Patent Description:
Extracorporeal blood treatment involves removing blood from a patient, treating the blood externally to the patient, and returning the treated blood to the patient. Extracorporeal blood treatment is typically used to extract undesirable matter or molecules from the patient's blood and add desirable matter or molecules to the blood. Extracorporeal blood treatment is used with patients unable to effectively remove matter from their blood, such as when a patient has suffered temporary or permanent kidney failure. These patients and other patients may undergo extracorporeal blood treatment to add or remove matter to their blood, to maintain an acid/base balance or to remove excess body fluids, or to perform extracorporeal gas exchange processes, for example.

For instance, in a haemodialysis treatment a patient's blood and a treatment liquid approximately isotonic with blood flow are circulated in a respective compartment of haemodialyser, so that, impurities and undesired substances present in the blood (urea, creatinine, etc.) may migrate by diffusive transfer from the blood into the treatment liquid. The ion concentration of the treatment liquid is chosen so as to correct the ion concentration of the patient's blood. In a treatment by haemodiafiltration, a convective transfer by ultrafiltration, resulting from a positive pressure difference created between the blood side and the treatment-liquid side of the membrane of a haemodiafilter, is added to the diffusive transfer obtained by dialysis. Hemoperfusion, oxygenation or decarboxylation treatments are also known.

A vascular access is used to remove the patient's blood so that it is filtered through the blood treatment unit (dialyzer, filter) and then returned to the patient. In case of chronic treatments, the vascular access may be arterio-venous. Two needles may be inserted into the vein, one to draw blood and one to return it. The orientation of the needles takes the normal flow of the blood into account. The "arterial" needle draws blood from the "upstream" location while the "venous" needle returns blood "downstream". In case of acute treatments, the vascular access may be veno-venous, i.e. using a double-lumen catheter inserted in a central vein. The blood treatment unit comprises pressure monitoring devices, as to check, for example, for circuit obstructions.

In the field of extracorporeal blood treatments and therapies, some problems reported by users are issues at the vascular access. Access Extremely Negative (AEN) is one of the most encountered alarm in the field, mainly linked to catheter tip stuck against blood vessel's wall or, more rarely, to clots obstructing the access way of the catheter. When this alarm relates to catheter positioning inside the vein, the nurse has to get the access pressure back closer to an atmospheric level, e.g. through the use of a Y-connector connected to the access line, unstick the catheter tip from the vein wall and then try to move the catheter inside the vein and resume the treatment.

Another drawback is that at the end of the treatment, when blood is to be returned to the patient, one operator has to disconnect the patient access and connect a saline bag to the set's access line, in aseptic conditions, and another operator has to operate on the monitor of the machine in non-aseptic conditions. Therefore, two operators are needed for one patient.

Another drawback is that, as per the blood return described above, both saline and blood recirculation procedures currently require sterile and non-sterile interventions and the manual connection of supplementary devices (Y-connector, saline bag).

In all the cases detailed above, the operator has to handle the vascular access, to disconnect and eventually reconnect the same to the patient. All this implies operator workload and increased probability of occurrence for non-aseptic handling.

Furthermore, the use of a Y-connector connected to the access line involves further risks. On the access side, the user may forget to clamp the Y saline line prior to resuming the treatment. In case of blood pump stop and slightly negative patient access pressure, the saline bag content would be sucked into the catheter, causing air ingress leading to set clotting (or potentially air embolism). Additional modules, configured to be placed in-line between the blood treatment apparatus and the patient vascular access and configured to divert the flow of blood without necessarily disconnecting the patient, are also known.

For instance, document <CIT> discloses a shunt valve device which is designed to be mounted permanently on a body member of a person and permanently connected to the artery and vein of the person. The device is provided with valve means for selectively connecting the artery and vein to an artificial kidney or the like. The device further has rotary shunt means for directing the flow of blood back to the body member when the device is not operatively connected to the artificial kidney.

Document <CIT> discloses a device for selectively controlling the direction of blood flow to and from the patient during hemodialysis. The device comprises two interlocking disks that rotate in relation to each other without separating. The two disks have fluid fittings that allow the blood lines attached to the patient to connect to one of the disks and the blood inlet and outlet for the hemodialysis machine to connect to the other. The center of each fluid fitting is a channel that aligns to a corresponding channel in the other disk. The disks rotate between two fixed relative positions, referred to herein as preferred alignments. The preferred alignments are such that the line drawing blood from the patient in the first preferred alignment becomes the line returning blood to the patient in the second preferred alignment, and the line returning blood to the patient in the first preferred alignment becomes the line drawing blood from the patient in the second preferred alignment. A bypass channel allows blood to flow from the outlet to the inlet of the hemodialysis machine when the device is in neither of its two preferred alignments. DocumentUS20110230772A1 discloses a device and method for invasive blood pressure measurement in a vascular access under continuous blood flows in a treatment device in extracorporeal detoxification methods. Systemic arterial pressure is determined directly or indirectly. A valve-controlled bypass system which goes around a blood pumping unit is provided so that the blood flow in the treatment device is not interrupted and alarms are suppressed. DocumentUS20130110028A1 discloses a valve arrangement for use in an extracorporeal blood circuit. The valve arrangement has a first valve arranged in the arterial blood line, a second valve arranged in the venous blood line, a fourth valve arranged in a first arteriovenous connection line between the arterial blood line and the venous blood line and a fifth valve arranged in a second arteriovenous connection line between the arterial blood line and the venous blood line and/or a third valve arranged for establishing a fluid connection in a blood line between the arterial and the venous blood lines and/or a sixth valve arranged between a blood treatment device and an air venting device. Document <CIT> discloses an extracorporeal fluid circulating device for realizing hemodialysis operation, comprising two tubes each having ends connected to one of two channels of a catheter and ends connected to one of two channels of a dialysis machine. Junctions are placed between the ends of the tubes, where two of the junctions are connected to the other two junctions by additional tubes. A closing unit closes simultaneously the tubes or two portions of the tubes each situated between the junctions. Document <CIT> discloses a method for monitoring for leaks or disconnections, comprising the steps of operating a blood pump to circulate blood through an extracorporeal blood circuit, opening a shunt connection between the arterial and venous blood flow portions, sensing the presence of air from any leaks or disconnections within the venous blood flow portion and taking corrective action if the presence of air is noted.

These devices allow a limited number of flow path configurations and, due to their structure and geometry of the ducts, may cause pressure drops and/or clotting.

It is therefore an object of the present invention to provide a fluid diverting device for an apparatus for extracorporeal treatment of blood, wherein the fluid diverting device is configured to divert the flow of blood or other fluid/s in order to perform a plurality of procedures (e.g. all the steps of the treatment, pre and post treatment and possible troubleshooting procedures) without necessarily disconnecting the patient.

It is an object of the present invention to provide a fluid diverting device which may be easily interposed between the apparatus for extracorporeal treatment of blood and the patient, featuring various functional components and able to be set in a plurality of configurations to perform the plurality of procedures.

In particular, it is an object providing a fluid diverting device able to provide easy and safe AEN troubleshooting, blood return at the treatment end, blood recirculation, saline recirculation.

It is a further object providing a fluid diverting device allowing to control its configurations in automated manner.

It is also an object of the present invention to provide a fluid diverting device enabling offering the device features as a supplemental option with respect to the apparatus.

It is a further object providing a fluid diverting device allowing a single person to handle the patient's vascular access in safe manner and in aseptic conditions.

It is a further object providing a fluid diverting device offering the possibility to have some commands located conveniently nearby the patient access.

It is a further object providing a fluid diverting device offering the possibility to operate disinfection procedures in aseptic conditions.

It is a further object providing a fluid diverting device which is structurally simple, cost effective and reliable.

It is a further object providing a fluid diverting device able to prevent clotting and/or to avoid high pressure losses and/or requiring minimal amounts of fluid needed for flushing said fluid diverting device.

At least one of the above objects is substantially reached by a fluid diverting device for an apparatus for extracorporeal treatment of blood and by an apparatus for extracorporeal treatment of blood according to one or more of the appended claims.

A fluid diverting device for an apparatus for extracorporeal treatment of blood, an apparatus for extracorporeal treatment of blood and a method for diverting a flow of liquid and/or blood in an apparatus for extracorporeal treatment of blood capable of achieving one or more of the above objects are here below described.

A <NUM>st aspect concerns a fluid diverting device for an apparatus for extracorporeal treatment of blood according to claim <NUM>.

A <NUM>nd aspect concerns a blood set for an apparatus for extracorporeal treatment of blood according to claim <NUM>.

An apparatus for extracorporeal treatment of blood is described comprising the blood set of the previous aspect.

A method for diverting a flow of liquid and/or blood in an apparatus for extracorporeal treatment of blood without disconnecting the patient is also described.

The attached drawings, which are provided by way of non-limiting example, wherein:.

Non-limiting embodiments of a fluid diverting device for an apparatus <NUM> for extracorporeal treatment of blood are shown in <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG>. In below description and in <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> same components are identified by same reference numerals.

An apparatus for the extracorporeal treatment of blood <NUM> is represented in <FIG>. The apparatus <NUM> of <FIG> comprises a blood treatment unit <NUM> (such as a hemofilter, an ultrafilter, an hemodiafilter, a dialyzer, a plasmafilter and the like) having a primary chamber <NUM> and a secondary chamber <NUM> separated by a semipermeable membrane <NUM>. Depending upon the treatment, the semipermeable membrane <NUM> of the blood treatment unit <NUM> may be selected to have different properties and performances.

A blood withdrawal line <NUM> is connected to an inlet of the primary chamber <NUM> and a blood return line <NUM> is connected to an outlet of the primary chamber <NUM>. In use, the blood withdrawal line <NUM> and the blood return line <NUM> are connected to a needle or to a catheter or other access device <NUM> which is then placed in fluid communication with the patient "P" vascular system, such that blood may be withdrawn through the blood withdrawal line <NUM>, flown through the primary chamber <NUM> and then returned to the patient's vascular system through the blood return line <NUM>. An air separator, such as a deaeration chamber <NUM>, may be present on the blood return line <NUM>. Moreover, a monitor valve <NUM> may be present on the blood return line <NUM>, downstream the deaeration chamber <NUM>.

The blood flow through the blood lines is controlled by a blood pump <NUM>, for instance a peristaltic blood pump, acting either on the blood withdrawal line <NUM> or on the blood return line <NUM>. The embodiment of <FIG> shows the blood pump <NUM> coupled to a pump section of the withdrawal line <NUM>. A control unit <NUM> is connected and controls the blood pump <NUM> to regulate a blood flow rate.

An effluent fluid line <NUM> or spent dialysate line may be connected, at one end, to a fluid outlet of the secondary chamber <NUM> and, at its other end, to a waste which may be a discharge conduit or an effluent fluid container <NUM> collecting the effluent fluid extracted from the secondary chamber <NUM>. An effluent pump <NUM> that operates on the effluent fluid line <NUM> under the control of the control unit <NUM> to regulate a flow rate of the effluent fluid through the effluent fluid line.

The apparatus of <FIG> includes a dialysis fluid line <NUM> connected at one end with a fresh dialysis liquid source <NUM> and at its other end with a fluid inlet of the secondary chamber <NUM> of the treatment unit <NUM> for supplying fresh dialysis liquid to the secondary chamber <NUM>. A dialysis fluid pump <NUM> is operative on the dialysis fluid line <NUM> under the control of the control unit <NUM> to supply fluid from the dialysis liquid source <NUM> to the secondary chamber <NUM> and to regulate the flow rate of the dialysis liquid.

The embodiment of <FIG> further presents an infusion line <NUM> connected to the blood withdrawal line <NUM> between the blood pump <NUM> and the treatment unit <NUM>. This infusion line <NUM> supplies replacement fluid from an infusion fluid container <NUM> connected at one end of the infusion line <NUM>. Note that, alternatively or in addition to the infusion line <NUM>, the apparatus of <FIG> may include a post-dilution fluid line (not shown) connecting an infusion fluid container to the blood return line <NUM> and/or a pre-blood pump infusion line <NUM>' with its own pre-blood pump infusion fluid container <NUM>'. Furthermore, an infusion pump <NUM> operates on the infusion line <NUM> and an infusion pump <NUM>' operates on the pre-blood pump infusion line <NUM>' to regulate respective flow rates through the infusion lines <NUM>, <NUM>'. Also the infusion pumps <NUM>, <NUM>' are operative under the control of the control unit <NUM>.

The effluent fluid line <NUM>, the dialysis fluid line <NUM> and the secondary chamber <NUM> of the blood treatment unit <NUM> are part of a fluid circuit of the apparatus <NUM>. The blood withdrawal line <NUM>, the blood return line <NUM>, the primary chamber <NUM> of the treatment unit <NUM> form part of an extracorporeal blood circuit of the apparatus <NUM>. The infusion lines <NUM>, <NUM>' form part of an infusion circuit of the apparatus <NUM>.

The control unit <NUM> may comprise a digital processor (CPU) with memory (or memories), an analogical type circuit, or a combination of one or more digital processing units with one or more analogical processing circuits. In the present description and in the claims it is indicated that the control unit <NUM> is "configured" or "programmed" to execute steps: this may be achieved in practice by any means which allow configuring or programming the control unit <NUM>. For instance, in case of a control unit <NUM> comprising one or more CPUs, one or more programs are stored in an appropriate memory: the program or programs containing instructions which, when executed by the control unit <NUM>, cause the control unit <NUM> to execute the steps described and/or claimed in connection with the control unit <NUM>. Alternatively, if the control unit <NUM> is of an analogical type, then the circuitry of the control unit <NUM> is designed to include circuitry configured, in use, to process electric signals such as to execute the control unit <NUM> steps herein disclosed.

The control unit <NUM> may also be operatively connected to sensors (like flow sensors and/or pressure sensors) on the blood circuit and/or fluid circuit and/or infusion circuit. The control unit <NUM> is also operatively connected to clamps and valves, like the monitor valve <NUM>. The control unit <NUM> may also be connected to a user interface, not shown, for instance a graphic user interface, which receives operator's inputs and displays the apparatus outputs. For instance, the graphic user interface may include a touch screen, a display screen and hard keys for entering user's inputs or a combination thereof. During extracorporeal blood treatment, the control unit <NUM> is configured to control at least the pumps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>' to make sure that a prefixed patient net fluid removal is achieved in the course of a treatment time, as required by a prescription provided to the control unit <NUM>, e.g. via the user interface.

The apparatus <NUM> comprises a main portion <NUM> comprising at least a casing for the control unit <NUM>, the control unit <NUM>, the user interface, the blood pump <NUM>, the effluent pump <NUM>, the dialysis fluid pump <NUM>, the infusion pumps <NUM>, <NUM>' and devices to mount a disposable set (comprising the blood treatment unit <NUM>, the extracorporeal blood circuit, the infusion circuit and the fluid circuit) to the main portion <NUM>.

The apparatus for the extracorporeal treatment of blood <NUM> shown in <FIG> further comprises a fluid diverting device <NUM> which is configured to be placed in-line between the main portion <NUM> of the apparatus <NUM> and the vascular access of a patient "P", in particular the access device <NUM> (e.g. a needle or a catheter) placed in fluid communication with the patient "P" vascular system. The fluid diverting device <NUM> may be placed in-line on the withdrawal line <NUM> and on the return line <NUM> and closer to the access device <NUM> than to the main portion <NUM> of the apparatus <NUM> for extracorporeal treatment of blood. The fluid diverting device <NUM> may be disposable, at least in part. The fluid diverting device <NUM> of <FIG> is an add-on module which may be supplied to the apparatus and connected to the withdrawal line <NUM> and return line <NUM> at a later stage with respect to the manufacturing of the apparatus <NUM>.

The fluid diverting device <NUM> comprises a substantially H-shaped conduits assembly comprising a withdrawal conduit <NUM>, a return conduit <NUM> and a bridging conduit <NUM> connecting the withdrawal conduit <NUM> to the return conduit <NUM>. Each of the withdrawal conduit <NUM>, the return conduit <NUM> and the bridging conduit <NUM> of the embodiments shown in the annexed Figures is a straight plastic tube. The withdrawal conduit <NUM> is parallel to the return conduit <NUM> while the bridging conduit <NUM> is perpendicular to the withdrawal conduit <NUM> and to the return conduit <NUM>.

The withdrawal conduit <NUM> has a first extremity 23a and an opposite second extremity 23b each provided with a quick connector, such as a Luer connector, to allow easy and quick connection/disconnection to/from the remaining portions of the withdrawal line <NUM>. The first extremity 23a is connected or configured to be connected to a portion of the withdrawal line <NUM> comprising the pump section coupled to the blood pump <NUM>. The second extremity 23b is connected or configured to be connected to a portion of the withdrawal line connected to the access device <NUM>. The return conduit <NUM> has a first extremity 24a and an opposite second extremity 24b each provided with a quick connector, such as a Luer connector, to allow easy and quick connection/disconnection to/from the remaining portions of the return line <NUM>. The first extremity 24a is connected or configured to be connected to a portion of the return line <NUM> comprising the deaeration chamber <NUM> and the monitor valve <NUM>. The second extremity 24b is connected or configured to be connected to a portion of the return line <NUM> connected to the access device <NUM>.

The bridging conduit <NUM> has a first extremity 25a forming a junction to the withdrawal conduit <NUM> and an opposite second extremity 25b forming a junction to the return conduit <NUM>. For instance, the bridging conduit <NUM>, the withdrawal conduit <NUM> and the return conduit <NUM> are connected through T-connectors. The withdrawal conduit <NUM> comprises two branches connected to the T-connector. A branch comprising the first extremity 23a and a branch comprising the second extremity 23b. The return conduit <NUM> comprises two branches connected to the T-connector. A branch comprising the first extremity 24a and a branch comprising the second extremity 24b.

A plurality of valves (e.g. clamps) operate on the withdrawal conduit <NUM>, on the return conduit <NUM> and on the bridging conduit <NUM> and are configured to divert a flow of liquid and/or blood without disconnecting the patient "P".

The fluid diverting device <NUM> of the embodiments of <FIG> and <FIG> comprises a first withdrawal valve <NUM> and a second withdrawal valve <NUM> operating on the withdrawal conduit <NUM>. The first withdrawal valve <NUM> is placed upstream, with respect to a flow of blood during treatment (flowing from the second extremity 23b to the first extremity 23a of the withdrawal conduit <NUM>), the junction of the bridging conduit <NUM> to said withdrawal conduit <NUM> and the second withdrawal valve <NUM> is placed downstream, with respect to said flow of blood during treatment, the junction of the bridging conduit <NUM> to said withdrawal conduit <NUM>. As disclosed in <FIG>, the first withdrawal valve <NUM> and the second withdrawal valve <NUM> are placed on opposite sides with respect to the T-connector joining the bridging conduit <NUM> to the withdrawal conduit <NUM>.

The fluid diverting device <NUM> of the embodiments of <FIG> and <FIG> comprises a single return valve <NUM> operating on the return conduit <NUM>. The return valve <NUM> is placed downstream the junction of the bridging conduit <NUM> to the return conduit <NUM> with respect to a flow of blood during treatment (flowing from the first extremity 24a to the second extremity 24b of the return conduit <NUM>). As disclosed in <FIG>, the return valve <NUM> is placed at a side of the T-connector joining the bridging conduit <NUM> to the return conduit <NUM> and on the branch comprising the second extremity 24b of said return conduit <NUM>.

In a variant embodiment, not shown, a first return valve and a second return valve operate on the return conduit <NUM> and are placed on opposite sides with respect to the T-connector joining the bridging conduit <NUM> to the return conduit <NUM>, similar to the first withdrawal valve <NUM> and the second withdrawal valve <NUM>. The return valve placed upstream the junction of the bridging conduit <NUM> to the return conduit <NUM> with respect to the flow of blood during treatment may perform the function of the monitor valve <NUM>. The fluid diverting device <NUM> of the embodiments of <FIG> and <FIG> comprises a first bridging valve <NUM> and a second bridging valve <NUM> operating on the bridging conduit <NUM>. The first bridging valve <NUM> is placed closer to the return conduit <NUM> (closer than the second bridging valve <NUM>) and the second bridging valve <NUM> is placed closer to the withdrawal conduit <NUM> (closer than the first bridging valve <NUM>).

The bridging conduit <NUM> comprises a first branch having the first extremity 25a and a second branch having the second extremity 25b. The first branch and the second branch are connected to each other through a T-connector delimiting also an access point <NUM> suitable to connect a liquid source. The first bridging valve <NUM> is placed on the second branch bridging conduit <NUM> and the second bridging valve <NUM> is placed on the first branch of the bridging conduit <NUM>. The access point <NUM> is located between the first bridging valve <NUM> and the second bridging valve <NUM>.

A stretch of tubing departs form the access point <NUM> and is provided with an access valve <NUM>. The stretch of tubing may be connected to a liquid source <NUM>, like a syringe, e.g. of <NUM>, or a bag, e.g. of <NUM>. The liquid of said liquid source may be saline.

In the variant embodiment of <FIG>, the fluid diverting device <NUM> comprises a single bridging valve <NUM>' operating on the bridging conduit <NUM> and does not comprise any access point <NUM>. In the variant embodiment of <FIG>, the fluid diverting device <NUM> further comprises (in addition with respect to the embodiment of <FIG>) a further access point <NUM>' on the return conduit <NUM>, e.g. for calcium infusion. The further access point <NUM>' is placed on the branch comprising the second extremity 24b and may be connected to a bag of the apparatus.

The substantially H-shaped conduits assembly and the plurality of valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are mounted on a holder <NUM> which may be shaped like a plate provided with seats, or other holding devices, configured to accommodate the substantially H-shaped conduits assembly and the plurality of valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. In the embodiments of <FIG> and <FIG>, the holder <NUM> comprises a seat, or other holding device to hold the syringe <NUM>, and a spring <NUM> for pressurizing the syringe <NUM> and ejecting the fluid contained therein through the access point <NUM>.

The fluid diverting device <NUM> may also comprise one or more sensors (e.g. pressure sensor, flowmeter, air detector, etc.), not shown, active on the H-shaped conduits assembly, i.e. on the return conduit <NUM> and/or on the withdrawal conduit <NUM>, on the bridging conduit <NUM>.

The plurality of valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the sensor/s are operatively connected or connectable to the control unit <NUM> of the apparatus <NUM> and/or to a control unit of the fluid diverting device <NUM> which may be slaved to the control unit <NUM> of the apparatus <NUM>. Said control unit/s is/are configured for commanding, optionally automatically, the configurations of the plurality of valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or the control unit of the fluid diverting device <NUM> may be connected to the control unit <NUM> of the apparatus <NUM> through a wired or wireless communication device.

The fluid diverting device <NUM> comprises a power supply to power the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or the sensor/s and/or control unit or said valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or the control unit of the fluid diverting device <NUM> may be connected to a power supply of the apparatus <NUM> to be powered by said apparatus <NUM>.

The fluid diverting device <NUM> may be a portable module and/or comprises an attachment device configured to install said fluid diverting device on another element, optionally in a removable manner, e.g. to clothing of a patient "P" or to a bed for the patient "P" or to a main portion of the apparatus for extracorporeal treatment of blood. The lengths of the portion of the return line <NUM> comprising the deaeration chamber <NUM> and the monitor valve <NUM> and of the portion of the withdrawal line <NUM> comprising the pump section coupled to the blood pump <NUM> are such to place the fluid diverting device close to the patient "P".

In use and according to a method for diverting a flow of liquid and/or blood in the apparatus <NUM>, before treatment of the patient "P", the blood circuit is primed and the control unit <NUM> controls the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to allow priming the withdrawal conduit <NUM>, the return conduit <NUM> and the bridging conduit <NUM>, using either solution bags of the apparatus <NUM> or saline from the liquid source <NUM> connected to the access point <NUM>.

During patient treatment (<FIG> and <FIG>), when blood flows from patient "P" through the withdrawal line <NUM>, into the primary chamber <NUM> of the blood treatment unit <NUM> and then back into the patient "P" through the return line <NUM>, the control unit <NUM> controls the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to configure said valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> in a treatment configuration. In the treatment configuration, the first bridging valve <NUM>, the second bridging valve <NUM> and the access valve <NUM> are closed, the first withdrawal valve <NUM>, the second withdrawal valve <NUM> and the return valve <NUM> are open.

During patient treatment, since blood may stagnate at the closed first bridging valve <NUM> and the second bridging valve <NUM>, in order to prevent coagulation, the first bridging valve <NUM> and the second bridging valve <NUM> and the access valve <NUM> are opened regularly (intermittently), to flush the bridging conduit <NUM> with fluid and prevent coagulation. According to a variant of the method, the first bridging valve <NUM> and the second bridging valve <NUM> are opened regularly (intermittently) while the access valve <NUM> is closed, to flush the bridging conduit <NUM> with blood, creating a short recirculation and preventing coagulation (<FIG>).

In case of Access Extremely Negative (AEN) alarm, the blood pump <NUM> is stopped, the second bridging valve <NUM> and the access valve <NUM> are opened to enable saline to be sucked from the syringe <NUM> until access pressure reaches an approximately atmospheric level or the first bridging valve <NUM> and the second bridging valve <NUM> are both opened to create connection between the withdrawal conduit <NUM> and the return conduit <NUM> and to normalize pressure. After the access pressure got closer to the atmospheric level, the first bridging valve <NUM> is kept closed, the second withdrawal valve <NUM> is closed while the access valve <NUM>, the second bridging valve <NUM> and the first withdrawal valve <NUM> are kept open. This way, the fluid from syringe <NUM> flushes the vascular access of the patient "P" backwards to help dislodge the catheter tip from vessel's wall (<FIG> and <FIG>).

According to another possible action to solve an AEN alarm, the first withdrawal valve <NUM> and the second withdrawal valve <NUM> are closed while the other valves are open. The blood pump <NUM> is controlled to turn in order to increase the access negative pressure till a defined value and then stopped. Then the first withdrawal valve <NUM> and the second withdrawal valve <NUM> are opened to create a sudden negative pressure peak in the catheter's access way to move or break a clot.

If these attempts fail, the control unit <NUM> controls the plurality of valves to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to engage blood recirculation, while notifying the staff that action is required (moving the patient "P", caring for the vascular access, etc.). Prior to enabling blood recirculation, flushing is needed in the return conduit <NUM> and withdrawal conduit <NUM> to avoid clotting and to enable patient reconnection after staff intervention. To this aim, the branch of the return conduit <NUM> comprising the second extremity 24b is flushed with fluid by closing the second bridging valve <NUM> and the monitor valve <NUM> while the first bridging valve <NUM>, the first withdrawal valve <NUM>, the second withdrawal valve <NUM>, the return valve <NUM> and the access valve <NUM> are open and fluid from the syringe <NUM> is injected (<FIG> and <FIG>).

The branch of the withdrawal conduit <NUM> having the second extremity 23b is then flushed. The first bridging valve <NUM> and the second withdrawal valve <NUM> are closed, the second bridging valve <NUM>, the first withdrawal valve <NUM> and the access valve <NUM> are open and saline from the syringe <NUM> is injected (<FIG> and <FIG>).

The blood recirculation starts with the return valve <NUM> closed, the first withdrawal valve <NUM> closed, the second withdrawal valve <NUM> open and the first and second bridging valves <NUM>, <NUM> open, so that blood recirculates in the blood treatment unit <NUM> of the apparatus <NUM> and staff intervention is executed (<FIG> and <FIG>). At the end of the treatment, with blood return to the patient "P", saline recirculation starts. With the first withdrawal valve <NUM> and the first bridging valve <NUM> closed and the second bridging valve <NUM>, the return valve <NUM>, the second withdrawal valve <NUM> and the access valve <NUM> open, saline is pumped by the blood pump <NUM> until all blood is returned to the patient "P". Then, the return valve <NUM> is closed and the first bridging valve <NUM> is opened while the second bridging valve <NUM> is still open, the second withdrawal valve <NUM> is open and the first withdrawal valve <NUM> is closed, to recirculate liquid in the blood treatment unit <NUM> of the apparatus <NUM> (<FIG> and <FIG>).

<FIG> show an embodiment of the fluid diverting device <NUM> according to the invention. The fluid diverting device <NUM> of this embodiment may be mounted on a side of the main portion <NUM> of the apparatus <NUM>.

The fluid diverting device <NUM> comprises the first withdrawal valve <NUM>, the second withdrawal valve <NUM>, the return valve <NUM>, the first bridging valve <NUM>, the second bridging valve <NUM> and the access point <NUM> as the embodiment of <FIG> and <FIG>.

The type of valves is different from the embodiment of <FIG> and <FIG>. Each of the plurality of valves is a rotating clamp or pinch.

The first bridging valve <NUM> and the return valve <NUM> share a common rotating body <NUM> and comprise two respective abutment elements <NUM>, one for the first bridging valve <NUM> and one for the return valve <NUM>. The second bridging valve <NUM> and the first withdrawal valve <NUM> share a common rotating body <NUM> and two respective abutment elements <NUM>, one for the second bridging valve <NUM> and one for first withdrawal valve <NUM>.

<FIG> also shows a calcium bag <NUM> connected to the further access point <NUM>' on the return conduit <NUM> for calcium infusion operated through a calcium pump <NUM>.

<FIG> show an enlarged view of the first bridging valve <NUM> and the return valve <NUM>. Each valve comprises the rotating body <NUM> and one abutment element <NUM>. The rotating body <NUM> comprises a presser <NUM> spaced form a rotation axis of the rotating body <NUM>. The presser <NUM> is placed close to the rotating body <NUM> such that a tube section may be positioned between the abutment element <NUM> and the presser <NUM>. The assembly comprising the first bridging valve <NUM> and the return valve <NUM> shown in.

<FIG> comprises one rotating body <NUM> and two abutment elements <NUM>. Said two abutment elements <NUM> are stationary with respect to the rotation axis of the rotating body <NUM> and are positioned on opposite sides with respect to the rotating body <NUM>. A tube section of the return conduit <NUM> is placed against one of the abutment elements <NUM> and a tube section of the bridging conduit <NUM> is placed against the other of the abutment elements <NUM>.

The rotating body <NUM> is rotatable between a first clamping position (one of the two valves is closed and the other is open), a second clamping position (one of the two valves is closed and the other open) and a release position (both valves are open).

In the first clamping position (<FIG>), the presser <NUM> of the rotating element <NUM> is close to one of the two abutment elements <NUM> to press and close a portion of a tube (the return conduit <NUM> in <FIG>) between said rotating element <NUM> and said abutment element <NUM>.

In the second clamping position (not show), the presser <NUM> of the rotating element <NUM> is close to the other of the two abutment elements <NUM> to press and close a portion of another tube (it should be the bridging conduit <NUM> in <FIG>) between said rotating element <NUM> and said abutment element <NUM>.

In the release position, the presser <NUM> of the rotating element is spaced from both the abutment elements <NUM>, to open both portions of tubes (<FIG>).

The assembly comprising the first withdrawal valve <NUM> and the second bridging valve <NUM> has the same structure and functionality shown in <FIG> and disclosed above.

The access point <NUM> of this embodiment is connected to the pre-blood pump infusion line <NUM>' with its own pre-blood pump infusion fluid container <NUM>' and infusion pump <NUM>'. The pre-blood pump infusion line <NUM>' has a branch connected to the access point <NUM> and a branch connected to the blood withdrawal line <NUM> at a site between the vascular access <NUM> and the fluid diverting device <NUM>. The infusion pump <NUM>' operates on the pre-blood pump infusion line <NUM>' to regulate respective flow rates through the cited branches. A first infusion valve or access valve <NUM> is placed upstream the branch of the pre-blood pump infusion line <NUM>' connected to the access point <NUM>. A second infusion valve <NUM> is placed downstream the branch connected to the access point <NUM>, i.e. on the branch connected to the blood withdrawal line <NUM>.

Also the access valve <NUM> is a rotating clamp or pinch. Like the assembly comprising the first withdrawal valve <NUM> and the second bridging valve <NUM> and the assembly comprising the first bridging valve <NUM> and the return valve <NUM>, also the access valve <NUM> is coupled to the second withdrawal valve <NUM>. The second withdrawal valve <NUM> and the access valve <NUM> comprise one common rotating body <NUM> and two respective abutment elements <NUM>.

An auxiliary withdrawal valve <NUM> operates on the withdrawal conduit <NUM> and is placed downstream, with respect to a flow of blood during treatment, the first withdrawal valve <NUM>. The second infusion valve <NUM> and the auxiliary withdrawal valve <NUM> comprise one common rotating body <NUM> and two respective abutment elements <NUM>.

As shown in <FIG>, the common rotating body <NUM> of the first bridging valve <NUM> and return valve <NUM> is placed between the return conduit <NUM> and the bridging conduit <NUM>, the common rotating body <NUM> of the first withdrawal valve <NUM> and second bridging valve <NUM> is placed between the withdrawal conduit <NUM> and the bridging conduit <NUM>, the common rotating body <NUM> of the access valve <NUM> and withdrawal valve <NUM> is placed between the withdrawal conduit <NUM> and the pre-blood pump infusion line <NUM>', the common rotating body <NUM> of the second infusion valve <NUM> and auxiliary withdrawal valve <NUM> is placed between the withdrawal conduit <NUM> and the pre-blood pump infusion line <NUM>'.

The position of the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> configured to perform patient treatment is shown in <FIG>. The first bridging valve <NUM>, the second bridging valve <NUM>, the access valve <NUM> and the second infusion valve <NUM> are closed, the first withdrawal valve <NUM>, the second withdrawal valve <NUM>, the auxiliary withdrawal valve <NUM> and the return valve <NUM> are open.

The position of the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> configured to perform flushing of the withdrawal conduit <NUM> and of the vascular access of the patient "P" is shown in <FIG>. The first bridging valve <NUM>, the second withdrawal valve <NUM> and the second infusion valve <NUM> are closed while the access valve <NUM>, the second bridging valve <NUM>, the auxiliary withdrawal valve <NUM> and the first withdrawal valve <NUM> are open. Fluid from the pre-blood pump infusion fluid container <NUM>' flows through the access point <NUM> into the withdrawal conduit <NUM> and towards to patient "P".

The position of the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> configured to perform flushing of the return conduit <NUM> is shown in <FIG>. The first bridging valve <NUM>, the return valve <NUM>, the access valve <NUM>, the first withdrawal valve <NUM> and the auxiliary withdrawal valve <NUM> are open while the second withdrawal valve <NUM>, the second bridging valve <NUM> and the second infusion valve <NUM> are closed. Fluid from the pre-blood pump infusion fluid container <NUM>' flows through the access point <NUM> into the return conduit <NUM> and towards to patient "P".

The position of the valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> configured to perform blood recirculation in the blood treatment unit <NUM> of the apparatus <NUM> is shown in <FIG>.

The return valve <NUM>, the first withdrawal valve <NUM>, the second infusion valve <NUM> and the access valve <NUM> are closed while the second withdrawal valve <NUM>, the first and second bridging valves <NUM>, <NUM> and the auxiliary withdrawal valve <NUM> are open.

<FIG> show a variant of the embodiment <FIG>. With respect to <FIG>, this variant additionally comprises an auxiliary bridging conduit <NUM> which is arranged in parallel with respect to the bridging conduit <NUM> and also connects or is configured to connect the withdrawal conduit <NUM> to the return conduit <NUM>. The auxiliary bridging conduit <NUM> is positioned between the bridging conduit <NUM> and the access device <NUM>. With respect to a flow of blood during treatment, the auxiliary bridging conduit <NUM> is connected to the withdrawal conduit <NUM> at a connection site placed upstream the bridging conduit <NUM> and is connected to the return conduit <NUM> at a connection site placed downstream the bridging conduit <NUM>.

An auxiliary pump <NUM>, e.g. a peristaltic pump, operates on the auxiliary bridging conduit <NUM> and is configured to recirculate blood on a patient "P" side.

The auxiliary withdrawal valve <NUM> operates on the withdrawal conduit <NUM> like in <FIG> and an auxiliary return valve <NUM> operates on the return conduit <NUM>. The auxiliary return valve <NUM> is placed downstream, with respect to a flow of blood during treatment, the return valve <NUM>. With respect to said flow of blood during treatment, the auxiliary withdrawal valve <NUM> is placed upstream the connection site of the auxiliary bridging conduit <NUM> to the withdrawal conduit <NUM> and the auxiliary return valve <NUM> is placed downstream the connection site of the auxiliary bridging conduit <NUM> to the return conduit <NUM>.

A first auxiliary bridging valve <NUM> and a second auxiliary bridging valve <NUM> operate on the auxiliary bridging conduit <NUM> and are placed on opposite sides with respect to the auxiliary pump <NUM>.

The first auxiliary bridging valve <NUM> and the auxiliary return valve <NUM> comprise one common rotating body <NUM> and two respective abutment elements <NUM>. Likewise, the auxiliary withdrawal valve <NUM> and the second auxiliary bridging valve <NUM> comprise one common rotating body <NUM> and two respective abutment elements <NUM>. As shown in <FIG>, the common rotating body <NUM> of the first auxiliary bridging valve <NUM> and auxiliary return valve <NUM> is placed between the return conduit <NUM> and the auxiliary bridging conduit <NUM>. The common rotating body <NUM> of the auxiliary withdrawal valve <NUM> and the second auxiliary bridging valve <NUM> is placed between the withdrawal conduit <NUM> and the auxiliary bridging conduit <NUM>.

During patient treatment (<FIG> and <FIG>), the first auxiliary bridging valve <NUM> and the second auxiliary bridging valve <NUM> are closed while the auxiliary withdrawal valve <NUM> and the auxiliary return valve <NUM> are open. The position of the other valves may the same as shown in <FIG>. The access valve <NUM> may be open and the pre-blood pump infusion line <NUM>' works to supply replacement fluid from the pre-blood pump infusion fluid container <NUM>' to the blood withdrawal line <NUM>.

When flushing the withdrawal conduit <NUM> (<FIG>) or the return conduit <NUM> (<FIG>), the auxiliary withdrawal valve <NUM> and the auxiliary return valve <NUM> are open while the first auxiliary bridging valve <NUM> and the second auxiliary bridging valve <NUM> are closed. The position of the other valves may the same as shown respectively in <FIG>.

During blood recirculation (<FIG> and <FIG>), the auxiliary withdrawal valve <NUM>, the auxiliary return valve <NUM>, the first auxiliary bridging valve <NUM> and the second auxiliary bridging valve all are open. The position of the other valves may the same as shown in <FIG>. The blood pump <NUM> works to recirculate blood through the treatment unit <NUM> and the auxiliary pump <NUM> is activated to recirculate blood on the patient "P" side.

<FIG> show another different embodiment of the fluid diverting device <NUM>. The fluid diverting device <NUM> of this embodiment comprises distributors <NUM>, <NUM> in place of valves. The distributors <NUM>, <NUM> may be disposable. The distributors <NUM>, <NUM> may be rotary distributors and may be operated through rotary actuators, not shown, part of the main portion <NUM> and controlled by the control unit <NUM>.

The fluid diverting device <NUM> comprises (<FIG>) the withdrawal conduit <NUM>, the return conduit <NUM>, the bridging conduit <NUM> and the auxiliary bridging conduit <NUM>. The withdrawal conduit <NUM> comprises a first branch <NUM>' and a second branch <NUM>''. Likewise, the return conduit <NUM> comprises a first branch <NUM>' and a second branch <NUM>''. The auxiliary bridging conduit <NUM> is coupled to the auxiliary pump <NUM>.

A first distributor <NUM> is operationally coupled to the withdrawal conduit <NUM>, to the bridging conduit <NUM> and to the auxiliary bridging conduit <NUM>. The first distributor <NUM> is operative between the first branch <NUM>' and the second branch <NUM>'' of the withdrawal conduit <NUM>. The first distributor <NUM> is also operative between a first end of the bridging conduit <NUM> and a first end of the auxiliary bridging conduit <NUM>.

A second distributor <NUM> is operationally coupled to the return conduit <NUM>, to the bridging conduit <NUM> and to the auxiliary bridging conduit <NUM>. The second distributor <NUM> is operative between the first branch <NUM>' and the second branch <NUM>'' of the return conduit <NUM>. The second distributor <NUM> is also operative between a second end of the bridging conduit <NUM> and a second end of the auxiliary bridging conduit <NUM>.

As better shown in <FIG>, the first distributor <NUM> comprises a rotating element <NUM> provided with a first through passage <NUM> and a second through passage <NUM>. The first through passage <NUM> and the second through passage <NUM> are parallel and each has open ends facing on opposite parts of the rotating element <NUM>. The second distributor <NUM> comprises a rotating element <NUM> provided with a first through passage <NUM> and a second through passage <NUM>. The structure of the second distributor <NUM> (not shown in an enlarged view) is the same as the first distributor <NUM>.

Each of the first distributor <NUM> and the second distributor <NUM> may be rotated between: a first configuration corresponding to the treatment configuration and a second configuration corresponding to the recirculation configuration.

In the first configuration of <FIG>, <FIG>, <FIG> and <FIG>, the withdrawal conduit <NUM> delimits a continuous passage connected to the withdrawal line <NUM>.

The first through passage <NUM> of the first distributor <NUM> connects the first branch <NUM>' and the second branch <NUM>'' of the withdrawal conduit <NUM> and the second through passage <NUM> of the first distributor <NUM> connects the first end of the bridging conduit <NUM> to the first end of the auxiliary bridging conduit <NUM>. In this first configuration, the return conduit <NUM> delimits a continuous passage connected to the return line <NUM> (<FIG>).

The first through passage <NUM> of the second distributor <NUM> connects a first branch <NUM>' and a second branch <NUM>'' of the return conduit <NUM> and the second through passage <NUM> of the second distributor <NUM> connects the second end of the bridging conduit <NUM> to the second end of the auxiliary bridging conduit <NUM>.

In this first configuration, the bridging conduit <NUM> together with the auxiliary bridging conduit <NUM> delimit a closed loop disconnected from the withdrawal line <NUM>, disconnected from the return line <NUM> and coupled to the auxiliary pump <NUM>.

In the second configuration of <FIG> and <FIG>, the bridging conduit <NUM> delimits a closed loop with the blood treatment unit <NUM> to recirculate blood in the blood treatment unit <NUM> and the auxiliary bridging conduit <NUM> delimits a closed loop connected to the access device <NUM>, to recirculate blood on the patient "P" side. The closed loop on the side of the blood treatment unit <NUM> is disconnected from the closed loop on the patient "P" side.

In this second configuration, the first through passage <NUM> of the first distributor <NUM> connects the first branch <NUM>' of the withdrawal conduit <NUM> to the auxiliary bridging conduit <NUM> and the second through passage <NUM> of the first distributor <NUM> connects the second branch <NUM>'' of the withdrawal conduit <NUM> to the bridging conduit <NUM> (<FIG>).

In this second configuration, the first through passage <NUM> of the second distributor <NUM> connects the first branch <NUM>' of the return conduit <NUM> to the bridging conduit <NUM> and the second through passage <NUM> of the second distributor <NUM> connects the second branch <NUM>'' of the return conduit <NUM> to the auxiliary bridging conduit <NUM> (<FIG>).

Claim 1:
Fluid diverting device for an apparatus for extracorporeal treatment of blood, wherein the apparatus (<NUM>) comprises:
a blood treatment unit (<NUM>);
an extracorporeal blood circuit coupled to the blood treatment unit (<NUM>) and comprising a blood withdrawal line (<NUM>) and a blood return line (<NUM>) connectable to a vascular access of a patient (P);
a blood pump (<NUM>) configured to be coupled to a pump section
of the extracorporeal blood circuit;
wherein the fluid diverting device (<NUM>) is configured to be placed in-line between a blood set of the apparatus (<NUM>) and the vascular access of the patient (P) and comprises:
- a substantially H-shaped conduits assembly comprising a withdrawal conduit (<NUM>), a return conduit (<NUM>) and at least one bridging conduit (<NUM>, <NUM>) connecting or configured to connect the withdrawal conduit (<NUM>) to the return conduit (<NUM>); wherein the withdrawal conduit (<NUM>) is connected or connectable upstream and downstream to the withdrawal line (<NUM>), wherein the return conduit (<NUM>) is connected or connectable upstream and downstream to the return line (<NUM>);
- a plurality of valves (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) or distributors (<NUM>, <NUM>) operating on the withdrawal conduit (<NUM>), on the return conduit (<NUM>) and on the at least one bridging conduit (<NUM>) and configured to divert a flow of liquid and/or blood without disconnecting the patient (P);
characterized in that at least one of the plurality of valves (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is a rotating clamp, wherein the rotating clamp comprises a rotating body (<NUM>) and an abutment element (<NUM>) ;
and in that at least two valves of the plurality of valves (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprise one common rotating body (<NUM>) and respective abutment elements (<NUM>).