RU2820002C1 - Adjustable implantable throttle - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention relates to an adjustable implantable throttle for controlling the flow rate in implanted drains for the removal of cerebrospinal fluid, in particular, to a hydrocephalic valve, for discharge of fluid from a patient’s ventricular system. Adjustable implantable throttle for control of flow rate in implanted drains for drainage of cerebrospinal fluid, wherein at least one effective length of at least one channel is adjustable, wherein the effective length is the length over which the cerebrospinal fluid actually flows. Throttle has at least two states, through and adjustment, wherein in the through state the adjustment disc does not contact the channel boundaries, and in the adjustment state the adjustment disc rests against the channel boundaries.

EFFECT: throttle can be cleaned, washed and/or inspected in a through state; in addition, the through state does not depend on the adjustment state; this simplifies maintenance of the adjustable throttle.

21 cl, 12 dwg, 1 tbl

Description

The invention relates to an adjustable implantable throttle for controlling the flow rate in implantable drainages for draining cerebrospinal fluid, in particular to a hydrocephalic valve for draining fluid from the ventricular system of patients, containing at least one housing with an internal part, at least one first passage for inlet and/or outlet, wherein at least one body is located in the inner part of the housing, wherein the housing is configured to move in at least one direction, and the valve contains at least one adjustment unit.

Patients with hydrocephalus have the following health problem.

The brain, located in the skull, is surrounded by a special fluid, namely cerebrospinal fluid. Cerebrospinal fluid is constantly produced and reabsorbed to the same extent. In hydrocephalus, also called dropsy, this balance is disrupted. Since the skull is a closed vessel, its size increases when more cerebrospinal fluid is produced than is reabsorbed. Due to the increase in size, the fusion of cranial sutures in an infant is difficult, and intracranial pressure increases in an adult. There is hydrocephalus in adults and childhood hydrocephalus.

Hydrocephalus can be divided into internal hydrocephalus, external hydrocephalus, external and internal hydrocephalus, normal pressure hydrocephalus and replacement hydrocephalus.

Hydrocephalus was initially treated by simple drainage of the cerebrospinal fluid. This was done by simply connecting the skull to a large venous blood vessel using a tube, or by correspondingly connecting the skull to the abdomen using a tube. However, it was soon recognized that the pressure in the skull must have a certain physiological significance so that other complications do not arise.

Modern methods of treating hydrocephalus use an implantable drain, an artificial connection between the ventricles of the brain and the drainage compartment, which is currently usually the abdominal cavity, to establish a certain physiological value.

There are various drainages that can be used to treat pressure in the patient’s skull. These drains must open at a certain critical pressure and allow the flow of cerebrospinal fluid (also called cerebrospinal fluid) to prevent excess pressure from building up in the skull. Typically, these drains are called shunts or drains to protect against excess cerebrospinal fluid (CSF) pressure.

The basis of implantable drainage is an implantable valve, which is designed to regulate drainage. This valve is called the hydrocephalic valve. Hydrocephalic valves are usually implanted directly under the skin. Such drains are usually implanted under the skin in the scalp area.

A possible definition of the term "shunt" according to Mitke's publication is: any artificial hydraulic connection between a first part of the body containing cerebrospinal fluid and a second part of the body capable of receiving that fluid, see Kombogiorgas D. (2016) "Shunts for the outflow of cerebrospinal fluid" ( Kombogiorgas, D. (2016) "The Cerebrospinal Fluid Shunts") (1st edition), Nova Science Publishers, Incorporated, pp. 130/131 (hereinafter referred to as Kombogiorgas, D. (2016)). On the subject of hydrocephalus, additional references include the book Normal Pressure Hydrocephalus, Fritsch et al., 2014 (hereinafter referred to as Fritsch (2014)) and the standards EN ISO 7197 and EN ISO 1463.

All sources contain, among other things, specific terms and definitions on the topic of hydrocephalus. In addition, they contain known principles of action and their grouping.

In Kombogiorgas (2016), Miethke proposes two groupings, see Table 1. In the first subgroup, he divides valves according to their operating principles into differential pressure valves and hydrostatic valves. In the second subgroup, he divides valves according to their clinical functions into fixed, i.e. non-adjustable, and adjustable types of valves.

According to Mitke, hydrostatic group valves are defined as valves or valve components whose design purpose is to prevent excessive drainage (Kombogiorgas (2016), p. 67). The task of valves of this group is to compensate for the force of hydrostatic pressure acting in the direction of opening the valve (the so-called balancing).

Valves with a hydrostatic operating principle can be divided into three types. They are called anti-siphon, flow-controlled, and gravity-assisted. All three types of valves have in common the presence of a pressure difference. This indicator is calculated as the difference between the pressure behind the valve and the pressure in front of the valve (ΔP = P _{behind the valve} - P _{in front of the valve} ). The pressure difference at which volumetric flow passes through the valve is defined as the valve opening pressure.

The anti-siphon means are configured to regulate the opening pressure depending on the level of suction force acting on the valve. Gravity means regulate opening pressure depending on their inclination in the Earth's gravitational field. Flow control means, on the other hand, are configured to regulate the flow rate of the flow passing through them depending on the pressure difference.

Similar terms for valves configured to regulate flow in the prior art are valves or means dependent on flow rate, configured to regulate flow or to reduce flow. In this context, the term "flow" is generally equivalent to the term "volume flow rate, volume per unit time."

Each hydrocephalic valve has a different characteristic curve. Alfred Aschoff, MD, describes characteristic curves in the book "In-Vitro-Testung von Hydrocephalus Ventilen", 1994, page 32. He discusses them because shunt valves are unidirectional flow regulators. According to Aschoff, these valves differ, firstly, in their unidirectional action, secondly, in their opening and closing characteristics, and thirdly, in their specific pressure-flow characteristics. The pressure-flow characteristic is generally more nonlinear. According to Aschoff, the characteristic of such a valve depends on the hydrocephalic valve itself, so the hydrocephalic valve can only be described by indicating the complete characteristic curve.

Non-adjustable hydrocephalic valves have one characteristic, while adjustable valves have multiple characteristics.

In the case of non-adjustable hydrocephalic valves, it is obvious that the valves of the hydrostatic principle group provide a certain volumetric flow passing through them, depending on the pressure of the cerebrospinal fluid. If for each CSF pressure the corresponding volumetric flow is plotted, a valve characteristic curve is obtained.

When using adjustable hydrocephalic valves, each characteristic provides valve regulation. Each configuration provides different valve characteristics. Experience shows that the various valve characteristics are similar.

Some significant hydrocephalic valves are described below.

US Patent No. 8870809 B2 (Christoph Miethke GmbH & Co KG) describes an implantable hydrocephalic device for treating patients with hydrocephalus with drugs. According to the description, it is proposed to deliver the drug into the ventricles of the brain of patients using liquids or auxiliary fluids. To do this, drugs must be delivered into the cavity of the hydrocephalic system, so that from there they can be hydraulically transported through the ventricular catheter into the ventricles of the brain. According to the description, this requires a device that is configured to admit medicinal fluids in one state and release them to the ventricles of the brain in another state. Thus, the device requires a valve and therefore includes valve means with a valve blade in a housing with an inlet port and an outlet port. Placing a valve in it opens or closes the inlet of the hydrocephalic system depending on the pressure of the medicinal fluid in the cavity.

According to EP 1523635 B1 (paragraph [0003]) (Aesculap AG), a fast switching ball valve is proposed in the patent document DE 3835788 A1. Phenomenologically, this is a driving means that ensures the movement of the ball to release or close the passage hole. When the valve is closed, the ball is pressed against the passage hole under the influence of the pressure difference in the gas flow. To release the passage hole, the drive means pushes the ball away from the passage hole. When the valve is closed, the ball is pressed against the orifice by applied pressure, such as gas flow; To release the hole, the drive means moves the ball away from the passage hole. To do this, the drive element of the drive means exerts lateral pressure on the ball, which is then disconnected from the bore or bore valve seat. An electromagnet with a pulse drive is used as a driving means for moving the ball, which, after operation, is returned to its original position under the action of a spring.

Patent document EP 1523635 B1 (Aesculap AG) proposes a valve with a compact drive means made of a shape memory alloy. This paper proposes a solution to create a valve that provides actuating travel in the millimeter range. In principle, the proposal combines a main body with a passage opening for closing and releasing the passage opening with two wire-like elements, in particular a shape memory alloy wire, as the driving means. Their alternate reduction is ensured depending on temperature changes. A shape memory alloy wire is connected to the valve body so that the valve body moves from a stable position on the bore to a stable position adjacent to the bore when one element is shortened on one side, and back to a stable position on the bore when the other the element is shortened on one side. In a particularly advantageous embodiment, this ensures that the valve has a binary opening characteristic. Phenomenologically, the switch function is achieved as a result of manipulating the position of the body in front of the passage hole.

Patent document US 20150182734 A1 (Christoph Miethke GmbH & Co. KG) discloses an adjustable hydrocephalic valve, a programmable gravity aid, for regulating pressure in the skull of a patient with hydrocephalus. The membrane ensures the release of the brake means to free the rotor with the possibility of free rotation around the axis. Returning the membrane to its original position signals the user to unlock or lock the brake with an audible click. Since the rotor contains magnets, it is rotatable about its axis by magnetic means. Rotation is used to adjust the valve characteristics. The valve has proven itself well.

The above-mentioned implantable hydrocephalic valves have the following common features: a body comprising an inlet port, an outlet port and at least one actuator means that is configured to open or close the inlet port or the outlet port by the housing depending on the pressure of the cerebrospinal fluid.

These valves have proven their effectiveness.

In US patent No. 4676772 A (Cordis-Cooperation) already in 1985 a device for regulating the pressure of cerebrospinal fluid was described. It includes an implantable fluid pressure relief valve that includes a housing and a control assembly for regulating the opening pressure of the pressure relief valve. Depending on the pressure applied to the pressure relief valve, the diaphragm flexes so that a passage is opened between the O-ring built into the diaphragm and the ball. To do this, the ball is installed in a bowl, on the circumferential surface of which a thread is cut. The thread allows the bowl to be screwed in or out of the lid to regulate the pressure between the ball and the seal. It is possible to display the bowl position, i.e. the number of threads in the pressure relief valve, on the display device using a magnetic bridge.

US Pat. No. 4,676,772 A describes valve opening pressure control, but unfortunately not specific volume flow control. In addition, the described method has the disadvantage that adjusting the valve opening pressure by screwing in the cup may lead to plastic deformation of the membrane. This occurs when force is applied to the membrane through the ball by screwing the cup too tightly, which exceeds the elastic limits of the membrane. Accurate setting of the valve opening pressure requires precise positioning of the bowl in the lid. The bowl is designed to be screwed into the lid using a magnetic bridge that corresponds to the movement of the user's hand. However, the user does not receive any feedback about the friction or relative position between the bowl and the lid. Therefore, the bowl cannot be accurately installed in the lid due to over- or under-turning by the user, so the valve opening pressure cannot be adjusted accurately.

The so-called Orbis-Sigma valve was developed by Sainte-Rose, and described by Hooven imd Hirsch in "A new approach in the treatment of hydrocephalus", Neurosrg, 1987, 66 (2), 213-26. The Orbis Sigma valve consists of a sapphire diaphragm with a hole and a pin passing through the hole. The pin has an undercut in cross section in the direction of its end facing the membrane. The membrane is installed circumferentially in the housing in the flow channel. The pin is installed with its end away from the membrane in the same body and in the same flow channel. When the pressure drops above the membrane, it is ensured that it bends along an arc with a pressure gradient. The thickness of the curvature and the shape of the undercut in the pin form the passage channel. Its size varies depending on the cutting stroke. Thus, the Orbis Sigma valve provides continuous regulation of the size of the passageway depending on the differential pressure applied to the membrane in interaction with the cutting stroke.

The disadvantage of the Orbis-Sigma valve is its dependence on differential pressure. In addition, the cutting path cannot be assumed to be constant for all patients. Rather, it must be tailored to the relevant characteristics of the patient's hydrocephalus.

Patent document EP 0873761 B1 (DePuy) describes a device for limiting the flow of liquid. The device demonstrates the operating principle of the so-called Siphon Guard® valve. In 1998, a method was introduced to limit the flow of fluid from the first area of the patient to the second. To this end, the device includes an inlet for receiving liquid from the first region and an outlet for directing liquid to the second region. In addition, the device includes a primary flow channel and a secondary flow channel, which are in flow communication with the inlet hole and the outlet hole. The detector in the device is configured to determine the flow rate, volumetric flow rate of the liquid, to ensure a decision is made on its direction along the primary or secondary flow channel, depending on its power. The detector is configured to make a decision by comparing the current flow rate with a threshold value. The detector ensures that fluid is directed from the inlet to the outlet through the primary flow channel when the fluid flow rate is less than a predetermined threshold value. Conversely, the detector ensures that liquid is directed from the inlet to the outlet through a secondary flow path when the flow rate exceeds a predetermined threshold value. The detector consists of four components: ball socket, ball, leaf spring and coil spring. The leaf spring is configured to push the ball out of the ball seat, while the coil spring is configured to push the ball into the ball seat. Thus, the difference between the two spring force values forms the detector threshold value.

Thus, the fluid flow limiting device allows the flow resistance to be digitally set between two states, high flow resistance and low flow resistance. Thus, its disadvantage is that it is possible to regulate the flow resistance force between two states, but unfortunately the volumetric flow cannot be maintained at a constant value. Both the primary flow passage size and the secondary flow passage size are preset at the factory when the device is designed. Thus, moving forward in the state of the art, the specialist is focused on the development of technologies that improve the factory dimensions of the flow channels.

Patent document US 2014/0276348 A1 (Depuy-Synthes Products, Inc.) from 2013 describes a surge protection device based on the principle of the so-called “Siphon Guard®”. It contains a housing with an inlet and an outlet and a first flow channel in the housing. The first flow path connects the inlet to the outlet. In addition, the housing contains a second flow channel, which also connects the inlet port and the outlet port. Both flow channels have flow resistance and flow resistance, respectively. In comparison, the flow resistance of the second flow channel is greater than the flow resistance of the first flow channel. In the first flow channel there is a valve with a valve seat and a first valve ball and a second valve ball. Said first valve ball is movable between a closed position in which said first ball is in contact with the valve seat and an open position in which said first ball is spaced from the valve seat. In this case, said first ball is located between the second valve ball and the valve seat, and said second valve ball is movable between closed and open positions.

The advantage is provided that the valve opening pressure, the force of the weight of both balls relative to the supporting surface of said first ball in the valve seat, is adjusted by the position of both balls in the gravitational field of the Earth. The greater the angle between the vertical line and the vertical axis of the valve, the less the force of the weight of both balls relative to the supporting surface of said first ball in the valve seat. Thus, the opening pressure of the valve is reduced when the valve moves from a vertical to a horizontal position.

However, adjusting the valve opening pressure according to the orientation of the valve in the Earth's gravitational field does not correspond to adjusting the valve opening clearance.

The overvoltage protection device also has the disadvantage that the flow resistance of said second flow channel is preset at the manufacturer's design. Flow resistance parameters such as thread number and thread height cannot be adjusted after implantation.

Patent document EP 1331019 A2 also describes a flow control device (Codman). This device, referred to in the publication itself as an anti-siphon shunt, describes a self-regulating valve with flow control capabilities, but not a valve with flow control means, as defined by Mitke. An anti-siphon shunt for regulating volume flow in a patient contains a housing that defines a fluid chamber, an inlet and an outlet. The inlet port is used to pass liquid into the chamber, the outlet port is used to release it. In addition, the anti-siphon shunt includes valve means for regulating the flow of liquid through the liquid chamber under the influence of a pressure gradient therein. To achieve this, the valve mechanism has a barrier in the fluid chamber, which has an opening to allow fluid to pass through. In addition, the anti-siphon shunt includes a pressure sensor configured to sense external pressure surrounding the fluid chamber, and a bias element, such as a spring. It is operatively connected to the pressure sensor and is configured to apply a first force to the first surface of the ball. This causes the ball to be pressed against the hole so that the passage of liquid through the barrier is accordingly prevented by the liquid chamber. The balancing force acts on the second surface of the sphere in the direction opposite to the first force. Both the first and second surfaces are approximately the same size.

Thus, herein, it is explained to one skilled in the art to close an opening in a barrier using a ball depending on the opening pressure. Closing is ensured until an opening pressure is reached that exceeds the ratio of the difference between the first force and the compensation force divided by the cross-sectional area of the hole.

In another embodiment of the invention, the document discusses a second method of moving one end of a bias element, a spring, so that its bias force is changed. To this end, the document proposes connecting the peritoneal cavity, also known as the abdominal cavity, to a fluid chamber using a first channel. This could be, for example, a tube. The proposal also contains a control chamber, which is also connected to the peritoneal cavity via a second channel. The fluid chamber and the control chamber are connected by a membrane, the membrane being connected to one end of a bias element - a spring. This connection changes the preload of the pretensioning element as the membrane flexes. The deflection follows the pressure difference between the peritoneal cavity and the reference chamber. Thus, the anti-siphon shunt is designed to independently regulate the opening pressure by adjusting the rigidity of the biasing element.

Unfortunately, this part of the document also does not describe the possibility of setting a passage, for example, a gap between the barrier and the ball.

The disadvantage of this method is that the size of the ventricles and their condition are not taken into account. As a result, the prior art does not take into account the importance of the drained volume of cerebrospinal fluid in different patients. In physiology, conformity describes the elasticity of the body's structure. In the field of application of hydrocephalus, this corresponds to the elasticity of the ventricles. Since the ventricles naturally vary in geometric shape and condition depending on the patient, their correspondence also varies. The elasticity of the ventricles is proportional to the change in their volume and inversely proportional to the change in pressure. If compliance varies by patient, pressure response varies for the same amount of drainage. Shunts described in the prior art provide drainage volume diversion through their valve function, so they have the disadvantage of varying pressure response depending on the patient.

Patent document US 20140336560 (Hakim Carlos) describes a programmable shunt with a magnetic rotor. The rotor is connected to the cam plate. The tongue of the bending element rests against the cam plate, so that when the rotor turns, the tongue moves along the cam track. Since the cam track is inclined, the tongue is raised or lowered when turning. Since the appropriate tongue height provides a preload on the lever that forces the ball into its seat, changing the preload causes the ball to adjust.

The challenge is to further improve the treatment of hydrocephalus.

The closest analogue of the proposed invention can be considered the device described in the patent document WO 2018/184717 A2 (Christoph Miethke GmbH). This document describes a valve with controlled cerebrospinal fluid outflow.

To accomplish this task, said known valve comprises a body which has an inlet, a passage and an outlet. The passage has a round profile. A body is installed in the throughput channel. This is a round body. Since the diameter of the body is smaller than the diameter of the passage, a gap is formed between the body and the channel.

Although this proven valve exists, the present invention aims to improve valves. The invention is based on the understanding that patients respond to cerebrospinal fluid drainage with varying degrees of well-being. In some cases, health worsens significantly. The present invention aims to overcome the above-mentioned disadvantages to further improve the control of fluid flows from one part of the patient's body to another.

All modern shunt devices remain at risk of blockage. This blockage, called an occlusion, requires complex cleaning of the blocked shunt, shunt system, or one of its parts. Alternatively, the shunt or one of its parts, such as a catheter, hydrocephalus valve or implanted throttle, should be removed. Both clearance and explantation require unnecessary surgery, which can become a source of infection. Unnecessary surgeries block treatment opportunities and are costly.

The invention provides a solution to further reduce the risk of occlusion of shunts or hydrocephalic valves, in particular implantable chokes.

This risk reduction is achieved thanks to the features specified in the independent claim of the invention. The dependent claims describe preferred embodiments of the invention.

[A1] The above object is achieved in an adjustable implantable throttle for controlling the flow rate of implantable cerebrospinal fluid drains, the throttle being configured to adjust at least one effective length of the at least one channel.

With the help of the adjustable implantable throttle according to the invention or, in other words, the hydrocephalic valve, a noticeable improvement in the well-being of patients is possible. As a rule, the patient feels more insecure if he subjectively realizes that there is a possible blockage, i.e. blockage, of the shunt or hydrocephalic valve implanted in him, in particular the implanted throttle. Conversely, the patient typically gains confidence in the implantable throttle when he subjectively perceives that the likelihood of throttle blockage is reduced.

Modern solutions are complex because they have a large number of components and a large number of small parts. On the contrary, the throttle according to the present invention proposes to minimize the number of small parts. This also minimizes the number of joints. According to the present invention, a variable implantable throttle is described below.

Since the effective length of at least one channel can be adjusted, the operation becomes clear and confidence in the throttle increases.

Adjusting the effective length provides the advantage of relatively precise control. Its action corresponds to that of a potentiometer, so the advantage of its setting states is provided. Phenomenologically, the possibility of establishing states can be understood as switching between parallel channels.

Each person's ventricular system varies in size when compared to other people. If one patient has a small volume ventricular system, the so-called slit-shaped ventricle, then another patient has a wide ventricular system. Since the implantable throttle of the invention has a wide range of adjustment states, it can be used for a wide range of ventricular system sizes. It can be used in different patient groups because its adjustability allows for variability.

If the effective length of the channel is variable and the condition is true that the cerebrospinal fluid, i.e., cerebrospinal fluid, flows only through the effective length, then the frictional resistance changes in proportion to the increase or decrease in the effective length. Therefore, the outflow rate decreases as the effective length increases and increases as the effective length decreases.

Thus, the invention allows individual adjustment and regulation of outflow depending on the patient.

Indeed, the proposed solution, which specifies the effective length, further improves the safety of the valve against occlusion. Since the length can be adjusted, the cross-section of the channel can remain constant. It has the advantage that it can be made significantly larger than the statistical size, for example the average deposit size. This size selection can prevent deposits from forming or wash away loose deposits. Thus, the proposed solution retains a possible blockage prevention principle: “length before cross-sectional narrowing.”

[A2] In a preferred embodiment, the throttle has at least one inlet and one outlet, wherein said inlet and outlet, or inlet or outlet, respectively have at least one point for attachment of the implantable tubing system. The advantage is provided that the connection point is made in the form of a so-called bushing. The sleeve is a one-piece tube profile containing three segments. The first segment is shaped like a cone or funnel. The second and third segments are cylindrical in shape. The radius of the second segment, the middle part, is smaller than the other two segments, so that the second segment forms a taper along the sleeve. The tube, in particular a medical catheter, can provide the advantage of being connected by a knitted cord, a so-called ligature, in the second segment.

[A3] In a preferred embodiment, the inductor includes a housing in which is located at least one movable part, configured to move from the outside of the housing.

The moving, internal part functions as a switch or as an adjustment unit. In this case, the movement of the element provides a greater advantage corresponding to switching or regulation. The correspondence can be direct or indirect. The advantage is provided that the flow rate can vary while the pressure ratio between the inlet port and the outlet port of the throttle remains constant.

[A4] If the implantable choke is provided with an adjustment disk with at least one hole for adjusting the effective length of the channel, so that it is possible to regulate by making or blocking the connection of the inlet port and the outlet depending on the position of the adjustment disk, then the risk of blockage is further reduced .

The presence of the adjustment disc has the advantage of separating the so-called cerebrospinal fluid space from the so-called adjustment space.

The cerebrospinal fluid space can be understood as the space that unites all the subspaces through which cerebrospinal fluid flows as it passes through the hydrocephalic valve. On the other hand, the control space can be understood as a space including all partial spaces that are part of the kinematic chain for changing the state, in particular, regulating or monitoring the characteristics of the valve.

The blockage usually results from the passage of so-called cerebrospinal fluid through the mechanism or part of shunts, hydrocephalic valves or implantable chokes. Cerebrospinal fluid is a protein. Its adhesive ability is very high. This ability causes an increased likelihood of sticking, accumulation, jamming, i.e. clogging or blocking of the mechanism.

If the hydrocephalic valve according to the invention contains at least one adjustment disc, for example in the form of a perforated disc, it is ensured that the cerebrospinal fluid passes exclusively through it for outflow through the channel. The channel itself is free of mechanical connections, which reduces the likelihood of blockage or obstruction.

The advantage is provided that the implantable throttle can be adjusted by simply turning or twisting the adjustment or perforated disk. Moreover, it is easy to understand. This way the patient has a chance to understand how the throttle works. This understanding allows the patient to recognize the functional reliability of the throttle, so that ultimately confidence in the continued operation of the throttle increases.

The throttle of the invention also increases the possibility of avoiding surgical cleaning or explantation in the event of a blockage. If a blockage is detected in the channel, it is possible to overcome it by adjusting it. For this purpose, the adjustment disc can advantageously be positioned so that it is located behind the blockage, i.e., so that the flow of cerebrospinal fluid into the canal occurs behind said disc. Even in unfavorable situations, the likelihood of creating an outflow of cerebrospinal fluid increases. The risk of blockage, i.e. throttle occlusion, is also further reduced if the patient is away from the hospital or doctor.

[A5] The advantage is provided that the hole in the adjusting disk is located on the radius of the circle of said disk outside the center of said circle. Thus, with a small angular rotation, a noticeable control can be achieved, since the radius of the circle corresponds to the gear ratio.

[A6] Due to the fact that the adjustment disk contains at least one magnet, it is possible to ensure its rotation using a second magnet.

[A7] In a preferred embodiment, at least one spring presses the adjustment disk against the channel. In such a case, the advantage is provided that the adjustable implantable choke is protected from unwanted loosening. If the spring force is high, throttle adjustment is difficult.

[A8] Thus, by virtue of the hole in the adjustment disc forming a connection between at least one space on the first side of the adjustment disc and the channel on the second side of the adjustment disc, a hydraulic bridge is formed. This bridge ensures the flow of cerebrospinal fluid into the passage, in particular into the canal. Since the diameter of the hole is larger than the geometric mean particle size, in particular the diameter of particles in the cerebrospinal fluid, the hole provides the advantage of reducing the risk of blockage. This risk is also minimized because slight twisting of the hole will result in shearing, breaking or chipping of dirty, partially plugged or clogged hole edges. The advantage is provided that the cut or tear can be washed through the opening and passage after the cerebrospinal fluid has flowed out.

[A9] In a preferred embodiment, the wall of the throttle body is elastic. This allows it to be pressed in and used as a switch button or switch.

[A10] Since the adjusting disk is movable against the force of the spring, it can be lifted from the seat.

[A11] In a particularly preferred embodiment, the throttle has at least two states, a pass-through state and a control state. In the pass-through state, the adjustment disk does not touch the channel boundaries. On the other hand, in the adjustment state, the adjustment disc rests against the channel boundaries. The advantage of at least two states is the possibility of dual use. The pass-through condition can be used to clean, flush, or check the throttle valve. The control state can be used to set the required flow resistance. Since the states are independent of each other, increased throttle safety is ensured.

[A12] Due to the fact that in the adjustment state the channel is partially or completely closed, it is possible for the cerebrospinal fluid to flow only in certain places, i.e. in passages, in particular holes or crevices.

[A13] In the preferred embodiment, in the through state, the channel is open along its entire length. The advantage is provided that the channel can be cleaned as a whole, in particular rinsed. In a preferred embodiment, a cleaning or flushing fluid may be introduced for this purpose. Alternatively, pumping can be created by repeated movement of the relief element to use the CSF or flushing fluid as a flushing agent when the channel is open.

[A14] Since the first state, particularly the pass-through state, can be switched to the second state, particularly the control state, by applying pressure to the body, a switching function is provided. The advantage of this result is further enhanced by the fact that the switching function integrates the threshold value and takes advantage of this integration. Since a switch with a threshold function is built into the housing, the proposed throttle provides switching only from pressure at a given level. Advantageously, the threshold value can be provided in accordance with its minimum level according to the standard, which reduces the risk of unwanted throttle switching.

[A15] A particular advantage is the design in which the adjusting disc is raised in such a way that the friction force between the adjusting disc on one side and the housing and channel on the other, preventing rotation, acts only at the center of rotation. This type of design has the advantage that the arms, which are only 0 to 0.5 mm long, 2 mm maximum, resist the rotary movement between the adjustment disc on one side and the housing and channel on the other. Thus, the advantage of this embodiment is that the braking torque due to friction is reduced to a minimum.

[A16] In a preferred embodiment, the adjustment disc is rotatable 360° in two directions. The advantage of this arrangement is that the opening and closing directions can be easily and clearly interpreted. In a preferred embodiment, if the hole of the adjustment disk is directed along the channel, then the adjustment, rotation of the adjustment disk in one direction corresponds to a reduction in the effective length of the channel. On the other hand, turning in the opposite direction corresponds to an increase in effective length. Thus, bidirectional rotation provides the ability to create outflow resistance.

[A17] If the adjustment disc interrupts the connection between the inlet and outlet in at least one position, it ensures that the outflow of cerebrospinal fluid is interrupted. The advantage is provided that the adjustable effective length allows the functionality of the switch to be integrated into the implantable inductor.

[A18] It is advantageous that the sealing surface between the disc and the channel is made of an implantable plastic having a hardness of preferably 50 to 80 Shore.

The hardness of TPE joint materials varies from 50 to 90 Shore units. Some of these materials have the advantage of being approved under the Guide to Hygienic Evaluation of Organic Materials. Approvals are also available, in particular for cold or temperature-controlled drinking water. Because cerebrospinal fluid has properties similar to water, plastics with a hardness of 50 to 80 Shore provide an advantage in regulatory hygienic assessment to ensure patient safety.

[A19] Since the direction of the channel is radial, this allows for easy guidance, i.e., positioning of at least one inlet hole above the channel. The advantage of easy direction is specified in the preferred embodiment. If a rotatable body, in particular a perforated disk, is located opposite the open side of the channel, the hole can be easily, conveniently and accurately guided along the side of the channel. This embodiment is particularly easy to accept by patients due to the advantage of its simplicity. Fabrication of the channel is simple and inexpensive.

[A20] If the cross-sectional area of the canal is 0.02 mm ² to 0.04 mm ² in a radial arrangement and the length is 30 mm to 40 mm, the cross-sectional design of the canal is appropriate for the pressure conditions of a patient with hydrocephalus.

[A21] The duct has a rectangular cross-section and is easy to design and manufacture, making it inexpensive.

Preferred embodiments are illustrated by examples with reference to the drawings, in which:

fig. 1 is a schematic perspective view of a preferred first embodiment;

fig. 2 is a top view of a preferred second embodiment;

fig. 3 is an exterior view of a preferred embodiment;

fig. 4 depicts a preferred embodiment and shows a fluid path;

fig. 5 is a side perspective view of a preferred embodiment of the inventive throttle with a non-pressure-loaded diaphragm cap;

fig. 6 is a side view of the preferred embodiment in two positions of use;

fig. 7 shows a preferred embodiment of the passage in the form of a channel labyrinth;

fig. 8 is a side view of a preferred embodiment;

fig. 9 shows a preferred embodiment with a labyrinth passage, or a labyrinth channel, or a labyrinth;

fig. 10 shows preferred embodiments taking into account different directions of the geometric shape of the channels;

fig. 11 depicts preferred embodiments with respect to various labyrinth designs; And

fig. 12 shows a preferred embodiment for separating the cerebrospinal fluid chamber and the control chamber.

In fig. 1 is a schematic top view of a structure of a hydrocephalic valve 100 according to the invention. In this preferred configuration, hydrocephalic valve 100 includes five assemblies: a body 200, a passage 300 with a passage 404 or internal portion (not shown), an adjustment assembly (not shown), and a spring element (not shown).

In the preferred embodiment shown, the housing 200 is divided into a cover and a base, in the intermediate space of which, in the internal part 201, an internal part (not shown) is located.

The housing cover and the housing base have passages, each of which is provided with an inlet 202 and an outlet 203 for cerebrospinal fluid. Together with the housing interior 201 and channel 404, they provide a fluid supply connection. In one preferred embodiment, this allows cerebrospinal fluid to flow from inlet 202 to outlet 203 through conduit 404 so that it passes through the adjustable throttle (hydrocephalic valve) 100.

In another embodiment, the passage 300, in particular the channel 404, is closed with a perforated disk (not shown) providing the function of an adjustment unit. Its rotation causes the channel 404 to close at end position A, and to open at end positions B, C or D. Since the different end positions provide an effective length 405 of the channel 404, i.e., its adjustable effective length through which cerebrospinal fluid flows, implantable inductor 100 can be described phenomenologically as a linear potentiometer. The potentiometer advantageously operates through a first movement, a rotary movement, allowing (not allowing) rotation of the perforated disk, the rotation being intended to change the position of the inflow channel.

In a preferred embodiment, the channel 404 has a radial shape, in particular in the form of an arc. Its radius, r _Kanal , corresponds to the radius r _Loch of the perforated disk. In other embodiments, the channel 404 may have a U-shaped or V-shaped profile in the cross section of the channel 406.

In fig. 2 generally shows a top cross-sectional view of a preferred embodiment of a hydrocephalus valve 100. Here, the embodiment is shown to have an outline representing the interaction of several components within a housing 200. These components are an inlet 202, an internal portion (not shown), adjustment assembly (not shown) and outlets 203. FIG. 2 shows an example with four outlets 203. The outlets 203 are circumferentially arranged and distributed around a pivot axis 705 in the interior housing portion 201.

Since the outlets 203 are arranged in a circumferential manner, fluid, such as cerebrospinal fluid, is allowed to flow into the various outlets 203 when the inner portion (not shown) together with the adjustment assembly (not shown) causes the outlet 203 to open, i.e. channel 404 as a result of rotary adjustment of the adjustment unit (not shown).

The corresponding lengths L1, L2, L3 and L4 of the outlet holes are different. In fig. 2 shows that the lengths of the outlets may vary in the preferred embodiment. They are different according to the ratio L4>L3>L2>L1.

In other embodiments, it is possible to use other ratios, for example, L4>2*L3>3*L2>4*L1, with L1 > inlet length. It is also possible to apply the ratio of inlet length to outlet length. Since the length of the outlet holes is different, the flow resistance is different.

Since the control unit (not shown) is designed as a rotor with one or more openings, fluid 900 flows through said one or more openings into one or more outlet openings 203. Thus, phenomenologically, the embodiment corresponds to a potentiometer with different control stages, where each control stage corresponds to the outlet 203, or its length L, or flow resistance.

In this embodiment, the adjustment unit (not shown) is made in the form of a symmetrical perforated disk (not shown). The term "perforated disc" includes a variety of disc and disc-shaped sheets or flaps. Preferably, the term "perforated disk" includes symmetrical circular disks or polygonal disks with at least one perforated disk passage, ie, a cutout or hole. According to another understanding, neither the perforated disk nor the passage of the perforated disk need be symmetrical; they can also be asymmetrical. According to this alternative understanding, they have lattice, mesh or gap profiles with increasing or varying cell densities.

In fig. 3 shows a preferred embodiment with a membrane cover. The membrane cover is a relief element 205, which in profile section corresponds to a staircase with multiple steps.

The advantage of embossed membranes is the “click” sound. When the membrane deviates from its rest position, if the deviation exceeds a certain level, it is pierced. If the diaphragm is dented, it no longer protrudes outward, but goes inward. Therefore, the top of the diaphragm is rotated 180°. The kneading occurs quickly, so it produces a sound that can be heard as a “click.”

In fig. 4 shows the proposed throttle 100 in a situation where the housing wall is a distance 212 from the pin 804. The distance is reduced by applying pressure to the relief 205 to allow the brake release to occur. The impact of pressure ensures deformation of the housing cover 204 until it stops against the pin 804 and ensures its direction further against the force of the spring element 800, against the spring 802. The relief element 205 is designed so that it gives a signal upon successful unlocking, i.e., releasing the brake means, by emitting the sound is in the form of a click, since the upper part of the housing is made in the form of a clicking membrane, i.e., a stepped round membrane (not shown). In fig. 4 also shows that fluid (not shown) can flow (arrow) along the throttle 100 in the absence of pressure from the relief element 205 acting on the pin 804. Cerebrospinal fluid (not shown) passes through the hole 721.

In fig. 5 shows a preferred embodiment of the brake means 1000. The brake means 1000 includes brake surfaces 1001 on the rotor 703 and internal brake surfaces 1003 on the internal part 400, a silicone element 1002 and a spring element 800.

In a preferred embodiment, the spring element 800 includes a spring seat 801, a spring 802, preferably a coil spring 803, and a pin 804. The spring seat 801 is rigidly formed in the adjustment assembly 700. Referring to FIG. 5, a spring seat is drilled into the rotor 703. In other embodiments, the spring seat may be milled, pressed, screwed, clamped, or welded.

By means of the spring element 800, the brake means 1000 can be tightened or released.

In a position of use, which may be called a “braking position” or a “rest position,” the hydrocephalic valve 100 is logically protected from opening.

In a preferred embodiment, the adjustable implantable choke 100 incorporates a brake 1000 configured to control the flow rate of the implantable CSF drains. It provides frictional braking or releases movement of the control assembly 700, in particular the rotor 703. In a preferred embodiment, the throttle 100 has at least one inlet and one outlet, each of which is connected through at least one connection point (not shown) The implantable tubing system is connected. The implantable throttle 100 includes a housing, in the interior of which is located at least one movable part, an adjustment assembly 700 configured to be activated from outside the housing, preferably by means of a magnet, such that its movement provides a variable flow rate at a constant pressure ratio between the inlet orifice and the outlet of the throttle 100. Movement of the adjusting assembly 700, in particular the rotor 703, converts rotation through a magnetically predetermined angle into an effective length adjustment (see FIG. 1, reference numeral 405) of at least one channel. Alternatively, the adjustment assembly 700 may be understood as a rotor 703, an adjustment disc, or a perforated disc.

In the throttle according to the invention, for draining cerebrospinal fluid from the ventricular system of patients, translational movement occurs kinematically as a result of releasing the brake means 1000. Since it contains at least one adjustment unit 700, which is configured to move in a first, axial direction, and the axial movement the adjusting unit 700 is braked by the brake means 1000, then when the brake means 1000 is released, the braked adjusting unit 700 is released and a stroke is executed that releases the inlet hole of the channel.

The brake means 1000 is configured to fix the adjustment by frictional connection. A silicone element 1002 is located between the adjustment assembly 700 and the interior 400 to provide a seal. To do this, a coil spring 803 forces the rotor 703 against the base of the housing 205. This force forces the rotor braking surface 1001 against the silicone element 1002 so that it abuts the inner braking surface 1003. The valve is sealed. In another embodiment, instead of the silicone element 1002, it is possible to use a biocompatible plastic or rubber.

In fig. 5, the diaphragm cap is shown in an unloaded state, so that no external force is applied to the pin through the diaphragm cap. Thus, the force of the helical spring 803 ensures free rotation of the rotor 703, i.e., the perforated disk, through kinematics. Cerebrospinal fluid (not shown) passes through opening 721.

In fig. 6 shows the use state of the implantable inductor 100 in two states. In the first state, the rest position, channel 404 is closed. In the second state, the regulation position, channel 404 is open.

When the implantable inductor is at rest, there is a distance 212 between the end of the pin 805 and the relief element 205.

The drawing shows that in the preferred embodiment, the adjustment unit 700 is installed in the symmetrical inner part 400. To achieve this, the adjusting unit 700 is integrally formed into a pin 804, which is located in the hole of the inner part 400.

First, the relief element 205 travels a distance 212 before the indentation force is transferred to the end of the pin 805 under the action of a spring. When the indentation force is applied, the external force becomes stronger than the opposing force of the spring, causing the assembly 700 to lift out of its position and causing the passage 404 to open.

In fig. 7 shows a preferred embodiment of the channel 404 with a U-shaped profile, the trajectory of which describes an arc of approximately 340°. In other embodiments, the total angular length of the arc may be 30°, 45°, 60°, 90°, 120°, 160°, 180°, or 270°. In other embodiments, the total angular length of the arc is greater than 20° and less than 200°, or greater than 30° and less than 180°.

In this embodiment, the length of the open side of the channel 404 is at least a quarter of the length of all other lengths of the closed sides of the channel 404, since three sides of its U-shaped profile have the same side length.

In fig. 7 shows an example of an effective length 405 between the opening 721 and the outlet 203. The effective length 405 may be adjusted to allow movement of the adjustment assembly 700 by magnetic coupling with the at least one magnet 723.

In fig. 8 shows two switching states of the housing cover 204. The housing cover 204 can also be understood as a housing wall. The proposed throttle is distinguished by the fact that an adjustment unit is installed in the housing cover 204 or the housing wall, which can be moved by pressing the relief element 205.

In the first state, in the rest position, the top of the membrane, i.e., the top of the relief element, before indentation and prominence is directed upward, whereas after indentation and prominence it is directed downward. When pressed through, a clicking sound is heard.

In fig. 9 shows the proposed throttle 100 with a preferred embodiment of the passage, in this case this passage or part thereof, in particular the channel 404, is made entirely or in parts in the form of a labyrinth 401, in particular milled from a plate.

In fig. 10 shows another embodiment of various shapes of channels, labyrinths 401.

Below are three preferred embodiments. Each of them has its own designation: “inside-in”, “outside-out” and “inside-out” (not shown). The notation helps the user classify embodiments according to one of their functions. The symbols describe the main function of the valve and contain two words each. The first word indicates the location of the maze input stream 905, the second the location of the maze output stream 906.

For example, in one in-in embodiment, a hydrocephalic valve 100 is described whose primary function is to introduce cerebrospinal fluid 901 into the labyrinth 401 close to the axis and to force the hydraulic bridge 600 toward the center of the hydrocephalic valve, i.e., its axis 705 between the perforated disk and the channel 404, i.e., the labyrinth 401.

The out-out embodiment, on the other hand, describes the proposed throttle 100, which provides off-axis input and output of cerebrospinal fluid 901 from the labyrinth 401.

Another in-out embodiment describes the introduction of cerebrospinal fluid 901 near the axis into the labyrinth 401. Since the turns (not shown) of the labyrinth 401 are directed upward, the cerebrospinal fluid 901 is directed in a spiral of increasing radius. Thus, the end of the descent, i.e. the exit from the maze (not shown), is at the outer edge.

In fig. Figure 11 shows alternative labyrinth designs, i.e. channel directions.

The term "labyrinth" covers a system of channels, paths or trajectories of a fluid. Fluid channels vary in direction.

In fig. 11 shows that the labyrinth is made as a continuous channel, the course of which follows the shape. In a preferred embodiment, the shape is based on a snail shell. Thus, the hydrocephalic valve is distinguished by the fact that the labyrinth 401 along its length follows the profile of the cochlea. The spiral labyrinth forms a channel that is long in relation to the area of its base. The profile of the labyrinth can be varied, so that it can have a U- or V-shaped profile along its entire length. The hydrocephalic valve according to this preferred embodiment can also be segmented, that is, divided into subsections. Here, each segment, each subsection has an alternative form of channel 404 or labyrinth 401.

In a preferred embodiment, the U-shaped profile has dimensions of 0.4 mm in height and 0.4 mm in depth. Advantageously, particles with a maximum diameter of 0.03 mm can pass through the labyrinth.

When fluid enters the valve 100, i.e., the housing 200, it is ensured that it passes through the housing inlet, the sleeve, and finally passes along the surface of the perforated disk 401. When partial volumes of cerebrospinal fluid reach the opening 401, they merge into the labyrinth. Various options for making a passage for the fluid between the conductive channel and the labyrinth are possible.

The proposed hydrocephalic valve described above can be combined with other valves. In this case, the proposed hydrocephalic valve can be located behind or in front of another valve in the flow/drainage direction. In combination with another valve, the closing body of which is spring-loaded and configured to open depending on the pressure of the cerebrospinal fluid, the valve described above can be used to create a switching effect.

Alternatively, a special gravity valve is used in the housing, namely a switchable gravity valve. The gravity valve is designed to be switched off and on. For this purpose, drive/switching means are preferably operatively connected to the shut-off part of the gravity valve.

In an extended embodiment, the hydrocephalic valve can be electrified. For this purpose, at least one drive means is located in the proposed hydrocephalic valve, configured to rotate the rotor. In addition, at least one transmission and reception unit and one sensor are installed. The purpose of the sensor is to register the so-called intracranial pressure in the patient's head in order, if necessary, to ensure that the recorded pressure value is transmitted to an external means using a transmitting and receiving unit. Conversely, the drive means is configured to receive signals from the external means to bring the drive means into an operating state.

The drive means is driven by means of a memory control means in which, for example, a desired time curve of the pressure drop in the cerebrospinal fluid is stored. This curve is compared in the control means using an algorithm with the pressure values of a pressure measuring device not shown. The difference between the two values results in a control pulse being sent to the electric drive.

The adjustable valve combinations described below, when electronically controlled in conjunction with a pressure measuring system not shown, provide the required pressure curve without any additional auxiliary measures. In combination with known hydrocephalic valves, they provide operation at least approximately with the required pressure curve on a purely mechanical basis.

In an embodiment, magnets are provided in the rotor for regulation. In addition, magnets are also used in so-called adjustment tools, so that the implanted valve can be adjusted manually by turning said adjustment tools. Instead of an adjusting device, it is also possible to use a stepper motor with position memory.

In fig. 12 shows the separation of the cerebrospinal fluid space and the control space. Leakage flows 903 are kept to a minimum.

LIST OF REFERENCE SYMBOLS

100 hydrocephalic valve, adjustable implantable throttle;

200 body;

201 internal body parts;

202 inlet;

203 outlet;

204 housing cover, housing wall;

205 relief element;

212 distance;

300 pass;

400 internal part;

401 labyrinth;

404 channel;

405 effective length;

406 channel cross section;

600 hydraulic bridge;

700 adjustment unit;

703 rotor;

705 rotary axis;

721 holes;

723 magnet;

800 spring element;

801 spring socket;

802 spring;

803 coil spring;

804 pin;

805 pin end;

900 fluid;

901 cerebrospinal fluid;

903 leakage flow;

905 labyrinth opening flow;

906 output flow of the labyrinth;

1000 braking agent;

1001 braking surfaces;

1002 silicone element;

1003 internal braking surface.

Claims (21)

1. An adjustable implantable throttle (100) for controlling the flow rate in the implantable cerebrospinal fluid drains, wherein at least one effective length (405) of the at least one channel (404) is adjustable, wherein the effective length is a length according to through which the cerebrospinal fluid actually flows, characterized in that the throttle (100) has at least two states, passing and adjusting, and in the passing state the adjusting disk does not contact the boundaries of the channel, and in the adjusting state the adjusting disk rests against the boundaries of the channel. 2. The adjustable implantable throttle according to claim 1, characterized in that it comprises at least one inlet (202) and one outlet (203), said inlet (202) and outlet (203), or an inlet (202) or outlet (203), respectively, have at least one point for attaching the implantable tubing system. 3. The adjustable implantable throttle according to claim 2, characterized in that it contains a housing (200) in which at least one movable part is located, wherein said movable part is movable outside the housing (200), so that its movement is ensured by variable flow rate at constant pressure ratios between the inlet (202) and outlet (203) of the throttle (100). 4. The adjustable implantable choke according to claim 2, characterized in that to regulate the effective length (405) of the channel (404) there is an adjustment disk with at least one hole (721), so that it is possible to adjust by making or blocking the inlet connection (202) and outlet (203) depending on the position of the adjustment disk. 5. An adjustable implantable throttle according to claim 4, characterized in that said hole (721) in the adjustment disk is located on the radius of the circle of the adjustment disk outside the center of said circle. 6. An adjustable implantable throttle according to claim 4 or 5, characterized in that the adjustment disk contains at least one magnet (723). 7. Adjustable implantable throttle according to one of paragraphs. 4-6, characterized in that it contains at least one spring (802), with the help of which the adjusting disk is pressed against the channel (404). 8. Adjustable implantable throttle according to one of paragraphs. 4-7, characterized in that said hole (721) in the adjustment disk forms a connection defining at least one space on the first side of the adjustment disk with a channel (404) on the second side of the adjustment disk. 9. Adjustable implantable throttle according to one of paragraphs. 4-8, characterized in that the wall of the housing (204) of the throttle (100) is made elastic. 10. Adjustable implantable throttle according to one of paragraphs. 4-9, characterized in that the adjusting disk is designed to move against the spring force. 11. Adjustable implantable throttle according to one of paragraphs. 4-10, characterized in that in the control state the channel (404) is partially or completely closed. 12. Adjustable implantable throttle according to claim 11, characterized in that in the through state the channel (404) is open along its entire length. 13. Adjustable implantable throttle according to one of paragraphs. 3-12, characterized in that it is configured to switch a first state, in particular a flow state, to a second state, in particular a control state, by applying pressure to the housing (200). 14. Adjustable implantable throttle according to one of paragraphs. 4-10, characterized in that when lifting the adjusting disk, the frictional forces between the adjusting disk on one side and the housing (200) and channel (404) on the other side, preventing rotation, act only in the center of rotation and thus counteract the rotational movement between the adjusting disc on one side and housing and channel (404) on the other side with a lever arm of only 0 to 0.5 mm, maximum 2 mm, ensuring that the braking torque due to friction is reduced to a minimum. 15. Adjustable implantable throttle according to one of paragraphs. 4-10 or 14, characterized in that the adjustment disk is rotatable 360° in two directions. 16. Adjustable implantable throttle according to one of paragraphs. 4-10 or 14-15, characterized in that the adjustment disk is configured to interrupt the connection of the inlet hole (202) and the outlet hole (203) in at least one position. 17. Adjustable implantable throttle according to one of paragraphs. 4-10 or 14-16, characterized in that the sealing surface between the adjusting disk and the channel (404) is made of implantable plastic. 18. The adjustable implantable throttle according to claim 17, characterized in that the implantable plastic from which the sealing surface is made has a hardness of 50 to 80 Shore units. 19. Adjustable implantable throttle according to one of the previous paragraphs, characterized in that the direction of the channel runs radially, in particular the channel (404) runs radially. 20. Adjustable implantable throttle according to one of the previous paragraphs, characterized in that the cross-section of the channel (406) has an area of 0.02 to 0.04 mm ² with a radial arrangement and a length of 30 to 40 mm. 21. Adjustable implantable throttle according to one of the previous paragraphs, characterized in that the cross-section of the channel (406) is rectangular.