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.

In particular, the invention relates to continuous renal replacement therapy (CRRT) systems. CRRT systems are configured for delivering treatments designed for patients versing in acute states of illness and who have temporarily lost their kidney function in its entirety. In this respect, CRRT systems may be structurally and/or operationally different from extracorporeal blood treatment systems designed for chronic patient care.

CRRT monitors should be able to deliver various therapies (SCUF CCVH, CWHDF, TPE). The delivery of these therapies requires a specific arrangement of circuit flow-path as well as a number variable of solutions which may be available under bag form.

Document <CIT> discloses a system for treating blood, which includes a single cassette permitting the distribution of the fluids in order to carry out various CRRT treatments. The cassette comprises distribution and connection chambers. One of these distribution chambers comprises an inlet channel and three outlet channels controlled by the controller so as to allow a fluid to be injected into the blood filtration means, into the blood before the blood filtration means and/or after the blood filtration means.

Document <CIT> discloses a fluid processing system including an integral flow control and distribution manifold for establishing fluid communication between conduit segments of the system. The manifold is received in an actuator head of an associated processor apparatus, wherein valving elements selectively crimp valving passageways in the manifold to perform the procedure.

Known issues, problems and limitations associated with known extracorporeal blood treatment systems include, on the fresh fluid circuit side, one or more of the following:.

Document <CIT> discloses a dialysis system comprises a filtration means, a pump, a back filtration system and a sorbent device for performing a dialysis treatment.

Document <CIT> discloses a kidney failure therapy system including a dialysate supply, a valve actuator; a pump actuator and a disposable unit including first and second flexible sheets sealed together for forming a flow path configured to be placed in fluid communication with the dialysate supply and operable with the valve actuator and a pumping portion configured to operate with the at least one pump actuator.

FB3: Injecting (e.g. once at a time) fluid coming from a single fluid container at different sites is typically not provided for.

FB4: Injecting a customized infusion liquid created by the ratio-metric mixing of fluid coming from two connected containers at a site in the blood circuit is typically not provided for.

FB5: There is typically no provision made for analyzing the composition of fluid coming from a connected fluid container.

Known issues, problems and limitations associated with known extracorporeal blood treatment systems include, on an effluent fluid circuit side:
EB1: Automatic recalibration of effluent sensor/s, e.g. blood leak detectors (BLD), by filling the BLD chamber with fresh dialysate or replacement fluid is typically not provided for.

A general aim of the present invention is to provide for an apparatus for extracorporeal blood treatment that alleviates or minimizes the above-mentioned drawbacks.

It is a further aim of the present invention to provide a method for controlling an apparatus for extracorporeal blood treatment that alleviates or minimizes the above-mentioned drawbacks.

It is in particular aim of the present invention to provide an apparatus for extracorporeal treatment of blood which may be set in a plurality of configurations to deliver various therapies (e.g. SCUF CCVH, CWHDF, TPE) and to accomplish other working requirements, such as:.

An apparatus according to one or more of the appended claims, taken singly or in any combination, attain at least one of the above-indicated aims.

An apparatus and a method, the method not claimed in the present invention, capable of achieving one or more of the above objects are here below described.

In a <NUM>st independent aspect there is provided an apparatus for extracorporeal blood in accordance with appended claim <NUM>. Further aspects are defined in the appended dependent claims.

Further characteristics of the present invention will better emerge from the detailed description that follows of some embodiments of the invention, illustrated by way of non-limiting examples in the accompanying Figures of drawings.

The description will now follow, with reference to the appended Figures, provided by way of non-limiting example, in which:.

<FIG> schematically shows an extracorporeal blood treatment apparatus in accordance with an example of prior art. The extracorporeal blood treatment apparatus <NUM> comprises an extracorporeal blood circuit BC coupled to a treatment unit <NUM>, a fresh fluid flow path FFP and an effluent fluid flow path EFP. The fresh fluid flow path FFP and the effluent fluid flow path EFP shown in <FIG> are part of an hydraulic circuit of the prior art.

The treatment unit <NUM>, for example a dialyzer, a plasmafilter, a hemofilter, or a hemodiafilter, includes a first chamber and a second chamber, which are separated by a semipermeable membrane, for example of the hollow-fiber type or of the plate type.

The apparatus <NUM> comprises the blood circuit BC (including the treatment unit <NUM>, a blood removal line <NUM>, a blood return line <NUM> and, optionally, a blood warmer <NUM> and/or an air separator/bubble trap <NUM> provided with a pressure sensor <NUM>) and a dialysate circuit comprising the treatment unit <NUM>, a dialysate line <NUM> and an effluent line <NUM>.

It is noted that the first chamber of treatment unit <NUM> is understood to be part of the blood circuit BC, being connected to the blood removal line <NUM> and to the blood return line <NUM>, and that the second chamber of treatment unit <NUM> is understood to be part of the dialysate circuit, being connected to the dialysate line <NUM> and the effluent line <NUM>. Thus, treatment unit <NUM> may be considered a component of both the blood circuit BC and of the dialysate circuit. In some embodiments, the apparatus <NUM> comprises additional fluid lines, like a pre blood pump (PBP) line <NUM>, a pre-infusion line <NUM> and a post-infusion line 70b.

The dialysate line <NUM>, the pre blood pump (PBP) line <NUM>, the pre-infusion line <NUM> and the post-infusion line 70b are part of the fresh fluid flow path FFP. The effluent line <NUM> is part of the effluent fluid flow path EFP. In the example shown in <FIG>, the fresh fluid flow path FFP and the effluent fluid flow path EFP are shown as schematically separated elements merely for clarity. It is noted that the distinction between FFP and EFP as shown in <FIG> (and in some subsequent Figures) does not entail any structural, operational, or otherwise shape or form corresponding to the separated elements shown in any of the Figures.

The blood removal line <NUM> has a first end <NUM>-<NUM> designed to connect to the vascular system of a patient. The particular manner of fluidly connecting the first end <NUM>-<NUM> of the blood removal line <NUM> to the vascular system of a patient may be realized in accordance with known components and methods. The blood removal line <NUM> further includes a second end <NUM>-<NUM> configured to connect to the treatment unit <NUM>, in particular to an inlet port <NUM> of a first chamber of the treatment unit <NUM>. A blood pump <NUM> is coupled to a section of the blood removal line <NUM>.

The blood return line <NUM> has a first end <NUM>-<NUM> configured to connect to the treatment unit <NUM>, in particular to an outlet port <NUM> of the first chamber of the treatment unit <NUM>. The blood return line <NUM> further has a second end <NUM>-<NUM> designed to connect to the vascular system of the patient. The particular manner of fluidly connecting the second end <NUM>-<NUM> of the blood return line <NUM> to the vascular system of a patient may be realized in accordance with known components and methods.

The dialysate line <NUM> is configured for supplying dialysate to the treatment unit <NUM> and the effluent line <NUM> is configured for discharging used fluid from the treatment unit <NUM> towards a drain (not shown) or into a corresponding effluent fluid container <NUM>. The dialysate line <NUM> has a first end <NUM>-<NUM> configured to connect to a dialysate container <NUM>, such as a dialysate bag or other source of dialysate fluid, and a second end <NUM>-<NUM> configured to connect to an inlet port <NUM> of the second chamber of the treatment unit <NUM>. A dialysate pump <NUM> is coupled to a section of the dialysate line <NUM>.

The effluent line <NUM> has a first end <NUM>-<NUM> configured to connect to an outlet port <NUM> of the second chamber of the treatment unit <NUM> and a second end <NUM>-<NUM> configured to connect to the effluent fluid container <NUM> configured to receive used fluid from the second chamber of the treatment unit <NUM>. In some embodiments, the second end <NUM>-<NUM> of the effluent line is directly connected to the drain and configured to discharge used fluid directly to the drain. An effluent pump <NUM> is coupled to a section of the effluent line <NUM>. A blood leak detector (BLD) <NUM> is installed on the effluent line <NUM> between the effluent pump <NUM> and the effluent fluid container <NUM>.

The pre blood pump (PBP) line <NUM> has a first end <NUM>-<NUM> connected to a pre blood pump container <NUM> and a second end <NUM>-<NUM> configured to connect to the blood removal line <NUM>. A pre blood pump <NUM> is coupled to a section of the pre blood pump (PBP) line <NUM>.

The pre-infusion line <NUM> has a first end <NUM>-<NUM> configured to connect to a replacement fluid container <NUM> and a second end <NUM>-<NUM> configured to connect to the blood removal line <NUM>. A replacement fluid pump <NUM> is coupled to a section of the pre-infusion line <NUM>.

The post-infusion line 70b branches off from the pre-infusion line <NUM> at a branch <NUM> placed downstream the replacement fluid pump <NUM>. The post-infusion line 70b has a second end 70b-<NUM> configured to connect to the blood return line <NUM>. The branch typically includes a flow controller (e.g. one or more valves or a clamp mechanism) configured to selectively enable fluid flow either through the pre-infusion line <NUM> or through the post infusion line 70b. Each of the dialysate container <NUM>, the effluent fluid container <NUM>, the pre blood pump container <NUM> and the replacement fluid container <NUM> is monitored by a respective sensor <NUM>, <NUM>, <NUM>, <NUM> configured to detect an amount of fluid in the container.

The replacement fluid pump <NUM>, active on the pre-infusion line <NUM> and arranged upstream branch <NUM> (with respect to fluid flow from the replacement fluid container <NUM> towards branch <NUM>), is configured to supply replacement fluid from the replacement fluid container <NUM> to the blood circuit <NUM>, <NUM>. Branch <NUM> (including, e.g., a flow controller, valve(s), and/or clamp(s); see above) is configured to selectively allow supply of replacement fluid from the replacement fluid container <NUM> through the pre-infusion line <NUM> or through the post-infusion line 70b. In case of pre-infusion, the replacement fluid is introduced into the blood removal line <NUM> at a first pre-infusion site <NUM>-3b upstream the treatment unit <NUM> (with respect to fluid flow from the first end <NUM>-<NUM> of the blood removal line <NUM> to the second end <NUM>-<NUM> of the blood removal line <NUM>). In case of post-infusion, the replacement fluid is introduced into the blood return line <NUM> downstream from the treatment unit <NUM> (with respect to fluid flow from the first end <NUM>-<NUM> of the blood return line <NUM> to the second end <NUM>-<NUM> of the blood return line <NUM>). An anticoagulant syringe <NUM> provided with a check valve 24c may be connected to the blood removal line <NUM> at the first pre-infusion site <NUM>-3b.

The hydraulic circuit may further comprise a second dialysate line 40b, which branches off from the dialysate line <NUM> at a branch <NUM>. The branch typically includes a flow controller (e.g. one or more valves or a clamp mechanism) configured to selectively enable fluid flow either (solely) through the dialysate line <NUM> (i.e. from the first end <NUM>-<NUM> thereof to the second end <NUM>-<NUM> thereof) or, alternatively, through the first part of the dialysate line <NUM> up to branch <NUM> and further through second dialysate line 40b and post infusion line 70b (i.e. from the first end <NUM>-<NUM> of dialysate line <NUM> to branch <NUM>, through second dialysate line 40b and post infusion line 70b, to the second end 70b-<NUM> of post infusion line 70b). In detail, dialysate pump <NUM>, active on the dialysate line <NUM> and arranged upstream the branch <NUM> (with respect to fluid flow from the dialysate container <NUM> towards branch <NUM>), is configured to supply dialysate from the dialysate container <NUM> to treatment unit <NUM>. Branch <NUM> (including, e.g., a flow controller, valve(s), and/or clamp(s); see above) is configured to selectively allow supply of dialysate from dialysate container <NUM> through the dialysate line <NUM> or through the second dialysate line 40b, and, subsequently further through post infusion line 70b.

Within the scope of this description, the terms "upstream" and "downstream" are based on a general direction of fluid flow along a fluid line and/or through components of the apparatus under treatment condition (e.g. from a first end of a line towards a second end of a line; and/or from an arterial access of a patient towards a venous access of a patient). In general (e.g. during treatment), fluid flows through the blood removal line <NUM>, treatment unit <NUM>, and blood return line <NUM> from the first end <NUM>-<NUM> of the blood removal line <NUM> towards the second end <NUM>-<NUM> of the blood return line <NUM>. Further, fluid flows from containers <NUM>, <NUM>, and <NUM> towards the blood circuit, while used fluid flows from the treatment unit <NUM> towards and into container <NUM> (or, alternatively, towards and into the drain). Unless otherwise specified, the terms upstream and downstream refer to the above general directions of fluid flow through lines and components during regular operation of the apparatus (e.g. during treatment).

The extracorporeal blood treatment apparatus <NUM> further comprises a control unit <NUM>, i.e. a programmed/programmable control unit, configured to control components of the apparatus (e.g. pumps, valves, clamps) and to receive signals from components (e.g. sensors). The control unit <NUM> may, for example, comprise one or more digital microprocessor units or one or more analog units or other combinations of analog units and digital units. The extracorporeal blood treatment apparatus <NUM> may further comprise a user interface (e.g. a graphic user interface or GUI). The user interface is also connected to control unit <NUM> and configured to both present information to a user or operator through an output unit (e.g. screen, touchscreen, monitor, led elements, etc.) and to receive input from the user/operator through an input unit (e.g. keyboard, hardware button(s), mouse, touchscreen, voice recognition, optical recognition).

As shown in <FIG>, the apparatus <NUM> may include a clamp <NUM> configured to receive a portion of the blood return line <NUM> and configured to clamp (e.g. close) fluid flow through the blood return line <NUM>, in particular proximal to the second end <NUM>-<NUM> of the blood return line <NUM>. Similarly, the apparatus <NUM> may further include a clamp <NUM> configured to receive a portion of the blood removal line <NUM> and configured to clamp (e.g. close) fluid flow through the blood removal line <NUM>, in particular proximal to the first end <NUM>-<NUM> of the blood removal line <NUM>.

Each one of the pumps <NUM>, <NUM>, <NUM>, <NUM>, <NUM> included in the extracorporeal blood treatment apparatus <NUM> may comprise a positive displacement pump, such as a peristaltic pump. Peristaltic pumps generally operate on a respective pump tube tract (e.g. 22t, 42t, 52t, 62t, 72t) configured to operably connect with the respective pump (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) such that pump motion (e.g. rotation) is transferred onto the pump tube tract, thereby moving a respective fluid along the respective pump tube tract and, thus, through the respective line or lines (<NUM>, <NUM>, 40b, <NUM>, <NUM>, <NUM>, 70b) as well as other components (e.g. treatment unit <NUM>, blood warmer <NUM>, and/or air separator/bubble trap <NUM>).

<FIG>, <FIG> schematically show an extracorporeal blood treatment apparatus in accordance with a first embodiment of the present invention.

The blood circuit BC is only represented schematically because may be the same as disclosed in the example of prior art of <FIG>.

According to the first embodiment, the hydraulic circuit (fresh fluid flow path FFP and effluent flow path EFP) according to the invention is provided with an air detector array <NUM> of air detectors <NUM>, <NUM>, <NUM> positioned (optionally immediately) downstream from the fluid containers <NUM>, <NUM>, <NUM> and upstream of the respective pumps <NUM>, <NUM>, and <NUM>. The air detectors <NUM>, <NUM>, <NUM> are connected to the control unit <NUM> and are configured to detect any gas or air in the fluid flowing through. The air detectors <NUM>, <NUM>, <NUM> are each configured to send a respective signal to the control unit <NUM>, the signal being indicative of gas or air detected in the fluid flowing through the respective air detector <NUM>, <NUM>, <NUM>.

According to the first embodiment, the hydraulic circuit (fresh fluid flow path FFP and effluent flow path EFP) is provided with a fluid dispatcher <NUM> including a plurality of valves <NUM> configured to control fluid flow between a respective fluid line <NUM>, <NUM>, <NUM> and a common zone <NUM> of the fresh fluid dispatcher. The control unit <NUM> is connected to the fluid dispatcher <NUM>, optionally to each valve <NUM>, <NUM>, <NUM> of the plurality of valves <NUM>, and configured to control the fluid dispatcher <NUM>, optionally to control (e.g. control to open or close) each valve <NUM>, <NUM>, <NUM> of the plurality of valves <NUM>.

In this manner, above-described problem FB2 may be addressed in that any one of lines <NUM>, <NUM>, <NUM> may be put in fluid communication with any one of pumps <NUM>, <NUM>, <NUM> so that the fluid from any one of containers <NUM>, <NUM>, <NUM> may be supplied to the blood circuit BC by any one of pumps <NUM>, <NUM>, <NUM> (each to a different site, see above). In other words, any one of pumps <NUM>, <NUM>, <NUM> may pump fluid from one or more of containers <NUM>, <NUM>, <NUM>.

The plurality of valves <NUM> includes a first valve <NUM> configured to selectively put the pre blood pump (PBP) line <NUM> in fluid communication with the common zone <NUM>. The plurality of valves <NUM> further includes a second valve <NUM> configured to selectively put the infusion line <NUM> in fluid communication with the common zone <NUM>. The plurality of valves <NUM> further includes a third valve <NUM> configured to selectively put the dialysate line <NUM> in fluid communication with the common zone <NUM>. Each of the connection to lines <NUM>, <NUM>, <NUM> branches off the respective line optionally downstream the fluid containers <NUM>, <NUM>, <NUM> (and downstream from the array <NUM>) and upstream from the pumps <NUM>, <NUM>, <NUM> such that the fresh fluid dispatcher <NUM> is configured to receive fresh fluid from containers <NUM>, <NUM>, and/or <NUM>, which has been checked for air or gas and configured to supply received fluid to pumps <NUM>, <NUM>, and/or <NUM>.

The hydraulic circuit further includes an air and fluid drainer <NUM> comprising a flow controller <NUM> (e.g. a pump, optionally an occlusive pump) and a drainer air detector <NUM>. The air and fluid drainer <NUM> is in fluid connection with the common zone <NUM> of the fluid dispatcher <NUM> and with the effluent line <NUM> of the effluent fluid flow path. A connecting drainer fluid line <NUM> branches off the effluent line <NUM> downstream effluent pump <NUM> and upstream the drain or the effluent fluid container <NUM>.

This arrangement of an air and fluid drainer <NUM> allows for sending any mix of air and fluid previously detected upstream from pumps <NUM>, <NUM>, <NUM> by (any one or more of) the air detectors <NUM>, <NUM>, and/or <NUM>, in order to address the above-described problem FB1.

Further, this arrangement allows for sending fresh fluid from (any one or more of) containers <NUM>, <NUM>, <NUM> to the effluent line <NUM> and, in particular, to blood leak detector (BLD) <NUM> in the effluent line <NUM>. In this manner, the blood leak detector <NUM> may be (re-) calibrated when the effluent pump <NUM> is stopped such that only fresh fluid is sent through the effluent line <NUM> from the air and fluid drainer <NUM>. This addresses the above-described problem EB1.

In one example, for (re-) calibrating the blood leak detector <NUM>, any one or more of valves <NUM>, <NUM>, and/or <NUM> may be opened while pumps <NUM>, <NUM>, <NUM>, and <NUM> remain stopped. Upon operation of flow controller/pump <NUM>, fresh fluid is drawn from the one or more containers <NUM>, <NUM>, <NUM> and conducted through the drainer fluid line <NUM> and into the effluent line <NUM> towards the drain or container <NUM>. The fresh fluid also passes through the blood leak detector <NUM> so that the (re-) calibration may be performed. It is noted that, to this aim, the control unit <NUM> is connected to the respective components (e.g. sensors, pumps, valves) and configured to operate such components according to the above.

<FIG> and <FIG> schematically show an example configuration of the extracorporeal blood treatment apparatus in accordance with the first embodiment of the present invention. As described above, the fresh fluid dispatcher <NUM> may be configured to alternatively associate one or more connected containers <NUM>, <NUM>, <NUM> to a single fluid pump. In this example, pre blood pump <NUM> and replacement fluid pump <NUM> are controlled to stop, while dialysate pump <NUM> is controlled to supply fluid from the dialysate container <NUM> and, via the fluid dispatcher <NUM>, from the pre blood pump container <NUM> and the replacement fluid container <NUM> to the dialysate line <NUM>. As shown, valves <NUM>-<NUM>, <NUM>-70b and <NUM>-70b are controlled to be closed and valve <NUM>-<NUM> is controlled to be open. The example of <FIG> shows a configuration in which fluid from all containers <NUM>, <NUM>, <NUM> is supplied to the dialysate pump <NUM>. This addresses the above-described problem FB2 and further allows replacement of an empty container without stopping blood circulation and/or therapy. Any container <NUM>, <NUM>, <NUM> may be replaced, e.g. if empty, during an ongoing treatment since fluid from the remaining container or containers may be supplied as shown. Although fluid is supplied from several containers, fluid flow is always controlled by the respective pump (in the example shown, by the dialysate pump <NUM>).

<FIG> and <FIG> schematically show another example configuration of the extracorporeal blood treatment apparatus in accordance with the first embodiment of the present invention. When air is detected (see problem FB1 above) upstream from a fluid pump (in the example shown, upstream the pre blood pump <NUM>), the pre blood pump <NUM> is stopped in order to avoid introduction of air into the blood circuit BC. If the associated fluid container, here the pre blood pump container <NUM>, is empty, an operator may change the container. After that, the relevant valve (first valve <NUM>) may be opened in fluid dispatcher <NUM>. Subsequently, the flow controller/pump <NUM> is controlled to remove air from the affected circuit segment (in the example shown between the pre blood pump <NUM> and the common zone <NUM> of the fluid dispatcher <NUM>) and to send it to the effluent circuit <NUM>. The flow controller/pump <NUM> may be controlled to operate while air is detected by the respective upstream air detector (here air detector <NUM>). When there is no more air detected at the upstream air detector <NUM>, the flow controller/pump <NUM> is further controlled to operate in order to fill the entire circuit of the fluid dispatcher <NUM> and the drainer <NUM> up to the downstream drainer air detector <NUM> with liquid in order to ensure that the common zone <NUM> of the fluid dispatcher <NUM> is free from air. It is noted that, during this procedure, it may be necessary to deactivate/disable blood leak detector <NUM> in order to prevent a false alarm (e.g. due to the detection of air by blood leak detector <NUM>).

In some embodiments it may be necessary to adapt the control loop in order to compensate for fluid removed from one of the containers <NUM>, <NUM>, <NUM> in the manner described, because such fluid flow control loop, controlling the flow rate or rates for respective pumps <NUM>, <NUM>, <NUM>, may be based on the weight or change of weight of a respectively associated container <NUM>, <NUM>, <NUM>.

<FIG>, <FIG>, <FIG>, and 3D schematically show an extracorporeal blood treatment apparatus in accordance with a second embodiment of the present invention. The blood circuit BC is only represented schematically because may be the same as disclosed in the example of prior art of <FIG>.

The hydraulic circuit in accordance with the second embodiment of the present invention also includes an air detector array <NUM> as described above with respect to the first embodiment. Further, the hydraulic circuit in accordance with the second embodiment of the present invention also includes a fresh fluid dispatcher <NUM> and an air and fluid drainer <NUM> as described above with respect to the first embodiment, with the exception of what is described below. The fluid dispatcher <NUM> in accordance with the second embodiment includes four two-way valves <NUM>, <NUM>, <NUM> and <NUM>'. Valve <NUM>' (flow controller) is arranged on the pre blood pump (PBP) line <NUM>, which is routed through the fluid dispatcher <NUM> downstream from pre blood (PBP) pump <NUM>. Pre blood pump line <NUM> branches off (pre blood pump line branch <NUM>) to valve <NUM>, which connects pre blood pump line <NUM> to the common zone <NUM>. Valves <NUM> and <NUM> respectively connect infusion line <NUM> and dialysate/infusion line <NUM> to common zone <NUM> through pre-infusion line branch <NUM> and a dialysate line branch <NUM>.

The air and fluid drainer <NUM> in accordance with the second embodiment also includes a flow controller <NUM> (e.g. a two-way valve), connecting the common zone <NUM> to the drainer fluid line <NUM> and further to the effluent line <NUM>, upstream of blood leak detector (BLD) <NUM>. In the second embodiment, the flow controller <NUM> comprises a two-way valve. Including a pump in flow controller <NUM> is not necessary since a pumping action may be provided by a respective one (or more) of pumps <NUM>, <NUM>, <NUM>. A non-return flow controller <NUM> is provided in drainer fluid line <NUM>. The non-return flow controller <NUM> (e.g. a check valve) is configured to allow fluid flow from the drainer fluid line <NUM> towards and into the effluent line <NUM>, while preventing fluid flow in the opposite direction.

The second embodiment also addresses problems FB1, FB2, and EB1, as described above with respect to the first embodiment. Further, the second embodiment addresses problems FB3 and FB4 (see above). The fluid dispatcher <NUM> may be configured to allow fluid from any one container <NUM>, <NUM>, <NUM> to be directed to any infusion site (e.g. through any of lines <NUM>, <NUM>, 70b, <NUM>) by controlling valves <NUM>, <NUM>, <NUM>, and <NUM>'. Likewise, the fluid dispatcher <NUM> may be configured to allow a customized fluid to be directed to any infusion site, the customized fluid being created by mixing of fluids from any two containers <NUM>, <NUM>, <NUM>.

<FIG> and <FIG> schematically shows an example configuration of the extracorporeal blood treatment apparatus in accordance with the second embodiment of the present invention. As described above, the fresh fluid dispatcher <NUM> may be configured to alternatively associate one or more connected containers <NUM>, <NUM>, <NUM> to a single injection site (here: supplying dialysate to the treatment unit <NUM>). The example of <FIG> shows a configuration in which fluid from all containers <NUM>, <NUM>, <NUM> is supplied to the dialysate line <NUM>. Similar to a corresponding configuration based on the first embodiment (see <FIG> and corresponding description above) valves <NUM>, <NUM>, and <NUM> are open while valve <NUM>' is closed. In contrast, pumps <NUM>, <NUM>, and <NUM> are all controlled to supply (the same) fluid to the dialysate line <NUM>, valve arrays <NUM> and <NUM> being controlled accordingly (see <FIG>; valves <NUM>-<NUM>, <NUM>-70b, and <NUM>-70b being closed, valve <NUM>-<NUM> being open). In detail, pumps <NUM> and <NUM> are controlled to supply fluid from containers <NUM> and <NUM>, via fluid dispatcher <NUM>, to dialysate line <NUM>, while pump <NUM> is controlled to supply fluid from container <NUM> directly to dialysate line <NUM>. This addresses the above-described problem FB2 and further allows replacement of an empty container without stopping blood circulation and/or therapy. Any container <NUM>, <NUM>, <NUM> may be replaced during an ongoing treatment since fluid from the remaining container or containers may be supplied as shown. As each fluid pump <NUM>, <NUM>, <NUM> is controlled to deliver fluid from each associated container <NUM>, <NUM>, <NUM> only, this configuration does not have any impact on a fluid balancing system control loop since the flow-rate of each pump is associated to the weighting of the respective single associated container.

<FIG> and <FIG> schematically shows another example configuration of the extracorporeal blood treatment apparatus in accordance with the second embodiment of the present invention. As described above, the fresh fluid dispatcher <NUM> may be configured to allow mixing of fluids coming from two separate containers <NUM>, <NUM>, <NUM> at a defined ratio and to infuse the mixture to a single site (or several sites) on the blood or dialysate side (e.g. lines <NUM>, 70b and/or <NUM>). The example of <FIG> shows a configuration in which fluids from the replacement fluid and dialysate containers <NUM>, <NUM> are mixed at a defined ratio and supplied to the post-infusion line 70b while fluid from the pre blood pump (PBP) container <NUM> is supplied, by the pre blood pump <NUM> and via fluid dispatcher <NUM>, to pre blood pump (PBP) line <NUM>. Valves <NUM>-70b, <NUM>, <NUM> and <NUM>' are controlled to open, while valves <NUM>-<NUM>, <NUM>-70b, <NUM>-<NUM> and <NUM> are controlled to close. Replacement fluid pump <NUM> and dialysate pump <NUM> are controlled to operate, each at a pre-determined rate in order to achieve the desired mixing ratio, thereby respectively supplying fluid from the containers <NUM> and <NUM>, via the fluid dispatcher <NUM>, to the post infusion line 70b. The pre blood ump <NUM> is controlled to supply fluid from the pre blood pump container <NUM> to the pre blood pump (PBP) line <NUM>, also via the fluid dispatcher <NUM>. Mixing of pre blood pump (PBP) fluid with the other fluids going through the fluid dispatcher <NUM> is prevented due to the first valve <NUM> being kept closed.

<FIG> and <FIG> schematically show another example configuration of the extracorporeal blood treatment apparatus in accordance with the second embodiment of the present invention. When air is detected (see problem FB1 above) upstream from a fluid pump (in the example shown, upstream the pre blood (PBP) pump <NUM>), the pump is stopped in order to avoid introduction of air into the blood circuit BC. If the associated fluid container, here the pre blood pump container <NUM>, is empty, an operator may change the container. After that, the relevant valve (here the first valve <NUM>) may be opened in the fluid dispatcher <NUM> and the flow controller <NUM> in the air and fluid drainer <NUM> may be controlled to open (other valves <NUM>, <NUM>, <NUM>' remain closed or are controlled to close). Subsequently, the respective pump (in this example, the pre blood pump <NUM>) is controlled to remove air from the affected circuit segment (in the example shown between the pre blood pump container <NUM> and the common zone <NUM> of the fluid dispatcher <NUM>) and sends it to the effluent line <NUM> via the drainer fluid line <NUM>. The respective pump (here, pre blood pump <NUM>) may be controlled to operate while air is detected by the respective upstream air detector (here air detector <NUM>). When there is no more air detected at the upstream air detector, the respective pump (here, pre blood pump <NUM>) is further controlled to operate in order to fill the entire circuit of the fluid dispatcher <NUM> and the drainer <NUM> up to the downstream drainer air detector <NUM> with liquid in order to ensure that the common zone <NUM> of the fluid dispatcher <NUM> is free from air. It is noted that, during this procedure, it may be necessary to deactivate/disable the blood leak detector (BLD) <NUM> in order to prevent a false alarm (e.g. due to the detection of air by the blood leak detector <NUM>). As shown in Figure 3D, the replacement fluid pump <NUM> and the dialysate pump <NUM> may be controlled to continue to operate and, thus, continue to supply, respectively, infusion fluid from the replacement fluid container <NUM> and dialysate or infusion fluid from dialysate/infusion container <NUM> to lines <NUM>/70b and <NUM>. Valve arrays <NUM> and <NUM> may be set as desired, while valves <NUM> and <NUM> of the fluid dispatcher <NUM> are controlled to remain closed. The configuration shown in <FIG> addresses problem FB1 as described above.

The hydraulic circuits and structures in accordance with embodiments of the present invention facilitate great modularity in the management of fluids, air in fluid removal, and rinsing of the BLD. Further, the possibility to distribute any of the supplied fluids to a single location or site of the hydraulic circuit flow-path facilitates a potential integration of a fluid analysis sensor at such a location or site. Owing to its position on effluent circuit, such devices may be used to carry out measurements on effluent fluid but also on fresh fluid from containers <NUM>, <NUM>, <NUM>. Several sensing technologies (spectrometry, electrochemistry, optode) may be employed in analyzing electrolytes and solutes of clinical interest of the fluids. Such circuit structure allows comparison of two consecutive measurements made by a same sensor onto two fluids samples.

For fresh fluids, it is possible to check before use if the composition of a new connected fluid container is the same as previous one (e.g. for verifying whether a multi-compartment bag has been well mixed, or whether a citrated PBP container is set up as replacement container). Such circuit structure allows comparing change in effluent composition versus fresh dialysate, fresh dialysate being used as reference sample. Such circuit structure allows detecting presence and also citrate concentration in PBP container.

Comparative measurement allows simplification and improvement of the accuracy of adsorption spectrometric and electrochemistry methods. The possibility to periodically rinse with fresh solutions amperometric/potentiometric electrochemistry sensors allows limitation of bias or polarization over time.

<FIG> schematically shows rinsing and calibration of the blood leak detector BLD <NUM> in accordance with embodiments of the present invention. As shown, in order to address above-described problem EB1, fresh fluid (e.g. pre blood pump PBP fluid, replacement fluid, or dialysate fluid) from any one or more of containers <NUM>, <NUM>, <NUM> (not shown) may be supplied to the fresh fluid dispatcher <NUM> and further, via the air and fluid drainer <NUM> to the effluent line <NUM>. While fresh fluid is delivered and with the effluent pump <NUM> being controlled to stop, the blood leak detector BLD <NUM> may be (re-) calibrated. In detail, the blood leak detector BLD <NUM> may be filled, in the manner described, with fresh dialysate or replacement fluid, such that the (re-) calibration may be performed and/or controlled by the control unit <NUM> (not shown). Since the fresh fluid from any one of the containers <NUM>, <NUM>, <NUM> used for recalibrating the blood leak detector BLD <NUM> may be collected by the effluent container <NUM>, the general principle for monitoring patient weight loss, which manages the activity of the effluent pump <NUM> isn't affected by this process. As for air in fresh fluids removal, the patient weight loss may always be calculated as the whole effluent weight minus the weight of all already used fresh fluids.

<FIG> schematically shows integration of a fluid analyzer and/or fluid sampler in accordance with embodiments of the present invention (in order to address above-described problem FB5). An integrated on line fluid analyzer <NUM> may be arranged on the effluent line <NUM> in order to determine properties of fluid going through line <NUM> or an external fluid analyzer <NUM> may be connected to the effluent line <NUM> via interface ports <NUM> and <NUM>. Further, a non-return valve <NUM> (e.g. a check valve, see <FIG>) may be arranged on the effluent line <NUM> in order to prevent back flow of unknown fluid from the effluent container <NUM> and/or a drain (not shown).

The use of the optional external fluid analyzer <NUM> may be required if the sensor technology isn't compatible with the CRRT set sterilization process. Otherwise some sensors may require wait states in their measurement process without flowing of a fluid sample. In such cases the external fluid analyzer <NUM> may be required to manage its own sampling pump (e.g. exhibiting a sampling flow rate lower than the fluid flow rate towards the effluent container <NUM>; see <FIG> and the corresponding description below). The zone of the effluent circuit including the non-return valve <NUM> allows to maintain fluid flow. A syringe pump <NUM> may be connected to a line connecting the external fluid analyzer <NUM> to the interface ports <NUM> and <NUM>.

<FIG> schematically shows integration of the external fluid analyzer <NUM> in accordance with embodiments of the present invention. In line with the general configuration is shown in <FIG> shows further details with respect to the external fluid analyzer <NUM>. The external fluid analyzer <NUM> includes, if required, an analyzer rinsing and calibration solution container <NUM>, a valve array <NUM> configured to selectively allow fluid flow from the calibration container <NUM> and/or from an inlet line <NUM> towards a sampling pump <NUM> and towards an array <NUM> of sensors configured to determine properties of the fluid going through the external fluid analyzer <NUM>. Further, a valve <NUM> is configured to selectively allow fluid to flow from the array <NUM> through an outlet line <NUM> and back towards the effluent line <NUM> and into the effluent container <NUM> or the drain (not shown). The outlet line <NUM> of the fluid analyzer <NUM> being in fluid connection with the effluent container <NUM> facilitates using said effluent container <NUM> also for collecting waste fluid from the fluid analyzer <NUM>. If the fluid analyzer <NUM> should require significant amounts of calibration or rinsing solution from the calibration container <NUM>, such additional fluid volumes may be taken into account in the CRRT monitor fluid balance.

<FIG> shows a third embodiment of the present invention similar to the second embodiment. In this third embodiment, the replacement fluid from the respective container <NUM> may be routed pre or post treatment unit <NUM>. A post-filter infusion line 70c is connected between the treatment unit <NUM> and the blood warmer <NUM>. The dialysate circuit has no capability for being routed to post-infusion 70b as it was the case in first and second embodiment. An additional fluid circuit (additional fluid container <NUM>, additional pump <NUM>, fourth valve <NUM>, air detector <NUM>, additional post-infusion line 70d with a flow controller valve <NUM>') is added to deliver post-infusion directly to the air separator/bubble trap <NUM>. Further flow controller valves <NUM>', <NUM>' are placed on the dialysate line <NUM> and on the pre blood pump (PBP) line <NUM>.

The blood circuit BC, the dialysate line <NUM>, the pre blood pump (PBP) line <NUM>, the pre-infusion line <NUM>, the post-infusion lines 70b, 70c, 70d, the effluent line <NUM> may be part of a disposable assembly according to an independent aspect of the invention.

Said lines are made of flexible plastic tubes and have respective sections configured to be coupled the respective fluid pumps or air detectors or flow controllers. The fluid lines may be connected one to the other, at the common zone, through bonding, welding or joints, optionally Y or T joints.

The apparatus as disclosed above comprises a machine comprising a main body with the pumps, the control unit, sensors and controllers and possible other elements configured to hold the various parts of the disposable assembly. The disposable assembly is coupled to the machine for performing one treatment on one patient only and disposed after use.

Claim 1:
An apparatus for extracorporeal blood treatment, comprising:
a treatment unit (<NUM>);
a blood circuit coupled to the treatment unit (<NUM>) and comprising a blood removal line (<NUM>) and a blood return line (<NUM>) connectable to a vascular system of a patient (P);
a blood pump (<NUM>) configured to be coupled to a pump section of the blood circuit;
a plurality of fluid lines (<NUM>, <NUM>, <NUM>, 70b, 70c, 70d) connected or connectable to respective containers (<NUM>, <NUM>, <NUM>, <NUM>),
wherein said fluid lines (<NUM>, <NUM>, <NUM>, 70b, 70c, 70d) are connected to the blood circuit and to the treatment unit (<NUM>);
a plurality of pumps (<NUM>, <NUM>, <NUM>, <NUM>) active on the fluid lines (<NUM>, <NUM>, <NUM>, 70b, 70c, 70d);
a fluid dispatcher (<NUM>) having a common zone (<NUM>), wherein at least two fluid lines of said plurality of fluid lines (<NUM>, <NUM>, <NUM>, 70b, 70c, 70d) are connected one to the other at said common zone (<NUM>) upstream the blood circuit, for selectively allowing fluid flow between said at least two fluid lines (<NUM>, <NUM>, <NUM>, 70b, 70c, 70d) through said common zone (<NUM>).