IMPLANTABLE INTERNAL DRAINAGE DEVICE AND SYSTEM FOR EDEMAS

Abstract

The invention relates to a medical fluid drainage device for drainage of edematous tissues comprising at least one pumping element (1, 23, 33), having an inlet and an outlet, at least one outlet member (2) having at least one lumen, connected directly or indirectly to the outlet of said pumping element and connecting said pumping element to a body cavity or to a vessel or to a subcutaneous area, and at least one inlet member (3) connected to said inlet of said pumping element and providing fluidic connection between said edematous tissue and said pumping element, and characterized in that the inlet member comprises at least two inlet lumens (4, 5, 6) connected in parallel to said inlet of said pumping element, each of said lumens (4, 5, 6) contains at least one fluid access region, wherein each fluid access region (8, 9, 10) being adapted to allow simultaneous edematous fluid entry from distinct regions of said edematous tissue.

Claims

1. A medical fluid drainage device for drainage of edematous tissues comprising: at least one pumping element (1, 23, 33), having an inlet and an outlet, at least one outlet member (2) having at least one lumen, connected directly or indirectly to the outlet of said pumping element and connecting said pumping element to a body cavity or to a vessel or to a subcutaneous area, and at least one inlet member (3) connected to said inlet of said pumping element and providing fluidic connection between said edematous tissue and said pumping element, and characterized in that the inlet member comprises at least two inlet lumens (4, 5, 6) connected in parallel to said inlet of said pumping element, each of said lumens (4, 5, 6) contains at least one fluid access region, wherein each fluid access region (8, 9, 10) being adapted to allow simultaneous edematous fluid entry from distinct regions of said edematous tissue.

2. Medical fluid drainage device of claim 1, wherein the values of hydraulic resistance of each inlet lumen, in the tract preceding each fluid access region, for the same fluid, have a maximum difference of 30%.

3. Medical fluid drainage device of claim 1 or 2, wherein each of said inlet lumen (4, 5, 6) is a tube with a circular section presenting a radius R and a hydraulic resistance according to the formula: Rh.sub.i=k*D.sub.i/R.sub.i.sup.4, where Rh.sub.i is the hydraulic resistance of the lumen i, k is a constant depending on the fluid flowing in the tube, Di is the length if the lumen i, or the distance between said pumping element inlet and the beginning of the fluid access region of the lumen i, and Ri is the radius of the section of the lumen i.

4. Medical fluid drainage device of claims 1 to 3, wherein the fluid access region includes at least one circular hole with dimensions between 0.1 and 2 mm in diameter, on the lumen wall.

5. Medical fluid drainage device of claims 1-4, wherein said inlet lumens (16, 17, 18) are embedded in one or more implanted, flat-shaped member (13) or patch.

6. Medical fluid drainage device of claim 5, wherein said flat-shaped member (13) or patch has a thickness between 0.1 and 3 mm and width between 5 and 100 mm.

7. Medical fluid drainage device of claims 1-6, wherein each of said inlet lumen (4, 5, 6, 16, 17, 18) has a rectangular section, presenting a height, a width, and a hydraulic resistance according to the formula: Rh.sub.i=[k*D.sub.i/(10.63h.sub.i/w.sub.i)]*(1/h.sub.i.sup.3w.sub.i), where Rh.sub.i is the hydraulic resistance of the lumen i, k is a constant depending on the fluid flowing in the tube, D.sub.i is the length if the lumen i, or the distance between said pumping element inlet and the beginning of the fluid access region of the lumen i, and h.sub.i and w.sub.i are the height and the width of the section of the lumen i.

8. Medical fluid drainage device of claims 1-7, wherein said pumping element (1, 23, 33), said outlet members (2, 14, 21) and said inlet members (3, 21) are made of PEEK, PEAK, titanium, silicone or any biocompatible materials.

9. Medical fluid drainage device of claims 1-7, wherein the pumping element (1, 23, 33) is a roller pump comprising at least a flexible tube (28) for holding a liquid to be moved, a wall (33) to support the tube having an arc-shaped profile, one or more rollers (52, 53) to compress the tube against the wall in one or more points, a central body (51) holding the rollers and free to rotate around his axis, a permanent magnet (29), integral with the central body, a case (23), including an inlet and an outlet for the tube; said pumping element being free of implanted electronic component, electric wires or batteries.

10. Medical fluid drainage device of claims 1-7, wherein the pumping element (1, 23, 33) is a gear pump, comprising at one driving gear integral with a permanent magnetic disc (40) and one driven gear (37), an inlet and an outlet; Said pumping element free of implanted electronic component, electric wires or batteries.

11. Medical fluid drainage device of claim 9 or 10, wherein said pumping element is an implantable pump.

12. Medical fluid drainage device of claim 9 or 10, wherein said pumping element is a non-implantable pump, connectable to said inlet and outlet members through percutaneous accesses.

13. Medical fluid drainage system comprising the medical fluid drainage device of claims 1-12 and an external controller adapted to activate and control said pumping element and comprising at least: one or more magnetic field sources for creating a dynamic magnetic field which causes the rotation of the magnetic material in the implantable part and the rotation of the central body and of the rollers as well as a power source able to create and maintain the dynamic magnetic field.

14. Medical fluid drainage system of claim 13, wherein said external controller contains at least one Hall sensor, which output is used to determine the distance and the orientation of said permanent magnet in said roller pump relative to said external controller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further particular advantages and features of the invention will become more apparent from the following non-limitative description of at least one embodiment of the invention which will refer to the accompanying drawings, wherein

[0054] FIG. 1A to 1C show a top view of the medical fluid drainage device of the present invention as well as three sectional views of the device at different positions.

[0055] FIG. 2 shows a perspective view of a preferred embodiment of an inlet member for a medical fluid drainage device containing multiple lumens of the present invention.

[0056] FIG. 3 shows an illustration of an implantation of the medical fluid drainage device of the present invention in which a right leg edema is drained connecting three access regions and 3 inlet lumens to the peritoneum through a pumping element.

[0057] FIG. 4A shows an isometric view of an implantable pumping element according to a first embodiment of the present invention.

[0058] FIG. 4B shows an exploded view of the implantable pumping element according to the first embodiment of the present invention.

[0059] FIGS. 4C and 4D show a bottom view of the rotating element of the implantable pumping element according to the first embodiment of the present invention.

[0060] FIG. 5A shows an isometric view of an implantable pumping element according to a second embodiment of the present invention.

[0061] FIG. 5B shows an exploded view of the implantable pumping element according to the second embodiment of the present invention.

[0062] FIG. 6 shows an isometric view of an external controller for the implantable pumping element according to a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0063] The present disclosure may be understood more readily by reference to the following detailed description presented in connection with the accompanying drawings, which form a part of this disclosure. It is to be understood that this disclosure is not limited to the specific conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed disclosure.

[0064] According to a first aspect of the invention, the implantable drainage system for distributed edemas is designed to be implanted subcutaneously and to drain fluid accumulated in an interstitium of a living host, actively and continuously transporting it, directly or indirectly, to the blood circulation. For instance, said drainage system may be designed to be connected to the peritoneum of a living host. For instance, said drainage system may be designed to transport the fluid from the accumulation interstitial area to another interstitial area, distant from the one to be drained, characterized by functional lymphatics (i.e., sternal area).

[0065] FIGS. 1 A, B and C show the first aspect of the invention which is a transverse view and three section views of the implantable drainage system according to a preferred embodiment of the invention. The system comprises one pumping element 1, one outlet member 2 including a lumen, and one inlet member 3, including three lumens 4, 5, 6 also called inlet lumens. In the present description a lumen shall be considered as any type of tubing element comprising a hollow space and capable of transporting a fluid. The inlet lumens 4, 5, 6 are connected in parallel between them through a common lumen 7. Each of the inlet lumens 4, 5, 6 has a fluid access region 8, 9, 10 in the distal part of said inlet lumen 4, 5, 6, respectively. In this embodiment, for example, the fluid access region 9 allows the entrance of fluid in the lumen 5, which is connected to the lumen 7, which is connected to the pumping element 1, which is connected to the outlet member 2.

[0066] In this embodiment, the fluid access regions are composed by four circular holes 11 through the inlet member 3, connecting the lumen 4 with the external fluid. However, the invention is clearly not limited to this embodiment and the fluid access regions may differ from one lumen to another or from one device to another both in number, in shape or even in structure like by adding a filter for regulating the flow rate, or the same for example.

[0067] In such embodiment, when the pumping element 1 creates a negative pressure in the lumen 7, such negative pressure will be distributed across the lumens 4, 5, 6, allowing fluid to enter from the access regions 8,9,10 and be transported to the outlet member 2.

[0068] The flow rate of the fluid in the lumen 4, 5, 6 depend on the hydraulic resistance offered by said lumens, in the tract between the end of lumen 7, i.e. the proximal end of common lumen 7 with respect to the pump, and the beginning of each lumens, i.e. at the fluid access region 8, 9, 10. If the lumens have a circular section, the hydraulic resistance depends on the length and on the radius of said section to the fourth power (R.sup.4).

[0069] Having an equal flow rate through the different lumens allows a uniform, thus more efficient, drainage of the edematous tissue. Thus, according to the preferred embodiment of the invention, the diameter of each lumen 4, 5, 6 is determined according to the length of said lumen 4, 5, 6 between the end of the lumen 7 to the first hole of each access region 8, 9, 10, so as to provide a device where each lumen offers the same hydraulic resistance to the edematous fluid.

[0070] In particular, the diameter of each lumen can be calculated through the formula:

Rh.sub.4,5,6=k*D.sub.4,5,6/R.sub.4,5,6.sup.4

[0071] where Rh.sub.4,5,6 is the hydraulic resistance of the lumens 4,5,6,

[0072] k is a constant depending on the fluid flowing in the tube, D.sub.4,5,6 is the length if the lumens 4,5,6, or the distance between said pumping element inlet and the beginning of the fluid access region of the lumens 4,5,6, and

[0073] R.sub.4,5,6 is the radius of the section of the lumens 4,5,6.

[0074] In particular, in order to have an efficient draining, the hydraulic resistance Rh of each lumen must not differ from each other for more than the 30% of their value.

[0075] In a further preferred embodiment of the invention, one of the inlet lumen 4, 5, 6 may not be entirely of tubular shape, but it may have a flat shape or any type of shape, as shown in FIG. 2. In this embodiment, one inlet member is composed of a tubular part 12 and a flat shaped part 13, which may be implanted in the subcutaneous space of a living body, with the tubular part 12 being connected to the input of an implanted pumping element.

[0076] The tubular part 12 contains a common lumen 14, which ends with the tip 15, which divides in several inlet lumens as, for example, the lumens 16, 17, 18. Such lumens may have a rectangular section for example. Each lumen has a fluid access region at his terminal part. For instance, lumen 17 has the fluid access region 19 composed by 3 rounded apertures in the upper part of the flat shape member 13.

[0077] Thanks to such geometry, when a negative pressure is applied to the tubular part 14, the edematous fluid can enter in the lumens from all the fluid access regions present on the member 13, allowing the drainage as extended as the surface of the flat shape member 13.

[0078] Moreover, in order to obtain a similar flow rate in all the lumens in the flat shaped member 13, as for example in the inlet lumens 16, 17, 18, the dimensions (radius) of each lumen can be calculated depending on the length of said lumen, from the common region 15 to the start of each fluid access region. For example, if the lumen 17 has a rectangular section, its height and width can be determined through the formula:

Rh.sub.17=[k*D.sub.17/(10.63h.sub.17/w.sub.17)]*(1/h.sub.i.sup.3w.sub.i),

[0079] where Rh.sub.17 is the hydraulic resistance of the lumen 17,

[0080] k is a constant depending on the fluid flowing in the tube,

[0081] D.sub.17 is the length of the lumen 17, as the distance between the common region 15 and the beginning of the fluid access region 19 of the lumen 17, and

[0082] h.sub.17 and w.sub.17 are the height and the width of the section of the lumen 17.

[0083] In order to have a similar flow rate in the different lumens, the hydraulic resistance of each lumen must be similar for different lumens, for example Rh.sub.17 must be similar to Rh.sub.16 and to Rh.sub.18. In particular, to have an efficient draining, the hydraulic resistance Rh of each lumen must not differ from each other for more than the 30% of their value.

[0084] The medical fluid drainage system may be configured to drain edematous fluid from a variety of positions in the body. For example, the outlet member 2 may be anchored to the wall of the peritoneum 20 while the system may be positioned in the subcutaneous space of on edematous leg. For instance, in FIG. 3 is shown an example of system configuration including one inlet member 21 comprising three separated lumens and three distinct fluid access regions 22 which drain the edematous fluid and send it the outlet member 2 which then guide it to the peritoneum 20.

[0085] The pumping element 1 of the fluid drainage system is the element that creates the necessary negative pressure on the inlet member 3 respect to the outlet member 2, in order to drive the fluid flow in from in the lumens.

[0086] Although several implantable pumping elements are present on the market, a first embodiment is shown in FIG. 4A, which includes an implantable pumping element 23 made in biocompatible material, for example PEEK, PEKK, titanium, silicone, between others. FIG. 4B shows an exploded view of the implantable pumping element 23. It includes an upper shell 24 which comprises two anchoring points 25 to secure the pumping element 23 in position in the subcutaneous space once implanted.

[0087] In this embodiment, the pumping element 23 further includes a housed component 51 which comprises an inlet connector 26 and an outlet connector 27, which may be connected to the inlet member 3, or 12, or 21 and to the outlet member 2, respectively. The connectors 26 and 27 are linked together through the flexible member 28. Said flexible member 28 may be in a tubular shape and may be made of a flexible biocompatible material, as for instance, silicone. The flexible member 28 may be in contact with a rotating element 30, which compresses the flexible element 28. The rotating element 30 is solidal with a permanent magnetic disc 29, which may be diametrically magnified, and may be made of a permanent magnetic material, as for instance neodymium. The magnetic disc 29 and/or the rotating element 30 may include a protection layer for the permanent magnet 29 to avoid the degradation of the material of the magnetic disc 29.

[0088] The pumping element 23 further includes a bottom shell 31, made of a biocompatible material as PEEK, PEAK, titanium, silicone, between others. The bottom shell 31 includes an anchoring point 32, on which the rotating element 30 may fit so as to be free to rotate. The flexible member 28 may fit between the wall 33 and the rotating element 30. The flexible member may thus be compressed in at least one point between the rotating element 30 and the wall 33. In such way, when the rotating element 30 rotates clockwise, the compression point on flexible member 28 will move clockwise accordingly, creating a negative pressure in the lumen connected to the member 26 respect to the lumen connected to the member 27.

[0089] In this embodiment, the rotating element 30 may not rotate unless positioned in a dedicated rotating external magnetic field.

[0090] FIGS. 4C and 4D show a bottom view of the central body 51 which clearly shows three of four rollers 52, 53. The central roller 52 is the one disposed on the anchoring point 32 of the bottom shell to allow stable rotation the external rollers 53 are the ones pressing the flexible member 28 thereby creating the negative pressure in the lumen upon rotation. FIG. 4C shows one embodiment of the invention, in which the pumping element contains 2 rollers, which are positioned at a radial angle between them, with 0.5>>5, with being the angle inside the arc formed by the flexible member 28 on the wall 33, so that it exist one position on the 360 in which none of the rollers 53 is occluding the flexible member 28, creating an open circuit, which is desirable if the pumping element must be compatible with external compression. In another variation of the invention, presented in FIG. 4D, three rollers 53 are present, placed at equal angle between each other, so that at least one of them is always occluding the flexible member 28, which improves the pump efficiency in case of high pressure loads.

[0091] FIGS. 5A and 5B show a second embodiment of the pumping member, which includes an implantable pumping member 33, having an inlet 34 and an outlet 35, integral in part with an upper shell 36 Said implantable pumping member 33 further includes an external 37, concentric with the upper shell 36, able to rotate around its central axis, and having a central hollow part with three concave teeth. The implantable member 33 further includes a central gear, eccentric in respect to the external gear 37, composed by a magnetic disc 40 and two radial bearing 39, each being a tooth of said inner gear. The magnetic disc 40 is solidal with the bearings 39, and can rotate around its axis thanks to the radial gear 42, positioned on a bottom shell 41 and supporting the magnet 40 and the rollers 39. The external gear 37 is supported by a series of bearings 38 placed between the lateral surface of the external gear 37 and the lateral surface of the bottom shell 41, in order to decrease the rotational friction of the external gear 37 and reduce the thickness of the implantable pumping member 33.

[0092] FIG. 6 shows an embodiment of a portable external controller creating a rotating magnetic field to drive and control the magnetic disc 29 and therefore the functioning implantable pumping element 23. The external controller may include a case 34, which contains an electromagnetic motor 35. The motor may have a mechanism to transfer the movement of the shaft 36 to a magnetic disc 37. The magnetic disc 37 may be magnetically magnetized and may include a permanent magnetic material as neodymium. In one possible version, shown in FIG. 5, the movement transfer is obtained through a so-called worm wheel, composed by a screw 38 mounted on the shaft 36, and a worm gear 39, integral with the magnetic disc 37. The case 34 may include a battery 40 and an integrated circuit 41.

[0093] The external controller may further include one or more Hall sensors, positioned in fixed positions around the magnetic disc, connected to the integrated circuit 41. The output of each hall sensor, combined, may be used to give a feedback on the relative position of the magnetic disc 37 in the external controller with respect to the magnetic disc 29 in the implantable pumping element 23.

[0094] While the embodiments have been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, this disclosure is intended to embrace all such alternatives, modifications, equivalents and variations that are within the scope of this disclosure. This is for example particularly the case regarding the fact that the device is primarily contemplated for use in human patients, but the invention will also have veterinary uses or product development purposes in horses, bovines, canines, felines, and other mammals. Further, the applications of the devices and systems discussed above are not limited to certain treatments, while they may include any other condition.