VALVE FOR PERMANENT IMPLANTATION, ESPECIALLY FOR THE TREATMENT OF NORMAL PRESSURE HYDROCEPHALUS DISEASE

Description

[0001] The present invention relates to an implantable valve, in particular for permanent implantation for the treatment of hydrocephalus.

[0002] For the treatment of patients with an imbalance between the production and reabsorption of cerebrospinal fluid (CSF), known as hydrocephalus, drainage devices are used to drain CSF from the brain's cerebrospinal fluid spaces into another body cavity. Fully implantable drainage devices typically consist of a ventricular catheter, the tip of which is placed in the patient's ventricle and guided under the skin to a valve. This valve prevents the backflow of CSF and maintains positive pressure. A peripheral catheter connects the valve's outlet to a body cavity, such as the abdominal cavity. These drainage devices are also called shunt systems, and the valves are referred to as shunt valves.While early and simple drainage systems consisted of just a tube, shunt valves are now used to prevent cerebrospinal fluid (CSF) overdrainage. CSF overdrainage, a well-known and feared complication of drainage systems, can lead to adverse consequences such as impaired concentration, headaches, and intracranial hemorrhage, even resulting in death.

[0003] A common operating principle of these pressure relief valves is that they are initially closed and only open above a certain pressure, the response pressure, and only then do they drain cerebrospinal fluid. This is intended to prevent over-drainage.

[0004] Valves suitable for such applications are either equipped with a fixed response pressure that can be individually selected to suit the patient, or they are adjustable.

[0005] Furthermore, shunt valves are known in which the response pressure automatically switches between a higher value in the upright position and a lower value in the lying position, or is continuously adjusted, depending on the body position. Various names are common for these systems; here they are collectively referred to as gravity-compensated valves.

[0006] Shunt systems were originally developed to treat hydrocephalus disorders associated with the development of significantly pathologically elevated pressure. This includes the large group of patients with early childhood hydrocephalus and those acquired in later life in which the outflow and reabsorption processes are disrupted, or in which one of the connections between the different cerebrospinal fluid spaces is narrowed or blocked.

[0007] A special group of hydrocephalus patients are those with normal pressure hydrocephalus (NPH). In these patients, the mean pressure in the cerebrospinal fluid is not pathologically elevated. However, fluctuating pressure increases occur, particularly during sleep and when lying down. Treating this patient group with drainage devices or shunt systems presents particular challenges: Because the mean pressure is not consistently elevated, setting or selecting the response threshold of the shunt valve is especially critical. Even slightly excessively high response thresholds lead to inadequate treatment outcomes. On the other hand, these patients, who are adults and mobile, often experience hydrostatic overdrainage when standing upright, which can lead to serious complications.The use of gravity-compensated systems brings improvements, but the characteristics of gravity compensation, just like the response threshold mentioned above, are very critical and must be adapted within narrow limits to the requirements of the individual patient.

[0008] Attempts have been made to treat non-conjunctival hydrocephalus (NPH) by draining cerebrospinal fluid from the subdural space beneath the dura mater (the tough outer membrane surrounding the brain) into the epidural space above the dura mater in the lumbar spine. The shunt systems used in these attempts differ significantly from conventional ventriculoperitoneal shunt systems. Fulcher and Enomoto (OH Fulcher and F. Enomoto, "Some simple methods of treating communicating hydrocephalus," in Surgical Forum, 1956, vol. 8, pp. 516-521) used an open piece of plastic tubing equipped with barbs to keep it in place. Quincke (H. Quincke, "Die Lumbalpunktion des Hydrocephalus", Berliner Klin. Wochenschrift, vol. 28, no. 38, pp. 929-933) punctured the subdural space and simultaneously incised the dura, resulting in a permanent drainage opening.Glenn (US020060224102, US020060224101, US000007513883) describes a system which has an inlet below the dura mater, an associated flow regulator and an associated outlet for placement in the epidural space.

[0009] Furthermore, valves from EP0268520A2, EP2253352A1, JPS5230089A, US4945947A, US2010056980A1, EP0414649, US4682 625, US2977 980, FR 2 685 206 or US 5 336 166 are generally known.

[0010] Furthermore, EP2221083A1 describes a valve for use in a line for conveying a liquid, wherein the valve is open between a predetermined lower liquid pressure limit and a predetermined upper liquid pressure limit and is closed at least temporarily and at least largely when the lower liquid pressure limit is undershot on the one hand and when the upper liquid pressure limit is exceeded on the other.

[0011] Furthermore, US5336166A describes an implantable drainage device for the treatment of hydrocephalus. The device functions as a combination of three valves, comprising a first pressure regulating valve in series with an assembly containing a flow regulating valve in parallel with a second pressure regulating valve.

[0012] Based on this, the present invention aims to provide an improved implantable valve that is particularly suitable for shunt treatment of NPH, taking into special consideration the specific needs of these patients.

[0013] This problem is solved by a valve having the features of claim 1 and by a drainage device having the features of claim 34. Advantageous embodiments of these aspects of the invention are specified in the corresponding dependent claims.

[0014] According to claim 1, an implantable valve for a drainage device for draining cerebrospinal fluid is disclosed, comprising: a valve housing extending along a valve axis, comprising an inlet and an outlet as well as an interior space surrounded by the valve housing, a valve body assembly arranged in the interior space, which is e.g. movably arranged in the direction of the valve axis, a first valve seat, wherein the valve body assembly is configured to seal against the first valve seat to close a flow connection between the inlet and the interior space of the valve housing, a second valve seat, wherein the valve body assembly is configured to seal against the second valve seat to close a flow connection between the outlet and the interior space of the valve housing, a spring device arranged in the interior space which exerts a spring force on the valve body assembly in the direction of the first valve seat, wherein the spring force is greater than a horizontal component of the weight force of the valve body assembly when the valve housing is in a horizontal position with the valve axis running horizontally, and wherein the weight force of the valve body assembly is greater than the spring force when the valve housing is in a vertical position.

[0015] Specifically, the valve body assembly is positioned along the valve axis between the two valve seats. The valve allows fluid or cerebrospinal fluid to pass through (from inlet to outlet) when the valve body assembly is not sealing against both valve seats. This state of the valve is referred to as open. Conversely, if the valve body assembly is in contact with one of the valve seats, the valve is closed and prevents the flow of cerebrospinal fluid. Surprisingly, treating physicians have observed that in NPH patients, a single drainage of small volumes is sufficient to achieve a treatment success lasting for several days.

[0016] The valve according to the invention can ensure this, since it is configured to be completely closed in an upright body position (or with a vertical valve axis) (e.g., by gravity pressing the valve body against the second valve seat) and is further configured to allow drainage at a (particularly low) response pressure (i.e., when the response pressure is open) in a lying body position (or with a horizontal valve axis), but in particular prevents backflow (in the sense of a check valve).

[0017] According to a preferred embodiment of the invention, the weight force of the valve body arrangement acts in the direction of the second valve seat when the valve housing is in a vertical position, the valve axis runs vertically and the first valve seat is arranged above the second valve seat.

[0018] According to a further preferred embodiment of the invention, it is provided that the second valve seat is closed by the valve body arrangement when the valve housing is in an inclined position, in which the valve axis forms an angle with the vertical in the range of 0° to 40°, wherein, if the angle exceeds 40°, the component of the weight force running parallel to the valve axis is less than the sum of the pressure force and the spring force, wherein the valve body arrangement moves (in particular abruptly) towards the first valve seat and closes it (in particular seamlessly).

[0019] According to a further preferred embodiment of the invention, the first valve seat is closed by the valve body assembly when the valve housing is in an inclined position, where the valve axis forms an angle with the horizontal in the range of 0° to 40°. During this transition, the increasing gravitational force (parallel to the valve axis) and the increasing pressure force due to the change in position act simultaneously on the valve body assembly, resulting in a steep characteristic curve. Thus, as the rate of increase of the pressure force increases, the transition area becomes progressively smaller, preventing a problematically large transition area from occurring.

[0020] In particular, the present invention now functions for the first time according to a reverse principle compared to the methods described at the outset: cerebrospinal fluid drainage is only possible at low differential pressures (in the horizontal position). At higher differential pressures, which only occur in the vertical position, the valve is closed.

[0021] This method is particularly effective in preventing overdrainage. Especially when there is a high pressure gradient (e.g., when standing – where approximately 30 cm to 60 cm of hydrostatic water column (in adults) is added from the head to the drainage site (spinal epidural space or abdominal cavity)), classic valve systems drain a particularly large amount of cerebrospinal fluid, posing a risk of overdrainage.

[0022] The solution according to the invention therefore has the advantage that unphysiologically high drainage volumes can be avoided (the valve is only open or in the flow state at a lower pressure).

[0023] The valve according to the invention also forms a reliable switch (valve open / closed) by utilizing a large pressure difference of 30 cm to 60 cm water column (hydrostatic pressure difference from the transition from lying to standing in an adult or transition from horizontal to vertical position of the valve housing)

[0024] Furthermore, it is advantageous that the pressure conditions in the drainage space (e.g., spinal subarachnoid space) and the receiving space (e.g., spinal epidural space or abdominal cavity) are at approximately the same level. This results in only slight pressure gradients. This implantation principle also reduces the risk of dangerous overdrainage.

[0025] Overall, the functioning of the valve according to the invention results in efficient drainage with significantly better protection against over-drainage.

[0026] According to one embodiment of the invention, the valve body arrangement is formed by the first valve body.

[0027] According to an alternative embodiment of the invention, the valve body arrangement comprises a second valve body, wherein the first valve body is configured to rest against the first valve seat, and wherein the second valve body is configured to rest against the second valve seat and / or is heavier than the first valve body.

[0028] According to a further embodiment of the invention, the valve body arrangement comprises (in addition to the first valve body) a second valve body and a third valve body, wherein the first valve body is configured to abut the first valve seat, and wherein the third valve body is configured to abut the second valve seat, and wherein the second valve body is heavier than the first valve body and / or than the third valve body. Furthermore, the valve can also have several second valve bodies, which are preferably arranged between the first and the third valve bodies.

[0029] Furthermore, according to one embodiment, it is preferably provided that the second valve body is arranged between the first and the third valve body and is in contact with the first and the third valve body.

[0030] Furthermore, according to a preferred embodiment, it is provided that the respective valve body (i.e., the first and / or the second and / or the third valve body) is at least partially cylindrical, and in particular the respective valve body can be cylindrical.

[0031] According to a further embodiment of the invention, the respective valve body (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) is spherically shaped.

[0032] Furthermore, according to a preferred embodiment of the invention, the respective valve body (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) is cylindrical and has a first flat end surface designed to abut the first valve seat or to abut an adjacent valve body, and a second end surface facing away from the first end surface, designed to abut the second valve seat or to abut an adjacent valve body.

[0033] Furthermore, according to a preferred alternative embodiment of the invention, the respective valve body (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) has a cylindrical central section arranged between a first end section and a second end section (the central section connects the two end sections, in particular integrally), wherein the first end section is designed to abut the first valve seat or an adjacent valve body, and wherein the second end section is designed to abut the second valve seat or an adjacent valve body. The two end sections can each be curved, hemispherical, frustoconical, or conical.

[0034] Furthermore, according to one embodiment of the invention, it is provided that the diameter of the second valve body is larger than the diameter of the first valve body and / or than the diameter of the third valve body of the valve body arrangement.

[0035] Furthermore, according to a preferred embodiment of the invention, the respective valve body of the valve body arrangement (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) is made of a material having a density of more than 10 g / cm 3<.

[0036] Furthermore, according to a preferred embodiment of the invention, the respective valve body (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) and / or the valve housing and / or the spring are made of or coated with a biocompatible or body-compatible material. A biocompatible material is, in particular, a material that has no negative impact on living beings, especially humans, in its environment.

[0037] According to a preferred embodiment of the invention, the respective valve body (or one of the valve bodies, in particular the first and / or the second and / or the third valve body) is made of or comprises one of the following materials: tungsten, a tungsten alloy, tungsten carbide, ditungsten carbide, an alloy comprising tungsten carbide and / or ditungsten carbide.

[0038] According to a preferred embodiment of the invention, the valve body is provided to consist of or comprise one of the following materials: silver, gold, platinum, tantalum or an alloy of one of the materials silver, gold, platinum, tantalum.

[0039] Furthermore, according to one embodiment of the invention, it is provided that the inlet of the valve is opposite the outlet of the valve in the direction of the valve axis, and / or that the second valve seat is opposite the first valve seat in the direction of the valve axis.

[0040] Furthermore, according to one embodiment of the invention, the spring device comprises a first spring. In particular, the spring device can be formed by the first spring.

[0041] Furthermore, according to one embodiment of the invention, the valve housing has a projection extending into the interior towards the first valve seat.

[0042] According to one embodiment, the projection forms an annular gap with a wall of the valve housing or a circumferential inner surface of this wall.

[0043] According to one embodiment, this circumferential wall connects a first wall of the valve housing with a second wall of the valve housing opposite in the direction of the valve axis, wherein, according to one embodiment, the outlet is provided on the first wall and the inlet on the second wall.

[0044] Furthermore, according to one embodiment of the invention, the second valve seat is provided on an end section of the projection facing the first valve seat or the second wall. The projection surrounds, in particular, a preferably longitudinally extended through-opening that forms the valve outlet. The second valve seat is formed, for example, by a circumferential end face of the projection that surrounds this through-opening at the end of the projection. Alternatively, the second valve seat can also be formed by a circumferential section of the projection (e.g., in the form of a step).

[0045] Furthermore, according to one embodiment of the invention, the first spring is provided to encompass the projection (and is in particular arranged in the annular gap). The first spring can in particular be designed as a helical spring.

[0046] Furthermore, according to one embodiment of the invention, it is provided that the first spring is supported with a first end section of the first spring on an inner side of the first wall of the valve housing, from which the projection extends into the interior of the valve housing.

[0047] Furthermore, according to one embodiment of the invention, the valve arrangement preferably consists of the at least one first valve body, wherein the first spring with a second end section contacts the at least one first valve body and exerts said spring force on the first valve body in the direction of the first valve seat.

[0048] Furthermore, according to an alternative embodiment of the invention, the valve arrangement consists of or comprises at least one first valve body and a second valve body, wherein the first spring contacts the second valve body with a second end section and exerts the spring force towards the first valve seat on the second valve body, wherein the second valve body is configured to transmit the spring force to the first valve body.

[0049] Furthermore, according to one embodiment of the invention, the valve arrangement consists of or comprises at least one first valve body, a second valve body and a third valve body, wherein the first spring contacts the second valve body with a second end section and exerts a first part of the spring force towards the first valve seat on the second valve body, wherein the second valve body is configured to transfer the first part of the spring force to the first valve body.

[0050] Furthermore, according to one embodiment, it is provided that the spring device has a second spring (in particular, the spring device is formed by the first and the second spring), wherein the second spring is supported with a first end section on an inside of the valve housing, and wherein the second spring contacts the third valve body with a second end section and exerts a second part of the spring force towards the first valve seat on the third valve body, wherein the third valve body is configured to transmit the second part of the spring force via the second valve body to the first valve body.

[0051] Furthermore, according to one embodiment of the invention, the outlet is formed by a longitudinally extending through-opening in the valve housing, wherein the through-opening has a step. In particular, the through-opening is designed as a stepped bore.

[0052] Furthermore, according to one embodiment of the invention, it is provided that the second spring is supported by the first end section on the step.

[0053] Furthermore, according to one embodiment of the invention, the second spring is arranged in the through-opening.

[0054] According to one embodiment, the second spring can also be a coil spring.

[0055] Furthermore, the second spring can be arranged coaxially to the first spring. The first spring can wrap around the second spring.

[0056] The valve inlet is specifically designed as a through-opening in the second wall of the valve housing,

[0057] According to one embodiment, the first valve seat is formed by a circumferential edge region of the inlet or the corresponding through-opening, wherein that edge region surrounds the inlet or the through-opening.

[0058] Furthermore, the valve according to the invention is not limited to a linear movement of the valve body. According to an alternative embodiment of the invention, the valve body is pivotably mounted on the valve housing inside the housing, so that the valve body can pivot back and forth between the first and the second valve seat, with the spring (in particular a torsion spring) also attempting to move the valve body towards the first valve seat.

[0059] Furthermore, the valve body can, in principle, be composed of several, in particular separate, bodies. For example, according to one embodiment, the valve body may have a first body and a second body, wherein the first body is configured to rest against the first valve seat, and wherein the second body is configured to rest against the second valve seat and / or is heavier than the first body. A large part of the weight of the valve body can be provided by the second body, while the first body, for example, provides the seal against the first valve seat.

[0060] Furthermore, according to one embodiment of the invention, the valve body may have a first body, one or more second bodies and a third body, wherein the first body is configured to abut the first valve seat, and wherein the third body is configured to abut the second valve seat, and wherein the second body(s) is / are heavier than the first body and / or the third body.

[0061] According to a further embodiment of the valve according to the invention, the mass of the valve body assembly and the spring device or its spring force are selected such that the force of gravity on the valve body assembly does not influence the position of the valve body assembly relative to the first and second valve seats, so that in particular the said position with respect to the valve seats does not change when the spatial position of the valve axis changes.

[0062] According to a further aspect of the present invention, a drainage device with the features of claim 34 is disclosed. Accordingly, the drainage device according to the invention for draining cerebrospinal fluid comprises at least the following: a valve according to the invention, a first catheter (in particular a ventricular catheter) which has an end section that can be positioned in a cerebral ventricle or the spinal cerebrospinal fluid space of a patient and is in flow communication with the inlet of the valve, so that cerebrospinal fluid can enter the first catheter via the first end section, and a second catheter which is in flow communication with the outlet of the valve and has an end section that can be positioned in a cavity (e.g. abdominal cavity, epidural space) of the patient's body, so that cerebrospinal fluid can flow out of the second catheter into the cavity via the end section.

[0063] In particular, the terminal segment of the first catheter has at least one inlet opening through which cerebrospinal fluid can enter the first catheter. Likewise, the terminal segment of the second catheter has at least one outlet opening through which cerebrospinal fluid can exit the second catheter.

[0064] The drainage device according to the invention is particularly suitable for the treatment of normal pressure hydrocephalus. The inlet of the valve can be connected via the first catheter to the cerebrospinal fluid space or subdural space of the patient in the lumbar spine region (the spinal cerebrospinal fluid space). The outlet of the valve, on the other hand, can be connected via the second catheter to the epidural space of the patient's lumbar spine.

[0065] Further embodiments, features and advantages of the present invention will be explained below in the description of exemplary embodiments with reference to the figures. The figures show: Fig. 1 an embodiment of a valve according to the invention in a vertical position; Fig. 2 an embodiment of a valve according to the invention in a horizontal position; Fig. 3 different shapes of a valve body of a valve according to the invention; Fig. 4 an embodiment of a valve according to the invention with a valve body composed of two bodies; Fig. 5 an embodiment of a valve according to the invention with a valve body composed of three bodies; Fig. 6 an embodiment of a valve according to the invention with a pivotable valve body; Fig. 7 an embodiment of a valve according to the invention, wherein the position of the valve body is independent of the spatial orientation of the valve; and Fig. 8 a modification of the one shown in the Fig. 7 The embodiment shown. Fig. 9 shows a drainage device according to the invention with a valve according to the invention.

[0066] Figure 1 shows in connection with Figure 2A valve 1 according to the invention. The valve 1 has a valve housing 10, which has an inlet 2, an outlet 3, and an interior 4. The valve housing 10 extends along a valve axis A, with the inlet 2 and the outlet 3 being opposite each other in the direction of the valve axis A.

[0067] Between the inlet 2 and the interior 4 is a first valve seat 5, which can be closed by a valve body assembly 600, consisting here of a valve body 6. Furthermore, between the interior 4 and the outlet 3 is a second valve seat 7, which can also be closed by the valve body 6.

[0068] The valve housing 10 has a circumferential wall 11, which has a circumferential inner surface 11a facing the interior 4. The circumferential wall 11 connects a first and a second wall 12, 13 of the valve housing 10 to each other, with the outlet 3 being located on the first wall 12 and the inlet 2 on the second wall 13.

[0069] Furthermore, a projection 40 is provided in the interior 4, which extends from an inner surface 12a of the first wall 12 towards the first valve seat 5 or the second wall 13. The projection 40 forms an annular gap 14 with the inner surface 11a of the circumferential wall 11 of the valve housing 10.

[0070] The second valve seat 7 is provided, in particular, at an end of the projection 40 facing the first valve seat 5 or the second wall 13. The projection 40 surrounds, in particular, a longitudinally extending through-opening 3, which forms the outlet 3 of the valve 1. The second valve seat 7 is formed, in particular, by a circumferential end face 7 of the projection 40, which surrounds that through-opening or outlet 3 at the end of the projection 40.

[0071] Furthermore, the valve 1 preferably has a spring device 800, which here consists of a spring 8 that presses the valve body 6 against the first valve seat 5. The spring 8, the dimensions and the material of the valve body 6 are dimensioned such that in the vertical position, which is in Figure 1As shown, the weight of the valve body 6 exceeds the spring force of the spring 8, so that the valve body 6 releases the first valve seat 5 and closes the second valve seat 7. In this vertical position of the valve housing 10 (the valve axis A is vertically oriented here), the valve 1 is therefore closed to cerebrospinal fluid present at the inlet 2. In the horizontal position (valve axis A is horizontal), which is shown in the Figure 2 As shown, the spring force of spring 8 predominates, and the second valve seat 7 is released. The valve body rests against the first valve seat 5 and closes valve 1. If the pressure of the cerebrospinal fluid exceeds a threshold value, the valve body 6 releases the first valve seat but does not come into contact with the second valve seat 7, so that cerebrospinal fluid can be drained via valve 1.

[0072] The combination of valve body 6, spring 8, and first valve seat 5 forms a pressure relief valve with a check valve function in this horizontal position. Valve 1 is therefore open to cerebrospinal fluid when a threshold value is exceeded. It is protected against backflow.

[0073] In particular, it is provided that the spring 8 engages the projection 40 (and is thereby arranged in the annular gap 14). The spring 8 can be arranged according to Figure 1 and 2 in particular, it may be designed as a coil spring. The spring 8 can be supported on an inner surface 12a of the first wall 12 of the valve housing 10, from which the projection 40 extends into the interior 4 of the valve housing 10.

[0074] In a particularly preferred embodiment of the invention, the valve housing 10 has a circular cross-section (perpendicular to the valve axis A), wherein the circumferential wall 11 has an outer diameter of 6.5 mm according to an example of the invention, and the diameter of the interior 4, or the inner diameter of the wall 11, is 5.5 mm. The diameter of the valve seats 5, 7 is 1.2 mm in the example.

[0075] The path of the valve body 6 in the direction of the valve axis A from valve seat 5 to valve seat 7 is, for example, 1 mm. The valve body 6 is specifically designed as a sphere, which in this example has a diameter of 5 mm and is made of tungsten carbide with a density of 16.63 g / cm³. The weight of the sphere 6 is therefore 1.088 g. The force of gravity in water is 0.01023 N (weight minus buoyancy). The spring 8 (in this example, a helical spring) has a wire diameter of 0.1 mm, an unstressed length of 10 mm, an inner diameter of 2.5 mm, and—with 10 turns—a spring constant of 0.005 N / mm. In the horizontal position, the spring 8 has a pre-tensioned length of 9.6 mm. The spring force is therefore 0.002 N.To press the ball 6 into the first valve seat 5 in the horizontal position against the force caused by the tilting moment resulting from the weight, a spring force of at least 0.0019 N is required, which is thus achieved. In the vertical position, the weight of the ball 6 compresses the spring 8 by a distance of a maximum of 2 mm to a minimum of 8 mm, so that the design-selected compressed length of, for example, 8.6 mm can be reliably achieved. The maximum intracranial pressure of 50 mmHg = 7000 Pa pushes the ball 6 towards the second valve seat 7 with a force of 0.005 N. The weight of the ball (0.01023 N) minus the closing force of the spring (0.002 N) equals 0.00823 N. Thus, the ball 6 is dislodged from the first valve seat 5 by the intracranial pressure and its own weight, and is pressed against the second valve seat, closing it.

[0076] In a further preferred embodiment of the invention, the ball has a diameter of 6.5 mm and is made of steel, and the housing has an inner diameter of 7 mm and an outer diameter of 8 mm. The mass of the spring and the diameters of the valve seats are configured as in the example given above.

[0077] According to Figure 3 The valve body can have 6 different designs and can in particular deviate from a spherical geometry.

[0078] Thus, according to Figure 3 the valve body 6 shall be cylindrical and shall have a flat first end surface 60a (dashed line) which is designed to abut the first valve seat 5, and a flat second end surface 60b (dashed line) facing away from the first end surface 60a which is designed to abut the second valve seat 7.

[0079] Alternatively, the valve body 6 can be used according to Figure 3The valve body 6 has a cylindrical central section 60, which is arranged between a first end section 61 (dashed line) and a second end section 62 (dashed line), wherein the first end section 61 is designed to abut the first valve seat 5, and wherein the second end section 62 is designed to abut the second valve seat 7. The two end sections 61, 62 can, for example, be curved, hemispherical, frustoconical, or conical.

[0080] Furthermore, it shows Fig. 4an embodiment of a valve 1 according to the invention, in which the valve body arrangement 600 has a first valve body 6a and a separate second valve body 6b, wherein the first (e.g., sectionally cylindrical) valve body 6a is configured to abut the first valve seat 5, and wherein the second (e.g., spherically shaped) valve body 6b is configured to abut the second valve seat 7 and / or is heavier than the first body 6a.

[0081] In accordance with the invention, embodiments of the valve 1 according to the invention are also possible in which the valve body arrangement 600 has a first valve body 6a, one or more second valve bodies 6b and a third valve body 6c, wherein the first (e.g. spherically or partially cylindrically shaped) valve body 6a is configured to abut the first valve seat 5, and wherein the third (e.g. spherically or partially cylindrically shaped) valve body 6c is configured to abut the second valve seat 7, and wherein the one or more second valve bodies 6b are heavier than the first valve body 6a and / or the third valve body 6c.

[0082] One such embodiment of a valve 1 according to the invention, comprising a valve body arrangement 600 formed from three valve bodies 6a, 6b, 6c, is described in the Fig. 5shown. Here, the valve bodies 6a, 6b, 6c are each spherically shaped (other shapes are also conceivable) and arranged next to each other along the valve axis A, wherein the middle second valve body 6b has a larger diameter than the other two valve bodies 6a, 6c, wherein the second valve body 6b is in particular heavier than the first valve body 6a and heavier than the third valve body 6c.

[0083] Similar to the one in the Figure 1 and 2In the configuration shown, it is preferably also provided here that the valve housing 10 has a projection 40 extending towards the first valve seat 5 into the interior 4 of the valve housing 10, wherein the projection 40 forms an annular gap 14 with a circumferential inner surface 11a of the valve housing 10. The first valve seat 5 is located opposite the projection 40 in the direction of the valve axis A and is formed by a circumferential edge region of the inlet 2 of the valve, which may, for example, be conical. In contrast, the second valve seat 7 is provided at an end section of the projection 40 facing the first valve seat 5 and may be designed as a circumferential section (e.g., a conical step) of a through-opening 3 arranged in the projection 40, which forms the outlet 3 of the valve 1.

[0084] The three valve bodies 6a, 6b, 6c are arranged along the valve axis A between the two valve seats 5, 7, with the first valve body 6a being configured to fit against the first valve seat 5 and the third valve body being configured to fit against the second valve seat 7.

[0085] According to Fig. 5 The valve 1 further comprises a spring device 800, consisting of a first and a second spring 8, 8a, wherein the first spring 8 is preferably a coil spring that surrounds the projection 40. It is provided that the first spring 8 is supported with a first end section 80 against an inner surface 12a of the valve housing 10, from which the projection 40 extends into the interior 4 of the valve housing 10.

[0086] Unlike the Figure 1 and 2It is here provided that the first spring 8 with a second end section 81 contacts the second valve body 6b and exerts a first part of a spring force, which is to be exerted by the spring device 800 on the valve body arrangement 600, in the direction of the first valve seat 5 onto the second valve body 6b, wherein the second valve body 6b transmits this first part of the spring force to the first valve body 6a.

[0087] Furthermore, the spring device 800 differs from the Figure 1 and 2A second spring 8a is provided, wherein the second spring 8a is supported by a first end section 80a on a step 3a of the through-opening 3 in which the second spring 8a is arranged. The second spring 8a is also preferably designed as a helical spring and has a smaller diameter than the first spring 8. The second spring 8a now contacts the third valve body 6b with a second end section 81a and thereby transmits a second part of said spring force towards the first valve seat 5 to the third valve body 6c, which in turn transmits the second part of the spring force via the second valve body 6b to the first valve body 6a.

[0088] The Figure 5Figure 1 shows the valve in a horizontal position (horizontal valve axis A), with the entire spring force provided by the two springs 8, 8a pressing the first valve body against the first valve seat 5, so that the valve 1 is closed. This design has the advantage that the second valve seat is closed by the valve body arrangement when the valve housing is tilted, where the valve axis forms an angle with the vertical in the range of 0° to 40°. Figure 2 further shows Fig. 6 An embodiment of a valve 1 according to the invention, in which the valve body 6 is pivotably mounted on the valve housing 10 in the interior 4 (e.g. via a rotary bearing 90) so that the valve body 6 can pivot back and forth between the first and the second valve seat 5, 7. The spring 8, which attempts to move or pivot the valve body 6 towards the first valve seat, can be designed as a torsion spring 8.

[0089] The Figure 7Figure 1 shows a further embodiment of a valve according to the invention. The valve 1 preferably has a valve housing 10, which has an inlet 2 and an outlet 3 as well as an interior 4. The valve housing 10 extends along a valve axis A, with the inlet 2 and the outlet 3 being opposite each other in the direction of the valve axis A.

[0090] Between the inlet 2 and the interior 4 is a first valve seat 5, which can be closed by a valve body assembly 600, which here consists of the spherical valve body 6. Furthermore, between the interior 4 and the outlet 3 is a second valve seat 7, which can also be closed by the valve body 6.

[0091] The valve housing 10 has a circumferential wall 11, which has a circumferential inner surface 11a facing the interior 4. The circumferential wall 11 connects a first and a second wall 12, 13 of the valve housing 10 to each other, wherein in particular the outlet 3 is provided on the first wall 12 in the form of a longitudinally extended through-opening 3, and wherein in particular the inlet 2 is provided on the second wall 13 in the form of a longitudinally extended through-opening 2.

[0092] The valve 1 further comprises a spring device 800, which is formed by a spring 8, wherein the spring 8 is supported with a first end section 80 on a step 3a of the through-opening 3 forming the outlet 3, in which the spring 8 is arranged. The spring 8 is preferably designed as a helical spring and contacts the valve body 6 with a second end section 81 and exerts a spring force on the valve body 6 in the direction of the first valve seat 5.

[0093] In the embodiment according to Figure 7It is now provided that the mass of the valve body 6, given the spring arrangement 800 or 8, is selected such that its position relative to the valve seats 5 and 7 is not influenced by gravity acting on the valve body 6. Accordingly, its function is independent of its position relative to the direction of gravity. In its resting position, with no pressure difference between inlet 2 and outlet 3, the valve body 6 is pressed against the first valve seat 5 by the force of the spring 8. In this situation, the valve body 6, together with the valve seat 5, acts as a check valve, so that in the case of a negative pressure difference between inlet 2 and outlet 3, the valve 1 does not allow flow. If the pressure difference between inlet 2 and outlet 3 is positive and large enough to overcome the force of the spring 8, the valve body 6 moves away from the first valve seat 5, and flow opens through the valve 1. The flow rate increases with increasing pressure difference.Due to flow resistance, the valve body 6 is moved towards the second valve seat 7 as the pressure differential increases. When a certain limit pressure is reached, the valve body 6 contacts the second valve seat 7 and closes it. The valve 1 is now closed and does not allow any flow. When the pressure differential falls below a certain second limit pressure, the force of the spring 8 becomes greater than the pressure force that pushes the valve body 6 against the second valve seat 7, and the valve 1 opens again.

[0094] Figure 8 shows a modification of the one in the Fig. 7 in the embodiment shown, wherein here, instead of the valve body 6, a valve body arrangement 600 is provided with a first valve body 6a and a second valve body 6b, wherein the first valve body 6a corresponds to the valve body 6 of the Figure 7 corresponds, and in contrast to Figure 7The force of the spring 8 does not act directly on the first valve body 6a, but rather via the second valve body 6b, which in this sense forms a spacer that contacts the first valve body 6a. The second valve body / spacer 6b has, in particular, the function of preventing the uppermost coil 8b of the spring 8 from becoming pinched between the second valve seat 7 and the first valve body 6a.

[0095] Figure 9Figure 1 shows a drainage device 1' according to the invention for draining cerebrospinal fluid, comprising a valve 1 according to the invention, which can be configured according to one of the embodiments described herein, and a first catheter 100, which has an end section 100a to be arranged in the cerebral ventricle H or in the cerebrospinal fluid space of a patient P and is in flow communication with the inlet 2 of the valve 1. Furthermore, the device 1' comprises a second catheter 200, which is in flow communication with the outlet 3 of the valve 1 and has an end section 200a to be arranged in a drainage site or cavity H' of the body of the patient P.

Claims

1. Implantable valve (1) for a drainage device (1') for draining cerebrospinal fluid, comprising: - a valve housing (10) extending along a valve axis (A), which has an inlet (2) and an outlet (3) as well as an interior space (4) surrounded by the valve housing (10), - a valve body assembly (600) arranged in the interior space (4), which is movably arranged in the interior space (4) and has at least a first valve body (6, 6a, 6b, 6c), - a first valve seat (5), wherein the valve body assembly (600) is configured to abut against the first valve seat (5) to close a flow connection between the inlet (2) and the interior (4) of the valve housing (10), - a second valve seat (7), wherein the valve body assembly (6) is configured to abut against the the second valve seat (7) to close a flow connection between the outlet (3) and the interior (4) of the valve housing (10), and - a spring device (800) arranged in the interior (4), which exerts a spring force on the valve body assembly (600) in the direction of the first valve seat (5), wherein the spring force is greater than a horizontal component of the weight of the valve body assembly (600) when the valve housing (10) is in a horizontal position in which the valve axis (A) extends horizontally, characterized in that the weight of the valve body assembly (600) in the vertical position of the valve housing (10) is greater than the spring force.

2. Valve according to claim 1, characterized in that the weight of the valve body assembly (600) acts in the direction of the second valve seat (7) when the valve housing (10) is in a vertical position in which the valve axis (A) runs vertically and the first valve seat (5) is arranged above the second valve seat (7).

3. Valve according to one of the preceding claims, characterized in that the valve body assembly (600) has a second valve body (6b), wherein the first valve body (6a) is configured to abut against the first valve seat (5), and wherein the second valve body (6b) is configured to abut against the second valve seat (7) and / or is heavier than the first valve body (6a).

4. Valve according to any one of claims 1 to 2, characterized in that the valve body assembly (6) comprises a second valve body (6b) and a third valve body (6c), wherein the first valve body (6a) is configured to abut against the first valve seat (5), and wherein the third valve body (6c) is configured to abut against the second valve seat (7), and wherein the second valve body (6b) is heavier than the first valve body (6a) and / or the third valve body (6c).

5. Valve according to claim 4, characterized in that the second valve body (6b) is arranged between the first and third valve bodies (6a, 6c).

6. Valve according to one of claims 1 to 5, characterized in that the respective valve body (6, 6a, 6b, 6c) of the valve body assembly has a first end section (61) and a second end section (62), wherein in particular the first end section (61) is designed to abut against the first valve seat (5) or to abut against an adjacent valve body, and wherein, in particular, the second end portion (62) is designed to abut against the second valve seat (7) or to abut against an adjacent valve body.

7. Valve according to one of claims 3 to 6, characterized in that a diameter of the second valve body (6b) is larger than a diameter of the first valve body (6a) and / or than a diameter of the third valve body (6c).

8. Valve according to one of the preceding claims, characterized in that the inlet (2) is opposite the outlet (3) in the direction of the valve axis (A), and / or that the second valve seat (7) is opposite the first valve seat (5) in the direction of the valve axis (A), and / or that the respective valve body (6, 6a, 6b, 6c) of the valve body assembly (600) is arranged in the interior space (4) so as to be movable in the direction of the valve axis (A).

9. Valve according to one of the preceding claims, characterized in that the spring device (800) has a first spring (8).

10. Valve according to one of the preceding claims, characterized in that the valve housing (10) has a projection (40) projecting into the interior space (4) in the direction of the first valve seat (5), wherein in particular the projection (40) forms an annular gap (14) with a circumferential inner side (11a) of the valve housing (10), and in particular the second valve seat (7) is provided at an end portion of the projection (40) facing the first valve seat (5), and in particular the first spring (8) engages around the projection (40).

11. Valve according to claim 10, characterized in that the first spring (8) is supported with a first end portion (80) on an inner side (12a) of the valve housing (10), wherein, in particular, the projection (40) projects from the inner side (12a) into the interior space (4) of the valve housing (10), wherein, in particular, the first spring (8) contacts the at least one first valve body (6) with a second end section (81) and exerts the spring force in the direction of the first valve seat (5) on the first valve body (6).

12. Valve according to claim 11, characterized in that the first spring (8) contacts the second valve body (6b) with a second end portion (81) and exerts the spring force in the direction of the first valve seat (5) on the second valve body (6b), wherein the second valve body (6b) is configured to transmit the spring force to the first valve body (6a), or wherein the first spring (8) contacts the second valve body (6b) with a second end portion (81) and exerts a first portion of the spring force in the direction of the first valve seat (5) on the second valve body (6b), wherein the second valve body (6b) is configured to transmit the first portion of the spring force to the first valve body (6a).

13. Valve according to claim 12, characterized in that the spring device (800) comprises a second spring (8a), wherein the second spring (8a) is supported with a first end portion (80a) on an inner side (12a) of the valve housing (10), and wherein the second spring (8a) contacts the third valve body (6c) with a second end portion (81a) and exerts a second portion of the spring force in the direction of the first valve seat (5) on the third valve body (6c), wherein the third valve body (6c) is configured to transmit the second portion of the spring force via the second valve body (6b) to the first valve body (6a).

14. Drainage device (1') for draining cerebrospinal fluid, comprising: - a valve (1) according to one of the preceding claims, - a first catheter (100) having an end section (100a) that can be positioned in the cerebral ventricle (H) of a patient (P) and is in fluid communication with the inlet (2) of the valve (1), and - a second catheter (200) which is in fluid communication with the outlet (3) of the valve (1) and has an end section (200a) that can be positioned in a cavity (H') in the body of the patient (P).