This application is a National Stage Application of PCT/EP2018/077813, filed Oct. 12, 2018, which claims priority to German Patent Application No. 10 2018 214 989.5, filed Sep. 4, 2018 and German Patent Application No. 10 2017 218 216.4, filed Oct. 12, 2017.

BACKGROUND

Clamps are used in many fields of medical technology to make it possible to switch the flow through a fluid-carrying channel, such as a tubing line, for example, or a channel, which is enclosed in a cassette and bordered by a flexible wall.

Such switchable clamps have a clamp element, a spring element and a current-controlled holding element. The spring element supplies a closing force to block the clamp in the currentless state of the holding element. In this state, the clamp element in a closed position blocks the fluid-carrying channel, and a fluid distribution line is suppressed.

In this case, the fluid may be a liquid or a gas.

In the event of a power outage, for example, the blocking position in a currentless state is advantageous in particular because a further (uncontrolled) supply of substances to a human or animal body should be suppressed.

When the clamps are in an open position, an electric current acts on a holding element, for example, an electromagnetic. The holding element thus supplies a holding force, which counteracts the spring force and holds the clamping element in the open position.

One disadvantage of this arrangement is that, because of the linear force-distance characteristic, the holding force must be fundamentally higher than the closing force provided by the spring element (seeFIG. 6).

In addition, a higher closing force requires a higher holding force accordingly.

A higher closing force requires a spring element having larger dimensions and therefore a greater weight and therefore also a heavy electromagnet, higher holding currents, higher energy consumption.

On one hand, this increases the cost of manufacturing and, on the other hand, also increases operating costs.

OBJECT

One object of the invention is therefore to provide a clamp that can be manufactured less expensively and has lower operating costs. It is a further object of the invention to provide clamps, the operation of which requires significantly less energy as compared to known clamps.

BRIEF DESCRIPTION OF THE INVENTION

This object is achieved by a clamp, which is such that the clamp can accommodate a fluid-carrying channel, that the clamp can compress the fluid carrying channel in a resting state and that in a working state the clamp can accommodate the fluid-carrying duct such that the fluid-carrying duct is not compressed, wherein the clamp has a first permanent magnet and a second permanent magnet, the permanent magnets being arranged at a distance from one another so that the permanent magnets can be rotated at least by an angle relative to one another, the relative rotation of the permanent magnets to one another resulting in a reduction in the distance, the resting state being provided at a first angle, and the working state being provided at a second angle.

The permanent magnets can in particular be arranged so as to be moveable relative to one another, wherein the permanent magnets can be rotated at least by an angle relative to one another, and wherein the permanent magnets can be moved linearly relative to one another, so that the distance between the permanent magnets can vary, wherein a rotation of the permanent magnets relative to one another leads to a change of the relative arrangement of the poles of the permanent magnets to one another, which, in turn, effects a change of the magnetic attractions between the magnets, as a result of which a change of the distance of the permanent magnets takes place, wherein the clamp in a first relative rotational position of the permanent magnets to one another assumes a resting state, and in a second relative rotational position of the permanent magnets to one another assumes a working state.

A fluid-carrying channel may be, for example, a tubing line or a channel created in a cassette and delimited by a flexible wall.

It is possible by means of the invention to provide a clamp, which permits a simple mechanical design with reduced holding currents at the same time.

In the case of one embodiment of a clamp (1) proposed here, the clamp (1) blocks flow by compression of a fluid-carrying channel (L) in a resting state and enables flow in a working state by releasing the compression. The clamp (1) thereby has a first magnet (M1) and a second magnet (M2), wherein the magnets (M1, M2) are arranged at a distance from one another so that the magnets (M1, M2) can be rotated at least by an angle relative to one another, the relative rotation of the magnets (M1, M2) to one another resulting in a reduction in the distance (d), the resting state being provided at a first angle, and the working state being provided at a second angle.

In one specific embodiment of the invention, the fluid is a liquid, i.e., the invention allows control of the supply of dialysate or other substances, for example.

In another specific embodiment of the invention, a fluid-carrying (inserted) channel is arranged between the permanent magnets.

According to another specific embodiment of the invention, the first permanent magnet and/or the second permanent magnet is/are a so-called polymagnetized magnet, such a magnet having a first number of sectors of a first magnetization and a second number of sectors of a second opposing magnetization.

Elements that are rotatable and/or displaceable relative to one another can be implemented especially easily in a small space by means of polymagnetized magnets.

In another specific embodiment of the invention, the difference in amount between the first angle and the second angle is less than or equal to 360° divided by the number of sectors, i.e., the required forces can be applied even with a rotation of less than 180°.

In yet another specific embodiment of the invention, a lever is also provided for opening the clamp, so that a fluid-carrying channel can be inserted into the clamp.

The clamp can also be opened by the lever in a currentless state, so that a fluid-carrying channel can be inserted.

According to another specific embodiment of the invention, an electromagnet is also provided, acting on at least one of the permanent magnets in the case of activation so that the working state is maintained, i.e., the electromagnet is designed so that the continuous flow through the fluid-carrying channel is made possible.

According to a refinement of the invention, the electromagnet acts on at least one of the permanent magnets in the case of activation, so that the working state is reached, i.e., the electromagnet is designed so that it is possible to switch from the resting state to the working state.

This specific embodiment is suitable in particular with clamps for channels, through which medical fluids, such as blood or infusion fluids are passed into or out of a patient. The clamp may be designed as part of a blood treatment machine, a peritoneal dialysis machine or an infusion pump, for example. If fault situations occur with such machines, in particular in the event of an interruption in the electrical power supply to the machine, it is necessary in general to induce a safe condition, in which the fluid connection to the patient is interrupted. A holding element designed as an electromagnet, which switches from the resting state to the working state by activation by means of power consumption, would necessarily switch from the working state to the resting state in the event of a power failure and would interrupt the flow through the channel.

According to one refinement of the invention, the first permanent magnet is guided relative to the second permanent magnet on a helical path in the transition from the resting state to the working state.

Different path profiles can thus be made available in this way.

In another specific embodiment, a rod-type shape of the closing force is available, wherein the force characteristic of the magnet pair, which is formed by the first permanent magnet and the second permanent magnet, is implemented, wherein the attractive force is great when the distance between the permanent magnets is small, is converted into a force characteristic of the closing force, which is great when the clamp is closed.

Additional advantageous embodiments are the subject matter of the dependent claims and the detailed description.

