WO2019211782A1

WO2019211782A1 - Peristaltic type pumping device and related medical apparatus, in particular for peritoneal dialysis

Info

Publication number: WO2019211782A1
Application number: PCT/IB2019/053586
Authority: WO
Inventors: Fabio Arrizza; Mario Bonomini; Arduino Arduini
Original assignee: Corequest Sagl
Priority date: 2018-05-04
Filing date: 2019-05-02
Publication date: 2019-11-07
Also published as: IT201800005075A1

Abstract

A peristaltic type pumping device, wherein a fluid is pushed along an elastically deformably tube, has a compact and particularly robust shape, and it comprises: a deformable tube tract (12) and a seat (6) which receives it extending for its whole length, the seat (6) comprising a bottom, thereupon a lower surface of the tube tract (12) rests, opposite to an upper surface of the tube tract (12), the lower and upper surfaces being separated by side surfaces of the tube tract (12) opposite to one another; a rotating operating element (16) which, by exerting a continuous squeezing on said upper surface of the tube tract (12) which moves according to a predetermined direction, produces a peristaltic compression of the tube tract (12), wherein the flowing direction of the fluid flow in the tube tract (12) is determined by the rotation direction of the rotating operating element (16); and means for compressing laterally said tube tract (12), arranged for exerting a continuous pressure on the side surfaces of the tube tract (12), simultaneously to the peristaltic compression on the upper surface of the tube tract (12), but so as to allow the mobile squeezing thereof, to restore the normal passage section of the tube tract (12) when said squeezing is not exerted.

Description

Peristaltic type pumping device and related medical apparatus, in particular for peritoneal dialysis

Description

The present invention relates to a peristaltic type pumping device, wherein a fluid is pushed along an elastically deformable tube, and to a medical apparatus comprising said device, in particular an apparatus for dialysis, with particular reference to a cycler for peritoneal dialysis, wherein a dialysing solution is slowly removed and fed from and towards a patient.

The insertion of the dialysing solution and its extraction from the abdomen of the patient represent the critical steps of the peritoneal dialysis, since they require a strict and precise control of time and treatment modes.

Moreover, the apparatuses performing this task, usually entrusted to patients who use them in domestic environment and even during sleeping, have to be particularly reliable, robust and simple to be used. As a matter of fact, any malfunction of the apparatus, and any obstacle in the dialysis procedures deriving from the wrong use of the cycler, which cannot be solved immediately, could have serious consequences on the patient's health and life.

Moreover, it is requested that the apparatus, and then in particular its pumping device, are compact and provide a use as intuitive as possible. At last, considering that this type of devices should not have economic obstacles for its spread, it should be simple to be implemented.

Several types of cycler are known using at least a pumping device for injecting a dialysing solution into the patient's abdomen and for discharging it subsequently by extracting it from the same site through a suitable catheter, but their use often has excessive complications, even deriving from the complexity of their structure .

US patent No. 6,270,326 B1 describes a device for transfusions comprising a peristaltic pump according to different embodiment versions, wherein a compression is exerted along the whole length of a deformable tube tract, but without a system causing simultaneously the return of the tube tract to a normal configuration, that is with the maximum passage section.

International patent application No. WO 99/53201 A1 describes a peristaltic pump wherein an elastically deformable tube tract is pressed alternatively according to directions perpendicular therebetween, to obtain a peristaltic effect and, separately, to deform the tube in an opposite way compared to the one of the peristaltic effect, to ease the return thereof to a normal section.

British patent application No. GB 369,037 A describes a peristaltic pump with a helical screw rotating element acting on a deformable tube tract, wherein a comb-like structure with prongs is placed therebetween which prongs are moved downwards by the helical screw thus exerting a peristaltic squeezing, without any tube return to a normal section being provided.

US patent application No. US 2011/242,234 A1 describes a peristaltic device wherein a deformable tube tract is pressed, on its own length, by a sequence of pistons acting sequentially to exert a peristaltic compression on the tube .

The technical problem underlying the present invention is to provide a pumping device for medical apparatuses allowing to obviate the drawback mentioned with reference to the known art .

Such problem is solved by a pumping device as above specified, and as defined by the enclosed claim 1.

Additional aspects of the invention are defined in the depending enclosed claims. The invention further relates to a medical pumping apparatus comprising at least a peristaltic pump as detailed hereinafter.

In the pumping device of the present invention thus there is an elastically deformable tube tract, arranged in a linear, in case rectilinear, configuration, arranged inside a destination seat having a bottom thereupon a lower surface of the tube tract is rested, whereas on the opposite upper surface a peristaltic compression is exerted .

It is determined by a rotating operating element, for example of the type provided with one or more helicoidal ribs arranged projecting on the surface of a cylinder, which determines on said tube tract a continuous mobile squeezing, which moves in a predetermined direction, in case mediated by a membrane kept still with respect to the tube itself; the direction according thereto the continuous squeezing moves determines the flowing direction of the fluid flow.

Simultaneously to said continuous squeezing, on the side surfaces of the tube, that is those separating said lower resting surface and upper squeezing surface, means acts for pressing laterally the elastically deformable tube tract .

Such compression is continuous and it is exerted on the whole length of the tube tract thereon the peristaltic compression is exerted, but it is so as to not prevent the squeezing of the tube tract caused by the mobile peristaltic compression: this guarantees an immediate and continuous return of the section of the tube tract to its starting configuration, that is the one with the maximum extension .

An additional advantage of the pumping device according to the present invention then lies in its reliability and operation simplicity, coupled with a considerable structural robustness. Moreover, it allows the use of tubes made of material having not perfectly elastic behaviour with respect to the currently used silicone tubes, but more resistant and reliable.

The present invention will be described hereinafter according to a preferred embodiment example thereof, within a medical apparatus for peritoneal dialysis, provided by way of example and not for limitative purposes with reference to the enclosed drawings, wherein :

• figure 1 shows an axonometric view of a pumping device according to the invention, in closed position;

• figure 2 shows an axonometric view of the pumping device of figure 1, in opened position;

• figure 3 shows a schematic representation of a kit for peritoneal dialysis which is used with the pumping device of figure 1;

• figure 4 shows an axonometric view of the pumping device of figure 1, in opened position and with a portion A of the kit of figure 3 inserted in the pumping device;

• figure 5A shows an axonometric view of the pumping device of figure 1, in opened position and with the cover the interior thereof is visible;

• figure 5B shows an axonometric view of the pumping device of figure 1, without cover and with a portion

A of the kit of figure 3 inserted into the pumping device ;

• figure 6 shows an enlarged perspective view of a detail of the device of figure 1;

• figure 7 shows a top perspective view of the detail of figure 6;

• figure 8 shows a plan view of the pumping device of figure 1, with opened cover and with a portion A of the kit of figure 3 inserted into the pumping device ;

• figure 8A shows a section view of the pumping device of figure 8, according to the plane B-B of figure 8;

• figure 8B shows an enlargement of a detail C of the view of figure 8A;

• figure 8 shows a plan view of the pumping device of figure 1, with the cover in closed position and with a portion A of the kit of figure 3 inserted into the pumping device;

• figure 9A shows a section view of the pumping device of figure 9, according to the plane B-B of figure 9; and

• figure 9B shows an enlargement of a detail D of the view of figure 8A.

With reference to figure 3 a kit for peritoneal dialysis is described, designated as a whole with 100, comprising a plurality of charging bags 8, including a dialysing solution for peritoneal dialysis which has to be introduced into the patient's abdomen so that it fills-in the so-called peritoneal cavity P. Once a certain period of time, of some hours, has elapsed, the dialysing solution absorbs, through peritoneum, a very vascularized intra-abdominal membrane, an amount of impurity from the patient's blood. At the end of the process, the "dirty" solution then has to be sucked from the peritoneal cavity P so that it is accumulated in a discharging bag 10.

The introduction and extraction take place through a peritoneal catheter 14 which is inserted surgically into the patient's abdomen and which has at a distal end a connector 13, represented schematically in figure 3, which is useful to connect the peritoneal catheter 14 to a connection duct 12 implemented by a tube made of elastically flexible material, in particular a material of rubbery type.

The connection duct 12, in turn, ends with a Y-like connection 11, connecting it to a first charging duct 29 which in turn branches, at a multi-way manifold 9, in a number of second charging ducts 30 connected to respective charging bags 8.

Moreover, the second branch of said Y-like connection 11 is connected to a discharging duct 31 leading to said discharging bag 10.

In figure 3, a portion of the kit for dialysis 100 is designated with A, which is concerned with the herein described pumping device, designated as a whole with 1, which implements the herein described cycler for peritoneal dialysis. It is meant, however, that the pumping device which will be described hereinafter could be useful for use in other apparatuses, in particular medical apparatuses requiring the controlled pumping of a fluid, for example even to perform transfusions.

The device 1 comprises a base 3 of box-like type, having a first operating top surface 32, apt to receive said portion A of the kit for peritoneal dialysis 100, and in particular the Y-like branch 11 and the connection duct 12, implemented by a tube even not suitable to the use in a peristaltic pump.

In fact, the tubes used in the peristaltic pumps normally are made of highly elastic and typically silicone-based materials, whereas the tubes used in the kits for peritoneal dialysis are made of less elastic materials, such as for example PVC, but however suitable chemically to the contact with the dialysis fluid formed by water enriched with several solutes suitable to produce, once they are in the patient's peritoneum, an osmotic effect which withdraws liquids and impurities from the body of the dialysed patient.

In the herein described case the fluid is a dialysing solution, generally purified water with solutes suitable to the purpose by type and quantity.

On said top surface 32 of the base 3, the device 1 comprises a seat 6 for receiving a portion of connection duct, that is a tube tract 12, having the above-mentioned features, and then it can be stressed mechanically for transferring to a fluid contained therein a prevalence so that it could flow, with a predetermined constant flow rate, in a direction or the other one towards the duct 12.

Such seat 6 then comprises even a Y-like bifurcation which divides it into two branches 61. At each one of said branches 61, the base 3 comprises respecting gripper clamping devices 5, of the electro-actuated type.

Each clamping device 5 comprises a cylindrical clamping gripper thereon a groove 52 (figure 5A) is implemented apt to receive a tract of charging duct 29 or discharging duct 31 of the kit 100 (figure 4) .

Under the condition wherein the groove is aligned with the path of the ducts 29, 31 imposed by the destination seat 6, such ducts are not obstructed or deformed in any way. On the contrary, the same will result wholly obstructed through the implementation of one of said grippers 51 according to suitable control modes apt to manage the flows during the dialysis treatment.

The grippers 51 are controlled from an open position, with respective not deformed duct, to a closed position, with the respective clamped duct, by an electro mechanical actuator included in the base 3 (figure 2) .

Said seat 6 then receives said tube tract 12 by extending for its whole length; the seat 6 comprises a bottom, thereupon a lower surface of the tube tract 12 rests, which is opposite to a corresponding upper surface of the tube tract 12, and the lower and upper surfaces are separated by side surfaces of the tube tract 12 opposite to one another.

The top surface 32 of the base 3 is closed again by a cover 2 of revolving type, hinged at one side of the base 3 itself by means of a hinge 4. The cover 2 too has a box-like structure and it closes again on the base 3 by overlapping thereto perfectly, thus forming therewith one single closed box-like structure (figure 1) .

Therefore, the cover 2 implements a substantially book like closing, wherein an open position (figure 2), with the cover 2 forming an angle of about 120° with the base 3, and a closed position (figure 1) are identified.

The exposed surface of the cover 2 comprises some push buttons 22, in particular a switching-on button, a switching-off button and a selection button 24, and a display 23 connected to an electric card inserted into the cover 2, constituting the control unit of the pumping device 1 and controlling the operation thereof (figure 1) ·

Moreover, there are light warning devices, associated to the selection buttons 24, showing a user which is the ongoing operation phase and, in particular, in which direction the fluid is pumped inside the duct 12.

It is meant that the display 23 can provide the user additional pieces of information about the ongoing process, and it can even be of touch screen type.

At the side of the base 3 and of the cover 2 opposite to said hinge 4, a recess 25 is implemented which eases the separation between base 3 and cover 2, by allowing the insertion of a user's fingers.

The cover 2 has a second operating surface 33 facing towards said first operating surface 32 of the base and matching therewith when the cover 2 is in closed position .

On said second operating surface 33 there is a stiff and deformable membrane 15 which, when the cover 2 is in closed position, is adhered to the seat 6, in particular to the upper surface of the tube tract 12, so that deformable membrane 15 and duct be in contact at least at said tube tract 12.

In the thickness of the cover 2 a rotating operating element 16 of the peristaltic pump is received which, in this embodiment example, has an endless screw-like shape with one or more helical ribs projecting from a cylindrical surface. In fact, it is constituted by a cylinder 161 which rotates around its own longitudinal axis and has, on its external cylindrical surface, a rib 162 (figure 6) with a helix-like profile extending on said surface with a constant helix pitch (figures 5A and 5B ) .

In this example, the cylinder 161 is supported at one end by an idle end pin 163, whereas on the other end there is a pinion 164 controlled by a toothed belt 18, dragged by an electric motor 17 received too inside the cover 2 and integral thereto.

The cover 2 could receive even a battery and a possible recharging unit, or the electric motor 17 could be connected directly to an external electric energy source, preferably having low voltage.

The electric motor 17, controlled by said control unit, extends with a longitudinal axis, which corresponds to its rotation axis, parallel to the rotation axis of the rotating operating element 16. It is capable of rotating the latter in both rotation directions.

Due to the effect of this rotation, the rib 162 deforms the deformable membrane 15 which, in turn, exerts a pressure on the duct 12 it its seat 6. Such pressure produces a peristaltic effect which transfers a certain prevalence to the fluid in the duct 12, by pushing it along a flow direction imposed by the rotation direction of the rotating operating element 16.

Therefore, the rotating operating element 16 exerts a continuous squeezing on said upper surface of the tube tract 12, in case mediated by the membrane 15, squeezing which is mobile by moving according to a predetermined direction, thus producing a peristaltic compression of the tube tract 12.

The flowing direction of the fluid flow in the tube tract 12 is then determined by the direction according thereto said peristaltic squeezing of the tube tract 12 moves, in turn determined by the rotation direction of the rotating operating element 16.

Thanks to the interposition of the membrane 15, the duct 12 does not receive by the rotating operating element 16 an axial stress but only a transversal stress which squeezes it (figure 9B) . To this regard, it is to be noted that the deformable membrane 15 is anchored to the cover 2, then independently with respect to the tube tract 12 so that it is still with respect thereto.

Due to the effect of the rotation of the rotating operating element 16, the squeezing deformation moves along the direction which, inside the duct 12, is imposed to the liquid flow which is then moved with a constant flow rate, without time variations, which can be determined with precision by the rotation speed of the rotating operating element 16.

Both the rotating operating element 16, which in the present example has no mobile portions such as rollers or the like, and the deformable membrane 15 are made of anti-friction material, to ease the sliding of the rib 162 without requiring a lubricant.

Even the seat 6 has a particular structure which is described hereinafter. In fact, the duct 12 is arranged resting upon a support 19 which implements said bottom of the seat 6, made for example of hard rubber or another high-friction material.

The support 19 is solid and extends from the resting surface of the duct 12 downwards, with two opposite side surfaces .

In the present pumping device then means is provided to compress laterally the tube tract 12 which act on the whole length of the tube tract 12 subjected to peristaltic compression, and acting continuously and simultaneously to the peristaltic compression, so as not to influence the fluid flow rate which has to remain constant and determinable with precision.

This compression means then is arranged to exert a continuous pressure on the side surfaces of the tube tract 12, simultaneous to the peristaltic compression on the upper surface of the tube tract 12, but the pressure therewith said side compression is exerted however is so as to allow the peristaltic squeezing of the tube tract 12, which is mobile and which then is not prevented from its motion, to restore the normal passage section of the tube tract 12 when said squeezing is not exerted.

In order to implement the above-mentioned compression means according to a preferred embodiment version thereof, on the sides of the support 19 a pressing element 20 is fastened, which exerts a pressure on the duct 12 when this is not stressed by peristalsis. In particular, the device 1 comprises a pair of pressing elements 20, one on each side of the support 19, which are symmetrical and have a substantially comb-like structure: they have a base sheet 26 and a plurality of approached prongs 21 pressing laterally on the side surfaces of the tube tract 12. Advantageously, the pressing element 20 is made of elastic material, with a prefixed elastic constant so as to determine on the side surfaces of the tube a continuous and constant pressure, and however well-known during planning.

The elastic pressure exerted on discrete portions along the extension of the duct 12, but arranged without any continuity solution, is then lower to the force deriving from the pressure exerted perpendicularly by the rotating operating element 16 which determines peristalsis, and it does not hinder then the squeezing of the tube tract 12.

However, when peristalsis ceases its effect at a certain discrete portion of the duct 12, this is compressed laterally and, in this way, acquires again quickly its circular shape and its original section, thus by easing the sliding of the fluid and decreasing the pressure drops along the duct 16.

Therefore, the connection duct 12 connected to the peritoneal catheter 14 constitutes the elastically deformable tube tract of the peristaltic pumping device, which is arranged with a rectilinear linear configuration in a destination seat wherein it can be easily inserted and extracted.

The rotating operating element 16 is capable of determining on said tube tract a squeezing of the section, squeezing which is mobile and moves, when the rotation of the rotating operating element proceeds, in a flowing direction of the fluid flow imposed indeed by the rotation direction of the operating element 16, but without any creeping effect on the tube tract.

In order to favour the quick restore of the normal passage section of the tube tract, the device has at least a pressing element, two in the present example, exerting a pressure on the tube tract in a direction which opposes to said squeezing, in particular a direction rotated by about 90° with respect to the direction of the squeezing pressure.

The extent of such restoring pressure is lower to the squeezing pressure, and then it is so as to allow squeezing, but it is exerted on a plurality of discrete portions, separated therebetween, of said tube tract. In this way, the discrete portions which are subjected to the squeezing pressure are deformed and determine the peristaltic effect, whereas the discrete portions which are not subjected to squeezing re-assume quickly their normal passage section.

This allows to implement a peristaltic effect on a duct linear tract, which then has not to be curved and bent in its insertion in the destination seat, insertion which is then simplified. Moreover, the duct linear arrangement makes the pumping device more compact, with a decrease in the mobile portions.

Moreover, downwards of the insertion of the duct 12 in its seat, the activation of the pumping device 1 is obtained by simply re-closing the cover 2 on the base 3.

There could be a sensor, of magnetic type or even a simple mechanical switch closed by the overlapping of cover and base, which detects the closing of the device and allows the ignition of the electric motor 17 at the requested rotation regime.

In case of peritoneal dialysis, once inserted the portion A of the dialysis kit 100, it is sufficient to close the device to start the process: by making the rotating operating element to rotate in a first direction, the dialysing solution is inserted into the peritoneal cavity P of the patient, after heating of the solution until physiological temperature. In this phase, the discharging duct 31 is suitably clamped by the respective clamping device 5. Once the insertion of the solution has ended up, the volume thereof can be controlled with precision by the flow rate and by the ignition time of the electric motor, the device will remain switched off for a predetermined time interval, wherein both the charging duct 29 and the discharging duct 31 are clamped by the respective clamping devices 5.

The volume of solution to be inserted, the length of the waiting interval and the volume of "dirty" solution to be extracted could be determined during the step for setting and customizing the device for a predetermined patient.

In case, once these parameters have been set with a specific activation key, the user will not be enabled to change such parameters .

Once said time interval has elapsed, the device will be activated again by its control unit, by rotating the rotating operating element 16 in opposite direction. The clamping of the discharging device 31 will cease, whereas the charging duct 29 will remain clamped.

In this way, the "dirty" solution is extracted until filling-in the target discharging bag 10.

Once the extraction has ended up, the discharging duct 31 is clamped again, and the process ends with the disconnection of the connection duct 12 from the connector 13 and then from the peritoneal catheter 13, and with its extraction from the pumping device 1.

At this point, the whole kit 100 could be disposed of as special waste and subsequently replaced by another kit for the subsequent dialysis.

TO the above-described pumping device a person skilled in the art, with the purpose of satisfying additional and contingent needs, could introduce several additional modifications and variants, however all comprised within the protective scope of the present invention, as defined by the enclosed claims.

Claims

1. A peristaltic type pumping device (1), wherein a fluid is pushed along an elastically deformable tube, comprising :

• a deformable tube tract (12) and a seat (6) receiving it extending for its whole length, the seat (6) comprising a bottom, thereupon a lower surface of the tube tract (12) rests, opposite to an upper surface of the tube tract (12), the lower and upper surfaces being separated by side surfaces of the tube tract (12) opposite to each another;

• a rotating operating element (16) which, by exerting a continuous squeezing on said upper surface of the tube tract (12), which moves according to a predetermined direction, produces a peristaltic compression of the tube tract (12), wherein the flowing direction of the fluid flow in the tube tract (12) is determined by the rotation direction of the rotating operating element (16); and

• means for pressing laterally said tube tract (12), arranged for exerting a continuous pressure on the side surfaces of the tube tract (12), simultaneously to the peristaltic compression on the upper surface of the tube tract (12), but so as to allow the mobile squeezing thereof, to restore the normal passage section of the tube tract (12) when said squeezing is not exerted.

2. The pumping device (1) according to claim 1, wherein said rotating operating element (16) has an endless screw-like shape and it is constituted by a cylinder

(161) which rotates around its own longitudinal axis and which has, on its external cylindrical surface, a rib

(162) with a helix-like profile, which extends on said surface with a constant helix pitch.

3. The pumping device (1) according to claim 2, wherein between the rotating operating element (16) and the tube tract (12), on the upper surface of the tube tract (12), a deformable membrane (15) is arranged, the rotating operating element (16) and the deformable membrane (15) being made of an anti-friction material, the deformable membrane (15) being anchored with respect to the tube tract (12) so as it is still with respect thereto.

4. The pumping device (1) according to claim 3, comprising a base (3) having a first operating surface (32), wherein said seat (6) is formed, which is re-closed by a cover (2) having a second operating surface (33) facing towards said first operating surface (32) of the base, and which mates thereto when the cover (2) is in closed position, at said second operating surface (33) said deformable membrane (15) being provided which, when the cover (2) is in closed position, is adhered to the seat (6) so that deformable membrane (15) and tube tract (12) are in contact, said rotating operating element (16) being received inside said cover (2) .

5. The pumping device (1) according to claim 1, wherein said seat (6) comprises a Y-like bifurcation which divides it into two branches, and at said each one of said branches the pumping device (1) comprises respective clamping devices (5) of a tube (29, 31) inserted therein.

6. The pumping device (1) according to claim 5, wherein the clamping device (5) comprises a gripper (51) on a diameter thereof a groove (52) is implemented, apt to receive a tube tract (29, 31), the disks (51) having a respective actuator controlling them from an open position, with the respective not deformed tube, to a closed position, with the respective clamped tube.

7. The pumping device (1) according to claim 4, wherein the rotating operating element (16) is controlled in rotation by an electric motor (17) received too in said cover (2), the closing of the cover (2) by authorizing the ignition of the electric motor (17) .

8. The pumping device (1) according to claim 7, wherein the cover (2) includes a control unit being responsible for the operation of the electric motor (17) .

9. The pumping device (1) according to claim 1, wherein said compressing element (20) has a substantially comb like structure and has a base sheet (26) and a plurality of prongs (21) approached and adjacent therebetween, pressing laterally on the tube tract (12) without continuity solution according to a direction substantially rotated by 90° with respect to the squeezing direction of the tube tract (12) .

10. The pumping device (1) according to claim 4, wherein the cover (2) is of revolving type, hinged at one side of the base (3) itself by means of a hinge (4) .

11. The pumping device (1) according to claim 1, wherein said tube tract (12) is made of PVC .

12. A medical apparatus for peritoneal dialysis, comprising a pumping device (1) according to one of claims 1 to 10, and a peritoneal dialysis kit (100) comprising a plurality of charging bags (8), which include a dialysing solution for peritoneal dialysis, at least one discharging bag (10), a connection duct (12) apt to be connected to a peritoneal catheter (14) and to be inserted into the seat of the pumping device.