Flow reducer

The application relates to a hydrocephalus valve for draining CSF from the ventricle systems of patients. The valve has a housing with a housing interior and at least one first passage for admission and/or discharge. The valve has at least one body provided in the housing interior. The body is designed to move in at least one direction. At least one adjusting unit is provided. The application aims to improve tried-and-tested existing valves. To achieve this, the adjusting unit is designed to adjust at least one drainage rate in the passage, and to allow the drainage rate to be adjusted between 1 ml per hour and 1000 ml per hour at a pressure at the hydrocephalus valve of 20 cm water column, in order to slow or accelerate, by means of this adjustment, a change in pressure in the ventricle system that results from the drainage.

TECHNICAL FIELD

The invention relates to a hydrocephalus valve for draining fluid from ventricular systems of patients, which valve has at least one casing with casing interior, at least one first passage for admission and/or discharging, with at least one body which is arranged in the casing interior, wherein the body is designed to be movable at least in one direction and which valve has at least one adjusting unit.

BACKGROUND

Hydrocephalus patients have the following medical problem:

The brain is surrounded, in the cranium, by cerebrospinal fluid (CSF). CSF is constantly produced and resorbed in equal quantities. In the case of disease of the hydrocephalus, also referred to as water on the brain, this equilibrium is disrupted. Since the cranium constitutes a closed vessel, an enlargement occurs if more CSF is produced than is resorbed. Owing to the enlargement, in infants, the cranial sutures cannot fuse, and in adults, the cranial internal pressure increases. Adult hydrocephalus and pediatric hydrocephalus therefore exist.

Hydrocephalus can be distinguished in terms of its forms into hydrocephalus internus, hydrocephalus externus, hydrocephalus internus et externus, normal pressure hydrocephalus and hydrocephalus e vacuo.

The treatment of hydrocephalus was originally performed by simply draining the CSF. This was done simply by way of a hose connection between the cranium and a large venous blood vessel or by way of a corresponding connection of the cranium via a hose to the abdominal cavity. It was however soon identified that the pressure in the cranium must have a particular physiological value if other complications are not to arise.

Modern hydrocephalus therapies utilize an implantable drainage facility, an artificial connection between the cerebral ventricles in the head and a drainage compartment, nowadays normally the abdominal cavity, in order to set a particular physiological value.

Various drainage facilities are known with which the pressure in the cranium of a patient can be treated. The drainage facilities are intended to open at a particular critical pressure and allow the drainage of fluid—also referred to as cerebrospinal fluid—such that the generation of an overpressure in the cranium is prevented. These drainage facilities for protecting against an overpressure of cerebrospinal fluid (CSF) are commonly referred to as so-called shunts or drains.

The core of the implantable drainage facility is an implantable valve by way of which the drainage facility is controlled. Said valve is referred to as hydrocephalus valve. Hydrocephalus valves are generally implanted closely under the skin. Such drainage facilities are generally implanted under the skin in the region of the head.

One possible definition of the expression “shunt” is given by Miethke: any artificial hydraulic connection between a first body part which contains cerebrospinal fluid and a second body part which can receive same, see The Cerebrospinal Fluid Shunts, pages 130/131 (source 1). On the topic of hydrocephalus, further sources are the book Normal Pressure Hydrocephalus, Fritsch et al., 2014 (source 2), and the standards EN ISO 7197 (source 3) and EN ISO 1463 (source 5).

All sources contain, inter alia, technical expressions and definitions relating to the topic hydrocephalus. They also contain known operating principles and the grouping thereof.

Miethke proposes, in source 1, a twofold grouping, in this regard see table 1. In a first sub-grouping, the differentiates valves, in accordance with their operating principles, into differential pressure valves and hydrostatic valves. In a second sub-grouping, the differentiates valves, in accordance with clinical functions, into fixed, that is to say non-adjustable, and adjustable valve types.

The valves of the group of the hydrostatic valve principle are, according to Miethke, referred to as valves or valve components, the design objective of which is based on preventing excessive drainage (source 1, page 67). The objective of the valves of this group is in this case to compensate a force of a hydrostatic pressure that acts in the direction of a valve opening (so-called counterbalance).

Valves with a hydrostatic operating principle can be differentiated into three valve types. These are referred to as anti-siphon, flow-controlled and gravitation-controlled devices. Common to all three valve types is a differential pressure. This is calculated from the difference between the pressure downstream of the valve minus the pressure upstream of the valve (Δp=pdownstream of the valve−pupstream of the valve). The pressure difference that permits a volume flow through the valve is defined as opening pressure of the valve.

Anti-siphon devices adapt their opening pressure to the magnitude of a suction force acting in the valve. Gravitation-controlled devices adapt the opening pressure to their inclination in the Earth's gravitational field. By contrast, flow-controlled devices adapt the volume flow passing through them to the pressure difference.

Similar terms for volume-flow-adapting valves in the prior art are flow-rate-dependent, flow-regulating or flow-reducing valves or devices. Here, the term flow is generally to be considered equivalent to the term volume flow, volume per unit of time.

Any hydrocephalus valve is characterized by a characteristic curve. Dr. med. Alfred Aschoff describes characteristic curves in In-Vitro-Testung von Hydrozephalus Ventilen [In vitro testing of hydrocephalus valves], 1994, page 32 (source 7). He discusses these therein because shunt valves are flow controllers with unidirectional direction preference. According to Aschoff, said shunt valves are distinguished by the fact that they are characterized firstly by a unidirectional action, secondly by an opening and closing characteristic, and thirdly by a specific pressure-flow characteristic curve. The pressure-flow characteristic curve is normally non-linear. The profile thereof is, according to Aschoff, dependent on the hydrocephalus valve itself, such that a hydrocephalus valve can be described only by specifying the complete characteristic curve.

Non-adjustable hydrocephalus valves are characterized by one valve characteristic curve, whereas adjustable hydrocephalus valves are characterized by multiple valve characteristic curves.

In the case of non-adjustable hydrocephalus valves, it is evident that valves of the group of the hydrostatic valve principle exhibit a particular volume flow, a throughflow, in a manner dependent on the fluid pressure. If an associated volume flow for every fluid pressure is plotted on a graph, this yields a valve characteristic curve.

In the case of adjustable hydrocephalus valves, every adjustment configures the valve. Every configuration yields a different valve characteristic curve. Certain relevant hydrocephalus valves are described below.

U.S. Pat. No. 8,870,809 B2 (Christoph Miethke GmbH & Co KG) relates to an implantable hydrocephalus system for the treatment of hydrocephalus patients with medications. The document presents an implantable hydrocephalus system with which it is also possible for medications to be administered into the patient. For this purpose, the medications must be introduced into a hollow space, a cavity of the hydrocephalus system, such that they can be transferred hydraulically from there through a ventricular catheter into the cerebral ventricle. According to the teaching, for this purpose, a system is necessary that, in one state, receives medicinal fluids and, in another state, transfers these in the direction of the cerebral ventricle. The system thus necessitates a valve and therefore comprises a valve arrangement with a valve flap in a casing with an inlet and an outlet. The valve arrangement in the valve opens or closes the inlet of the hydrocephalus system in a manner dependent on the medicinal fluid pressure in the cavity.

The teaching of DE 38 35 788 A1 concerns, as per EP 1 523 635 B1 paragraph [0003] (Aesculap AG), a fast-switching ball valve. In one state, medicinal fluid is received, and in another state, said medicinal fluid is released in the direction of the brain. In the closed state of the valve, the ball is pressed against the passage opening. To open up the passage opening, the actuating mechanism pushes the ball laterally away from the passage opening. For this purpose, an actuating element of the actuating mechanism exerts a lateral pushing action on the ball, which thereupon moves away from the passage opening or the valve seat of the passage opening. As an actuating mechanism for displacing the ball, use is made here of a pulse-driven electromagnet, which, after an actuation, is pulled back into the initial position again by a spring force.

EP 1 523 635 B1 (Aesculap AG) offers a solution for providing a valve that permits actuating travels in the millimeter range. In principle, the proposal combines a main body with a passage opening and two elements in wire form, in particular SMA (shape memory alloy) wires. These reciprocally shorten in a manner dependent on a temperature change. In a particularly advantageous embodiment, the result is a valve with a binary opening characteristic. Phenomenologically, a function of a switch results from a position manipulation of a body upstream of a passage opening.

U.S. Pat. No. 4,676,772 (Cordis Cooperation) disclosed, as early as 1985, a system for pressure control of cerebrospinal fluid. Said system comprises an implantable pressure relief valve for fluids, which pressure relief valve has a casing and an adjusting unit in order to adjust the opening pressure of the pressure relief valve. Here, in a manner dependent on a pressure prevailing at the pressure relief valve, a membrane is deflected such that a passage between a sealing ring embedded in the membrane and a ball is opened. The ball is, for this purpose, mounted in a pot, into the lateral surface of which a thread is cut. By way of the thread, the pot can be screwed into or out of a cover, such that a pressure between the ball and the sealing ring is adjustable. The position of the pot, that is to say the number of screwed-in thread turns in the pressure relief valve, can be depicted via a magnetic bridge on a display device.

In summary, the teaching of U.S. Pat. No. 4,676,772 concerns a setting of a valve opening pressure, but disadvantageously not the setting of a defined volume flow. Furthermore, the described technology has the disadvantage that a setting of a valve opening pressure by virtue of a pot being screwed in can lead to a plastic deformation of the membrane. This arises if, as a result of the pot being screwed in too far, the membrane is subjected, via the ball, to a force which exceeds the elasticity limit of the membrane. A precise setting of a valve opening pressure necessitates a precise positioning of the pot in the cover. The pot is rotated in the cover via a magnetic bridge, which corresponds to a hand movement of a user. The user however is not provided with any feedback regarding the friction or the relative position between pot and cover. Thus, because the pot in the cover is turned too far or not far enough by the user, said pot is not positioned precisely, such that the valve opening pressure cannot be precisely set.

The so-called Orbis Sigma valve was proposed by Sainte-Rose, Hooven and Hirsch in: A new approach in the treatment of hydrocephalus, Neurosrg, 1987, 66(2), 213-26. The Orbis Sigma valve comprises a sapphire membrane with a bore, and a pin which extends through said bore. Here, the pin has, in its cross section, an undercut in the direction of its end facing toward the membrane. The membrane is mounted along its circumference in a casing in a flow channel. The pin is mounted at its end averted from the membrane in the same casing and the same flow channel. If a differential pressure prevails across the membrane, said membrane deflects by bulging with the pressure gradient. The degree of bulging and the form of the undercut in the pin thus then define a passage. The size of said passage varies with the profile of the undercut. Thus, the Orbis Sigma valve adjusts the size of a passage continuously along a differential pressure prevailing across a membrane in interaction with a profile of an undercut.

The disadvantage of the Orbis Sigma valve is the dependency thereof on the differential pressure. Furthermore, the profile of the undercut cannot be assumed to be constant for all patients. It must rather be adapted to the respective severity of the hydrocephalus of a patient.

EP 0873761 B1 (DePuy) describes a device for limiting a liquid flow. The device exhibits the principle of a so-called SiphonGuard®. Said document disclosed, in 1998, a technology for limiting a flow of a fluid from a first region of a patient to a second region. For this purpose, the device comprises an inlet, for admitting the fluid from a first region, and an outlet, for conducting the fluid into a second region. Furthermore, the device comprises a primary flow path and a secondary flow path, which both fluidically communicate with the inlet and the outlet. A detector in the device can detect the flow rate, the volume flow of the fluid, such that, in a manner dependent on the magnitude thereof, a decision can be taken as regards whether said fluid is conducted along the primary or the secondary flow path. Here, the detector makes the decision by comparing a present flow rate with a threshold value. The detector conducts the fluid from the inlet to the outlet along the primary flow path if the fluid flow rate is lower than a predefined threshold value. Conversely, the detector conducts the fluid from the inlet to the outlet along the secondary flow path if the flow rate is higher than a predefined threshold value. Here, the detector is made up of four components, a ball seat, a ball, a leaf spring and a spiral spring. The leaf spring presses the ball out of the ball seat, whereas the spiral spring presses the ball into the ball seat. The difference between the two spring strengths thus defines the threshold value of the detector.

The device for limiting a fluid flow thus adjusts its flow resistance digitally between two states, high flow resistance and low flow resistance. It thus has the disadvantage of subjecting the magnitude of a flow resistance to adjustability between two states, without keeping the magnitude of a volume flow constant. Both the size of the passage of the primary flow path and the size of the passage of the secondary flow are predefined at the factory by the design of the device.

US 2014/0276348A1 (DePuy-Synthes Products, Inc.) from the year 2013 discloses an overvoltage protection unit which is based on the principle of the so-called “SiphonGuard®”. Said overvoltage protection unit comprises a casing with an inlet and an outlet and with a first flow path within the casing. The first flow path connects the inlet to the outlet. Additionally, the casing comprises a second flow path, which likewise connects the inlet and the outlet. Both flow paths have a respective flow resistance. The flow resistance of the second flow path is relatively greater than the flow resistance of the first flow path. Within the first flow path, there is provided a valve with a valve seat and a first valve ball and a second valve ball. The first valve ball is positioned so as to be movable between a closure position, in which the first valve ball is in contact with the valve seat, and an opening position, in which the first valve ball is spaced apart from the valve seat. Here, the first valve ball is arranged between a second valve ball and the valve seat, and the second valve ball is arranged so as to be movable between a closure position and an opening position.

The valve opening pressure, the weight force of both balls in relation to the contact area of the first ball in the valve seat, is advantageously adapted by way of the position of both balls in the Earth's gravitational field. The greater the angle between a vertical and the vertical axis of the valve, the lower the weight force of both balls is in relation to the contact area of the first ball in the valve seat. Thus, the valve opening pressure decreases as the patient with the valve moves from a vertical position into a horizontal position.

The association of the valve opening pressure exclusively with the valve orientation in the Earth's gravitational field is disadvantageous.

Also, the overvoltage protection unit has a disadvantage: the flow resistance of the second flow path is predefined at the factory by the construction thereof. The parameters of the flow resistance, such as for example the number of thread turns and the thread pitch thereof, cannot be adjusted after implantation.

EP 13310192 also discloses a flow-controlled device (Codman). This apparatus, referred to in the publication document itself as anti siphon shunt, discloses, in accordance with the differentiation according to Miethke, a self-adjusting flow-controlled valve, but not an adjustable valve. The anti siphon shunt for regulating a volume flow in a patient comprises a casing, which defines a fluid chamber, and an inlet opening and an outlet opening. The inlet opening serves for a passage of a fluid into the fluid chamber, and the outlet opening serves for the release of said fluid. Additionally, the anti siphon shunt comprises a valve mechanism for regulating the fluid flow through the fluid chamber on the basis of the pressure gradient prevailing across said fluid chamber. For this purpose, the valve mechanism has, in the fluid chamber, a barrier which exhibits an opening through which fluid can pass. Furthermore, the anti siphon shunt comprises a pressure sensor for detecting the external pressure surrounding the fluid chamber, and a preloading element, for example a spring. The latter is operatively connected to the pressure sensor and serves for imparting a first force against a first surface of a ball. As a result, the ball is pressed against the opening, such that a passage of the fluid through the barrier and consequently through the fluid chamber is prevented. A compensating force acts on a second surface of the ball in a direction opposite to the first force. Both the first and the second surface are in this case of approximately equal size.

The ball is intended to close the opening in the barrier by way of a ball until an opening pressure is attained which exceeds the ratio of the difference between the first force minus the compensating force.

In a further embodiment, the document discloses a second technical facility for displacing one end of the preloading element, the spring, such that the preload force thereof changes. For this purpose, the document proposes connecting the peritoneal cavity to the fluid chamber by way of a first channel. The latter may for example be a hose. The proposal furthermore includes a reference chamber, which is likewise connected to the peritoneal cavity via a second channel. The fluid chamber and reference chamber are connected to one another via a membrane, and the membrane is connected to one end of the preloading element, the spring. By way of this connection, the preload of the preloading element is changed as soon as the membrane deflects. Here, the deflection follows the pressure difference between peritoneal cavity and reference chamber. The anti siphon shunt therefore automatically adjusts its opening pressure by way of an adaptation of a stiffness of a preloading element.

Said document however does not disclose any way of adjusting a passage, for example a gap between a barrier and a ball.

The following features of flow-reducing valves for the treatment of hydrocephalus are therefore known from the prior art:A.) a casing having an inlet and an outlet, thatB.) comprises at least one flow path which runs through the casing,C.) wherein the casing has a barrier and a body that can open and close the barrier.

The prior art therefore has the common disadvantage of disregarding the ventricle sizes and the state thereof. As a result, the prior art disregards the significance of a discharged drainage volume of fluid in different patients. In physiology, the so-called compliance describes the distensibility of body structure. In the field of hydrocephalus, this corresponds to the compliance of the ventricles. Since the ventricles naturally differ both in terms of their geometry and in terms of their state in a manner dependent on the patient, the compliance thereof does also. The compliance of the ventricles is proportional to their change in volume, and inversely proportional to their change in pressure. If the compliance is patient-dependent, then the pressure response in the case of an equal discharged drainage volume varies in a manner dependent on said compliance.

US 2014 0336 560 (Hakim Carlos) discloses a programmable shunt with a magnetic rotor. The rotor is connected to a cam disk. A tongue of a bending element lies on the cam disk, such that a travel of the tongue along the cam track follows a rotation/pivoting of the rotor. Because the cam track has a gradient, the tongue is raised or lowered owing to the rotation/pivoting. Because the respective height of the tongue preloads a lever that pushes a ball into its seat, a change in the preload results in an adjustment of the valve.

U.S. Pat. No. 5,167,615 has been taken as the closest prior art. Said document discloses a physiological shunt system for controlling a fluid flow from one human body part to another.

For this purpose, said shunt system comprises a casing which has two inlet channels. A closing unit, that is to say a valve, is arranged in each inlet channel.

The first closing unit is a valve plug, and the second closing unit is a flap. The plug opens the inlet channel in the presence of a particular inlet pressure. The flap permits flexible adjustment of a gap, in a manner dependent on the size of which a fluid volume can be flowed through by said gap. Because the inlet pressure is co-determined by the form of the plug, said inlet pressure is not adjustable during use, that is to say after implantation. If the gap is adjusted during use, this determines the inlet pressure of the valve.

For this purpose, the flap is mounted rotatably upstream of an open inlet channel end. Because the flap is rotationally mounted in floating fashion at its first end, its position in relation to the open inlet channel end is described by an angle between the flap and the open inlet end. If the magnitude of the angle is zero, the the inlet channel end is closed. The greater the magnitude of the angle, the further open the inlet channel end is. Because a closing and opening result from a rotation of the flap, said flap is connected by way of a member to a rotary disk, such that the rotation thereof results in an opening and closing. The connection of the member to a rotary disk is implemented by way of a bolt. The latter is inserted at its first and into the member and runs with its second end in a slot. The movement of said bolt in the slot restricts a second end of the flap, the end facing toward the inlet channel end, to one movement path. Because the rotary disk is magnetized, it can be rotated by way of a separate magnet.

By contrast to the rotational mounting of the flap, the valve plug is mounted unidirectionally in a seat. The position of said valve plug, either opened or closed, is co-determined by a pressure in the inlet channel. Said valve plug opens above a particular pressure, the valve plug opening pressure. The closing unit consequently allows a flow to pass through it. The opening pressure is also co-determined by the installation of said valve plug in the casing, because this can no longer be changed during the use of the valve, that is to say after implantation, the first valve unit is not adjustable.

A closing unit is also provided in the outlet channel of the valve. Said closing unit corresponds in terms of construction and function to the first closing unit, that is to say is also no longer adjustable during use.

Flap and valve plug, both closing units, are connected to the outlet channel of the valve.

A first disadvantage of the closest prior art is that the disclosure thereof prevents an exact setting of a drainage rate. The disclosure necessitates second closing units, two differential pressure closing units, and, arranged between these, a first, rotational closing unit with a flap. An opening and closing of the flap duly varies a volume flow through the closing unit, and thus duly influences the opening pressure, situated downstream thereof in the flow path, of the second closing unit, but does not imperatively open the latter. The setting of an intended drainage rate is therefore inexact.

This inexactness is yet further increased by a mechanism proposed by the disclosure. The mechanism comprises the rotary disk with guide slot, a bolt (cam rider) running therein, a coupling member, and a closure element (plug) which couples said coupling member. In each case two of the five members have tolerances with respect to one another, giving rise to a cumulative overall tolerance for the mechanism. Because the disclosure proposes a rotary closure as mechanism, said overall tolerance is yet further increased. Reliable running of a bolt in a slot necessitates that the slot provides, with regard to its tolerance, a compromise between running freedom and running guidance. The compromise in terms of running freedom increases the tolerance.

According to the disclosure of the closest prior art, plastic must be used for the manufacturing process. Plastic is an elastic material, owing to which it can scarcely be a basis for highly precise parts of valves. The elasticity of plastic contributes to the inexactness of the adjustment of the prior art.

A second disadvantage of the prior art lies in the risk of its disclosure. This results from possible contact of the closure member (plug) against the open end of the inlet channel. If the closure member makes contact, the inlet channel is closed. Because it is closable, a switching function is realized. Imprudent, incorrect or mistaken adjustment of the valve leads to a shutting-off of the throughflow, with the resulting consequences for patients. This risk can be visualized by considering the adjustment dimensions of the disclosure. A precise adjustment requires positioning of the flap in front of the inlet channel in the metric minimal range. Conversely, the risk results to open up the inlet channel by way of a minimal change in setting, resulting in an undesired drainage rate.

A third disadvantage of the disclosure follows from a combination of three closing units; it makes the disclosure unduly complex. All three closing units have in common the ability to serve as a switching function. The disclosure thus has triplex redundancy with regard to shutting-off. Triplex redundancy is complex, it prevents ease of understanding by a user, and thus opposes safe use.

SUMMARY

The invention is based on the problem of improving the valves. Here, the invention is based on the realization that patients react with different sensitivity to a drainage of CSF. Well-being is in some cases greatly impaired. This realization as a starting point gives rise to the demand to overcome the abovementioned disadvantages in order to further improve the control of fluid flows from one human body part to another.

The improvement is achieved by way of the features of the main claim. The subclaims describe preferred exemplary embodiments.

One advantageous embodiment of a hydrocephalus valve for draining CSF from ventricular systems of patients provides at least one casing with casing interior, which casing comprises at least one first passage for admission and/or discharging, wherein at least one body arranged in the casing interior is designed to be movable at least in one direction, and wherein at least one adjusting unit is provided. With the adjusting unit, the drainage rate in the passage can be adjusted, such that a fluid positive pressure prevailing in the ventricle in relation to a fluid pressure that is advantageous for the respective hydrocephalus patient is slowly dissipated without significantly disrupting the condition of the patient. For example, the desired fluid pressure in the ventricle may be 20 mm WC (water column) and the positive pressure may also be 20 mm WC. Limited drainage of the excess fluid then occurs.

Drainage is performed with a level of drainage performance (fluid volume per unit time). For this purpose, the drainage performance is limited to at most 1000 ml/h (milliliters per hour). The limitation is dependent on the well-being of the patient. Here, the following upper limits may also arise:900 ml/h800 ml/h700 ml/h600 ml/h500 ml/h400 ml/h300 ml/h200 ml/h100 ml/h

The upper limit preferably amounts to 200 ml/h, even more preferably 100 ml/h and most preferably 50 ml/h.

The lower limit is likewise dependent on well-being. Furthermore, faster drainage may be demanded for medical reasons. For as long as faster drainage is not demanded for medical reasons, the lower limit is 1 ml/h preferably 1 ml/h, even more preferably at least 3 ml/h and most preferably at least 5 ml/h. Lower limits of at least 10 ml/h or 30 ml/h may also be considered. Nevertheless, the following ranges may arise for the drainage performance:

The respective limits of the drainage performance are embodied in the adjusting unit.

The adjusting unit can adjust the opening so finely that the desired drainage performance is attained. The embodiments discussed below illustrate the structural details.

With the hydrocephalus valve, it is surprisingly possible to increase the well-being of patients.

The ventricular system of any person varies in terms of its size in relation to other persons. Whereas a first patient has a ventricular system of small volume, so-called slit ventricles, a second patient has a wide ventricular system.

Owing to this size variance, hydrocephalus therapy of both patients using an identical hydrocephalus valve has different consequences. Drainage of a defined fluid volume, for example of one drop, results in a different change in pressure in the ventricular system of both patients. If drainage, for example of a small fluid volume, is significant for a patient with a small-volume ventricular system—that patient feels discomfort—, the same drainage is insignificant for a patient with a large-volume ventricular system.

In summary, the invention thus permits patient-specific individual adjustment of drainage or of the rate thereof.

Optionally, a drainage facility is equipped exclusively with the above adjustment facility. The drainage performance is then preferably selected such that, by contrast to conventional drainage facilities, constant drainage is performed. At the same time, excessive drainage is however prevented. Droplet drainage is then realized. For this purpose, excessive drainage is however prevented. Droplet drainage is then realized. For this purpose, it is for example possible for the fluid volume accumulating per unit of time to be determined in that the excess fluid is initially extracted to the outside over a relatively long period of time (several days) and can be determined using a measuring vessel.

Subsequently, from the collected fluid quantity, a mean fluid accumulation/drainage quantity per unit of time can be determined. The value may then be adopted in the valve adjustment.

Alternatively, such an adjustment may be performed during the course of approximation tests with measurement of the ventricular pressure. Here, the patient is accompanied with pressure measurements and the adjustments to the valve are varied until a normal pressure has become established in the ventricle.

The valve bodies that are moved for the adjustment of the drainage may be moved both rectilinearly and on a curved path.

A rectilinear movement of the valve body preferably occurs.

In another advantageous exemplary embodiment, at least one hydrocephalus valve is combined after with at least one second valve which is connected downstream or upstream the hydrocephalus valve. Here, one valve may be a conventional valve with an “open” and “closed” function. The first valve then has the task of preventing excessive drainage. The second valve may then concentrate on the limitation of the throughflow.

Here, both valves may be arranged in one casing or may have separate casings.

A valve combination increases the chances of successful treatment because it permits an adaptation of a combination of the valve with the hydrocephalus valve to the respective usage situation. The valve combination thus yields the advantage of being able to react flexibly to the treatment requirements of a patient.

What is preferable for the valves is the principle of a body in an (opening) gap. The principle of the invention fluid can enter the gap in a flow-optimized manner.

The improved fluid guidance also safeguards against deposits.

The hydrocephalus valve may for example be combined with a gravitational valve. The gravitational valve has a closing part, normally a ball, which, in the standing position of the patient, owing to a corresponding arrangement in the patient, closes the drainage line under the weight of the closing part. In the recumbent position of the patient, the valve opens already in the presence of a low fluid pressure, which displaces the closing part into the open position. Such valves open fully or close fully.

Also known are gravitational valves with two balls, one of which is small and the other of which is large. The smaller ball effects the sealing in the valve seat in the closed position. The large ball serves for increasing the weight in the closed position.

The hydrocephalus valve is also combinable with at least one differential pressure valve. In this case, the differential pressure valve may be regarded as a switch. The adjustable differential pressure valves commonly have a spring-loaded closing part, normally a spring-loaded ball. In the event of a particular fluid pressure being exceeded, the closing part opens. The opening increases in size with increasing pressure counter to the resistance of the spring that exerts load on the closing part. In the recumbent position, the fluid pressure is at its greatest; accordingly, the opening and the drainage are at their greatest. In the standing position, the fluid pressure is at its lowest, and accordingly the valve opening is at its smallest. Differential pressure valves have the advantage of a continuously variable adaptation to intermediate pressures in positions between the standing position and the recumbent position. The adjustability of such valves furthermore has the advantage of the adaptation to different drainage requirements. Different drainage requirements in the case of different patients are normal. However, even in the case of an individual person, a change in the setting arises. This is generally the case after implantation until the correct drainage for the clinical picture has been found.

The valve combination may also comprise a multiplicity of valves. In the combination of a gravitational valve with a differential pressure valve, the differential pressure valve performs its function in the recumbent position. In the recumbent position, the gravitational valve is open. In that situation, the differential pressure valve regulates the drainage. The gravitational valve may, in the combination of the two valves, be positioned upstream or downstream of the other valve in a flow direction of the fluid in the casing.

The valve is preferably, after an adjustment, secured in the respective position in order that no inadvertent adjustment can occur. A suitable securing facility is formed by a brake which is released prior to every adjustment and which automatically assumes the braking position/securing position after a change in the setting. This yields the following steps that occur during the adjustment: passing at least one magnet over the hydrocephalus valve; releasing a brake of an adjusting unit of the hydrocephalus valve; rotating the adjusting unit such that the body is arranged in an intended position in the gap in the hydrocephalus valve.

Because the body can be moved into an intended position, the method offers the advantage of adjusting the drainage rate. Through this adjustability, the pressure change in the ventricular system of each patient can be set independently of the condition of the ventricular system. If two patients have different ventricle sizes, it is possible by way of different setting, that is to say positioning, of the body in the passage to set a different drainage rate, such that the pressure responses in the ventricular systems of the patients are equal. Irrespective of the ventricle sizes, the invention thus makes it possible to set one, that is to say the same, pressure response for different patients.

The body is preferably arranged in at least one first passage. Here, different bodies may be used, for example:body with a larger diameter than the passagebody with a smaller diameter than the passagebody with a rounded portion at the end facing toward the passagebody with a conical tip at the end facing toward the passagebody with a wedge-shaped tip at the end facing toward the passageplug-like bodyrod-like body with round and/or polygonal cross sectionsprofile-like body with indentations and/or protuberances in the cross section

Use is preferably made of a body with a conical tip and a smaller diameter than the passage.

The bodies may correspond to different passage openings, for example:at the area of contact with the body, sharp-edged and/or rounded and/or smooth openingsconically widening openingswedge-shaped widening openingsopenings without an area of contact with the bodyopenings with guides for the body

If the body is smaller in terms of its dimensions than the passage, at least one gap is formed between them. This gap formation can also be utilized for the setting according to the invention.

In a further advantageous embodiment, as a body, use is made of at least one guided plug, wedge, cone, profiled bar or a ball.

Different levels of fluid accumulation may optionally result in different geometries on the body and on the associated passage opening. Accordingly, for example, for low levels of fluid accumulation, geometries of the body and passage opening are particularly suitable in the case of which the body movement

If a cylindrical profiled bar is provided as body, that is to say as closing part, and if this issues with a conical tip into a casing bore, this advantageously results in a precisely adjustable closure mechanism. In this case, the conical tip in interaction with the casing bore defines an opening cross section, which is definitive of the drainage flow, of the casing bore.

It is advantageous if the longitudinal axis of the cylindrical profiled bar is aligned with the central axis of the casing bore that forms the inlet or outlet. Inserts for the inlet and/or outlet are optionally provided in the casing. The bores for the inlet and/or outlet are then provided in the insert.

The body preferably has a collar, wherein, between the collar and at least one surface portion of the adjusting unit, there is provided a spring which ensures permanent contact of the body with the surface portion. Adjustability of the invention over time is realized by way of this assurance.

The collar advantageously supports the spring such that the spring force thereof seeks to push the body, for example a needle, out of a bore. Collar and spring thus assist a principle, the aim of which is to keep the invention in an open state at all times. By way of this principle, a risk of undesired closure is avoided. If a valve closes in an undesired manner, no further fluid is drained, and the symptoms of hydrocephalus remain untreated.

It is furthermore advantageous if more than one adjustable body is arranged in the passage, for example one body at the inlet and one body at the outlet. Use may also be made of valve bodies in a so-called parallel configuration. If the two bodies can thus be of small design, even smaller than a single body which imparts an identical action thereto, the structural volume of the valve inlets and outlets can be made smaller, such that the valve structural volume is reduced in size.

It is advantageous if the passage is at least one first valve outlet, which prevents a build-up of fluid within the casing. If the passage is a first valve outlet, that is to say if the body is seated in a valve outlet, and body and valve outlet form a permanent gap, the invention is permanently open at the side of the outlet. Fluid is consequently permanently drained, the build-up of which fluid is prevented.

It is furthermore advantageous if the adjusting unit comprises or is a cam disk. Then, an actuating device, the adjusting unit, is formed, the actuating variable of which is the cam profile. If the cam disk is formed from a durable material such as titanium, the result is a durable actuating device. The durability thereof advantageously satisfies the requirement for one-off implantation. Multiple implantation is, with high probability, avoided.

In a particularly advantageous embodiment, the cam disk is a rotor.

The rotor/cam disk may be of stepped design. Said rotor/cam disk thus has a multiplicity of cam tracks. Each cam track may be used for controlling different valves. A first closing part for closing the valve against the inlet opening or outlet opening may be controlled by way of a first cam track. A second closing part may be controlled by way of a second cam track.

The cam disk, a rotor, advantageously has protuberances and indentations. Opening-up and shutting-off are achieved by way of corresponding protuberances and indentations of the rotor/cam disk. Here, the protuberance pushes a ball out of a seat. The indentation provides the seat for a ball. The function of a switch is thus advantageously achieved.

Stepped switching, that is to say opening-up, is selectively also provided. The switching steps may involve a step opening of the valve. It is thus possible, even in the case of relatively large drainage lines with an inherently relatively large fluid flow, to maintain a relatively small fluid flow.

In the case of a rotor/cam disk being used as an adjusting device for the gravitational valve, it is possible, in the case of a combination with a second valve in the common casing, to realize a combination with a further cam disk or a rotor, if the second valve is also adjustable by way of a rotor/cam disk. It is advantageous for the two rotors/cam disks to then be adjusted jointly. Suitable for the adjustment are inter alia the known magnets in the rotor/cam disk in conjunction with known adjusting devices, which are placed onto the skin of the patient over the casing and which in turn are equipped with magnets, such that, by way of a rotation of the adjusting device, the rotors/cam disks can be pivoted.

It may be advantageous for each of the rotors/cam disks to be produced separately and adapted to the requirements of the patient and subsequently connected to one another in the correct position relative to one another in order for both rotors/cam disks to be adjusted jointly. Here, the region of the indentation in the cam disk/rotor belonging to the gravitational valve determines the activation of the gravitational valve and the drainage of the fluid. The second valve should impart its action within this range. Therefore, the cam disk belonging to the second valve should assume the desired position in relation to the second valve.

A preferred embodiment is characterized in that the cam disk has an axis, wherein the axis is arranged in front of the passage.

As a result of the positioning of the center of rotation of the rotor or of a cam disk in front of the passage, imbalanced running of the rotor is avoided. This is yet further improved if the axis of rotation lies on the axis of symmetry of a passage. Because no imbalance, a spacing between axis of symmetry and axis of rotation, is present, the body is guided in a precise manner, that is to say in parallel, in the passage by way of the cam track of the cam disk or of the rotor.

The adjusting unit preferably comprises at least one rotor. The rotor is be regarded a rotatable/pivotable part of a hydrocephalus valve. The rotors may have different forms: round, or have the form of a disk, of a partial disk, of a screw, of a partial screw or of a thread.

It is furthermore advantageous if the adjusting unit or the rotor comprises at least one magnet. Magnetic forces pass through the skin of patients. It is advantageously then possible for the rotor of the adjusting unit to be rotated or pivoted by way of a tool which likewise has at least one magnet.

It is advantageously also possible in this way for pivot arms, levers, springs and also the body of the adjusting unit to be moved with the rotor. The movement of the adjusting unit preferably comprises a partial rotation and/or one rotation and/or a number of rotations and/or pivoting movements or a sliding movement and/or a stroke movement. The body of the adjusting unit can thus be adjusted in a precise manner. The precision thereof advantageously increases if a partial rotation or rotation of the adjusting unit is converted into a linear movement of the body. By way of this conversion, it is possible for partial rotations or rotations or pivoting movements of the adjusting unit, which are comfortable for a person to perform, to be converted into precise linear movements.

It is furthermore advantageous if the adjusting unit controls the movement of the body along a cam track. Cam-track control arrangements are durable and can be produced precisely and easily.

In a further advantageous embodiment, the cam track is formed by the circumferential surface or the face surface of the adjusting unit or of the rotor. In this way, partial rotations or rotations and pivoting movements of the adjusting unit can be transmitted easily and in uncomplicated fashion to other mechanism members.

The body, that is to say the closing part of the outflow-side valve, preferably bears under spring pressure against the cam track. In this way, an instantaneous adjustment is possible; any change in the cam track results in a change in the position of the body in the gap.

It is furthermore advantageous if the body bears at its first end against the cam track. In this way, play between body and cam track is prevented. Any change in a setting is immediately transferred to the body.

In a further advantageous embodiment, the body bears at its first end with a rounded portion against the cam track. Rounded portions can easily slide along on a cam track, such that the profile of the cam track can advantageously be transferred with little friction to the rounded portion.

It is preferable for a body in the form of a profiled rod to project with a tip into an opening of the outlet, wherein the tip is preferably conical, and even more preferably the outer diameter of the profiled rod is greater than the opening width of the outlet.

It is furthermore advantageous if the outlet has a tubular form with a cylindrical inner shell. This can be manufactured easily and precisely.

In a further advantageous embodiment, the outlet is formed by an insert of the casing, and the guide for the body is formed by the insert of the casing. Inserts can be provided and stocked, and made available during an implantation, for different embodiments of inlets and outlets. In this way, it is possible, as necessary, to decide during the implantation what body and what inlet or outlet dimensions must be used. By way of different inserts in interaction with different inlets or outlets, it is possible for each patient to be treated individually.

The body is preferably supported at its first end in the insert. This provides a holding action for said body.

In a further advantageous embodiment of the combination of the hydrocephalus valve with a further valve, both valves are arranged in one flow path.

Because they are situated in one flow path, a common pressure prevails across them. This has the advantage of easier coordination of the valves. By contrast to the closest prior art, the novel valve is uncomplicated and is easy for users to understand. A flow channel requires merely the manufacture thereof; this reduces outlay and production errors.

Furthermore, numerous flow-calmed zones are avoided. This has the advantage that no deposits can form there. In an advantageous embodiment, the second valve of the valve combination is a differential pressure valve. In this way, the functionality of the valve combination can be limited by a lower or upper threshold value.

In a further advantageous embodiment, the second valve is a spring-loaded closing part, which closes and opens in a manner dependent on the fluid pressure.

In the case of a gravitational valve being used as second valve, this is preferably formed by at least one ball, optionally by two balls. The second valve may also have a rotor/cam disk, which are in direct contact with the ball that forms the closing part or with a ball that forms an additional weight and which push the ball which forms as closing part into the valve seat thereof. In the case of common materials being used for ball, valve seat and rotor/cam disk, significant wear is not to be expected on the ball or on the rotor/cam disk or in the valve seat. If wear nevertheless poses a problem, it is possible for wear-resistant materials such as titanium to be selected for the ball, valve seat and/or rotor/cam disk. Even a small leakage flow between ball and valve seat owing to required play is generally not detrimental. If a small leakage flow nevertheless poses a problem, it is for example possible for the valve seat to be designed to be flexible. In addition to or instead of a flexible valve seat, it is also possible for the sliding surface to be designed to be flexible. Even a small degree of flexibility reduces possible leakage flows. With the flexibility, in the presence of the corresponding pressure of the valve ball in the valve seat, leakage flows can also be prevented.

It is advantageous, if a common casing is provided for both valves, if only said one casing then needs to be inserted during an implantation. This saves outlay. If the casing is of modular construction, it is possible for the casing to be pre-configured, in a manner dependent on the ventricle size of the patient, long before being implanted. For example, by contrast to the prior art, it is possible for individual inserts to be used for individual inlets or outlets and/or bodies, rotors. On-site assembly at remote locations is also made possible, such that different patient groups such as children or elderly persons can be treated using adapted valves.

Particularly advantageous is the combination of multiple valves in one casing, preferably of a gravitational valve with a differential pressure valve or some other valve in a common casing. This facilitates the implantation process. A line piece between the two valves of the earlier proposal is thus omitted. With the combination of both valves in a single casing, the structural outlay is reduced. Furthermore, the casing offers the possibility of expedient configuration of the connection of the two valves. The connection is formed by channels. The channel cross section may be selected to be greater in the valve casing than in the case of a connecting line of the earlier proposal.

Furthermore, the transition from one valve to the connecting channel and from the connecting channel to the other valve (for example from the gravitational valve to the connecting channel and from the connecting channel to the differential pressure valve) can be designed in a more flow-optimized manner. This is manifest in a lower flow resistance than in the case of a connection of the two valves by way of a line for feeding fluid to the common casing and/or for discharging fluid.

It is furthermore advantageous if, in the casing, the hydrocephalus valve is assigned to the inlet and the second valve is assigned to the outlet, or the second valve is assigned to the inlet and the hydrocephalus valve is assigned to the outlet, and that, in the casing, channels are provided from the hydrocephalus valve to the second valve, which channels have a lower flow resistance than a connection of the two valves to a drainage line as are provided for the feed of fluid to the common casing and/or for the drainage of fluid from the common casing.

Preferred embodiments of the invention will be discussed by way of example on the basis of a drawing. Specifically, in the figures of the drawing:

DETAILED DESCRIPTION

FIG.1shows a hydrocephalus valve100in terms of its construction in a schematic view from above. Said figure shows a construction with a casing200, in which an adjusting unit700in the form of a cam disk704, a coupling element400and a body500are mounted. The casing furthermore comprises an inlet202and an outlet203.

The movement of the cam disk704is positively guided in the casing interior201centrally by an axle705, whereas the body500is guided not by way of its drilled-out body axis502but by way of its body lateral surface503.FIG.1shows that the body500is formed as a wedge, such that its body lateral surface503tapers from a first body end504in the direction of a second body end505.FIG.1likewise shows that the shape of the passage300is of wedge-shaped or cup-shaped form in cross section. By virtue of the tapering of the body lateral surface503corresponding to the tapering of the passage, the wedge506is guided in the passage300along its body surface.

The coupling element400is arranged with its first end401on the wedge506and with its second end402against the cam disk704. The coupling element400may expediently be rigid or elastic.FIG.1shows an embodiment with a rigid coupling element400. This may be a pin or a plate. Here, the cross section through the pin may be round, elliptical or polygonal. In the present embodiment, the pin may be a round metal or polygonal metal part composed of titanium. It may however alternatively also be manufactured from high-grade steel, a thermoset or a thermoplastic. By virtue of the coupling element400being connected to the cam disk704and to the wedge506, a movement of the cam disk704guides the movement of the wedge506.

The movement of the wedge506in the passage300results in a gap600between the lateral surface of the wedge506and the passage inner surface304of the passage300. The further the wedge506is moved into the passage300in the passage direction302, the longer the gap600becomes. With increasing gap length602, the gap inner surface thereof increases in size. The gap inner surface is made up of the lateral surface of the wedge506and the passage inner surface304from the start of the gap to the end thereof. The larger the gap inner surface is, and the narrower the gap is, the greater is the friction of a fluid900which is intended to pass through, or which passes through the gap600, with the gap inner surface. The lateral surface of the wedge506thus acts as a flow resistance, that is to say also the wedge506. Because the position of the wedge506is adjustable by way of its movement in the gap600by way of the cam disk704via the coupling element400, the flow resistance is also adjustable. Consequently, the flow resistance of the hydrocephalus valve100is adjustable owing to the adjustability of the gap length.

The throughflow quantity of the fluid per unit of time is adjusted by way of the flow resistance.

A movable arrangement of the body500in the first passage direction302permits different, advantageous variants for producing a gap600. This may mean that an angle exists between a movement direction of the body500and the movement of said body along a positive guide, which is determined for example by a linear bearing405. The angle between the main movement direction of the body and the first passage direction302is, in other exemplary embodiments, less than 80°, preferably less than 50°, in particular less than 20° or even smaller, that is to say amounts to less than 5°. In the exemplary embodiment, the angle is 0 degrees. Thus, the main movement direction of the body500is coaxial with respect to the passage direction302, and a symmetrical gap600is formed as soon as the body500is spaced apart from the passage300. In the exemplary embodiment, those portions of the body500and of the passage300which face toward one another are symmetrical. Alternatively to the gap length602and/or in addition, other geometrical features of a body500can be changed in order to vary a flow resistance through the passage300. In a further embodiment, the roughness of the lateral surface of the wedge506, or the profile thereof, may be varied.

In a preferred embodiment, a spring seat800is formed into an edge of the passage300. Here, the spring seat800may be a pin to which a spring802, for example a spiral spring, can be mounted. The secure seat of a spring802promotes the positioning thereof between an edge of the passage300and the wedge506, such that the spring force of the spring802pushes the wedge506out of the passage300in the direction of the passage end301.

Owing to the rotation or pivoting movement of the cam disk704and the consequential movement of the body500, the spacing702between a center of rotation of the cam disk704and a reference point of the body500varies.

Aside from cam disks704, alternatively other adjusting units may be used which, in terms of their direction701, are also movable in translation.

FIG.1ashows a detail view fromFIG.1, which illustrates two alternatives of a coupling element400.

FIG.1bshows a detail view fromFIG.1, which illustrates an opening state of the hydrocephalus valve100(spring802not illustrated). In the open state, the second body end505coincides with the cross-sectional area303.

FIG.2ashows a detail with a preferred embodiment of a body with a gap. The preferred embodiment is based on the interaction of two components, a passage300and a body500.FIG.2ashows that the passage300is composed of a funnel-shaped inlet region306a hose-like portion307.FIG.2aalso shows that a gap600exists between the two components if the body500has been produced as a wedge506. For this purpose, the wedge506may for example be formed out of a titanium, steel or biocompatible elastomer block. In the preferred embodiment, the wedge506has been milled from a titanium block. It can however alternatively also have been cut out of a biocompatible plastics block. A movement of the wedge506into or out of the funnel-shaped inlet306of the passage300varies the gap length602and thus the flow resistance between wedge506and passage300. In a preferred embodiment, the wedge506seals against the passage300if the encircling edge of the wedge face surface507abuts against the transition edge508between funnel-shaped inlet306and hose-like in the portion307.

FIG.2bshows a detail with an alternative embodiment of a body with a gap. The body500has the form of a rod509. The greater the gap length602and the smaller the gap width, the greater is the flow resistance between rod509and passage300. The pushing-in of a rod509with a great length thus results in an increase in the flow resistance. If the rod509is pushed deep enough into the passage300, this results in an infinitely high flow resistance. In the present embodiment, the length of the rod509, that is to say the maximum level of the flow resistance, has been adapted to the position-dependent weight force of a volume of CSF in the Earth's gravitational field. Alternatively, the body500may be a ball (not illustrated), a cone (not illustrated) or a cylinder (not illustrated).

FIG.3ashows a detail with an alternative embodiment of a body with a gap, in the case of which a gap600can be produced between an outer edge of a spherical body500, such as for example a ball, and a bore. For this purpose, the ball is positioned with a spacing702in front of the bore. The bore acts as a passage300, and the spacing between outer edge and bore edge forms the gap600. In a manner dependent on the spacing702, the passage volume thereof varies.

FIG.3bshows a detail with an alternative embodiment of a body with a gap, wherein a gap600between a rod509and a bore forms the passage300.

FIG.3cshows a detail with an alternative embodiment of a body with a gap600, which is produced between a wedge506and a passage bore300.

FIG.3dshows the exemplary embodiment fromFIG.3cin a closure state. The encircling edge of the wedge face surface507of a wedge506seals against the transition edge508of a passage300between funnel-shaped inlet and hose-like portion.

FIG.4shows an alternative, second embodiment of the invention in a side view. In this, in the casing interior201of a casing200with inlet202and outlet203, a cam disk704and a body500are connected by way of a coupling element400in order to convert a rotation or a partial rotation of the cam disk704into a decrease or increase of the spacing702. This variation corresponds to an adjustment of the gap600and, in association with this, to an adjustment of the passage volume. For this purpose, the cam disk704is mounted on an axle705.

For this purpose, a mechanism member403, for example a mechanism rod, is attached at at least two different ends in each case to the cam disk704and to the body500. In the present embodiment, the mechanism member403is, by way of a journal404at the second end402thereof, connected to the cam disk704in the vicinity of the outer edge thereof. By contrast, the other end, the first end401of the mechanism member403, that has a passage bore, is mounted in a jaw of the body500.

For guidance of the body500, the latter is mounted in a linear bearing405.

By virtue of the fact that an adjusting unit700, in the present embodiment at least one magnet707, is embedded into the cam disk704, it is possible by way of a magnetic coupling between the cam disk704and an adjusting tool (not illustrated) for the cam disk704to be rotated, that is to say adjusted. By way of the conversion of this rotation into a defined spacing702between body500and passage300, the flow resistance, that is to say the size of the gap600or the passage volume thereof, can be adjusted, such that the drainage volume of the hydrocephalus valve100, that is to say the setpoint outflow of a volume of CSF, is made adjustable.

FIG.5shows an alternative, third embodiment of the invention in a side view. In this embodiment, the hydrocephalus valve100comprises a cam disk704with an axle705, a plug406, a linear bearing405, a spring802or some other desired spring element801and a passage300. For this purpose, the spring802or the spring element are mounted in a spring seat800. In terms of principle, in this embodiment, a rotation of the cam disk704is, by way of a contact point703between cam disk704and plug406, transmitted to the latter in the linear movement thereof. The plug406is, during its movement, pressed by the spring against the cam disk. To ensure that the closure end407of the plug406slides reliably into and out of the passage300or the passage end thereof, the plug406may be mounted by way of a linear bearing405. In a preferred embodiment, the plug406is mounted in one of its uniform portions. For this purpose, the plug406is formed from a material block, in particular a titanium block, by turning. Turning simplifies production of the plug406with five main portions, a contact portion408, a neck portion409, a collar portion410, an elongation portion411and a closure portion412. The spring802is mounted in a spring seat800, which is formed as a ring. By way of the movement of the plug406, for example in the form of a needle1152, a gap600or a gap passage1154or a gap-like passage is generated.

FIG.6shows an alternative, fourth embodiment of the invention in a view from above. Here, the illustrated hydrocephalus valve100comprises not only a cam disk704but also a sleeve412and an elongate outlet203in the form of a pipe204. The pipe204may be a small pipe, a hose piece, a hose end, a pipe portion or a flexible or rigid hollow body. In a further embodiment, the sleeve inner diameter413approximately corresponds to the pipe outer diameter205. For a first embodiment, the correspondence means: the sleeve inner diameter413has the same dimension as the outer diameter205plus a required movement clearance for a movement of the closure portion412on the pipe204. In a preferred embodiment, the diameters differ from one another to a greater extent, such that a gap600is formed between the sleeve412and the pipe204. The pipe204runs with a first pipe end415in the sleeve412.FIG.7shows a hydrocephalus valve100with a coupling element400of telescopic design in a side view, which is preferably based on the embodiment inFIG.6. In the further, telescopic embodiment, the sleeve412is likewise formed, specifically milled, from a titanium block, but a central plug416and an edge417have been milled out. In addition to an elongate outlet203in the form of a bushing204, a round outlet bushing308has been formed in the casing200coaxially with respect to the passage203. Alternatively, the outlet bushing308may also, coaxially with respect to the passage203, be adhesively bonded, plugged, screwed, pressed or fused in the casing200, on the casing200or, by way of holding elements, within the passage300. In a further embodiment, the outlet bushing308is manufactured as a single piece from the casing200, a casing cover or a casing pot. The sleeve412is supplementarily guided in a linear bearing405. The tip of a sleeve end makes contact, at a contact point703or in a contact line or over a contact area, with the outer edge of the cam disk705. In this embodiment, a spring802is a compression spring, such that it pushes the sleeve412out of the outlet203, such that a gap600results between the central plug416and the pipe204and between the edge417and the pipe204and between the edge417and the outlet bushing308. The spacing702between the cam disk704and the end of the coupling element describes the adjustability of the gap600, or the gap passage, as a possible adjustment parameter. The adjustability can thus be mathematically described by presenting the relationship between rotation of the cam disk704in its direction of rotation701and the change in the spacing702.

The spring802is mounted in a spring seat800.

FIG.8shows the hydrocephalus valve100illustrated inFIG.7with a rotor706and with a magnetic coupling member711with magnet707, a north pole708and a south pole709. The adjusting unit700comprises multiple parts, including a cam disk704, a rotor706and a pivot arm1050or a rotor706with pivot arm1050or a cam disk704with pivot arm1050. The cam disk704is mounted together with the rotor706on the axle705as one assembly. The rotor706comprises a pivot arm1050or may be formed as a pivot arm1050. Furthermore, the cam disk704and the rotor706are connected to one another. In a preferred embodiment, they are screwed, adhesively bonded or welded together or are formed from one piece. The connection between rotor706and cam disk704results in the common rotation/pivoting movement thereof, such that a rotation of the rotor706or of the pivot arm1050or of an additional pivot arm1050corresponds to a proportional rotation of the rotor704. Here, the proportionality follows the offset of the cam disk704on the rotor706. In a further preferred embodiment, two stops710are formed into the casing200in order to prevent a collision between magnet707or rotor706and spring802or sleeve412. In the preferred embodiment, the size of the gap600between outlet203and sleeve412may be adjusted by virtue of said sleeve being inserted into the passage300or being pushed out of the passage300by way of a rotational/pivoting movement of the rotor706. Here, the sleeve41is pushed out of the passage by way of a spring801,802. The spring is held in its spring seat800. This may be described by way of a parameterization of the spacing702.

In a further embodiment, a brake1000is provided in the hydrocephalus valve100in order to secure a set rotational angle of the rotor706. For this purpose, the brake1000blocks the freedom of rotation of the rotor706or of the pivot arm1050thereof. In a preferred embodiment, the brake1000blocks the rotor706by virtue of frictional engagement being activatable and deactivatable between said brake and a rotor surface. In an alternative embodiment, the brake1000imparts a blocking action by virtue of an electromagnetic force field fixing the rotor706in a desired position.

In an independent variant, a multiplicity of different valves is combined with one another.

FIG.9shows, on the basis of a conventional hydrocephalus valve with spring-loaded ball as closing device and with a conventional drainage line, a record of the fluid pressure versus the time. Here, a pressure curve1103has been obtained. The pressure curve1103shows that a fluid pressure of 40 cm water column has been dissipated within around 10 seconds to a normal level of approximately 20 cm water column. Firstly, with this rate of pressure dissipation, many patients will feel discomfort. Secondly, the pressure curve for different patients with different ventricular system sizes can be obtained only if it can be adjusted by way of structural parameters. If this is the case, it can be set in a patient-specific manner; it can be adjusted to a setpoint profile. Therefore, provision is made for drainage, or the drainage rate thereof, to be made adjustable in order to realize a pressure dissipation which, over a longer time, preferably over at least 20 seconds, even more preferably over at least 30 seconds and most preferably over at least 40 seconds, yields the same effect for the patient irrespective of the patient. The pressure dissipation is preferably distributed over at most 60 seconds, even more preferably over at most 50 seconds.

The pressure curve1103inFIG.9shows a profile of the pressure curve over 50 seconds. The pressure curve1103plotted versus the time (abscissa) in seconds exhibits an inclination relative to the abscissa which is dependent on the scale for the pressure values (ordinate) and to the scale for the seconds (abscissa). The scope of the invention encompasses everything which, in the case of equal scales for pressure values and seconds, has an identical or reduced inclination with respect to the abscissa, assuming the inclination is no lower than in the case of a distribution of the pressure dissipation over 60 seconds, preferably no lower than in the case of a distribution of the pressure dissipation over 50 seconds.

FIG.10shows a preferred embodiment of a variant of the hydrocephalus valve as a valve combination1100.

The adjustable valve combinations discussed below are, in the case of electronic control together with a pressure measurement (not illustrated), capable of implementing a desired pressure curve1103(FIG.9) without further auxiliary measures. They are, in combination, even in combination with conventional hydrocephalus valves, also capable of at least approximately implementing a desired pressure curve1103on a purely mechanical basis. The valve combination is schematically illustrated inFIG.10. According toFIG.10, said valve combination comprises a drainage line1102. A conventional hydrocephalus valve and one of the hydrocephalus valves100discussed below are installed in the drainage line1102.

Alternatively,FIG.10shows the invention as an interconnection of a conventional valve with a valve combination1100, that is to say an extended valve combination.

FIG.11shows a hydrocephalus valve100in a sectional view from above.FIG.11showsFIG.1on a smaller scale. The hydrocephalus valve100includes a liquid-tight casing200, which is equipped with an inlet202and an outlet203. An axle705is arranged in the casing200. A rotor706is seated on the axle. The rotor706forms a cam disk704with a first cam track712. A coupling element, a pin400, slides with its second end402on the first cam track712. The pin400is held, so as to be movable in a radial direction with respect to the axle705, between guides405of the casing200. At the oppositely situated first end401of the pin400, there is provided a body500in the form of a plug. The body500has a conical tip and a collar510. As perFIG.11, the collar510can sealingly close against a sealing surface304of the casing200. This prevents an undesired escape of fluid. Here, the plug is pushed outward in a radial direction by the cam track712. When the rotor706is pivoted counterclockwise inFIG.11, the radius of the cam track712decreases. Here, the pin400remains in contact with the cam track712. This is realized under the pressure of a spiral spring803. The spiral spring803is seated with one end in a recess of the conical tip. The spiral spring803is supported at the other end on a web804of the outlet203. If the pin400is moved in a radial direction into the casing200under the pressure of the spiral spring802, a passage for fluid forms between the plug and the sealing surface on the casing. In the exemplary embodiment inFIG.1, the cam disk706is seated fixedly on the axle, and the axle is connected to an electrical stepper motor (not illustrated). The stepper motor is activated by a storable controller. In the controller, there is stored a profile with respect to time, which is desired inFIG.9, of the pressure drop in the fluid. In the controller, with the aid of an algorithm, said profile is compared with the pressure values of a pressure measuring device (not illustrated). The difference between the two values leads to a control impulse on the electrical stepper motor.

FIG.12illustratesFIG.5on a smaller scale. The exemplary embodiment ofFIG.12differs from the exemplary embodiment ofFIG.11in that the body500is a wedge506, or is a wedge-shaped plug, which projects into a matching outflow. In the exemplary embodiment, this means that the outflow surrounds the wedge-shaped plug with a spacing in all positions. The spacing arises correspondingly to the dimensions of the plug at the face surface and in a manner dependent on the respective position of the wedge-shaped plug. Wedges506have a rectangular cross section with two sides which are inclined relative to one another and two sides which are parallel to one another. The wedge-shaped plug is, like the plug inFIG.11, held by way of a pin which is not illustrated here. Also, in the embodiment inFIG.12, a spiral spring803is provided which ensures permanent contact of the pin with the cam disk. By contrast to the situation inFIG.1, the spiral spring803is seated not on the tip of the plug but on the pin, wherein a collar510is seated on the pin. The spring is situated between the collar and the casing inner wall, wherein the spring surrounds the pin and the plug. The wedge-shaped plug has a different rotational and pivoting drive, specifically a rotor706, than a conventional hydrocephalus valve, together with a conventional arresting facility between two adjusting processes. As discussed above, the rotor is particularly commonly moved by way of magnets, of which one part is installed in the rotor and the other part is arranged in an adjusting device which is placed over the implanted valve onto the skin of the patient and, by pressing, releases the arresting action and, by rotation, pivots the rotor. The valve thus created is, as perFIG.10, combined with a conventional hydrocephalus valve,FIG.10andFIG.12show a drainage line1101(FIG.10) with a hydrocephalus valve100, which is designed for adjusting a drainage rate and which is connected downstream of a conventional hydrocephalus valve in the drainage line1101.

FIG.13illustratesFIG.8on a smaller scale.FIG.13shows a situation in which the casing wall has a spacing to the pivot arm1050. The spacing arises if a pressing action is exerted on the implanted casing from above by way of the adjusting device for adjusting the cam disk. The casing deforms as a result, such that the pivot arm1050, which was previously in frictionally engaging contact with the casing inner wall, is released for adjustment purposes. A successful release is signaled by a clicking sound, because the upper part of the casing is designed as a click membrane, that is to say a stepped round membrane (not illustrated). It is preferable, for this purpose, for a multiplicity of steps to be formed into the round membrane (not illustrated). The body500with collar510is designed as a stepped cover.

FIG.11,FIG.12andFIG.13likewise show a body500which, in all positions, has a spacing to the surrounding inlet or outlet. In the embodiment as perFIG.12andFIG.13, the body is in indirect contact with a cam disk704. By contrast to FIG.11, the contact is made by way of a thickened elongation of the body500. The discussed collar510is illustrated at the transition of the body500to its elongation. The spring denoted by802is arranged between the collar510and the casing inner wall. The spring802surrounds a body500, in this case a plug, and in so doing engages into a centering groove. Furthermore, two described magnets are embedded in cam disk704(FIG.12).

Aside from the above-stated combinations with valves from the figuresFIG.1,FIG.5andFIG.8, further advantageous combinations arise with the embodiments ofFIG.4,FIG.6andFIG.7.

A combination (not illustrated) with the embodiment fromFIG.4results in a body which is in the form of a spherical plug. The diameter of the spherical plug is greater than the opening width of the inlet or outlet, such that the spherical plug can perform both the role of a valve with open-closed function and also an adjustment of the opening width. Here, the spherical plug is held, by way of a rod, displaceably in a guide. Furthermore, the spherical plug is, by way of an articulated rod, held in articulated fashion with a pivotable rotor in the valve casing. In the exemplary embodiment, for the adjustment of the spherical plug, magnets in the rotor and an adjusting device are provided, which adjusting device likewise has magnets and is placed over the implanted valve onto the skin of the patient and is rotated/pivoted by hand. Instead of the adjusting device, use may also be made of a storable stepper motor. With a stepper motor, the spherical plug can be moved into any desired position.

A combination (not illustrated) with the embodiment fromFIG.6makes it possible to form a further valve with a body formed as a pot-like plug, wherein the pot-like plug is seated over an outlet which projects into the valve casing. The pot-like plug is also adjusted by way of a cam disk. Here, the pot-like plug is, like the plug inFIG.6, guided in a manner which is not illustrated in the valve casing and held in contact with the cam disk by way of a spring. Said plug offers the same usage possibilities as the cylindrical plug as perFIG.3b. Whereas it is the case inFIG.3bthat the remaining gap between the cylindrical plug and the surrounding, tubular inlet or outlet form the limit value for the fluid flow, it is the case in the exemplary embodiment that the remaining gap (limit value) between the tubular outlet or inlet and the inner shell of the surrounding pot-shaped plug is definitive. As in the case of the plug as perFIG.3b, opening movements of the plug remain without influence even in the case of the exemplary embodiment if they overshoot the limit value for the opening cross section.

A combination (not illustrated) with the embodiment fromFIG.7shows a valve which also comprises a cylindrical plug. The cylindrical plug includes an adapted tubular outlet. The tubular outlet surrounds the cylindrical plug with a selected spacing. The cylindrical plug has a collar and, in a radial direction with respect to a cam disk, a thickened elongation. The elongation makes contact with the cam disk. At the contact point, the elongation is rounded. The cylindrical plug is, at the elongation, held in a guide of the casing so as to be displaceable in a radial direction. By way of a spiral spring between the collar and the inner wall of the casing, it is ensured that the plug always remains in contact with the cam disk. By pivoting the cam disk, the opening gap between the collar and the outlet is adjusted. In the case of a reduction of the opening gap, the cam disk pushes the collar outward. In the case of an enlargement of the opening gap, the cam disk provides space such that the plug follows the cam track of the cam disk under the pressure of the spiral spring. The pivoting of the cam disk is performed in the exemplary embodiment by way of magnets, wherein the magnets are situated both in the cam disk and in an adjusting device which, for the purposes of adjustment, is placed over the implanted valve onto the skin of the patient and rotated. In the exemplary embodiment, concentrically with respect to the cylindrical plug and the outlet, provision is also made of a ring-shaped web on the collar and a ring-shaped web on the inner wall of the casing. These webs force the fluid to follow a meandering flow profile. The exemplary embodiment differs by a pivot arm on the cam disk. The pivot arm serves for receiving the magnets. Furthermore, different guidance of the plug in the valve casing is provided.

A preferred form of the above-stated body is the form of a needle.FIGS.2a,2b,3aand3bshow different bodies. Aside fromFIG.2b, these are conical plugs for a valve, wherein the plug has a tip which is thicker than the opening of the inlet or outlet for the fluid. The conical plug may also be regarded as a needle. The embodiment as a needle is part of each above-stated embodiment, for example inFIG.11,FIG.12andFIG.14.

Owing to the form of a needle, the body or the plug closes the inlet or outlet when the needle is pushed far enough into the inlet or outlet.FIG.3cshows the open position of the valve, andFIG.3dshows the closed position. The valve belonging to the plug as perFIGS.3cand3dotherwise corresponds to the valve as perFIG.2a.FIG.2bshows an exactly cylindrical plug instead of a conical or wedge-shaped plug. The cylindrical plug includes a matching tubular inlet or outlet on the valve, which surrounds the plug with a spacing. Irrespective of the extent to which the cylindrical plug is moved into the inlet or outlet, the spacing between the plug and the surrounding inlet or outlet remains unchanged. The cylindrical plug is suitable for a valve that otherwise has the features of the valve belonging toFIG.2a. The cylindrical plug is however also suitable for a drainage facility with a single valve in the drainage line and a simultaneous, above-described reduction of the pressure drop. Here, the cylindrical plug and the matching tubular inlet or outlet replace the conventional ball and the conventional valve seat for the ball. Furthermore also provided on the cylindrical plug a collar as perFIG.1. Here, the collar has a closing function. The collar bears with a closing action against the inner wall of the valve casing. The cylindrical plug is subjected to load by a spring, which determines the opening pressure of the valve. The spring is adjustable in a conventional manner such that the opening pressure is also adjustable. The higher the fluid pressure rises, the further the collar moves away from the closing surface of the inner wall of the valve casing. This however also leads to a greater opening width of the valve only up to a limit. The opening width can become no greater than the gap between the plug and the surrounding inlet or outlet. The greater the flow rate of the fluid through the valve caused by the fluid pressure becomes, the greater the flow resistance becomes. This causes a slowing of the increase of the flow rate and of the pressure drop.

FIGS.14to18show a preferred embodiment of the invention. This embodiment may also be implemented independently.

FIG.14shows a section through a device100with two valves in a common casing, a valve combination1100. The casing with the two valves is a constituent part a fluid drainage facility or of a shunt of a hydrocephalus patient. The valve combination1100is, for this purpose, implanted with corresponding lines (not illustrated), so-called catheters, under the skin of the patient. The lines conduct the fluid from the cranium (not illustrated) of the patient to the device and from there into the abdominal cavity (not illustrated) of the patient, where the body of the patient absorbs the fluid. The casing is composed of a base1110, a ring1111of a ring-shaped support disk1112and a cover1113. An axle1120is seated displaceably centrally in the casing. Here, the axle1120is held at one end in the support disk1112and at the other end in a guide1114of the base1110. The axle1120has an outer collar1121and is supported with the outer collar1121by a spiral spring1122on the base1110.

Also seated on the axle1120are a rotor1130and a securing ring1131. Here, the rotor1130engages with an inner collar1132between the outer collar1121and the securing ring1131. Furthermore, the rotor1130surrounds the spiral spring1122. For this purpose, a corresponding recess1133is provided in the rotor1130. The spiral spring1122pushes the rotor1130against the support disk1112in the casing, such that frictional engagement exists between the rotor1130and the support disk1112, and the rotor1130is arrested in the respective position. In this position, the cover1113has an outwardly directed bulge. The arresting action can be released by virtue of the casing being subjected to a pressing action by way of an adjusting device which is placed over the casing onto the skin of the patient. Alternatively, the brake may also be released by manually pressing on the cover1113.

The pressure leads to an indentation of the cover1113and to a displacement of the axle1120toward the base1110. Here, the axle1120can be displaced in the cavity1115of the guide1114. Even a small displacement of the axle1120leads to a release of the rotor1130from the support disk1112. The rotor1130can subsequently be pivoted. For the pivoting of the rotor1130, magnets1134are installed in the rotor1130at diametrically oppositely situated positions.

FIG.14shows a situation of an invention100,1100with a ball1141in the case of a deactivated valve. Here, the ball1141is pushed by a plate spring1147a valve seat.FIG.14shows a second insert1151. Arranged displaceably in the insert1151is a body500,1152in the form of a cylindrical closing part1152, for example in the form of a needle1152. The needle1152projects with a conical tip1153into the gap passage1154, a small channel, a gap. The position of the tip1153determines the opening width of the gap passage1154for the passage of fluid. The greater the distance by which the tip1153extends into the gap passage1154, the smaller the opening width for the passage of fluid into the outlet1150becomes. The smaller the distance by which the tip1153extends into the gap passage1154, the larger the opening width for the passage of fluid becomes.

The position of the tip1153or of the closing part1152is likewise determined by a second cam track714on the rotor1130. InFIGS.14and15, the cam track714for the closing part1152, a body500, that is to say the needle1152, runs above the first cam track712for the ball1141for the differential pressure valve1140bor a gravitational valve1140a(not illustrated). The second cam track surface715is formed by the contact surface of the needle1152with the rotor1130. The first cam track surface713is formed by the contact surface of the ball1141and the first cam track712. The rotor1130is mounted on an axle1120. An outer collar1121of the axle1120supports the inner collar1132of the rotor1130and is held by a securing ring1131. For this purpose, the axle1120is seated in a recess1133of the rotor1130.

As in the case of the ball1141, permanent contact of the closing part1152, the needle1152, with the rotor1130is provided, such that the needle1152permanently follows the cam track715provided for it. For this purpose, the needle1152is surrounded by a spiral spring1155, which pushes the needle1152against the rotor. The spiral spring1155is, for this purpose, supported with one end in the insert1151. With the other end, the spiral spring presses against the needle1152.

FIG.15shows the invention as perFIG.14in the same sectional illustration but different pivoting position of the rotor1130, in an opened state. The spiral spring1155pushes the needle500,152out of the gap passage1154, such that the channels1117can be flowed through by fluid. Furthermore, matching magnets1134are situated in the adjusting device, such that a rotation of the adjusting device about the axle1120in its guide1114by way of the attraction force of the magnets1134causes a pivoting of the rotor. If, after a desired pivoting movement, the adjusting device is removed again, a renewed automatic arresting of the rotor occurs. By pivoting of the rotor1130, a gravitational valve1140a(not illustrated) or a differential pressure valve1140bin the casing can be activated or deactivated.

The gravitational valve1140or the differential pressure valve1140bis arranged at the inlet side in the casing. The flow direction is denoted by1146. The gravitational valve1140aor the differential pressure valve1140bincludes a ball1141The ball1141is seated in an insert1142in its valve seat1116. The insert1142projects with a connection grommet1143through an opening in the ring1111of the casing. The connection grommet1143serves for the connection of a hose line.

FIG.15shows the differential pressure valve1140bopen in a recumbent position of the patient. The rotor1130pushes with a first contact surface, first cam track surface713, against the outer wall of the ball, such that the latter is moved in the direction of the opening1144counter to the spring force of a plate spring1147in the first insert1142. As a result of this movement, channels1117are opened up, such that inflowing fluid can pass. Because channels1117lead through the casing, the fluid can flow through the invention.

For the case that a gravitational valve1140ais installed and the patient with the valve position illustrated inFIG.15assumes a standing position, the gravitational valve1140acloses under the pressure of the ball1141. Independently of this, the gravitational valve1140can be deactivated, such that a fluid flow is always prevented, even in the recumbent position of the patient.

In order to move from the cam track surface illustrated inFIG.14—closed—to the cam track surface illustrated inFIG.15—open—, the rotor1130must be pivoted to a certain extent. This is performed in the manner described above by way of the adjusting device. Channels1117are also situated in another insert1151, which is arranged at the outlet side.

FIGS.14and15show different positions of the closing part1152. InFIG.14, the tip1153has moved a great distance into the gap passage1154. InFIG.14, the second cam track714for the closing part1152with the rotor1130runs, at the contact surface, with a spacing to the axle1120which is large enough for the position of the tip1153. InFIG.15, the spacing of the contact surface to the axle1120is significantly smaller, such that the tip1153is set back in relation to the position inFIG.14to this extent, resulting in a greater opening width between the tip1153and the gap passage1154.FIG.15therefore shows the invention in an opening state.

FIG.16shows a section through the device, wherein the central axes of the inserts1142and1151lie in the section plane. The closing part1152, the needle1152, can be seen to a limited extent in the sectional illustration because it has a spacing to the section plane. The ball1141is illustrated in the closed position.

The rotor1130has an indentation1135and a protuberance1136. In the region of the indentation1136, the ball1141is situated in the closed position. The gravitational valve1140aor differential pressure valve1140bis deactivated. In the region of the protuberance1135, the gravitational valve is opened up again. In the case of stepped opening-up, indentations of smaller depth and/or protuberances of lesser magnitude are also provided between the indentation1135and the protuberance1136.FIG.16shows, in the exemplary embodiment, four magnets1130for the rotor1134the adjustment thereof.

FIG.17shows a section through the device, wherein the central axis of the closing part1152lies in the section plane. Here, the section plane runs through the second cam track714belonging to the closing part1152. It can be seen that the second cam track714belonging to the closing part1152runs in spiral-shaped fashion, such that a continuously variable adjustment of the closing part1152between two extreme values is possible.

Preferably, of two valves arranged in one casing, one valve is arranged at the inlet202of the casing and the other valve is arranged at the outlet203of the casing.

Consideration may also be given to other combinations of valves in a casing. These include combinations of gravitational valves with valves other than differential pressure valves, and also of differential pressure valves with valves other than gravitational valves. The valves other than differential pressure valves also include cam-track-controlled valves. Here, a cam track is guided along on a closing part. The cam track determines the opening and closing positions of the closing part. The guidance of the closing part may be realized in positively locking and/or non-positively locking fashion. Positively locking within the meaning of the invention, and at the same time non-positively locking, is a groove in a rotor, into which groove the closing part engages by way of a journal or the like. The positively locking and non-positively locking connection may also be formed by a rail as cam track, which rail is encompassed by the closing part. It is preferable for only a non-positively locking connection to be provided between the cam track and the closing part. The non-positively locking connection is formed here by a spring, by way of which the closing part is pushed or pulled against the cam track. Even more preferably, the closing part is formed at least partially as a profiled bar and held displaceably in a guide or is connected to a profiled bar which is held displaceably in a guide. Most preferably, a cylindrical profiled bar is provided, which pushes with one end against the cam track under the spring pressure and which corresponds, by way of the other end, with a valve seat. The valve seat may be a ring or a bore in the casing. The bore may widen toward the closing part. The widening may be conical or have some other lateral surface.

It is advantageous if the body, that is to say a needle1152, is arranged in the second insert1151, such that the second insert1151can be installed together with the needle1152in the casing. In the part that protrudes out of the casing, the second insert1151forms a connection for a drainage line. At the other end, the insert projects into the casing interior. There, the second insert1151forms the guide for the cylindrical closing part, the needle1151.

At the same time, the second insert1151may form a cavity in which the spiral spring1155surrounds the cylindrical closing part1152. For conducting fluid, a bore1156may be formed, transversely with respect to the longitudinal axis, in the region of the above-described tip of the second insert, such that the fluid can flow in or flow out past the tip transversely with respect to the longitudinal direction of the insert. At the other end, which is averted from the into the casing bore, the cylindrical closing part1152slides on a second cam track714. Here, the closing part1152is pushed by a surrounding spiral spring1155against the second cam track714, such that the closing part1152follows any change in the second cam track714. For the sliding bore of the closing part1152on the second cam track, a rounding of the closing part in the region of contact is advantageous. The second cam track714may be situated on the face surface and/or on the shell of a rotor1130. Use is preferably made of a disk-shaped rotor1130, the circumferential surface of which is designed as second cam track714such that the closing part1152performs all desired closing movements and opening movements. This is referred to as cam disk704.

The rotor/cam disk is mounted, pivotably in the valve casing, on an axle. The rotor/cam disk is preferably adjusted by way of magnets. For this purpose, magnets are firstly installed in the rotor/cam disk, and, secondly, an adjusting device with other magnets is provided. The adjusting device is placed onto the skin of the patient over the casing and is rotated. During a rotation of the adjusting device, the rotor/cam disk follows the magnetic force or adjusting force of the adjusting device. After every adjustment, the rotor/cam disk is arrested in the attained position until the next adjustment. The arresting action is realized optionally by clamping of the rotor/cam disk. The clamping may be performed at the circumference or at the face surface of the rotor/cam disk. For the clamping at the circumference, the casing may be utilized by virtue of a casing being used which has a flexible cover and flexible side walls, such that, when a pressure is exerted on the casing cover, the side walls bulge outward and release the rotor. When the pressure is released, the casing springs back and encloses the rotor/cam disk between the side walls.

The pressure required for the casing deformation is generated by way of the adjusting device. The adjusting device is therefore firstly pressed against the casing cover, in order to eliminate the arresting action, before the pivoting is performed.

For the clamping of the rotor at the face surface, an axle which is adjustable in an axial direction is preferably provided in the casing. The axle is subjected to the pressure of a spring, which pushes the rotor in frictionally engaging fashion against a slightly outwardly bulged cover. As soon as the axle is displaced to a certain extent in an axial direction owing to pressure on the cover, the rotor releases from the cover. The certain extent is a slight inward indentation of the cover. The rotor can subsequently be rotated in the above-described manner. The pressure is generated by way of the adjusting device as in the case of an arresting action at the circumference; the same applies for the rotation. The displacement is possible in the casing because a corresponding clearance is provided between the end of the axle and the base of the casing. The axle has a collar by way of which it engages behind the rotor formed as cam disk. The spring by way of which the arresting pressure is exerted on the rotor/cam disk by the axle and the collar thereof is arranged between the casing base and the collar of the axle. Additionally, on that side of the rotor which faces toward the cover, there may be mounted a ring which forces the rotor to lift off from the cover in the event of an inwardly directed deformation of the cover. The ring is, for this purpose, fastened to the rotor or to the axle.

The differential pressure valve described above may be combined with other valves. Here, the differential pressure valve may be arranged upstream or downstream of the other valve in a flow direction/drainage direction. In combination with another valve, the closing body of which is spring-loaded and which opens in accordance with the fluid pressure, the above-described valve may be utilized to dampen the drainage rate, that is to say to homogenize the pressure drop over a certain period of time.

Gravitational valves are preferably used as other valves.

These gravitational valves may be above-described conventional valves.

The gravitational valve opens to a maximum extent in the recumbent position.

This also leads to a maximum pressure drop.

With the differential pressure valve, the pressure drop can advantageously be homogenized, that is to say made adjustable in a patient-specific manner.

A special gravitational valve, specifically a switchable gravitational valve, is optionally inserted in the casing. The gravitational valve can be activated and deactivated. For this purpose, an actuating device/switching device is preferably provided in operative connection with the closing part of the gravitational valve.

The length of the indentations on the rotor/cam disk on the circumference or on the face surface of the rotor/cam disk is determined, in the case of a combination of the gravitational valve with a second, adjustable valve, from the adjustment range desired for the second valve.

The above-described gravitational valve may also, independently of the combination with a second valve, have advantages for the fluid drainage. That is to say, the described gravitational valve may also be advantageous as sole valve for the control of the fluid flow.

As soon as the form of the individual cam tracks and the rotational position or pivoting position of the associated rotor/cam disks are defined, it may also be advantageous to provide a common rotor/cam disk for both valves in the common casing. Then, on the common rotor/cam disk, two cam tracks are provided, one of which is designed for one valve and the other of which is designed for the other valve. The two cam tracks than preferably lie in different, mutually parallel planes. It is however also possible for both cam tracks to lie in a common plane. The cam tracks then preferably extend on different circumferential surfaces.

After a pivoting/rotation of the rotor/cam disks, arresting of the rotor/cam disk is performed, such that an undesired adjustment is prevented. The arresting action is released prior to the adjustment and reactivates after every adjustment. Such an adjustment may be realized with different embodiments. In one embodiment, a toothing is provided on the casing and on the rotor. If the toothings engage into one another, the rotor/cam disk is blocked. The blocking is released by virtue of the toothings being moved apart.

Other embodiments are based on the casing bearing in frictionally engaging fashion against the rotor/cam disk in the arresting position. To release the arresting action, the casing is deformed so as to lift off from the rotor/cam disk. The deformation required to release the arresting action is preferably performed by way of the adjusting device for rotating the rotor. To release the arresting action, the adjusting device is not only placed over the implanted valve onto the skin of the patient, but is also pressed against the valve until the arresting action has been released by deformation of the casing. After the lift-off of the adjusting device, the casing automatically springs back and engages the arresting action.

FIG.18shows a preferred embodiment of a rotor in a plan view. It is possible to see two different stages, each outer edge of which is a cam track. The lower stage is characterized by a first cam track712, and the upper stage is characterized by a second cam track714. An indentation1135has been formed into the lower stage; a protuberance1136can be seen.

LIST OF REFERENCE DESIGNATIONS