein, together with the outer protective structure, the outer protective structure of the aspiration element can have a larger diameter than the outer protective structure of the fluid-conducting element of the intravenous cannula. So it slides over the outer protective structure of the indwelling cannula when the indwelling cannula and the aspiration element are connected. It is also conceivable that the outer, protective structure of the aspiration element has a smaller diameter than the outer, protective structure of the fluid-conducting element of the indwelling vein cannula. In such a case, the outer protective structure of the aspiration element can push itself under the outer protective structure of the venous cannula when the venous cannula and the aspiration element are connected. In an advantageous embodiment, the outer protective structure of the aspiration element can slide into a cavity which is formed on the venous catheter between the outside of the fluid-conducting element and the inside of the outer protective structure of the venous catheter.

Connection points of infusion lines or other hose systems, eg ventilation hose systems, can also be designed in the manner described, independently of an indwelling vein cannula, as well as connection points from and to medical filter systems, eg bacterial filter systems. Known Luer lock elements can also be advantageously further developed in the manner described. In general, it can be used independently of an indwelling vein cannula.

Likewise, a semicircular or trough-shaped structure can be attached to the end of the chamber 7 and/or the connection element 9 that is remote from the vein, which is open at the top and protects the connection of the chamber remote from the vein from contamination by skin germs. This structure can be designed in such a way that it can be kneaded or deformed and can be shaped by the user or the patient as well as adapting to the individual anatomical features. Likewise, the structure can have thermoplastic or antimicrobial properties and be provided with a friction-increasing or sticky surface in order to reduce the risk of the venous catheter slipping out of the patient.

Spring retention mechanism for stab protection

The indwelling cannula can advantageously be further developed with a spring retaining mechanism for retaining the puncture needle in the venous catheter.

This spring retention mechanism can be designed in such a way that a spring or spiral structure (hereinafter "spring") in the initial/resting state ensures that the entire puncture needle is surrounded by the venous catheter, in particular the end of the puncture needle close to the vein and the puncture needle tip. This protects the patient and user from needlestick injuries. In this case, the spring is in its relaxed, deactivated state of rest or initial state and is longer in the case of a compression spring than in the activated state, or shorter in the case of a tension spring than in the activated state. During the transition to the activated state, i.e. when the puncture needle is to be pushed out of the venous catheter at the end near the vein, the user then has to overcome the spring force.

The spring can be designed in such a way that it surrounds the puncture needle over its partial, predominant or entire length, ie the puncture needle is guided through the spring at least partially in a longitudinally displaceable and/or rotatable manner.

In an advantageous embodiment, the outer diameter of the puncture needle can be different, e.g. smaller, than the rest of the outer diameter of the puncture needle over at least a partial length over which the spring surrounds the puncture needle.

The ability of the spring to move longitudinally can be reduced or eliminated by at least one path-limiting element, which can be located on the puncture needle. The path-limiting element can be designed in such a way that the puncture needle has a changing diameter, e.g. also in the form of elevations, edges, protrusions, wings or protrusions, which fix the spring surrounding the puncture needle in a specific position. These can be formed at one or both ends of the spring or also between the existing coil spring turns. It is also possible that the diameter of the puncture needle increases in a ramped or stepwise manner.

Because the longitudinal displaceability of the spring relative to the puncture needle is reduced or eliminated by at least one path-limiting element as described above, the spring prevents the puncture needle from spontaneously shifting relative to the venous catheter in the longitudinal direction. The spring must be activated by an external influence, e.g. be compressed/compressed, in particular in order to achieve a longitudinal displacement of the puncture needle in the direction of the vein, which is necessary for the puncture needle tip to protrude beyond the venous catheter in the direction of the vein in the longitudinal direction. This is the only way a puncture can be carried out.

The spring can also be integrated directly into the puncture needle or connected to the puncture needle. The spring can, for example, be connected to the puncture needle in such a way that it adjoins the puncture needle remote from the vein. The spring can also emerge remotely from the puncture needle, ie it can be inseparably connected to the puncture needle. In a further advantageous development, the spring can be located in a hollow extension element, which represents the continuation of the venous catheter in the direction of the user and to which, for example, an aspiration element or an infusion tube can be connected. In a further advantageous embodiment, the spring can surround the puncture needle in the area where the puncture needle is connected to other components of the venous catheter and/or merges into them.

The coil spring coils of the spring may be spaced less apart at the two ends in the direction of the longitudinal axis of the spring than between the ends. Alternating spacing over the entire length of the spring is possible.

Likewise, the puncture needle can be coupled to, connected to, or surrounded by an element that is in contact with a spring. This element can be designed, for example, in the form of a disk-like structure with a central opening through which the puncture needle can be passed in a displaceable and/or rotatable manner. However, it is also conceivable that this element is firmly connected to the puncture needle and thus the element cannot be displaced longitudinally relative to the puncture needle.

If the puncture process is now started, the user can activate the spring retention mechanism and thus move the puncture needle along its longitudinal axis in the direction of the vein. The end of the puncture needle close to the vein, in particular the puncture needle tip, now projects beyond the venous catheter in the longitudinal direction in the direction of the vein. This enables the vein to be punctured.

The user must always exert a force from the outside on the spring in the longitudinal direction so that it is activated and the tip of the puncture needle is pushed over the venous catheter in the longitudinal direction in the direction of the vein. If no external force is applied, the puncture needle is automatically pulled back into the venous catheter by the spring and is thus deactivated, and puncture protection is provided since the entire puncture needle is surrounded by the venous catheter. If a force only acts temporarily, the stab protection is only lifted during this time.

The spring retention mechanism can, for example, also be activated via a user-friendly actuating element, e.g. a button or stamp (hereinafter "button"), which can be pressed down and triggers the displacement movement of the puncture needle, e.g. in the manner of a ballpoint pen mechanism.

In an advantageous development, the puncture needle can be displaced in the longitudinal direction in the direction of the vein when the button is pressed down for the first time and then initially remain in this position, e.g. by latching or some other interaction with a path-limiting element. The button can also remain in the depressed position, e.g., by snapping or otherwise interacting with a travel limiting element. At least one path-limiting element can therefore ensure that the puncture needle and/or button remain in the desired position.

When you press the button down a second time, the puncture needle and button return to their respective starting positions, meaning that the puncture needle is now pushed away from the vein. In this way, a temporary state can be reached in which the puncture needle and button are pushed even more longitudinally in the direction of the vein than before.

The button can be connected directly to the puncture needle, e.g. continue it at the end of the indwelling cannula away from the vein, or e.g. also surround it. It is also conceivable that the button is connected to the puncture needle only indirectly via another component, e.g. another spring.

If the vein is reached during a puncture, which is indicated by blood flowing back into components of the indwelling cannula, the spring retention mechanism initially activated for the puncture is deactivated again by the user, and the puncture needle is pushed away from the vein in the longitudinal direction. The venous catheter can now be advanced into the vein without the tip of the puncture needle protruding beyond the venous catheter in the longitudinal direction in the direction of the vein. However, since the puncture needle is still in the venous catheter, it can splint it for advancement into the vein and thus stabilize it.

In principle, the spring retention mechanism can be activated or deactivated by pressure or tension on a connection or holding element which is located on the venous catheter on the venous catheter. In particular, both activation and deactivation by pressure are possible. It can be particularly advantageous if the spring can remain in the activated state without a force acting continuously from the outside being required for this purpose. A mechanism may be employed to latch the spring when activated.

In an advantageous embodiment, a connecting element located on the upper side of the indwelling vein cannula, to which an aspiration element can be connected, for example, can also be connected to the puncture needle via a spring. The connecting element can be connected to a spring directly or via another element. It is then possible for the user to vary the position of the puncture needle in the longitudinal direction, e.g. with a finger of the puncture hand. This holding element can have a complementary shape or a negative contour of a human thumb or a human fingertip. The surface can consist of at least one friction-increasing material or be coated with at least one such material.

It is conceivable that due to special properties, for example due to different Number and / or spacing of the windings and / or elastic properties of the spring, before the puncture process, the distance can be adjusted, which protrudes beyond the tip of the puncture needle, ie the end of the puncture needle near the vein, the venous catheter in the longitudinal direction. Due to the properties just mentioned, the maximum mobility of the puncture needle in the longitudinal direction can also be predetermined, in particular also the maximum advancement in the direction of the vein.

The properties just mentioned can also specify the maximum pressure that can be exerted on the puncture needle or the venous catheter, so that unwanted traumatization and possibly a second perforation of the vein wall can no longer occur, especially when the venous catheter is advanced into the vein .

A traffic light system with the colors "green", "yellow" and "red" is conceivable here. It is also conceivable that in the red area the advancement of the components to be advanced in the direction of the vein is automatically interrupted or made impossible.

In an advantageous development, a puncture protection can also be designed in such a way that an invertible structure or an invertible element (hereinafter "invertible element") is on the inside of the venous catheter or on the inside of a component that is connected to the venous catheter in the longitudinal direction towards the vein is connected.

This invertible element can be designed, for example, in the form of a tube that narrows or widens in diameter, in the shape of a trumpet or in a hat-like shape with a brim. If the tip of the puncture needle close to the vein now moves away from the vein, this element folds over when the tip passes and encloses it protectively and permanently.

The inside of the element that can be everted can advantageously consist of a friction-increasing material or be coated with such a material. The invertible element may be formed from at least one puncture resistant material. It can also have spiral, wavy and/or braided structures.

The puncture-resistant material can be a metal, also in the form of a metal alloy, or a correspondingly puncture-resistant plastic or natural material. For example, carbon fiber reinforced laminate materials, polymers and/or Teflon come into consideration as plastic materials, also in combination with one another. Aramids can also be used to advantage. The invertible element can also be formed from nitinol. All materials mentioned in this document can be used individually or in any combination with each other.

It is also conceivable that the element just described does not turn inside out, but is brushed/pushed over the puncture needle tip when the puncture needle moves relative to the venous catheter. If the element has at least two layers, at least one layer of the element can also be slipped/slid over the puncture needle tip by a rolling movement.

Multi-layer puncture needle as puncture protection

A puncture protection can also be designed in such a way that the puncture needle has or consists of two hollow bodies that are mounted so that they can be displaced longitudinally relative to one another. These hollow bodies can be made of a metal or a metal alloy, for example, but also of any other puncture-proof material as described above.

The outer hollow body can be cylindrical and stamp-shaped at both ends. The inner hollow body, which is guided in the outer hollow body, can also be cylindrical, but have a smaller outside diameter compared to the outer hollow body.

The end of the inner hollow body close to the vein can be provided with a pointed structure and/or with a cut suitable for puncture and thus form the puncture needle tip.

The spring retention mechanism with compression or tension springs explained above in relation to the interaction between the puncture needle and the venous catheter can alternatively or additionally also be present in relation to the interaction between the inner and the outer hollow body of the puncture needle. The spring retention mechanism then serves to retain the inner hollow body in the outer hollow body of the puncture needle. This spring retention mechanism can be designed in such a way that a spring or spiral structure (hereinafter "spring") in the initial/resting state ensures by means of spring force that the pointed structure of the inner hollow body close to the veins assumes a position such that the outer hollow body towers over the inner hollow body together with the pointed structure or at least absorbs it and in particular that this position does not change without pressure from the outside. At the end remote from the vein, the inner hollow body can be provided with a spring, for example, or surrounded by one. At the distal end of the inne Ren hollow body can be formed a holding element or a connector for an aspiration element.

If the inner hollow body is actively pressed manually in the direction of the vein, its tip near the vein protrudes beyond the outer hollow body in the direction of the vein and can be used for venipuncture. The vein-distant spring is actively stretched (compressed/shortened). If the manual pressure is now released, the spring ensures that the inner hollow body moves away from the vein again, so that the tip of the same is again surrounded by the outer hollow body. In this way, stab protection is always provided outside of the direct puncture process.

The inner and outer hollow body can be mounted in a venous catheter so that they can be displaced longitudinally or rotated about the longitudinal axis, and also in relation to one another. The movements, also against each other, can be reduced or eliminated by at least one path limiting element.

At least one material or substance can be located between the inner and the outer hollow body, which reduces the frictional resistance between these two bodies. These can be, for example, germ-free fat or oil-like substances or nanoparticles. The same can apply to the space between the outer hollow body and the venous catheter. Closing elements can ensure that these substances cannot leave the respective space, which means that it is sealed off on all sides in a fluid-tight manner. The space between the inner and the outer hollow body or the space between the outer hollow body and the venous catheter can also be designed as a ball bearing or other roller bearing.

Non-linear design of the puncture needle and/or the venous catheter

Due to the special nature of the venous catheter, the risk of damage to the same, even if the puncture needle is not straight, is minimized. Thus, in addition to the puncture needle, the venous catheter can also be bent, angled or designed in the shape of a spiral spring/screw in the initial position before, during or after use on the patient.

It is also possible for puncture needles and/or venous catheters to contain straight sections between curved, angled or spiral spring/helical sections. It is also possible for curved, angled or spiral spring/helical sections to be combined with one another as desired. In an advantageous development, the venous catheter consists of at least one material which ensures that the venous catheter retains its original shape over part of its length, most of it or its entire length, even without the inserted puncture needle.

With a suitable design for this purpose, the parts of the puncture system to be introduced into the patient can be introduced into the patient by means of a rotary movement, similar to screwing in a screw. The axis of rotation runs orthogonally to the skin surface.

Traditional blood glucose meters, which have a sensor under the skin, use a straight needle that goes under the skin. But then the sensor can easily slip out of the skin. In addition, damage can be caused if the straight needle bores too deeply into other anatomical structures due to excessive pressure from the outside. A spiral needle, for example, can easily fix such problems.

Likewise, the entire venous cannula can be curved, angled or designed in the shape of a spiral spring/screw. However, it is also possible that, in particular, the components of the indwelling cannula that are distant from the vein continue to be straight.

At its end close to the vein, a puncture needle designed as described above and/or a venous catheter can contain a sensor which measures parameters in the blood or under the skin, for example in the subcutaneous fatty tissue. For example, the glucose value can be measured. The oxygen partial pressure can also be measured, for example. This sensor can be designed in such a way that it allows data to be transmitted to a receiving device outside the patient, for example a smartphone or another electronic device. The sensor can represent a part of the puncture needle and/or the venous catheter and can also be located on the inner or outer surface of the puncture needle and/or the venous catheter. The sensor can be designed, for example, in the form of a spiral or foil, but other configurations are possible. The construction just described can also be designed for prolonged or permanent implantation, eg directly under the skin. The construction just described can, for example, also serve as a measuring device for measuring the glucose value in diabetic patients. The puncture needle and/or venous catheter can be hollow, partially solid or completely solid and can also be connected to a pump, eg an insulin pump, also via other connecting elements, eg hoses. The construction just described does not have to have a vein cath ter contain more, a puncture needle can have reduced dimensions in terms of length and / or outer diameter and be designed more in the sense of conventional hypodermic needles.

Bending of the puncture needle and/or the venous catheter in the area of the skin entry point

The puncture needle and/or venous catheter can be bent and/or angled, particularly in the region of the transition into other components of the indwelling cannula that is distant from the vein. When the venous catheter is in the patient, the bending or angling point corresponds to the skin level. There, the venous catheter can be exposed to special mechanical loads due to use. In contrast to a venous catheter running straight out of the venous cannula in the direction of the vein, it can project at least 1° from its straight line, but preferably at an angle of 2 to 5°, 6 to 10°, 11 to 25°, 26 to 45° or more than 45°. The venous catheter thus forms a kink that can be directed upwards or downwards. In the area mentioned, the venous catheter can also be developed with at least one spiral/wavy or net, mesh or lattice-like structure and with a sealing coating, e.g. a PTFE coating. A combination with structures running transversely, longitudinally or diagonally is conceivable; these alone can ensure the desired stability of the wall of the venous catheter in this area. However, the venous catheter can also be designed as a conventional venous catheter in the area mentioned and additionally contain the elements just mentioned. In particular, these can also be embedded in the wall of a conventional venous catheter.

The puncture needle guided in the venous catheter can be further developed in the same way.

Adjustable rigidity of the outer shell

According to an advantageous embodiment of the invention, it is provided that the outer shell has two hollow bodies that are mounted so that they can be displaced longitudinally relative to one another. The two hollow bodies can be designed, for example, as an inner tube and an outer tube, in which the inner tube is at least partially arranged and in which it can be displaced. For example, a displacement mechanism can be present, which can be used to set the amount by which the inner tube is displaced relative to the outer tube. In this way, in particular, the extent of the overlap between the inner tube and the outer tube can be adjusted, for example by manual adjustment. If the amount of overlap is set to a small value, the rigidity is reduced and the outer shell is therefore more elastic. If the amount of overlap is set to a high value, the rigidity is increased and the outer shell is therefore less elastic. This functionality can be used advantageously when applying an indwelling cannula to a patient, for example. During the application process, i. H. when advancing into the vein, it is advantageous if the rigidity of the outer sheath is adjusted to a higher level, i. H. the outer shell is more rigid. When the venous cannula is inserted, i. H. when staying in the patient, a lower rigidity is advantageous because the venous catheter can then better adapt to the blood vessel and possible movements of the patient.

side holes

According to an advantageous embodiment of the invention, it is provided that the outer shell has lateral passage openings (sideholes) through which liquid can flow from the inside to the outside of the outer shell and vice versa. In this way, better medication administration can be achieved in certain cases, in particular better distribution of the medication. In addition, it is possible that some or all through-openings initially, i. H. when the intravenous cannula is delivered, are closed and only open when they are applied to the patient. For example, some or all through-openings can initially be closed by a bioresorbable material. If the bioresorbable material then dissolves, the through-openings are released.

• 1 eine schematische Darstellung einer Venenverweilkanüle in einer ersten Ausführungsform im Längsschnitt,
• 2 eine schematische Darstellung einer Venenverweilkanüle in einer zweiten Ausführungsform im Querschnitt,
• 3 eine schematische Darstellung der Venenverweilkanüle gemäß 2 im Längsschnitt,
• 4 eine schematische Darstellung einer Venenverweilkanüle in einer dritten Ausführungsform im Querschnitt,
• 5, 6 schematische Darstellungen eines Ausschnitts der Wand einer Venenverweilkanüle gemäß 4 im Längsschnitt
• 7-9 eine Venenverweilkanüle in einer vierten Ausführungsform,
• 10-12 eine Venenverweilkanüle in einer fünften Ausführungsform,
• 13-15 eine Venenverweilkanüle in einer sechsten Ausführungsform,
• 16,17 eine Venenverweilkanüle in einer siebten Ausführungsform,
• 18-20 eine Venenverweilkanüle in einer achten Ausführungsform,
• 21-24 eine Venenverweilkanüle in einer neunten Ausführungsform,
• 25-29 eine Venenverweilkanüle in einer zehnten Ausführungsform,
• 30-35 eine Venenverweilkanüle in einer elften Ausführungsform,
• 36,37 eine Venenverweilkanüle in einer zwölften Ausführungsform,
• 38,39 eine Venenverweilkanüle in einer dreizehnten Ausführungsform,
• 40-42 eine Venenverweilkanüle in einer vierzehnten Ausführungsform.

The invention is explained in more detail below on the basis of exemplary embodiments using drawings. It shows:

• 1 a schematic representation of a venous cannula in a first embodiment in longitudinal section,
• 2 a schematic representation of a venous cannula in a second embodiment in cross section,
• 3 a schematic representation of the venous cannula according to FIG 2 in longitudinal section,
• 4 a schematic representation of a venous cannula in a third embodiment in cross section,
• 5 , 6 Schematic representations of a section of the wall of a venous cannula according to 4 in longitudinal section
• 7-9 a IV catheter in a fourth embodiment,
• 10-12 a venous cannula in a fifth embodiment,
• 13-15 a venous cannula in a sixth embodiment,
• 16 , 17 a venous cannula in a seventh embodiment,
• 18-20 an indwelling cannula in an eighth embodiment,
• 21-24 a venous cannula in a ninth embodiment,
• 25-29 a tenth embodiment of an indwelling cannula,
• 30-35 an IV catheter in an eleventh embodiment,
• 36 , 37 a venous cannula in a twelfth embodiment,
• 38 , 39 a thirteenth embodiment of an indwelling cannula,
• 40-42 an IV catheter in a fourteenth embodiment.

the 1 shows a schematic representation of a venous cannula 1 in longitudinal section. The indwelling cannula 1 has a venous catheter 2, with a puncture needle 3 being able to be guided in the venous catheter 2 in a longitudinally displaceable manner.

The venous cannula 1 is designed as a peripheral venous cannula 1 . It is clear that the venous catheter 2 was formed from a puncture-proof material like a tightly coiled spiral spring, so that a wavy surface is formed. The venous catheter 2 consists of a puncture-proof material over its entire length. The flexibility of the venous catheter 2 is ensured by the spiral structure. Such a design of the venous catheter 2 provides puncture and cut protection, which protects the venous catheter 2, for example, from being punctured by a tip 6 of the puncture needle 3 near the patient when the venous catheter 1 is being applied. The risk of a damaged venous catheter 2 is thus minimized. This can no longer be sheared off by the tip 6 of the puncture needle 3 near the patient, even if the puncture needle 3 is repeatedly displaced relative to the venous catheter 2 . The scrap caused by damaged venous catheters can thus be significantly reduced. In addition, repeated use of the venous cannula 1 within the scope of a puncture process under permanent sterile conditions on a living being is possible. This is particularly important if an incorrect puncture initially took place, ie the blood vessel was accidentally missed during the first puncture or the venous catheter 2 could not initially be advanced far enough into the blood vessel.

The venous catheter 2 is provided with a sealing coating 4 for improved aspiration. The wavy surface can create minimal openings that make aspiration difficult, since unwanted air can be drawn through these openings, for example. A sealing coating 4 can minimize or prevent the undesired aspiration of air. The sealing coating 4 is advantageously a PTFE coating, which at the same time facilitates the insertion of the venous catheter 2 into the punctured part of the body. An additional dilation element 10 at the end of the venous catheter 2 close to the patient achieves a uniform expansion when the venous catheter 2 is advanced in the punctured part of the body.

1. 1. Punktion einer Vene mit der Punktionsnadel 3
2. 2. Vorschieben des spiralförmigen Venenkatheters 2 mit der abdichtenden Beschichtung 4 über die patientennahe Spitze 6 der Punktionsnadel 3 hinweg in die Vene an die gewünschte Position
3. 3. Entfernen/Zurückschieben der Punktionsnadel 3
4. 4. Verschließen des spiralförmigen Venenkatheters 2 an einem patientenfernen Ende.

The application of the indwelling cannula 1 to a living being can take place, for example, in the following steps:

1. 1. Puncture of a vein with the puncture needle 3
2. 2. Advancing the spiral-shaped venous catheter 2 with the sealing coating 4 over the tip 6 of the puncture needle 3 near the patient into the vein to the desired position
3. 3. Remove/push back the puncture needle 3
4. 4. Closing the spiral-shaped venous catheter 2 at an end remote from the patient.

The indwelling cannula 1 has two holding elements 5. These holding elements 5 enable the user to operate the indwelling cannula 1 with one hand, the second hand being able to be used, for example, to stabilize the part of the body to be punctured. The puncture needle 3 is designed as a hollow needle. After the puncture has been carried out by the tip 6 of the puncture needle 3 near the patient, the user can immediately see whether the vein has been punctured correctly, in that the hollow puncture needle 3 fills with venous blood and enters the chamber 7, whereby the blood is immediately perceived by the user can.

After the puncture has taken place, the venous catheter 2 can be pushed into the punctured part of the body and the puncture needle 3 together with the chamber 7 can be pulled out of the components of the indwelling vein cannula 1 remaining in the part of the body. A safety mechanism can be designed so that the tip 6 of the puncture needle 3 close to the patient is shielded after it has been pulled out of the venous catheter 1 and thus protects the user which protects as well as the living being from possible stab injuries.

In its final position in the punctured part of the body, the venous catheter 2 can be held fixed to the living being by means of fastening elements 8 . The fixation can be done by a self-adhesive wound bandage, which fixes the venous cannula 1 via the fastening elements 8 on the living being. The fastening elements 8 described, which can be designed as wings, for example, are optional elements of the IV catheter 1.

Here, the puncture needle can run essentially in the middle between the holding elements 5 and/or the fastening elements 8 .

It becomes clear that the function of the holding element 5 and the fastening element 8 can be combined in one element. This enables simple production of the venous catheter 1, while at the same time the structure of the venous catheter 1 is kept simple for the user.

An aspiration element such as a syringe can be connected via a connection element 9 . The connection element 9 can be designed as a valve, which enables simple administration of medication or aspiration of blood. In the untouched state, the valve prevents liquids, such as blood, for example, from flowing backwards out of the connecting element 9. In the untouched state, the valve also prevents air from penetrating from the outside into the connecting element 9. The connecting element 9 can also contain a filter, which prevents coarse particles, bacteria and air from penetrating into the interior of the connection element 9 and thus into the interior of the venous catheter.

An aspiration element such as a syringe can be connected to the chamber 7 . The indwelling cannula can thus be inserted into a vein with a syringe while continuously aspirating. Thus, the success of the puncture can be determined immediately and very precisely. Chamber 7 can also be designed as a further valve, which allows the flow of fluids in only one defined direction. In addition, chamber 7 can alternatively or additionally also be designed in such a way that it prevents the ingress of air or only allows air and other gases and vapors to pass in a defined direction. The chamber 7 can be designed in the same way as the connecting element 9, for example.

The chamber 7 and the connection element 9 can be covered by a protective cap so that undesirable contamination does not occur when the chamber 7 and the connection element 9 are not being used. The protective cap can be connected to the chamber 7 and/or to the connection element 9 via a tab.

It is also conceivable that when a protective cap, which can be connected to the connecting element 9 or to the chamber 7 via a strap, is pressed down, the fluid flow in the indwelling vein cannula is interrupted or slowed down.

The venous catheter 2 has recesses 11 distributed over the circumference at the end near the patient. The recesses 11 can be used to achieve a homogeneous release of a medication, for example, into the living being. An undesired, locally highly concentrated release of the drug into the living being is thus avoided. By arranging several recesses 11, the flow rates of the applied infusion solutions and medication can also be increased. In addition, this can make it easier to aspirate liquids, such as taking a blood sample, via the existing venous catheter or via the existing venous indwelling cannula from the living being. With a corresponding design of other components of the venous cannula, a desired retrograde spontaneous escape of fluids, vapors and/or gases from the venous cannula can also be possible if this is used, for example, to drain fluids, vapors and/or gases, e.g. as part of a puncture of the pleural space, other cavities or the interbody spaces described above is to be used.

As the 2 and 3 show, the venous catheter 2 has a wall 43. The wall has an inside 41 and an outside 40. The venous catheter 2 or the wall 43 can have a circular or elliptical contour on the outside 40, or as in FIG 2 shown, a polygonal contour, eg a hexagonal contour. In addition, flow channels in the form of depressions 42 can be formed or inserted into the outside 40 of the wall 43 . The indentations 42 can, for example, be in the form of elongated grooves and can extend along the venous catheter 2 over a greater or lesser length L1, L2, L3.

the 4 shows an embodiment of the venous catheter 2 in which flow channels running in the longitudinal direction are present in the form of hollow channels 44 running inside the wall 43 . The hollow channels 44 can each have an inlet opening 45 for the inflow of the fluid on the outside 40, such as the 5 and 6 demonstrate. The outlet opening 46 at which the through Hollow channel 44 flowing fluid can flow out of the respective hollow channel 44 can optionally also be on the outside 40, like the 5 shows, or on the inside 41 of the wall 43, ie towards the inner lumen of the venous catheter 2.

The flow channels do not have to run exactly in the longitudinal direction or parallel to the longitudinal direction of the venous catheter 2, they can also run obliquely thereto in whole or in sections, e.g. in a spiral shape.

the 7 until 9 show another embodiment of an indwelling cannula 1 in which the venous catheter 2 has flow channels in the form of depressions 42 running in the longitudinal direction on the outside 40 of the wall 43 . the 7 shows the complete venous cannula 1 in a perspective view. The Indian 7 marked area A is in the 8th partially enlarged. the 9 shows a cross-sectional view through the venous cannula 1 in the area of the depressions 42. As can be seen, the venous catheter 2 has a circular contour on the outside. The depressions 42 extend over a length L in the longitudinal direction of the venous catheter 2.

the 10 until 12 show another embodiment of an indwelling cannula 1 in which the venous catheter 2 has flow channels running in the longitudinal direction in the form of hollow channels 44 running inside the wall 43 . The 10 the complete venous cannula 1 in a perspective view, the 11 the in 10 marked area B in an enlarged view and the 12 a cross-sectional view through the venous catheter 1 in the area of the hollow channels 44. It can be seen that the hollow channels 44 do not necessarily have to have a circular cross-sectional shape, but can, for example, have a flattened cross-sectional shape, e.g. an elliptical contour or a curved contour following the arched shape of the wall 43.

the 13 until 15 show an embodiment of an indwelling cannula 1 in which the venous catheter 2 has a polygonal outer contour 25 over a specific limited longitudinal section on the outside. the 13 shows the complete venous cannula in a perspective view, the 14 the in 13 marked area C in an enlarged detail view and the 15 a cross-sectional view through the area of the polygonal outer contour 25. It can be seen that the venous catheter 2 can have the polygonal outer contour 25 over a longitudinal section limited in length L and can otherwise be designed like a conventional venous catheter, eg with a circular outer contour. For example, the polygonal area 25 can be arranged at the end of the venous catheter 2 near the patient. A hexagonal outer contour is shown as an example, but other polygonal configurations are also possible.

the 16 and 17 show an embodiment of an indwelling cannula 1 in which the puncture needle 3 is blunt at the tip 6 and at least part of the puncture needle 3 consists of a bioresorbable material 26 . the 16 shows the complete venous cannula 1 in a perspective view, the 17 the in 16 marked area D in an enlarged detail view. As can be seen, the puncture needle 3 is formed in the section close to the hollow body with an area made of bioresorbable material 26 which resorbs itself after a certain time when it comes into contact with the patient. In addition, the puncture needle 3 is comparatively blunt at the tip 6 . For example, the puncture needle 3 can consist of the bioresorbable material 26 over a region of length L. It is also possible for parts of the venous catheter 2, in particular in the area close to the hollow body, to consist of bioresorbable material.

the 18 until 20 show an embodiment of an indwelling cannula 1 which has a spring retaining mechanism 20 for retaining the puncture needle 3 in the outer casing (ie in the venous catheter 2). The spring retention mechanism 20 serves as a puncture protection in the initial or resting state of the venous cannula 1. In this state, the puncture needle 3 with its tip 6 is completely retracted into the venous catheter 2.

the 18 shows the venous cannula 1 in a perspective view, the 19 and 20 show the venous cannula 1 in plan view. In the 18 and 19 is the spring-retaining mechanism in the initial state, in which 20 in the activated state.

The spring retaining mechanism 20 can have a compression spring 21 which exerts a compressive force between a component connected to the puncture needle 3, e.g. the chamber 7, and a component connected to the venous catheter 2, e.g. a base body 80 to which, for example, the holding elements 8 are attached are, generated or at least can generate in certain operating states. The spring retaining mechanism 20 also has first latching elements 22 which are coupled to the component connected to the puncture needle 3 , and second latching elements 23 which are coupled to the base body 80 . If the venous cannula 1 is now transferred into the activated state, namely by pushing out the puncture needle 3 from the venous catheter 2, like the 20 shows what is achieved by applying a compressive force to the holding element 5 can take place, then the compression spring 21 is compressed. From a certain position, the first latching elements 22 latch onto the second latching elements 23. As a result, the activated state of the indwelling cannula 1 is assumed and maintained.

To release the latching, the first latching elements 22 can simply be pressed manually, i. H. these are compressed in the direction of the base body 80 . The latching can be released in that, for example, the second latching elements 23 have a T-shaped profile. By compressing the first latching elements 22, they can then, supported by the compression spring 21, slide past the second latching elements 23. After the latching between the first latching elements 22 and the second latching elements 23 has been released, the puncture needle 3 is automatically pulled back into the venous catheter 2 by the force of the compression spring 21 .

the 21 until 24 show an embodiment of an indwelling cannula 1 in which a material 47 with increased lubricity is present on the outside of the puncture needle 3 and/or the inside of the outer sleeve 2 over at least a longitudinal section. the 21 shows the venous cannula 1 in a perspective view, the 22 in longitudinal section, the 23 the in 22 marked area E in an enlarged detail view and the 24 a cross-section through the venous catheter 1. The material 47 acting between the outside of the puncture needle and the inside of the outer casing 2 increases the ability to slide between the puncture needle 3 and the outer casing 2, in particular in the longitudinal displacement direction of the puncture needle 3. The material 47 can be in the form a friction-reducing additional substance or in the form of individual rolling bodies, similar to a roller bearing.

the 25 , 26 , 27 , 28 , 29 show an embodiment of an indwelling cannula 1, in which the outer shell has two hollow bodies, namely an inner tube 27 and an outer tube 28. The 25 shows the venous cannula in a perspective view, the 26 in a side view, the 27 in longitudinal section, the 28 in side view and the 29 in longitudinal section. In the 25 until 27 is the venous cannula 1 in the retracted state, in the 28 and 29 in the extended state.

The inner tube 27 is guided in the outer tube 28 and is mounted in it so that it can be displaced longitudinally. The outer tube 28 is firmly connected to the base body 80 . The inner tube 27 is firmly connected to a displacement mechanism 29 . The shifting mechanism 29 has a manual operating element 30. The manual operating element 30 can be moved back and forth in a specific area of the main body 80. FIG. The respective position can be fixed, for example, by a detent. If the manual control element 30 is used, for example, by the in 27 position shown in the in 29 moves the position shown, the inner tube 27 is also moved and the outer tube 28 is thus further pushed in. When retracted, such as in 27 shown, the overlap between the inner tube 27 and the outer tube 28 is relatively small, while in the extended state in 29 the overlap is much larger. In the retracted state, the rigidity of the outer shell 2 is therefore lower than in the extended state, since in the extended state the outer tube 28 is additionally reinforced by the inner tube 27 located therein. As a result, the rigidity of the outer shell 2 can be adjusted in certain steps or steplessly.

the 30 until 35 show an embodiment of an indwelling cannula 1, in which the outer shell has two hollow bodies, namely an inner tube 27 and an outer tube 28. The 30 and 31 show perspective views that 32 and 34 side views and the 33 and 35 longitudinal sections. In the 30 , 32 and 33 is the venous cannula in the retracted state, in the 31 , 34 and 35 in the extended state.

In contrast to the embodiment of 25 until 29 In this embodiment, the inner tube 27 is designed much longer, in particular longer than the outer tube 28. In the retracted state, the inner tube 27 is located completely or at least predominantly inside the outer tube 28. In the extended state, the inner tube 27 protrudes by a certain Measure out of the outer tube 28. For example, the indwelling vein cannula can be applied to the patient in the retracted state. In the later operation of the venous cannula on the patient, the transition is then made to the extended state. Via the part of the inner tube 27 protruding from the outer tube 28, medication can then be dispensed or blood taken, for example. The inner tube 27 can have the mentioned lateral passage openings (sideholes) at least in the area that can protrude from the outer tube 28 .

the 36 and 37 show an embodiment of a venous cannula 1, in which the inside of the venous catheter 2 spiral or wave-shaped structures 48, for example spirally circumferential, predominantly longitudinally extending flow channels in the form of grooves, are formed. In general, the wall 43 of the venous catheter 2 can have a plurality of spiral or wavy structures 48, for example the one directed towards the inside 41 in FIG 37 recognizable structure 48, and alternatively or in addition to the outside 40 directed spiral or wavy structures. In this way, for example, the ability of the puncture needle 3 to slide in the venous catheter 2 can be improved. In addition, additional flow channels are created. The 36 the venous cannula 1 in a perspective view and the 37 the in 36 marked area F in an enlarged detail view. Due to the spiral design of the structures 48, a turbulence effect of liquids conducted through the outer shell 2 can be achieved. For example, an infusion liquid can be swirled and in this way be distributed to the patient in a better way.

the 38 and 39 show an embodiment of an indwelling cannula 1 in which spiral or wavy structures 48, for example spirally encircling, predominantly longitudinal flow channels in the form of grooves, are formed on the inside of the venous catheter 2, similar to the previously described embodiment. The 38 the venous cannula 1 in a perspective view and the 39 the in 38 marked area G in an enlarged detail view. In addition, the venous catheter 2 has several lateral passage openings 31 in the area close to the patient, through which liquids can flow.

the 40 until 42 show an embodiment of an indwelling venous cannula 1, in which the venous catheter 2 has several lateral passage openings 31 in the area close to the patient, through which liquids can flow, similar to the previously described embodiment. The 40 the venous cannula 1 in a longitudinal sectional view, the 41 the venous cannula 1 in a perspective view and the 42 the in 41 marked area H in an enlarged detail view. In addition, the venous catheter 2 has several hollow channels 44 running in the longitudinal direction within the wall 43 in the area near the patient. The hollow channels 44 can each have an inlet opening 45, but are designed without the previously described outlet opening 46, i.e. closed at least on one side. Advantageously, the entry opening 45 is located in the area of the venous catheter 2 that is not inserted into the patient, ie away from the area close to the patient. The hollow channels 44 then extend into the area close to the patient. These hollow channels 44 can, for example, be filled with air or another medium that can be identified in an imaging examination. If the hollow channels are filled with air, the end of the venous catheter 2 close to the patient can be made visible during an ultrasound examination, for example.

The present illustrations are merely schematic illustrations that give a good overview of the components of the IV catheter according to the invention. However, the lengths and proportions can differ in reality.

The figures are to be understood as a possible exemplary embodiment. Other forms of the teaching according to the invention are also conceivable. Furthermore, the configurations of the exemplary embodiment are not inseparably linked to one another, so that, for example, the implementation of the invention is not dependent on the configurations of the exemplary embodiment specifically described. For example, variability in the number, length or size of the individual elements is conceivable at any time.

Reference List

1

indwelling cannula

2

Venous catheter/outer sheath

3

puncture needle

4

sealing coating

5

holding element

6

near the patient tip of the puncture needle

7

chamber

8th

fastener/retainer

9

connection element

10

dilation element

11

recess

20

Spring retention mechanism

21

compression spring

22

first locking elements

23

second locking elements

25

polygonal outer contour

26

bioresorbable material

27

inner tube

28

outer tube

29

sliding mechanism

30

manual control

31

side openings

40

outside

41

inside

42

indentations

43

Wall

44

hollow channels

45

entry opening

46

exit port

47

Material with increased lubricity

48

spiral or wavy structure

80

body

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP2019057097 [0005, 0135, 0155, 0260]

Claims (32)

Puncture device (1) for puncturing a hollow body using a puncture needle (3), the puncture device (1) having at least one tubular outer casing (2) in which the puncture needle (3) can be guided in a longitudinally displaceable manner, the outer casing (2) being set up for this purpose to be pushed through the opening created by the puncture needle (3) through the shell of the hollow body to be punctured and to stay there for a period of time after performing a puncture of a shell of the hollow body to be punctured over at least part of its length. puncture device claim 1 , characterized in that the outer shell (2) and/or another part of the puncturing device (1) has one or more flow channels running predominantly or completely in the longitudinal direction of the puncturing device (1) through which a fluid flowing through the punctured hollow body flows along the outer shell (2) and/or the other part of the puncturing device (1) can flow past. Puncture device according to one of the preceding claims, characterized in that there are barb-like structures on the outside of the outer shell (2) which make it difficult or prevent the puncture device (1) inserted into the hollow body to be pulled out. Puncture device according to one of the preceding claims, characterized in that the outer shell (2) has an arrangement of a large number of elongated cavities which extend at least predominantly in the longitudinal direction of the outer shell (2), wherein the cavities can be designed in particular in the form of capillaries. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has a further tubular structure which is arranged between the outer casing (2) and the puncture needle (3). Puncture device according to one of the preceding claims, characterized in that the outside of the puncture needle (3) and/or the inside of the outer sleeve (2) has a surface layer which is made of a material with increased lubricity compared to the other material of the puncture needle (3) and / or the outer shell (2) is formed. Puncture device according to one of the preceding claims, characterized in that there is a friction-reducing additional substance, in particular a substance containing oil or fat, on the outside of the puncture needle (3) and/or the inside of the outer casing (2). Puncture device according to one of the preceding claims, characterized in that at least that part of the outer casing (2) which is designed to remain in the hollow body, over its entire length or the majority of its length, in which the puncture needle (3) can be guided in a longitudinally displaceable manner , has a helically wound, hollow-internal guidewire. Puncture device according to one of the preceding claims, characterized in that the section of the puncture needle (3) close to the hollow body is blunt and/or consists of a bioresorbable material and/or any area of the puncture needle (3) consists of a bioresorbable material or is coated with it and/or at least part of the outer shell (2) consists of or is coated with a bioresorbable material. Puncture device according to one of the preceding claims, characterized in that the puncture needle (3) has an external thread and/or the outer casing (2) has an internal thread. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has a guide wire which can be guided through the outer sheath (2) or through the puncture needle (3), the guide wire being partially, predominantly or completely made of at least one bioresorbable material is trained. The puncturing device according to one of the preceding claims, characterized in that the puncturing needle (3) can be rotated about the longitudinal axis relative to the outer casing (2), the puncturing device (1) having holding elements (5) by which the rotatability of the puncturing needle (3) is at least is restricted or eliminated in certain longitudinal displacement positions of the puncture needle (3) relative to the outer casing (2). puncture device claim 12 , characterized in that the puncture device (1) has at least one restoring spring by which the puncture needle (3) is held by spring force in a longitudinal displacement position in which the rotatability of the puncture needle (3) is restricted or eliminated. Puncture device according to one of the preceding claims, characterized in that at least one component of the puncture device device (1), in particular the outer shell (2), has at least one detectable marker with an imaging examination device. Puncture device according to one of the preceding claims, characterized in that the outer cover (2) has a fluid-permeable lattice, mesh or pore-like structure with fine openings which can be closed by blood components flowing through when the puncture device (1) is in operation. Puncture device according to one of the preceding claims, characterized in that at least parts of the puncturing device (1) have electrically insulating elements and/or electrically conductive elements, through which electrically conductive connections from one part of the puncturing device (1) to another part of the puncturing device (1 ) are formed. Puncture device according to one of the preceding claims, characterized in that the outer casing (2) has a larger outside diameter in the area close to the hollow body than in the area remote from the hollow body. Puncture device according to one of the preceding claims, characterized in that at least one region of the outer shell (2) has a material which swells when it comes into contact with a fluid. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has an automatic blocking mechanism which prevents the puncture needle (3) from being advanced to the end near the hollow body if the puncture needle (3) is more than a predetermined distance away from the hollow body -near end was withdrawn. Puncture device according to one of the preceding claims, characterized in that the outer shell (2) is constructed in multiple layers with one or more removable layers. Puncture device according to one of the preceding claims, characterized in that the wall of the outer shell (2) has at least two spiral or wavy structures, in particular one spiral or wavy structure directed towards the inside of the outer shell (2) and one towards the outside of the outer shell (2 ) directed spiral or wavy structure. Puncture device according to one of the preceding claims, characterized in that the outer shell (2) has one or more reinforcing elements in each case in one or more areas which are exposed to increased mechanical stress. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has at least one adjusting element with which the flexibility of at least one area of the outer casing (2) can be adjusted by the user. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has an applicator at the end near the hollow body for the application of a substance in the region of the puncture point of the puncture needle (3) on the hollow body. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has a mechanism by means of which the outer casing (2) can be converted into a spiral shape by a movement relative to the puncture needle (3). Puncture device according to one of the preceding claims, characterized in that the outer shell (2) has multiple lumens, with two or more lumens being able to be connected to one another via one or more openings. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has an automatic feed mechanism, by which, optionally depending on at least one external condition, an automatic feed of the outer shell (2) into the punctured hollow body through the puncture needle ( 3) generated opening is generated. Puncture device according to one of the preceding claims, characterized in that the puncturing device (1) has a contamination protection device for protecting the end of the puncturing device (1) remote from the hollow body from contamination. Puncture device according to one of the preceding claims, characterized in that the puncture device (1) has a spring retaining mechanism (20) for retaining the puncture needle (3) in the outer casing (2). Puncture device according to one of the preceding claims, characterized in that the puncture needle (3) has two hollow bodies which are mounted so as to be longitudinally displaceable relative to one another. Puncture device according to one of the preceding claims, characterized in that the outer shell (2) has two hollow bodies which are mounted so that they can be longitudinally displaced in relation to one another. Puncture device according to one of the preceding claims, characterized in that the outer shell (2) has lateral passage openings through which liquid can flow from the inside to the outside of the outer shell (2) and vice versa.

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