WO2017089882A1

WO2017089882A1 - Apparatus for the treatment of the blood and peristaltic pump

Info

Publication number: WO2017089882A1
Application number: PCT/IB2016/001669
Authority: WO
Inventors: Michele Fontana
Original assignee: Everflow SRL
Current assignee: Everflow SRL
Priority date: 2015-11-27
Filing date: 2016-11-24
Publication date: 2017-06-01
Anticipated expiration: 2018-05-27
Also published as: ITUB20155959A1

Abstract

An apparatus for the treatment of the blood, of the type usable to perform an extracorporeal treatment of the blood by means of one or more elements through which the blood is passed under the pressure of a peristaltic pump acting on a tube segment or sub-pump tube; the apparatus comprises a kit (102) and a base (101) which, in use, are associated themselves to enable the implementation of the treatment on the blood, in which: said kit (102) supports said one or more elements (106) for the treatment of the blood, and comprises a stator (2) defining a support for said sub-pump tube (3), the sub-pump tube (3) being wound around the stator (2), leaving outside its outer or convex side; said base (101) being provided with a motorized pressing roller (1) which, when said kit (102) is associated with said base (101) is disposed and is acting externally with respect to the stator (2) and to the path of the sub-pump tube (3), so as to compress the sub-pump tube (3) on its outer or convex side.

Description

TITLE: APPARATUS FOR THE TREATMENT OF BLOOD AND PERISTALTIC PUMP.

* * *

DESCRIPTION

The present invention relates to an apparatus for the treatment of blood and a peristaltic pump.

In particular, the present invention has a particular use for the treatment defined as "extracorporeal circulation" treatments, in which a peristaltic pump is used to move the blood that undergoes the treatment.

The invention is able to eliminate the drawbacks of the known art, allowing an extended service life of the tube, a minor damage to any solid parts within the fluid (less hemolysis, in case the fluid being pumped is blood) and extreme rapidity in the mounting of the coupling tube/pump that can (in the preferred embodiment) be realized as a disposable kit.

It is known that the current peristaltic pumps are composed of a cylindrical outer stator and an inner rotor coaxial to the stator. The rotor comprises one or more pads or rollers and is moved by a motor connected to it.

A portion of the pipe or "sub-pump tube" (in such a way is in fact called in technical jargon the portion of elastic tube which undergoes to the action of the peristaltic pump) is placed manually between the space comprised between the inner surface of the stator, which acts as a reaction plan, and the circumference described by the pressor elements (pads or rollers) that rotate integral with the rotor, arranged along the outer surface of the latter.

In conventional peristaltic pumps, the space for housing the sub-pump tube is designed so that it is equal to the sum of the thickness of the walls of the tube to be pressed (more or less small variations are chosen in function of the type of tube or of the fluid to be pumped). The rollers compress the tube progressively against the stator in their rotational movement. The compressed tube generates the flow due to the variation of its internal volume.

In the section of tube disposed upstream of the compression carried by the rotor (or on a portion already been affected by the compression of the pressure rollers), the tube returns to its original shape by sucking the fluid to be pumped. The cyclical and one-way repetition of this action permits pumping. The advantages of the present invention will be more evident thanks to the description which follows, made with reference to the accompanying figures in which:

- Fig.l is a top plan view of a possible embodiment of a pump made in accordance with the invention;

- Figs.1 A and IB are, respectively, two views in section along the lines A-A and B-B of Fig. l ;

- Fig. 2 is a side view of the example of embodiment of the pump shown in Fig.1 ;

- Figs. 3, 4, 5 are schematic perspective views showing the stator and the sub-pump tube of the embodiment of the preceding figures; in particular, Fig.3 is relative only to the body of the stator, Fig.4 is relative only to the sub-pump tube in the arrangement assumed when associated to the stator, and Fig.

5 is relative to the whole formed by the stator and sub-pump tube;

- Figs. 6, 7, 8 represent a possible example of embodiment of a kit usable in the apparatus of the invention; in particular, Fig. 6 is a top perspective view, Fig. 7 is a perspective view from below, and Fig. 8 is a side view;

- Figs. 9, 10, 11 are diagrams illustrating the configuration of the stator and the mode of interaction between the pressor and sub-pump tube;

- Figs. 12, 12A, show a possible example of embodiment of a sub-pump tube and a stator, represented, respectively, a side view and in a sectional view along the line A-A of Fig.12;

- Fig. 13 shows a possible embodiment of a stator according to the invention;

- Fig. 14 shows a base made in accordance with the present invention, in a perspective view from above;

- Fig.14A is an enlarged detail of the base of Fig.14;

- Figs. 15 and 16 show the embodiment of the base of Fig.14 together with a kit according to the present invention; Fig. 15 represents the two parts during assembly, Fig. 16 represents them after assembly. For a better understanding of the invention reference it will first be made to Figs. 1-5. In a pump (10) according to the present invention, the stator (2), rather than external, is placed inside the circumference (4) described by the rotation of the pressing roller (1). On the stator (2) is mounted the sub-pump tube (3); said tube is compressed between the pressing roller (1) and the stator itself. The stator (2) is removable to facilitate the mounting of the tube on the stator and especially the positioning of the whole tube/stator on the pump.

In the preferred (but not limiting) solution shown in the drawings, the set tube/stator is designed as a preassembled disposable kit to further increase the ease of assembly and the operational safety.

In the preferred (but not limiting) solution it is a single pressing roller to increase the pump efficiency but especially to reduce the wear of the tube. This solution has a helical arrangement of sub-pump since the same must necessarily make one complete revolution (360°) so that, at each point of the cyclic rotation of the pressing roller there is a portion of tube occluded by the same roller.

In the preferred (but not limiting) solution further arcs of a circumference of the sub-pump tube are dedicated to allow a gradual achievement of full occlusion and the full reopening of the tube by the pressing roller, which, in its path around the stator will compress always at least 2 coils of sub-pump, one of them always occluded while the other, alternately, in occlusion or opening.

The pressing roller (1) is provided with motor means acting to allow the rotation (Rl) of the same roller, in a clockwise direction in the example, around the vertical axis, indicated with (5) in the drawings. The pressing roller (1) is supported by an idle rotatable base (11), which rotates around the stator (2)

(clockwise rotation about the axis 6 of the stator, indicated with R2) allowing the cyclic interaction between the sub-pump tube supported from the same stator (2) and the pressing roller (1). In the example represented in Figs.1-5, the swivel base (11) is rotatable relative to a fixed base (12) on which is fixed, preferably in a removable manner, the stator (2).

In Figs. l and IB, to better show the structure and operation of the peristaltic pump (10) of the invention, the references (3A) and (3B) indicate two portions of the sub-pump tube (3) disposed, respectively, upperly (3A) and at the bottom (3B). Fig. IB shows as the bottom of the tube (3B) is compressed by the pressor (1) for a maximum value, while the upper part (3 A) is in the configuration in which the compression is to a lesser value.

The stator (2) is provided with an external groove (20) (the development of which will be described below) in which is received the sub-pump (3); the inlet end (3in) is fixed in correspondence of the locking portion (21); the outlet end (3 out) passes through the hole (22) of the stator (2).

To better describe the operation of the present invention is hereinafter considered the path of the fluid as a reference.

A first section of tube (3in) defines the input connection of the sub-pump placed inside the removable stator. The stator is therefore "removable" from the base of the pump where the pressing roller is housed but is always solidly connected with the mounting plate to the pump base on which the connection tubes and other components are mounted. Said portion of said tube is, in the present description, represented by a normal tube for medical use.

The sub-pump tube (3) (of elastic material with shape memory, for example PVC or silicone), mounted on the detachable stator (2), is inserted into the housing (21) and is wound around the wall of the same stator. The stator, in this first portion, is shaped as a spiral (20) that (as shown in Figs.1-5) in 180° grows to an appropriate value, bringing the tube from a position in which it is only touched by the circular path of the pressing roller up to a position in which it is subjected, with a slow and progressive pressing, to the complete compression.

The sub-pump tube remains at this distance (fully compressed by the roller) for a full turn (360°), wrapped around the stator which, in this portion, has a constant circular section.

After the completion of the rotation, in the subsequent 180°, the groove (20) of the stator (2) has again a spiral section, and the distance from the pressing roller gradually decreases up to allow the sub-pump tube that surrounds the complete distension (less interference with the roller) and return to the original diameter. Here sub-pump tube passes inside the stator to exit at the ends marked by the reference (3 out).

In practice, the stator (2) is a body substantially cylindrical and hollow inside to allow connections to the hydraulic circuit for the fluid input and output (see central axial hole 22). Externally, referring to the arrangement of Fig.5, from the top down, the stator (2) has a first portion which extends in a spiral section with increasing diameter until reaching a maximum value that is maintained for 360° (small variations in more or less compared to that amplitude of arc will be decided on according to the type of tube or fluid to be pumped) assuming a circular cylindrical shape, and a final portion (180° in the example) when again a path spiral-shaped, but this time decreasing, brings back to the minimum initial diameter. The path of the sub-pump tube defines a helix along the axis of the stator to prevent the tube overlaps.

The advantages deriving from this configuration are, in the purpose of the present invention, the following:

a) The pressing roller compresses the tube from the convex side, namely externally to the curve that the same tube accomplishes around the stator. In this case, the necessary force to the compression of the tube is smaller because the tube from the convex side is subjected to a tensile force (due to its arrangement along a circumference) which tends to bring towards the walls of the tube. This results in less wear of the tube and a reduction of the trauma against the pumped fluid (important in the case of blood). It is obtained a longer life of the tube and less hemolysis.

b) Compared to a conventional peristaltic pump, with the same diameter of the pressing roller and the same circumference formed by the tube, the deformation given by the pressing roller to the compressed tube from the outer side is lower; it follows a further reduction in the wear of the tube. Furthermore, the volume subtracted from the compression of the rotor in the tube is less. It is obtained a more efficiency in the volume pumped per revolution.

c) The compression of the tube is very gradual if compared to traditional pumps thanks to a slow increase in the diameter of the stator. The stress on the tube caused by the compression / decompression of the same against the stator is distributed along an arc of 180° + 180° (in the embodiment shown). In traditional pumps this variation, from the full diameter to the complete occlusion and vice versa, takes place in a limited arc (10°-20°). To increase this value often the stator is designed not circular but elliptical. The solution illustrated here, in addition to further increase the duration of the tube, also it allows to reduce the pressure peaks due to the sudden tube compression / decompression. This reduces the pulse on the tube due to sudden variations in flow and pressure and back flow.

d) In the illustrated and preferred embodiment (but not limiting) is used a single -roller rotor which offers the advantages of greater pumping efficiency and less wear of the tube (that is compressed once for each revolution of the pressor).

e) To obtain the solution described in the preceding paragraph it is necessary that the path of the sub- pump tube is not coplanar but that it develops along a cylindrical helix of at least one loop (two loops in the described example). This need could complicate the manual assembly of sub-pump. To obviate this difficulty, and to achieve further advantages, it has been foreseen the possibility of making the stator removable from the seat of the pump.

f) The removable stator simplifies the operations of the tube fitting because this operation contemplates the association to the pump of the already assembled whole (preferably disposable) constituted by the coupling tube / stator. There are advantages for the safeness due to the reduced mounting requirements and subsequent reduction of operating errors.

g) The whole tube/stator can be integrated with auxiliary means for the proper locking in place and with suitable hydraulic connections to connect to the rest of the circuit.

Further advantages and features of the invention will hereinafter be described with reference to Figg.6- 16.

An apparatus (100) for blood treatment according to the invention is substantially composed of two parts: a base (101) and a kit (102), preferably of disposable type. The base (101) is constituted by a housing of appropriate shape containing:

- a screen (103) (which can be a touch screen) for providing information on the treatment and for allowing the operator to intervene on the parameters of the treatment; the interaction can be integrated with knobs and / or various cursors;

- the management electronics, the electric motors, the contacts and the means for exchanging data and connectors for exchanging gas and liquid;

- the peristaltic pump (10) with a single outer pressor (1) provided so as to be easily and quickly "loaded" with the kit (102).

The kit (102), which can advantageously be of the disposable type, is pre-assembled at the source to avoid errors and to simplify the procedure. The kit is ideally divided into two parts by a plate (104) made of plastic material. In accordance with the example illustrated, the plate (104) is used to associate the kit (102) to the base (101) in the predetermined position by means of simple joints as fixing means which provide also for the proper positioning and alignment of the kit on the base to ensure the geometric correctness of the couplings between the same removable kit and the pressing roller (1) of the pump (10) on the base (101).

In the part which will called "lower" (inferiorly arranged in Figs 6, 7, 8, 15, 16), and which is destined to interact with the pump, is located a rigid support (2) that corresponds to the stator (2) previously described for the example of Figs.1-5, and which supports the sub-pump tube (3) and guides the same along a specially shaped path. In this embodiment of the invention the support (2) it is rigidly fixed to the plate (104).

The sub-pump tube (3), which is subjected to the pumping action of the pressing roller (1) in the lower part of the plate (104) is connected, through the plate (104), to the upper part of the kit (102), where are placed components for the chosen extracorporeal treatment (106) (for example, haemofilters, adsorbers, oxygenators or other), the inlet and outlet tubes for the blood that are connected to the patient (not shown), various sensors (pressure, temperature, blood losses, air bubbles, etc.) that communicate the data to the base (101) through appropriate means (sliding electric contacts and / or connectors for the physical transmission of pressures or other), as well as the ducts and connection tubes between the various components (not illustrated).

The kit (102) so formed provides a set which allows the operator to realize a simple loading of the same kit (102) on the base (101) forgoing complex manual operations otherwise required on existing machines for extracorporeal treatments, while maintaining a compact shape and reducing greatly fitting errors.

The lower part of the kit (102), namely the one arranged below the plate (104), contains the support (2) for the sub-pump tube and the tube sub-pump (3) itself.

The support (2), called also stator in the present description, has the following particular characteristics: by means of a first cylindrical surface with a spiral development (marked by I in Fig. 12), allows the sub-pump tube to gradually engage with the action of the pressing roller in an arc of at least 90° (preferably 180°) to minimize the mechanical impact and the consequent wear of the tube itself as well as to minimize the traumatic effects of pressure against the solid particles transported by the blood (in conventional roller pumps the transition from full opening of the sub-pump tube to its total or almost total occlusion it takes place in an arc of a few degrees);

- a second cylindrical surface with a circular development (marked by II in Fig. 12) maintains occluded

(or almost occluded) the sub-pump tube for an arc variable between 300° and 360°;

- a third spiral cylindrical surface (substantially specular to the first and marked by III in Fig. 12) allows a gradual relaxation of the sub-pump tube, bringing the same away from the action of the pressor in an arc of at least 90 ° (preferably 180 °) useful to prevent abrupt phenomena of "back flow" due to too rapid return of the tube (3) to its original dimensions.

Since the support (2) of the sub-pump tube (3) consists of two symmetrical halves (indicated by 2A and 2B in Fig.13) having a common axis (X in Fig. 13, corresponding to the axis 6 of Figs. 1- 5), varying the mutual angular position by rotation about said axis of said two halves (2A, 2B), it is possible to mechanically intervene on the arc of occlusion, that can also be varied during operation of the pump, from an initial maximum of 360° to make self-priming the pump, and gradually reducing it in order to decrease the "shear stress" or the tangential friction which is the main cause of damage to blood cells (hemolysis), ensuring a pumping effect more smoothly and with low pulsation. The variation of said angle can be effectuated automatically with a servo motor and also be dependent on the pumping speed: 360° when the pump is stopped and during the filling of the tubes to decline gradually when the tubes are filled and as the speed increases.

The support (2) of the sub-pump tube or stator (2) has a profile (see the portion of Fig.12) defining a helix whose projection, on the plane orthogonal to the helix itself, has initially a part which is spiraling from a smaller diameter to a larger diameter along an arc preferably of 180 degrees; after it has a part of 300/360 degrees (see the portion II of Fig.12) that has a circular development of diameter (D2) and a last part (see portion III of Fig.12) which has a spiral development from the diameter (D2) to the diameter (Dl) along an arc preferably of 180 degrees to the diameter (Dl) around the surface of the support (2). The diameters Dl and D2 differ in at least the value of the internal diameter of the sub- pump tube (3) employed; this is to allow for a smooth transition from the total patency of the tube to the total or almost total occlusion of the same. The support of sub-pump tube (3) provides for two fixings of the tube to said support only near the ends of the tube (3) itself. This is to keep the tube in its ability to move partially and limitedly along its own axis, thus it is avoided the "stretching" and other mechanical stresses that impair the efficiency of pumping and the mechanical life of the sub-pump tube itself. This "freedom" of the sub-pump tube movement is made possible by the characteristic of the pressor (1) of the pump that being "active", i.e. directly put into rotation on its axis (5), along the orbit around the support (2) and to sub-pump tube (3) driven by its own rotary movement, advancing on the surface of the tube (3) by friction instead of being pushed by an arm that drags, dragging and "stretching" in turn the sub-pump tube itself, as will be seen better later. The support (2) is advantageously realizable in rigid plastic material (polycarbonate, PVC or other) capable of ensuring the sufficient rigidity to counter the pressor action of the rotor (1) and, then, the effectiveness of the pumping action. It can be obtained by molding or injection, thereby allowing a reduction of costs adapted to make it a disposable component therefore suitable to be replaced at every single treatment although the duration of some days.

The pressing roller (1) rotates externally to the stator (2) where is housed the sub-pump tube (3) effecting thereby a compression of the tube radially and from the outside and towards the inner axle of the stator (2).

It is extremely advantageous the fact that the pumping apparatus is formed by two parts, the base (101) and the kit (102), distinct from each other and easily associable; this characteristic determines a more secure and fast assembly in the phase of preparation of the treatment and a more efficient implementation of the treatment.

In accordance with the present invention, the pressing roller (1) is active, that is to say that it is put in rotation on its vertical axis (5) thanks to an electric motor connected to it. The kinematic connection between the motor (not shown in the drawings) and the pressor (1) can be realized with a gear system, for example with gears or pulleys, chains and similar means of transmission of motion.

Another advantage provided by the present invention is related to the fact that the pressing roller (1) can rotated about itself, but is constrained at only one end to the rest of the apparatus. This allows a quick and easy replacement of the kit. Preferably the same pressor (1) is arranged on a platform (105) free to rotate about an axis coaxial to the axis of the stator (2), platform on which will be placed the stator itself. In practice, the pressing roller (1) does not rotate around the axis of the base (101) if it is not dragged for reaction by the friction on the tube (3); the movement impressed to the pressor (1) is only that necessary to determine its rotation around its vertical axis (5), the revolution movement around the stator (2) being determined by the interaction of the same pressor (1) with the sub-pump tube (3) supported by the stator (2). In this way the pump exerts no thrust if the stator is not properly positioned, resulting therefore inactive in the event of incorrect assembly and therefore harmless to any operator that it comes in contact.

When the kit (102) is inserted into the appropriate seat on the base (101), the pressing roller (1) comes into contact with sub-pump tube (3) mounted on the stator (2) compressing the part that follows the circular path of diameter ( D2). The stator (2) together with the sub-pump tube (3) mounted around itself is the lower part of the kit (102). The rotary movement of the same pressing roller (1), pressed against the sub-pump (3) tube, by friction and reaction, makes the pressing roller (1) rotate around the stator (2) and to the sub-pump tube (3) mounted on the latter. This movement induces a reaction even in sub- pump tube (3) which, contrary to what would happen if the pressure roller (1) were not activated but were dragged by the rotation of the platform (105), does not tend to stretch upstream of the passage of the pressing roller (1) because dragged and "stretched" by the same. This further advantageous feature of the invention allows to improve the tendency of the same tube (3) to recover the original diameter. Furthermore, it is possible to affirm that the pressing roller (1) even "pushes" backwards the tube (3) (that is, toward upstream considering the revolution path of the pressor 1), and the tube tends to rapidly return to the original diameter of not jeopardizing thus the efficiency of the pump.

The pressure roller (1) therefore describes a circumference around the stator (2) providing for the subsequent compression of all the points of the sub-pump tube (3) suitably positioned on the stator (2) thereby ensuring the pumping effect.

In order to facilitate the insertion and the extraction of the kit (102), and then of the stator (2) of which is an integral part, the platform (105) on which the pressing roller (1) is mounted may be able, thanks to a cam system, to remove or to approach the axis of rotation of the pressing roller (1) by a distance necessary to the extraction or insertion of the kit. In practice, the platform (105) is rotatably mounted idle around a vertical axis which coincides, when the apparatus (100) is mounted, with the vertical axis of the stator (2). The platform (105) is connected to a pin with vertical axis (not shown in the drawings) by means of an eccentric connection that in a rotation direction (for example clockwise) allows a free rotation (neutral) of the platform itself about its vertical axis keeping the distance constant between the pressor (1) supported and the vertical axis of the same platform (105); in the central zone allowing the introduction (and extraction) the opposite rotation direction (counterclockwise then, with the reference of the present example), the platform is moved to a very low value but also sufficient to remove the pressor (1) of the kit (102) with respect to the bases (101). In practice, the inversion of the direction of motor rotation mechanically determines the detachment of the pressing roller (1) from sub-pump tube (3): this characteristic constitutes a further operating safety in that it prevents that by mistake (human or management software) can occur a blood pumping in the opposite direction to that desired.

The association of the kit (102) to the base (101) can be realized or improved by fixing means of the type illustrated in the drawings. In particular, the kit (102) may be provided with a series of holes (108) which can be fitted on corresponding pins (110) presented by two top brackets (109) provided on the base (101). The pins (110) may have a free end with an enlarged section, adapted to be inserted with interference in the holes (108) presented from the kit (102) on the plate (104). Moreover, each of said supports (109) is provided with a lever (111) with longitudinal development, which is pivoted around an axis (K) and provided with resilient thrust means. The two levers (111) are also provided with corresponding grooves (112) so as to grip the plate (104) of the kit (102). In practice, the plate (104), and consequently the kit (102), is fixed to the base (101) because the levers (111) grip the plate (104) on two opposite sides and the pins (110) are inserted in the holes (108) of the kit (102).

The apparatus of the invention, as stated above, is usable in the blood treatments and is advantageously effective for extracorporeal treatments which have the need of a single pump (pump blood) which, by way of example, can be the subtraction of C0₂ from the blood or the subtraction of Cholesterol, Cytokines, treatments by non-injectable drugs for the elimination of Graham negative bacteria, etc. and that do not require the complexity of a machine for haemofiltration with scales, heaters, etc. to enable the health care facility to access such simple treatments with ease and without the costs arising from the use of more complex machines that can be used more profitably in cases that require specifically.

As described and illustrated it has value of example and not of limitation of any modification or variant which is comprised within the protection defined by the claims.

Claims

1. Apparatus for the treatment of the blood, of the type usable to perform an extracorporeal treatment of the blood by means of one or more elements through which the blood is passed under the pressure of a peristaltic pump acting on a tube segment or sub-pump tube, characterized in that it comprises a kit (102) and a base (101) which, in use, are associated themselves to enable the implementation of the treatment on the blood, in which:

- said kit (102) supports said one or more elements (106) for the treatment of the blood, and comprises a stator (2) defining a support for said sub-pump tube (3), the sub-pump tube (3) being wound around the stator (2), leaving outside its outer or convex side;

- said base (101) being provided with a motorized pressing roller (1) which, when said kit (102) is associated with said base (101) is disposed and is acting externally with respect to the stator (2) and to the path of the sub-pump tube (3), so as to compress the sub-pump tube (3) on its outer or convex side.

2. Apparatus according to claim 1 , characterized in that the stator (2) is provided with a helical guide for receiving said sub-pump tube (3).

3. Apparatus according to claim 1, characterized in that the stator (2) is provided with a guide for receiving said sub-pump tube (3) having three differentiated portions, with a first helical portion at increasing diameter (I), a second constant diameter helical portion (II) and a third helical portion at decreasing diameter (III).

4. Apparatus according to claim 1, characterized by the fact that said pressing roller (1) is motorized by a motor that induces the rotation of the roller around its vertical axis (3) and that is supported by a freely rotating base (105; 11), which rotates around said stator thrust by the friction between the pressing roller (1) and the sub-pump tube mounted on the stator (2) to allow the cyclic compression of said sub-pump tube (3) by means of the pressing roller (1).

5. Apparatus according to claim 1, characterized in that said kit (102) comprises a support and connecting plate (104) complementarily associable with corresponding fastening means (111, 112) provided on said base (101).

5. Peristaltic pump characterized in that it is made according to one or more of the preceding claims.

6. Peristaltic pump of the type usable to move a fluid in a tube through the compression of a portion of tube or sub-pump tube, characterized in that it comprises a motorized pressing roller (1), arranged on a first element or base (101) and a stator (2) for supporting a sub-pump tube (3) disposed on a second element or kit (102), said kit (102) being associable with said base (101) in a stable and resolvable configuration in which the said pressing roller (1) is in contact with the sub-pump tube (3) supported by said stator (2).

7. Pump according to claim 6, characterized in that the stator (2) is provided with a helical guide for receiving said sub-pump tube (3).

8. Pump according to claim 6, characterized in that the stator (2) is provided with a guide for receiving said sub-pump tube (3) having three differentiated portions, with a first helical portion at increasing diameter (I), a second constant diameter helical portion (II) and a third helical portion at decreasing diameter (III).

9. Pump according to claim 6, characterized in that said pressing roller (1) is motorized rotatable about its vertical axis (5) and it is supported by a rotating base (105; 11), which rotates around said stator ( 2) to allow the cyclic compression of said sub-pump tube (3) by means of the pressing roller (1).

10. A pump according to claim 1, characterized in that said kit (102) comprises a support and connecting plate (104) complementarily associable with corresponding fastening means (111, 112) provided on said base (101).