Arteriovenous graft system

Abstract

An arteriovenous graft system (1) comprising:-an arteriovenous graft (2) provided with a valve device (3) wherein the valve device (3) has an open state in which a fluid flow through the graft (2) is possible and a closed state in which a fluid flow through the arteriovenous graft (2) is blocked,-wherein the valve device (3) is provided with a valve element (4), the graft system (1) comprises actuator means (4) to actuate the valve means (3) between a closed state and an open state, and wherein a transmission cable (5) connects the actuator means (4) with the valve means (3) wherein the actuator means (4) comprises at least one movable magnet (6) connected to a rotatable plate (7), the rotatable plate is equipped with a spiral groove (7 '), where the spiral groove (7') receives a pin (8) movable in a linear path, where the pin (8) is connected to the transmission cable (5) so as to be arranged to convert a movement of the at least one magnet (6) into a linear displacement of the pin (8) and of the transmission cable (5) connected to the pin.

Description

[0001] The present invention relates to an arteriovenous graft system, the arteriovenous graft system comprising an arteriovenous graft provided with a valve device, wherein the valve device has an open state, in which a fluid flow through the graft is possible, and a closed state, in which a fluid flow through the arteriovenous graft is blocked, wherein the graft system comprises an actuator device to actuate the valve device between the closed state and the open state, and wherein a transmission cable connects the actuator device with the valve device.

[0002] This arteriovenous graft system is particularly useful for hemodialysis patients. Hemodialysis is a process used to filter a patient's blood and remove toxins with the help of an extracorporeal dialysis machine. One end of the artificial graft is connected to an artery and the other end to a vein, and the graft is usually placed in the patient's leg or arm. Artificial arteriovenous grafts are used as shunts to avoid complications in hemodialysis patients who require peripheral vascular access, which has a very high complication rate due to the constant elevated turbulence over the shunt.

[0003] WO2020 / 055247 discloses such an arteriovenous graft system for subcutaneous placement, wherein an actuator device can be wirelessly controlled outside the patient's body to move a valve device between a first position and a second position. The wireless control can, for example, use an electric field or a magnetic field, with which the actuator device can be controlled without direct contact. The magnetic field can, for example, be provided by a permanent magnet.

[0004] The teaching of WO2020 / 055247 does not address how a magnetic field operating on an actuator device can be implemented in practice and does not disclose how specific requirements can be met, such as how to provide a stable position of the valve device in each position between the open state and the closed state.

[0005] One of the objects of the present invention is therefore to ensure that the valve device can be stably positioned in every position between the open state and the closed state.

[0006] Another object of the present invention is to provide a locking member for the valve device when the valve device is in the closed position.

[0007] It is a further object of the invention that the valve arrangement shall not be back-actuable.

[0008] It is a further object of the invention that there shall be a high transmission ratio between the actuator means and the valve means.

[0009] These and other objects of the invention are achieved by an arteriovenous graft system having the features according to one or more of the appended claims.

[0010] According to a first aspect of the invention, the actuator device comprises at least one movable magnet, the at least one magnet being directly or indirectly connected to a rotatable plate, the rotatable plate being provided with a helical groove, wherein the helical groove receives a pin movable in a linear path, wherein the pin is connected to a transmission cable so as to be arranged to convert the movement of the at least one magnet into a linear displacement of the pin and the transmission cable connected to the pin. With the arteriovenous graft system of the invention, the graft can be kept stable at any selected position, since the graft is not back-drivable. Thus, the flow through the graft can be adjusted to any desired flow.

[0011] In addition to the above objectives, over-actuation of the at least one magnet may be prevented by arranging the at least one magnet to be sensitive to excitation of an external magnetic field that drives the at least one magnet into a desired motion.

[0012] In order to increase the precision and sensitivity of the movement of the at least one magnet to be set in motion, it is preferred that the actuator device comprises a ring of magnets that can be moved along a circular path.

[0013] Preferably, the ring of magnets provides an asymmetric magnetic field.Such an arrangement makes contact with an external device providing said external magnetic field possible only by a predetermined positioning of the external device.

[0014] In a suitable embodiment, the ring of magnets is oriented in such a way that adjacent magnets have alternating north and south poles except that at least one pair of adjacent magnets have the same north and south pole orientation.

[0015] Desirably, the pin connected to the transmission cable is mounted on a driven element movable in a linear groove provided in a support base plate of the actuator device.

[0016] Reliable handling of the magnets is facilitated by an arrangement in which a ring of magnets is held in a predetermined position relative to one another by placing the magnets in a magnet holder provided with regularly distributed receptacles for the magnets along a circular path.

[0017] Although one or more magnets may be directly connected (by direct mounting or by magnetism) to the rotatable plate provided with the helical groove, it is preferred that such connection is provided indirectly by arranging to rotationally fix the magnet holder relative to the rotatable plate.

[0018] Suitably, the actuator means, the transmission cable and the arteriovenous graft provided with the valve means are configured to be placed subcutaneously in a human or animal.

[0019] Preferably, the actuator device is provided with suture holes to enable the actuator device to be sutured to the subcutaneous tissue in order to prevent migration of the actuator device.

[0020] In another aspect of the invention, which may be applied independently of all other features disclosed herein or in combination with any of such other features, the transmission cable is provided with a loop, wherein the loop is preferably stabilized to prevent it from loosening. The loop can be customized to the desired distance between the valve device and the actuator device. This allows limiting any traction on the subcutaneous tissue and blood vessels without interfering with the operation of the arteriovenous graft system. Tying a knot on the loop can stabilize it and prevent the loop from loosening.

[0021] The invention will be further explained in the following with reference to the accompanying drawings of exemplary embodiments of an arteriovenous graft system according to the invention which are not limited to the appended claims.

[0022] In the attached picture:

[0023] - Figure 1A The arteriovenous graft system of the present invention is shown in an isometric view;

[0024] - Figure 1B Shows Figure 1A details to indicate the graft and valve device;

[0025] - Figure 2 shows an exploded view of an actuator device forming part of the arteriovenous graft system of the present invention;

[0026] - Figure 3 shows a preferred magnet configuration for an actuator device forming part of the arteriovenous graft system of the present invention; and

[0027] - Figure 4 The arteriovenous graft system of FIG. 1 is shown, wherein the transmission cable is provided with a loop, and the loop is stabilized to prevent it from loosening.

[0028] Whenever the same reference numbers are used in the drawings, they refer to the same parts.

[0029] Figure 1A An arteriovenous graft system 1 is depicted, comprising an arteriovenous graft 2 provided with a valve arrangement 3, wherein the valve arrangement 3 is in an open state in which a fluid flow through the graft 2 is possible. Figure 1B Shown in detail Figure 1A An arteriovenous graft 2 and a valve device 3 are provided, wherein the valve device 3 and the graft are in a closed state, in which the fluid flow through the arteriovenous graft 2 is blocked.

[0030] The placement and operation of the combination of the valve device 3 and the arteriovenous graft 2 is itself prior art and does not require further elaboration to explain the present invention. A skilled person may refer to WO2020 / 055247 to understand the background of the present invention.

[0031] The inventive implant system 1 as explained below comprises an actuator device 4 to actuate the valve device 3 between a closed state and an open state, wherein a transmission cable 5 connects the actuator device 4 with the valve device 3 .

[0032] Now turn to Figure 2 For explanation of the actuator device 4, Figure 2 The actuator device 4 is shown to comprise at least one movable magnet 6. In fact, in the preferred embodiment shown, the actuator device 4 comprises a ring of magnets 6 that can be moved along a circular path. The ring of magnets 6 is preferably held in a predetermined position relative to each other by placing the magnets 6 in a magnet holder 9 equipped with receptacles 10 for the magnets 6 that are regularly distributed along the circular path.

[0033] At least one magnet or a ring of magnets 6 is connected to a rotatable plate 7 which is provided with a spiral groove 7' (as in the Figure 2 The connection of the ring of magnets 6 to the plate 7 is preferably provided by providing a magnet holder 9 which is rotationally fixedly mounted to the plate 7 .

[0034] Reference Figure 3 , shows that a ring of magnets 6 provides an asymmetric magnetic field by being arranged in such a way that the ring of magnets 6 is oriented in such a way that adjacent magnets have alternating north and south poles except that at least one pair of adjacent magnets have the same north and south pole orientation.

[0035] Back to Figure 2 , it is shown that the helical groove 7' at the lower side of the plate 7 receives a pin 8 movable in a linear path. The movability of the pin 8 along the linear path is preferably arranged by mounting the pin 8 on a follower element 8' movable in a linear groove 11 provided in a supporting base plate 12 of the actuator device 4. The pin 8 is connected to the transmission cable 5 so as to be arranged to convert the movement of at least one magnet or ring of magnets 6 into a linear displacement of the pin 8 and likewise into a linear displacement of the transmission cable 5 connected to the pin 8.

[0036] As already mentioned above, the actuator device 4, the transmission cable 5 and the arteriovenous graft 2 provided with the valve device 3 are equipped to be placed subcutaneously in a human or an animal. In order to operate the arteriovenous graft system 1 of the present invention, one or more magnets 6 forming part of the actuator device 4 are sensitive to the excitation of an external magnetic field, which drives the one or more magnets 6 into a desired state of motion in order to actuate the valve device 3 through the intermediate transmission cable 5.

[0037] Figure 2 The actuator device is shown to be provided with suture holes 13 to enable suturing of the actuator device 4 to the subcutaneous tissue.

[0038] Figure 4 The transmission cable 5 is shown provided with a loop, wherein the loop is preferably stabilized to prevent it from loosening. The loop can move freely to keep the distance between the valve device 3 and the actuator device 4 variable during daily movements, thereby limiting the subcutaneous traction force.

[0039] Embodiments of the present invention may include every combination of features disclosed independently of one another herein. Although the present invention has been discussed in the foregoing with reference to exemplary embodiments of the present invention, the present invention is not limited to this particular embodiment, which may be varied in many ways without departing from the present invention. Therefore, the exemplary embodiments discussed should not be used to strictly interpret the appended claims accordingly. On the contrary, the embodiments are intended only to interpret the wording of the appended claims, and are not intended to limit the claims to the exemplary embodiments. Therefore, the scope of protection of the present invention should be interpreted only in accordance with the appended claims, wherein the exemplary embodiments should be used to resolve possible ambiguities in the wording of the claims.

[0040] Variations and modifications of the present invention will be apparent to those skilled in the art, and it is intended that all such modifications and equivalents be covered in the appended claims. The entire disclosures of all references, applications, patents, and publications cited above are incorporated herein by reference. Unless specifically stated as "essential" above, the various components or their interrelationships are not essential for the operation of the present invention. On the contrary, the desired results can be achieved by replacing the various components and / or reconfiguring their relationships to each other.

Claims

1. An arteriovenous graft system (1), comprising: - an arteriovenous graft (2), said arteriovenous graft (2) being provided with a valve device (3), wherein said valve device (3) has an open state, in which a fluid flow through said graft (2) is possible, and a closed state, in which a fluid flow through said arteriovenous graft (2) is blocked, wherein the implant system (1) comprises an actuator device (4) for actuating the valve device (3) between the closed state and the open state, and wherein a transmission cable (5) connects the actuator device (4) with the valve device (3), It is characterized in that The actuator device (4) comprises at least one movable magnet (6), the at least one magnet (6) being directly or indirectly connected to a rotatable plate (7), the rotatable plate (7) being provided with a helical groove (7'), wherein the helical groove (7') receives a pin (8) movable in a linear path, wherein the pin (8) is connected to the transmission cable (5) so as to be arranged to convert the movement of the at least one magnet (6) into a linear displacement of the pin (8) and the transmission cable (5) connected to the pin (8).

2. The arteriovenous graft system according to claim 1, characterized in that: The actuator device (4) comprises a ring of magnets (6) which can be moved along a circular path.

3. The arteriovenous graft system according to claim 2, characterized in that: The (6) ring of magnets provides an asymmetric magnetic field.

4. The arteriovenous graft system according to claim 2 or 3, characterized in that: The ring of magnets (6) is oriented in such a way that adjacent magnets have alternating north and south poles except for at least one pair of adjacent magnets having the same north and south pole orientation.

5. The arteriovenous graft system according to any one of claims 1 to 4, characterized in that: The pin (8) is mounted on a driven element (8') which is movable in a linear groove (11) provided in a supporting base plate (12) of the actuator device (4).

6. The arteriovenous graft system according to any one of claims 1 to 5, characterized in that: The ring of magnets (6) is held in a predetermined position relative to each other by placing the magnets (6) in a magnet holder (9), which is equipped with receptacles (10) for the magnets (6) regularly distributed along a circular path.

7. The arteriovenous graft system according to any one of claims 1 to 6, characterized in that: The magnet holder (9) is rotationally fixed relative to the rotatable plate (7).

8. The arteriovenous graft system according to any one of claims 1 to 7, characterized in that: The actuator device (4), the transmission cable (5) and the arteriovenous graft (2) provided with the valve device (3) are configured to be placed subcutaneously in a human or an animal.

9. The arteriovenous graft system according to any one of claims 1 to 8, characterized in that: The actuator device (4) is provided with suture holes (13) so that the actuator device (4) can be sutured to the subcutaneous tissue.

10. The arteriovenous graft system according to any one of claims 1 to 9, characterized in that: One or more of the magnets (6) are sensitive to excitation by an external magnetic field, which drives the one or more of the magnets (6) into a desired state of motion.

11. The arteriovenous graft system according to the preamble of claim 1 or any one of claims 1 to 10, characterized in that The transmission cable is provided with a loop, wherein the loop is preferably stabilized to prevent it from coming loose.

Images