Device and method for the efficient cleaning of a blood filter

Abstract

A method for cleaning a blood filter comprises: (i) pumping a physiologically safe fluid in both directions through the inner and / or outer portions of a plurality of hollow fiber membranes of the blood filter to remove or separate blood residues, such as blood clots, proteins, and / or biological fluid; (ii) injecting air into the physiologically safe fluid to form an air / fluid mixture; (iii) pumping the air / fluid mixture through the inner and / or outer portions of the plurality of hollow fiber membranes of the blood filter to further remove or separate blood residues from it; and (iv) disposing of the physiologically safe air / fluid mixture with the removed or separated blood residues to the purge.

Description

Title of the invention: Device and method for the efficient cleaning of a blood filter

[0001] The examples described below relate, in general, to the administration of medical fluids. More specifically, the examples relate to devices, methods, and apparatus for cleaning blood filters, such as dialyzers or hemodialysis filters.

[0002] Many conventional dialyzers are not reused; instead, they are discarded after a single use. When dialyzers are reused, they are most often rinsed with copious amounts of water and / or very strong chemical agents to remove residual biological fluids and disinfect the membrane. Alternatively, dialyzers can be disinfected with heat, eliminating the need for chemical agents but still requiring water. Dialysis devices also require that excess biological residues be periodically removed from the dialyzer. For ecological and cost reasons, and particularly for devices used at home and for travel, it is desirable to minimize the amount of water used for such cleaning and disinfection.

[0003] Improved blood filter cleaning and disinfection devices and methods are therefore required.

[0004] In summary, the present invention creates a method for cleaning a blood filter comprising: pumping physiologically safe fluid in both directions through the inner and / or outer parts of a plurality of hollow fiber membranes of the blood filter so as to remove or separate blood residues, such as blood clots, proteins and / or biological fluid; injecting air into the physiologically safe fluid to form an air / fluid mixture; pumping the air / fluid mixture through the inner and / or outer parts of the plurality of hollow fiber membranes of the blood filter to further remove or separate the blood residues from them; and removing the physiologically safe air / fluid mixture with the removed or separated blood residues to the purge.

[0005] Preferably, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes involves the fractionation of the air into microbubbles.

[0006] Preferably, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes comprises pumping the mixture from a lower part of the blood filter to an upper part of the blood filter.

[0007] Preferably, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes comprises pumping the physiologically safe air / fluid mixture in both directions through the membranes.

[0008] Preferably, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes involves circulating the physiologically safe air / fluid through the membranes a plurality of times.

[0009] Preferably, the removal of the physiologically safe air / fluid mixture to the purge involves the injection of air in order to push the mixture towards the purge.

[0010] Preferably, the process further comprises priming or disinfecting the blood filter after removing the physiologically safe air / fluid mixture to the purge.

[0011] Preferably, the air injection includes air filtration.

[0012] Preferably, the air injection comprises pumping air into the blood filter by via a blood pump.

[0013] Preferably, pumping the physiologically safe fluid in both directions involves reversing a blood pump.

[0014] Preferably, the pumping of the physiologically safe fluid in both directions involves the sequential control of a plurality of valves.

[0015] The process may include transferring the physiologically safe fluid from outside the hollow fiber membranes, through the membrane walls, and into the inner parts of the membranes in order to pump the treatment fluid in both directions.

[0016] Preferably, the physiologically safe fluid used to ensure pumping in both directions through the inner parts of the membranes is obtained by means of a return blood flush to the patient, leaving the physiologically compatible fluid inside the membranes.

[0017] Preferably, the physiologically safe fluid is selected from the group consisting of dialysate, a replacement fluid and saline solution.

[0018] Preferably, the process is used with renal therapy equipment.

[0019] Preferably, the blood filter is a dialyzer.

[0020] The invention further relates to a kidney therapy device comprising: a blood filter (30) having a plurality of hollow fiber membranes; arterial and venous lines in fluidic communication with the blood filter (30); a blood pump (28) for pumping blood through the arterial and venous lines and the blood filter; a treatment fluid pump (40, 50) in fluidic communication with (a) a treatment fluid side of the blood filter or (b) the arterial or venous line; and a control unit (60) that controls the blood pump and the treatment fluid pump during treatment and at least one of the pumps to blood and the processing pump during a filter cleaning sequence in which (i) a physiologically safe fluid is transferred in both directions through the inner and / or outer parts of the plurality of hollow fiber membranes, (ii) the physiologically safe fluid mixed with air is transferred at least once through the inner and / or outer parts of the plurality of hollow fiber membranes, and (iii) the physiologically safe fluid mixed with air and blood residues separated or removed from the hollow fiber membranes is transformed (or transferred) to the purge.

[0021] Preferably, the renal therapy device includes a filtered air access in fluidic communication with the blood pump and a valve, the control unit ensuring the control of the valve in order to allow the air to be mixed selectively during the operation (ii).

[0022] Preferably, the process fluid pump is a replacement fluid pump, the process fluid being a replacement fluid.

[0023] Preferably, the control unit ensures the control of the replacement fluid pump so as to perform at least one of the operations (i), (ii) or (iii).

[0024] Preferably, the treatment fluid pump is a fresh dialysate fluid pump, and in which the treatment fluid is dialysate.

[0025] Preferably, the renal therapy device comprises a saline solution source in fluidic communication with the arterial or venous line, the treatment fluid pump being a saline solution pump, and the physiologically safe fluid being saline solution.

[0026] Preferably, the control unit is configured to cause the blood pump to perform operations (i) to (iii) and the treatment fluid pump to operate during at least one of operations (i) and (ii) on the outer parts of the hollow fiber membranes so as to try to balance the pressures across the hollow fiber membranes.

[0027] Alternatively, the control unit is configured to cause the blood pump to perform only operations (i), (ii) and (iii).

[0028] Alternatively, the control unit is configured to cause the blood pump and the treatment fluid pump to perform operations (i) and (ii) and the blood pump to perform operation (iii) alone.

[0029] By recirculating the fluid through a blood filter, and injecting air bubbles into the circuit at opportune times, the efficiency of the cleaning procedure for the blood filter can be maximized without consuming vast quantities of water.

[0030] The examples below describe devices and methods that provide blood treatment for a patient. Blood treatment can be a treatment of Any type of blood filtration, such as hemodialysis ("HD"), hemofiltration ("HF"), hemodiafiltration ("HDF"), or continuous renal replacement therapy ("CRRT"), is used. A common feature of these treatments is that an associated filter, for example, a hemodialyzer or hemodialysis filter, can be reused. If it is not reused, the filter is discarded. If it is reused, the filter must be cleaned periodically, for example, between each use. In one embodiment, the device and method of the present invention provide filter cleaning after each treatment, just before a disinfection sequence in which the treatment fluid lines and blood lines are cleaned either with hot water or with a chemical disinfectant.It is envisaged that the filter cleaning process of the present invention will be carried out after treatment when the blood lines have been disconnected from the patient and connected together either directly or via a treatment fluid loop.

[0031] One objective of the present invention is to clean or rinse the dialyzer without using large quantities of fluid, such as dialysate, replacement fluid, or saline solution. Another objective of the present invention is to clean or rinse the blood filter efficiently. In the device and method described herein, a volume of 250 ml of dialysate, saline solution, or replacement fluid can be used to clean the dialyzer. As will be described in detail below, the flow of dialysate, saline solution, or replacement fluid is reversed in both directions, or pulsed, through the blood filter and mixed at opportune times with air so as to efficiently remove blood clots, proteins, residual biological fluids, and the like from the filter membranes in order to clean the filter for future use.

[0032] As previously mentioned, regardless of the type of machine or therapy used, a filter is provided. The filter is fluidically connected to a blood pump such that the blood pump can pump blood through the inner portions of the filter membranes to clean the blood. At least one treatment fluid pump is provided to pump the treatment fluid, for example, dialysate in HD, HDF, and CRRT, or replacement fluid in HF, HDF, and CRRT, to clean the blood and remove the used treatment fluid from the filter. In HD, for example, a first treatment fluid pump pumps the dialysate to the dialyzer, while a second treatment fluid pump removes the used dialysate from the dialyzer.In HF, a first replacement fluid pump pumps the replacement fluid directly to the blood tubing connected to a hemodialysis filter, while a second pump removes the used replacement fluid from the hemodialysis filter. In HDF, the HD configuration is combined with a third pump that pumps the replacement fluid directly to the tubing. Blood is connected to the hemodialyzer. CRRT can have any of the pumping configurations and performs any of the HD, HF, or HDF therapies and is generally a slowed or low-flow version of the corresponding HD, HF, or HDF therapy. CRRT is implemented in a hospital setting and, typically, in cases of acute kidney failure.

[0033] Another component of the present invention, which is provided independently of the type of machine or therapy used, is an access to ambient air. In one embodiment, air is introduced on the blood side of the filter such that the air can move towards the blood sides or inner portions of the filter membranes. The air may be introduced through an air filter that removes contaminants from the air and purifies the air so as to be suitable for injection into the blood circuit, even if the air is eventually purged from the entire device and the circuit is disinfected.

[0034] Blood and treatment pumps can be of a type suitable for administering medical fluids and are conventionally peristaltic or volumetric diaphragm pumps. The pumps can operate with one or more valves that selectively open and close a line or piping leading to or from each pump. Each pump and valve is automatically controlled by a control unit or controller that uses one or more processing units and memories. The pumps and valves can be controlled pneumatically, electromechanically, or by a combination thereof. In one embodiment, the controller or control unit activates the pumps and valves in the following sequence to clean or rinse the dialyzer.

[0035] In a first phase of the sequence, the device and method of the present invention attempt to separate blood clots, proteins, and biological fluids from the inner parts of the filter membranes by reversing the flow of the treatment fluid in one direction and then the other (fluid pulsation) through the inner and / or outer parts of the filter membranes. The reversal of the treatment fluid can be achieved by means of the blood pump, the treatment fluid pump, or both. In this way, the inner and / or outer parts of the membrane walls are purified fluidically. And because the same fluid is moved in both directions to suspend the debris within the fluid, and not sent to the purge, a relatively small quantity of fluid is actually required when implementing this first phase.The treatment fluid that is used may be (i) fresh fluid that has not been used during the treatment, (ii) residual treatment fluid extracted from the treatment fluid circuit, or (iii) residual treatment fluid that has been used to ensure blood return flushing to the patient at the end of the treatment.

[0036] In one embodiment, the cleaning fluid is a physiologically safe fluid, such as dialysate, replacement fluid, or saline solution. Thus, although water can be used instead of a physiologically compatible treatment fluid in this first phase, a physiologically compatible fluid is preferred because pure water is considered to be more likely to create new blood clots than the physiologically safe fluid. Alternatively, for example, if the machine is disinfected after the dialyzer cleaning procedure of the present invention, the cleaning fluid can be a more potent fluid such as a strong acid, a strong base, or an enzymatic stripper, which are good blood clot removal agents.

[0037] In a second phase, air is injected into the blood filter from an air inlet, optionally protected by an air filter. The air is drawn into the treatment fluid, creating an air / treatment fluid mixture, which has a consistency and thus a purification capacity different from that of the pure treatment fluid. The air / treatment fluid mixture is pumped at least once from the lower part of the filter to the upper part of the filter. If the air inlet is arranged so that the air must enter the filter from its upper part, then the device and method of the present invention first push the air / treatment fluid mixture towards the lower part or beyond the lower part of the filter, and then reverse the pumping to move the air / treatment fluid mixture from the lower part of the filter, through the filter.By doing so, microbubbles (or an effervescence effect) are created, which further facilitate the removal of blood from the dialyzer. As the microbubbles move through the small diameter of the filter fibers, they expose blood particles to alternating phases of liquid and gas, as well as to high levels of shear stress and turbulence at the boundary layer between the two phases, resulting in improved removal from the filter wall.

[0038] In a third phase, the device and method of the present invention perform a depriming procedure by drawing in more air from the filtered air inlet. By doing so, the air / treatment fluid mixture, now laden with suspended blood particles containing blood clots and proteins, is pushed towards the purge. It should be noted that, in one embodiment, no fluid is discharged from the device before this third phase. In different embodiments, phases two, three, and four can be repeated successively, for example, to achieve better cleaning, at the cost of higher water consumption.

[0039] In a fourth phase, the blood and treatment fluid circuits are primed, for example, with purified water or other fluid uncontaminated by Blood particles from the previous step are removed. Priming eliminates any remaining process fluid or air / process fluid mixture from each circuit, sending it to the purge. Once primed with water, the device is considered to be performing a hot water or chemical disinfection sequence. The disinfection sequence cleans the entire device, including the process fluid lines, blood lines, and filter. The disinfection fluid or water can then be discarded and replaced with filtered air, leaving the machine disinfected, dry, and ready to perform another treatment.

[0040] While the present invention is described primarily in relation to a dialysis machine that reuses the same dialyzer for multiple treatments, for example, approximately thirty treatments, the concepts described herein are not limited to such an application. For example, the device and methodology can be used on a dialyzer cleaning machine. In this case, the dialyzer is removed from the dialysis machine after treatment, taken to the dialyzer cleaning machine, which uses the structure and methodology described herein to clean the dialyzer, which is then returned to the dialysis machine for reuse.

[0041] Furthermore, while the present invention is described primarily in connection with a hemodialysis or blood processing machine, the present invention can also be applied to a dialysis machine that uses a filter to clean peritoneal dialysis fluid or PD solution. In such a case, the lower blood circuit is replaced by a peritoneal dialysis circuit that pumps the PD solution into and out of the patient's peritoneum.

[0042] It is, therefore, an advantage of the present invention to create improved renal failure therapy devices and methods.

[0043] Another advantage of the present invention is to create improved blood filter cleaning devices and methods.

[0044] Another advantage of the present invention is to create improved blood filter cleaning devices and methods that do not require large amounts of fluid to clean the blood filter.

[0045] It is yet another advantage of the present invention to create effective blood filter cleaning devices and methods.

[0046] Other features and advantages are described here, and will become evident from the detailed description and the following figures.

[0047] The figures will then be briefly described.

[0048] Fig. 1 is a schematic representation of a device configured and arranged to perform a filter cleaning procedure of the present invention.

[0049] Fig. 2 is an algorithm representing a method for cleaning a filter according to the present invention.

[0050] In the detailed description, HD / HF / HDF / CRRT / PD devices and methods will be addressed first.

[0051] With reference now to the drawings, and in particular to [Fig. 1], an embodiment of the device and method of the present invention is represented by the device 10. The device 10 comprises a blood circuit 20 and a treatment fluid circuit 40. The blood circuit 20 comprises an arterial line 22 and a venous line 24. The arterial line 22 terminates with an arterial needle connector A. The venous line 24 terminates with a venous needle connector V. During treatment, an arterial needle connector A is connected to an arterial needle or other access device (e.g., a catheter), which is inserted into the patient for treatment. The venous needle connector V is connected to a venous needle or other access device (e.g., a catheter), which is inserted into the patient for treatment.After processing, the arterial needle connector A can be connected to the venous needle connector V, as shown in [Fig. 1], for the cleaning procedure described below. Alternatively, the arterial needle connector A and the venous needle connector V can be connected to the processing fluid circuit 40 at conjugate connectors marked A and V respectively, after processing for the cleaning operation described below.

[0052] The venous line 24 includes a bubble trap or air trap that removes air from the blood before returning it to the patient via the venous line. The arterial line 22 includes a blood pump 28 in the illustrated embodiment. The blood pump 28 may be an electrically driven peristaltic blood pump. However, in the illustrated embodiment, the blood pump 28 is a volumetric or diaphragm type pump that operates with an upstream valve 28a and a downstream valve 28b. During operation, the upstream valve 28a is open, the downstream valve 28b is closed, while the pump diaphragm 28c is retracted so as to draw blood or other fluid towards the blood pump 28. During the next stroke, the upstream valve 28a is closed, the downstream valve 28b is open, while the pump diaphragm 28c is pushed back in order to push blood or other fluid from the blood pump 28 in the same way.

[0053] The blood pump 28 pushes blood through the blood filter 30, such as a dialyzer for hemodialysis ("HD") or hemodiafiltration ("HDF"), or a filter for hemofiltration ("HF"). Any of an HD, HDF, and HF can be implemented for continuous renal replacement therapy ("CRRT"). The filter 30, as mentioned above, can also be a filter used for filtered peritoneal dialysis ("PD"). In all cases, the blood filter 30 has a blood side 30a and a treatment fluid side 30b separated by a plurality of hollow fiber membranes 30c (shown as a single line in [Fig. 1]). The inner portions Hollow fiber membranes 30c form the blood side 30a, while the treatment fluid side 30b of the blood filter 30 is formed between the outer portions of the hollow fiber membranes 30c and the inner surface of the blood filter housing 30. In the embodiment shown, blood or other fluid flows into the blood filter 30 at its upper end 30d, through a blood side 30a, and exits the blood filter 30 at its lower end 30e. The arterial and venous lines 22 and 24 can alternatively be reversed, such that the blood flow during treatment flows from the lower end 30e of the blood filter 30, through the filter, and exits through its upper end 30d.

[0054] A source of saline solution and / or replacement fluid 32 can be prepared. Replacement fluid is prepared if HDF or HF is implemented during treatment. The replacement fluid is a physiologically compatible, injectable-grade fluid, which is introduced directly into the blood circuit 20, represented here by the arterial line 22, but, alternatively, or in addition, injected into the venous line 24. Saline solution is used in many dialysis devices for priming. In the embodiment shown, a replacement fluid and / or saline solution pump 34 pumps the replacement fluid and / or saline solution as needed into the arterial line 22.Pump 34 can be a peristaltic pump or, alternatively, a volumetric or diaphragm type pump, as shown, which operates with an upstream valve 34a and a downstream valve 34b in the same way as previously described for the volumetric version of the blood pump 28.

[0055] A heparin source 36 is arranged in the embodiment shown. A heparin pump 38 pumps heparin as needed into the arterial line 22. The pump 38 can similarly be a peristaltic pump or, alternatively, be a volumetric or diaphragm type pump, as shown, which operates with an upstream valve 38a and a downstream valve 38b in the same way as previously described for the volumetric version of the blood pump 28. The heparin from the source 36 facilitates the prevention of blood clots in the blood circuit 20 and the filter 30, as is known.

[0056] The treatment fluid circuit 40 delivers the treatment fluid, for example, dialysate, inline in one embodiment, by receiving purified water from a purified water source (not shown). Purified water is delivered to an inline treatment fluid generation unit 42 in the illustrated embodiment. The inline treatment fluid generation unit 42 mixes the purified water with acid and bicarbonate concentrates to produce a solution that is physiologically compatible with the patient's blood. A suitable inline treatment fluid generation unit 42 is described in the US patent application No. 2009 / 0008331, which was published on January 8, 2009, entitled "Hemodialysis Systems and Methods (device and method of hemodialysis)".

[0057] A pre-filter pump 44 pumps treatment fluid from the inline treatment fluid generation unit 42 through a pathogen filter 46, such as an ultrafiltration filter. The pump 44 is shown to be a peristaltic pump but is alternatively a volumetric diaphragm pump, such as pumps 28, 34, and 38. By taking purified water, for example, ultrapure water, transforming it into treatment fluid or dialysate, and passing the treatment fluid through an ultrafiltration filter, a solution of injectable or near-injectable quality is obtained. The pump 44 carries the dialysate through an inline heating device 48, which heats the dialysate to approximately body temperature or 37°C. The heating device 48 is arranged to ensure patient comfort and can, if desired, be removed from the treatment fluid circuit 40.

[0058] The pump 44 delivers fresh treatment fluid, for example, dialysate, under a certain pressure from the treatment fluid side 30b of the blood filter 30. During treatment, the treatment fluid, for example, the dialysate, cleans the circulating blood (for example, counter-currently) from the blood side 30a of the blood filter 30. The pump after filter 50 carries the exhausted or used dialysate from the treatment fluid side 30b of the blood filter 30 and delivers it to the purge. Pump 50 is represented as a peristaltic pump but is, alternatively, a volumetric diaphragm pump, as is represented by pumps 28, 34 and 38. If it is in the form of a volumetric diaphragm pump, it is envisaged to use pump 50 to push the exhausted or used dialysate under a certain pressure towards the pump after filter 50 during its filling stroke.In this way, the treatment fluid is never under negative pressure inside the blood filter 30, which can cause air to escape from the solution. Although not shown, one or more air traps can be positioned upstream or downstream of the pre-filter pump 44.

[0059] As is likewise not shown, the treatment fluid circuit 40 in one embodiment includes balancing chambers that balance the amount of fresh treatment fluid delivered to the blood filter 30 with the amount of spent or used fluid removed from the blood filter 30, or make these amounts equal, thereby preventing an increase or decrease in the amount of fluid present inside the patient. The operation of balancing chambers is known to specialists in the field but generally involves a chamber of known volume that is divided by a diaphragm, somewhat like a diaphragm pump. The chamber on one side of the diaphragm receives the spent treatment fluid, which displaces the The diaphragm moves to dissipate an equivalent amount of fresh treatment fluid. On a subsequent stroke, the chamber on the other side of the diaphragm receives fresh treatment fluid, which moves the diaphragm to dissipate an equivalent amount of used treatment fluid, and so on. Two balancing chambers can be used out of phase with each other such that there is always a certain flow of fresh fluid to the blood filter 30 and a certain flow of used or depleted fluid from the blood filter 30.

[0060] Once the fresh and exhausted treatment fluids are balanced, an ultrafiltrate ("UF") pump 52 is arranged to remove a precise amount of additional fluid from the patient during treatment. The UF pump 52 is shown to be a peristaltic pump but is, alternatively, a volumetric diaphragm pump, like pumps 28, 34, and 38. The UF pump 52 extracts a certain amount of UF from the patient during treatment in an attempt to return the patient to their dry weight.

[0061] A control unit 60, which may include one or more processing units and one or more memories, is used. The control unit 60 executes one or more computer programs, each comprising one or more computer programs designed to implement the process 100 shown in [Fig. 2]. The processing and memory of the control unit 60 also operate with a user interface (not shown), which allows a user to interact with and control the device 10. The control unit 60 controls, via electrical signals (dashed lines), the electrically driven peristaltic pumps, such as pumps 44, 50, and 52, and the heating device 48. The control unit 60 can also control the inline process fluid generation unit 42 using electrical signals (dashed lines) and / or pneumatic signals (dashed lines), as shown.The control unit 60 also controls, via electrical signals (dashed lines), each of a plurality of pneumatic valves 70a, 70b, 70c, 70d,..., 70n, which in turn control pneumatic signals (dashed lines) extending to diaphragm pumps, such as pumps 28, 34 and 38, and fluid valves, such as fluid valves 28a, 28b, 34a, 34b, 38a, 38b.

[0062] One or more of the pneumatic valves 70a, 70b, 70c, 70d,..., 70n also control pneumatic signals (dashed lines) extending to an air valve 18. The air valve 18 allows air filtered by a filter 16, such as a high-efficiency particulate air ("HEPA") filter, to be pumped into the device 10 via the heparin pump 38. It should be noted that although air filtration is preferred, the air need not necessarily be filtered for the present invention, for example, if the device 10 is to be disinfected. In one embodiment, a The depression exerted on a vial of heparin 36 by means of a heparin pump 38 is released by opening the air valve 18 and allowing air to enter through the filter 16 and the vial of heparin 16 at atmospheric pressure.

[0063] In one embodiment, each of the pneumatic valves 70a, 70b, 70c, 70d,..., 70n communicates fluidically with an overpressure source 72 and a vacuum source 74. In this way, the pneumatic valves 70a, 70b, 70c, 70d,..., 70n can deliver an overpressure from the source 72 to a fluid valve (for example, so as to close the valve) or a vacuum from the source 74 to the fluid valve (for example, so as to open the valve). Similarly, valves 70a, 70b, 70c, 70d,..., 70n can deliver overpressure from source 72 to a fluid pump (for example, in order to pump fluid out of the pump) or a vacuum from source 74 to the fluid pump (for example, in order to extract fluid into the fluid pump).

[0064] Referring now to [Fig. 2], an embodiment of a dialyzer cleaning process activated under the control of the control unit 60 is represented by process 100. Process 100 begins at oval block 102. At block 104, the treatment under the control of device 10 is completed. The treatment can be any type of blood cleaning treatment, such as hemodialysis ("HD"), hemofiltration ("HF"), hemodiafiltration ("HDF"), and continuous renal replacement therapy ("CRRT"). The end of the treatment for device 10 conventionally involves a flush with return of blood to the patient. Thus, the patient does not lose blood as a result of the treatment; the blood at the end of the treatment is returned to the patient. In one embodiment, the treatment fluid, such as the dialysate, is used to push blood through the arterial line 22 and the venous line 24 back to the patient.Alternatively, replacement fluid or saline solution from source 32 is used to push blood through arterial line 22 and venous line 24 towards the patient.

[0065] In block 106, the patient, after flushing back blood, disconnects the arterial line 22 and the venous line 24 from their respective needles and either (i) connects the arterial line 22 and the venous line 24 together (for example, using a separate recirculation fitting to connect the arterial needle fitting A to the venous needle fitting V) or (ii) connects the arterial needle fitting A to the corresponding port A on the treatment fluid circuit 40 and the venous needle fitting V to the corresponding port V on the treatment fluid circuit 40.

[0066] In one embodiment, the process 100 automatically transitions from block 106 to block 108 after the arterial and venous lines 22 and 24 have been connected together or to the treatment fluid circuit 40. In a variant of the embodiment, the process 100 transitions from block 106 to the block 108 at the end of treatment and disconnection of the needle via one or more user inputs using the user interface (not shown) in control unit 60.

[0067] At block 108, the device 10 causes the fluid to move in one direction and then the other, for example, vigorously, so as to remove blood clots, proteins, and / or residual biological fluids from the membranes of the blood filter 30. In one embodiment, the blood pump 28 is used to draw the treatment fluid, replacement fluid, or saline solution in one direction and then the other along the inner portions of the membranes of the blood filter 30. For this purpose, the membrane 28c is drawn in and pushed in one direction and then the other according to time with the sequential control of the valves 28a and 28b. If the blood pump 28 is a peristaltic pump, the pump rotor is driven to rotate while alternating the direction.In one embodiment, the blood pump 28 performs cycles of approximately 50 to 300 millilitres ("ml"), for example, 250 ml of treatment fluid, replacement fluid or saline solution in one direction and the other, along the inner parts of the membranes of the blood filter 30 approximately twenty times or cycles over a period of about five to twenty minutes, for example, fifteen minutes.

[0068] Alternatively, or in addition, one or both of the treatment fluid pumps 44 and 50 are used to draw the treatment fluid, replacement fluid, or saline solution in one direction and the other along the outer portions of the blood filter membranes 30. For this purpose, the rotors of the pumps 44 and 50 are driven in rotation while alternating the direction. If the pumps 44 and 50 are instead volumetric diaphragm pumps, the pump diaphragms and associated valves are controlled sequentially and in cycles as previously described for the blood pump 28.If the treatment pumps 44 and / or 50 are used, the treatment fluid pumps 44 and 50 can perform a cycle of approximately 50 to 300 ml, for example, 250 ml of treatment fluid, replacement fluid or saline solution in one direction and the other along the outer parts of the membranes of the blood filter 30, again, approximately twenty times or cycles over a period of about five to twenty minutes, for example, fifteen minutes.

[0069] The operation of the blood pump 28 in conjunction with one or both of the treatment pumps 44 and 50 may desirablely equalize the pressures on both sides 30a and 30b of the membranes 30c during one or both of the operations described in relation to blocks 108 and 110. Alternatively, it may be desirable to maintain a pressure gradient across the membranes 30c, for example, by maintaining side 30a at a higher pressure than side 30b. The gradient may be obtained by operating only the blood pump 28, or by operate the blood pump 28 at a pressure higher than that at which the treatment fluid pumps 44 and 50 are activated.

[0070] In one embodiment, the treatment fluid, such as dialysate, already resides on both the blood side 30a and the treatment fluid side 30b of the blood filter 30 from the end of the treatment (or) the backflush procedure. It is therefore logical to use the treatment fluid already present to ensure pulsed cleaning of block 108. The treatment fluid, such as dialysate, is physiologically safe and does not tend to coagulate or lead to blood lysis compared to purified water.

[0071] If saline solution resides on one or both of the blood side 30a and the treatment fluid side 30b of the blood filter 30, due to the end of treatment or the backflushing procedure, it is logical to use the saline solution already present to ensure pulsed cleaning of block 108 (for one or both of the blood side 30a and the treatment fluid side 30b). Saline solution is similarly physiologically safe and does not tend to coagulate or lead to blood lysis, unlike purified water.

[0072] If replacement fluid resides on one or both of the blood side 30a and the treatment fluid side 30b of the blood filter 30, due to the end of treatment or the backflushing procedure, it is logical to use the replacement fluid already present to ensure pulsed cleaning of block 108 (for one or both of the blood side 30a and the treatment fluid side 30b). The replacement fluid is similarly physiologically safe and does not tend to coagulate or lead to blood lysis, unlike purified water.

[0073] In alternative embodiments, the device 10 extracts the treatment fluid, for example, dialysate or replacement fluid, from a source or a storage tank for the latter. The device 10 can extract saline solution from the source 32, extract replacement fluid from the source 32, or extract dialysate from a storage tank (not shown in [Fig. 1]). The physiologically safe extracted fluid is carried from the treatment fluid side 30b of the blood filter 30, through the membranes 30c, to the blood side 30a of the blood filter 30, and to the blood circuit 20. In one embodiment, approximately 50 to 300 ml (for example, 250 ml) of such fluid is extracted and used to provide pulsed cleaning of the blood filter membranes of block 108.In all cases, because the fluid used to separate blood clots and proteins from the membrane walls of blood filter 30 is pulsed back and forth and is not sent to the purge, no fluid is consumed in block 108.

[0074] At block 110, air is injected into the blood circuit 20 and the blood side 30a of the blood filter 30, in which it produces an air / treatment fluid mixture (e.g., air / dialysate). The air / treatment fluid is pumped in an embodiment such that the mixture enters through the lower end 30e of the blood filter 30, which may require the air / treatment fluid mixture to be first pumped downwards through the blood filter 30 and then reversed upwards and exits through the upper end 30d of the blood filter 30, depending on how, as previously described, the blood lines 22 and 24 are connected to the blood filter 30. The air / treatment fluid mixture may be circulated once or several times through the entire blood circuit 20 and / or the treatment fluid circuit 40.Pumping the treatment fluid upwards from the bottom of the blood filter forces air through the membranes and breaks it into microbubbles (e.g., creating effervescence), which facilitates the removal of residual blood, such as clots, proteins, and biological fluids from the blood filter. In particular, the effervescence effect is thought to create areas of high shear and turbulence at various air / water interfaces on the membrane surfaces, thus facilitating the separation of blood residues.

[0075] In one embodiment, the air valve 18 is open and the heparin pump 38, comprising cyclic control of the fluid valves 38a and 38b (or blood pump 28), is used to extract either air as needed or a known and desired quantity of air, for example, 25 ml, from the blood circuit 20 and the blood side 30a of the blood filter 30. Here, the heparin vial 36 may be empty or removed in such a way that heparin is not injected into the blood lines simultaneously with air. Alternatively, an additional heparin valve (not shown) may be arranged to isolate the heparin vial 36 from the air line. As an alternative, the entry of heparin into the blood circuit 20 is permitted. And again, any air entering the device 10 via the air valve 18 and the heparin pump 38 is filtered first via the filter 16.

[0076] The blood pump 28 is used to pump the air / treatment fluid along the filter 30 (e.g., from top to bottom) and through the blood circuit 20. If the connections A and V of the blood lines 22 and 24 are connected to the treatment fluid circuit 40, then the blood pump 28 can also be used to pump the air / treatment fluid through the treatment fluid circuit 40. Alternatively, the treatment fluid pumps 44 and 50 can be used, either alternatively or in addition, to pump the air / treatment fluid through the treatment fluid circuit 40. In all cases, it is envisaged that the external part of the membranes 30c of the blood filter 30 will be cleaned, either alternatively or in addition, by passing the air / treatment fluid mixture through the treatment fluid side 30b of the blood filter 30.

[0077] Although not shown, a second air valve 18 and a second filter 16, for example, a HEPA filter, may be placed in the fluid circuit of Treatment 40. For example, a second air trap 26 can be placed between the heating device 48 and the pump 44 to trap the air produced by heating the treatment fluid. The second vent valve 18 and the second filter can then be connected to the upper or air collection section of the air trap 26.

[0078] In block 110, it is envisaged for the device 10 and the control unit 60, as an alternative or in addition, to extract air in the treatment fluid circuit 40 by opening the second air valve 18 and by controlling the treatment fluid pump 44 and / or the treatment fluid pump 50 in order to circulate the air / treatment fluid on the treatment fluid side 30b so as to purify the treatment fluid side 30b of the blood filter 30 comprising the outer parts of the membranes 30c.

[0079] The air / treatment fluid can be pulsed in one direction and the other along the inner and / or outer portions of the membranes 30c or flowed around and around a plurality of times from the upper end 30d to the lower end 30e of the blood filter 30. The air / treatment fluid has a consistency and shear effect different from that of the pure liquid, which is considered to ensure good separation of blood particles in association with the pure treatment fluid, for example, dialysate, saline, or replacement fluid. It should be noted that no dialysate, saline, or replacement fluid is sent to the purge during step 110, just as with step 108.

[0080] At decision block 112, process 100 determines whether the steps in blocks 108 and 110 need to be repeated. If so, process 100 returns to block 108. Here, dialysate, saline solution, or pure replacement fluid may need to be extracted from a source or storage tank in order to repeat the step in block 108. The operational loop between block 108 and decision block 112 can be repeated any desired number of times. If process 100 determines that the steps in blocks 108 and 110 do not need to be repeated, process 100 proceeds to block 114. Various methodologies are envisaged for determining whether the steps in blocks 108 and 110 need to be repeated. The number of repetitions can be defined in memory as a predefined number. The number of repetitions can be defined as a part of a device prescription that is patient-specific.The number of repetitions may, alternatively or in addition, be based on other factors, such as one or more of the following, for example: a pressure reading, a dialyzer beam volume measurement, the results of a dialyzer elimination test, or the age of the dialyzer (number of uses). It is therefore expressly understood that even for the same patient, the number of repetitions at decision block 112 may vary from one treatment to another.

[0081] At block 114, the air valve 18 is open or remains open, and the heparin pump 38, which includes cycle control of the fluid valves 38a and 38b, is used to draw air into the blood circuit 20 and the blood side 30a of the blood filter 30 to purge the blood circuit 20 of any fluid. Again, the heparin vial 36 can be emptied or removed so that the heparin is not injected with the air. Or similarly, an additional heparin valve (not shown) can be arranged to isolate the heparin vial 36 from the air line. And again, any air entering the device 10 via the air valve 18 and the heparin pump 38 is first filtered through the filter 16.

[0082] The blood pump 28 can be used to push the air / treatment fluid, now laden with blood residues, through the filter membranes, from the treatment fluid side 30b of the blood filter 30, from there into the treatment fluid circuit 40, and optionally to the purge. If the connections A and V of the blood lines 22 and 24 are connected to the treatment fluid circuit 40, then the blood pump 28 can be used, in addition or alternatively, to pump air so as to push the air / treatment fluid, now laden with blood residues, directly into the treatment fluid circuit 40 and to discharge it through the purge.

[0083] At decision block 116, process 100 determines whether the steps in blocks 108 to 114 need to be repeated. If so, process 100 returns to block 108. Here again, dialysate, saline solution, or pure replacement fluid may need to be extracted from a source or storage tank in order to repeat the step in block 108. The operational loop between block 108 and decision block 116 can be repeated any desired number of times. If process 100 determines that the steps in blocks 108 to 114 need to be repeated, process 100 proceeds to block 118.

[0084] In block 118, the device 10 performs a priming / disinfection procedure to clean the entire device comprising the blood circuit 20 and the dialysate circuit 40. Hot water or a chemical solution can be used to prime and disinfect the device. The hot water or chemical solution facilitates the forcing of any remaining blood residue, for example, clots or proteins, towards the purge. The disinfection fluid can be left inside the device 10 until the next use or purged again with filtered air so that the device 10 is left in a dry state until the next treatment.

[0085] At oval block 120, the process is completed.

[0086] As previously mentioned, while the present invention has been described primarily in relation to a blood therapy machine, for example, dialysis, which reuses the same blood filter 30 during several treatments, for example, over approximately thirty treatments, the concepts described herein are not limited to such an application. The device and methodology described herein can, by For example, they are more likely to be used on a dialyzer cleaning machine. Here, the blood filter 30 is removed from the blood therapy machine after each treatment, brought to the dialyzer cleaning machine, which uses the structure and methodology described here to clean the blood filter 30, which is then placed back into the blood therapy machine for reuse.

[0087] As previously mentioned, while the present invention has been described primarily in relation to a blood therapy machine, the present invention can also be applied to a dialysis machine that uses a filter to clean peritoneal dialysis fluid or PD solution. In such a case, the blood circuit 20 described herein is replaced by a peritoneal dialysis fluid circuit that pumps the PD solution into and out of the patient's peritoneum, and through the inner portions of the membranes of a PD filter 30. Here, the heparin pump 38 and heparin are not required. The treatment fluid circuit 40 can remain substantially unchanged and pumps inline or bag dialysate through the PD filter 30 onto the outer portions of the filter membranes to clean the sterile solution returning from the patient's peritoneum.

[0088] Other aspects of the present invention are presented below.

[0089] Certain aspects of the content described herein may be used alone or in association with any or more of the other aspects described herein.Without limiting the foregoing description, according to a first aspect of the present invention, a method for cleaning a blood filter comprises: pumping a physiologically safe fluid in both directions through the inner and / or outer portions of a plurality of hollow fiber membranes of the blood filter so as to remove or separate blood residues, such as blood clots, proteins, and / or biological fluid; injecting air into the physiologically safe fluid to form an air / fluid mixture; pumping the air / fluid mixture through the inner and / or outer portions of the plurality of hollow fiber membranes of the blood filter so as to further remove or separate the blood residues therefrom; and disposing of the physiologically safe air / fluid mixture with the removed or separated blood residues to the purge.

[0090] According to a second aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes involves the fractionation of the air into microbubbles.

[0091] According to a third aspect of the present invention, which can be used in combination with any other aspect or combination of aspects presented herein, the pumping of the physiologically safe air / fluid mixture through the internal parts and / or the parts external membranes involves pumping the mixture from a lower part of the blood filter to an upper part of the blood filter.

[0092] According to a fourth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the pumping of the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes comprises the pumping of the physiologically safe air / fluid mixture in both directions through the membranes.

[0093] According to a fifth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, pumping the physiologically safe air / fluid mixture through the inner and / or outer parts of the membranes involves circulating the physiologically safe air / fluid through the membranes a plurality of times.

[0094] According to a sixth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the removal of the physiologically safe air / fluid mixture to the purge involves the injection of air in order to push the mixture towards the purge.

[0095] According to a seventh aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the method further comprises priming or disinfecting the blood filter after removing the physiologically safe air / fluid mixture to the purge.

[0096] According to an eighth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the air injection includes the air filtration.

[0097] According to a ninth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the air injection comprises pumping air into the blood filter by means of a blood pump.

[0098] According to a tenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, pumping the physiologically safe fluid in both directions involves reversing a blood pump.

[0099] According to an eleventh aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the pumping of the physiologically safe fluid in both directions comprises the sequential control of a plurality of valves.

[0100] According to a twelfth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the method comprises transferring the physiologically safe fluid from outside the hollow fiber membranes, through the walls of the membranes, and into the inner parts of the membranes in order to pump the treatment fluid in both directions.

[0101] According to a thirteenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the physiologically safe fluid used to ensure pumping in both directions through the inner parts of the membranes is obtained by means of a return blood flush to the patient, leaving the physiologically compatible fluid inside the membranes.

[0102] According to a fourteenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the physiologically safe fluid is selected from the group consisting of: dialysate, a replacement fluid and saline solution.

[0103] According to a fifteenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the method is used with renal therapy equipment.

[0104] According to a sixteenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, the blood filter is a dialyzer.

[0105] According to a seventeenth aspect of the present invention, which can be used in association with any other aspect or combination of aspects presented herein, a renal therapy device comprises: a blood filter having a plurality of hollow fiber membranes; arterial and venous lines in fluidic communication with the blood filter; a blood pump for pumping blood through the arterial and venous lines and the blood filter; a treatment fluid pump in fluidic communication with (a) a treatment fluid side of the blood filter or (b) the arterial or venous line;and a control unit that controls the blood pump and the treatment fluid pump during treatment and at least one of the blood pump and the treatment pump during a filter cleaning sequence in which (i) a physiologically safe fluid is transferred in both directions through the inner and / or outer parts of the plurality of hollow fiber membranes, (ii) the physiologically safe fluid mixed with air is transferred at least once through the inner and / or outer parts of the plurality of hollow fiber membranes, and (iii) the physiologically safe fluid mixed with air and blood residues separated or removed from the hollow fiber membranes is transformed (or transferred) to the purge.

[0106] According to an eighteenth aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the device further comprises a filtered air access in fluidic communication with the blood pump and a valve, the control unit ensuring the control of the valve in order to allow the air to be mixed selectively during the operation (ii).

[0107] According to a nineteenth aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the process fluid pump is a replacement fluid pump, the process fluid being replacement fluid.

[0108] According to a twentieth aspect of the present invention, which can be used with the nineteenth aspect in association with any other aspect or association of aspects presented herein, the control unit ensures the control of the replacement fluid pump so as to perform at least one of the operations (i), (ii) or (iii).

[0109] According to a twenty-first aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the treatment fluid pump is a fresh dialysate fluid pump, and in which the treatment fluid is dialysate.

[0110] According to a twenty-second aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or combination of aspects presented herein, the device comprises a saline solution source in fluidic communication with the arterial or venous line, the treatment fluid pump being a saline solution pump, and the physiologically safe fluid being saline solution.

[0111] According to a twenty-third aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the control unit is configured to cause the blood pump to perform operations (i) to (iii) and the treatment fluid pump to operate during at least one of operations (i) and (ii) on the outer parts of the hollow fiber membranes so as to try to balance the pressures across the hollow fiber membranes.

[0112] According to a twenty-fourth aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the control unit is configured to cause the blood pump to perform only operations (i), (ii) and (iii).

[0113] According to a twenty-fifth aspect of the present invention, which can be used with the seventeenth aspect in association with any other aspect or association of aspects presented herein, the control unit is configured to cause the blood pump and the treatment fluid pump to perform operations (i) and (ii) and the blood pump to perform operation (iii) alone.

[0114] According to a twenty-sixth aspect of the present invention, any one of the structures and functionalities represented and described in relation to Figures 1 and 2 can be used in association with any other aspect or association of aspects presented herein.

[0115] It should be understood that various changes and modifications to the currently preferred embodiments described herein will become obvious to specialists in the technique.

Claims

Demands

1. Renal therapy apparatus (10) comprising: a blood filter (30) comprising a plurality of hollow fiber membranes (30c); a blood circuit (20) comprising arterial and venous lines (22, 24) in fluidic communication with the blood filter; a blood pump (28) for pumping blood through the blood circuit and the blood filter; a treatment fluid pump (44, 50) in fluidic communication with (a) a treatment fluid side (40) of the blood filter or (b) the blood circuit; a selective filtered air access (18) in fluidic communication with (a) the treatment fluid side of the blood filter or (b) the blood circuit (20);and a control unit (60) configured to control the blood pump (28) and the processing fluid pump (44, 50) during blood processing and at least one of the blood pump (28) or the processing fluid pump (44, 50) during a filter cleaning sequence in which: (i) a blood-compatible and physiologically safe fluid is transferred through the interiors and / or exteriors of the plurality of hollow fiber membranes (30c) at least once, (ii) a fluid mixture is formed by opening the filtered air access (18) to mix the air with the blood-compatible and physiologically safe fluid, and (iii) the fluid mixture is transferred through the interiors and / or exteriors of the plurality of hollow fiber membranes (30c) at least once, in which the filter cleaning sequence is performed such that the fluid mixture is delivered to the blood filter instead of a drain.

2. A renal therapy device according to claim 1, wherein the selective filtered air access is fluidically coupled to the blood circuit.

3. Renal therapy device (10) according to claim 1, further comprising an air passage filter (16) in fluidic communication with the filtered air access (18) and configured to filter the air passing through the filtered air access.

4. Renal therapy device (10) according to claim 1, wherein the treatment fluid pump (44, 50) is a replacement fluid pump and the blood-compatible and physiologically safe fluid is a replacement fluid which is pumped by the replacement fluid pump.

5. Renal therapy apparatus (10) according to claim 1, wherein the treatment fluid pump (44, 50) is a fresh dialysate fluid pump, and wherein the blood-compatible and physiologically safe fluid is a dialysis fluid which is pumped by the fresh dialysate fluid pump.

6. Renal therapy device (10) according to claim 1, wherein the blood-compatible and physiologically safe fluid comprises a saline solution supplied by a saline solution feed (32) in fluidic communication with the blood circuit (20).

7. Renal therapy apparatus (10) according to claim 1, wherein the control unit (60) is configured so that the blood pump (28) performs operations (i) and (iii) and the treatment fluid pump (44, 50) is operated simultaneously to attempt to equalize the pressure across the hollow fiber membranes (30c).

8. Renal therapy device (10) according to claim 1, wherein the control unit (60) is configured so that the blood pump (28) performs operations (i) and (iii), and pauses the treatment fluid pump (44, 50).

9. Renal therapy device (10) according to claim 1, wherein the control unit (60) is configured so that the blood pump (28) and the treatment fluid pump (44, 50) perform operation (ii) and the blood pump only performs operations (i) and (iii).

10. Renal therapy apparatus (10) according to claim 1, wherein the blood filter (30) is a dialyzer.

11. Renal therapy apparatus (10) according to claim 1, wherein the control unit (60) is configured to cause the blood-compatible and physiologically safe fluid to be transferred back and forth through the plurality of hollow fiber membranes (30c) a plurality of times before mixing the blood-compatible and physiologically safe fluid with air.

12. Renal therapy device (10) according to claim 1, which is configured to transfer the fluid mixture to the drain after (iii).

13. A method for cleaning a blood filter during a cleaning sequence comprising: (i) pumping a blood-compatible and physiologically safe fluid through the interior and / or exterior of the plurality of hollow fiber membranes (30c) of a blood filter (30); (ii) forming a fluid mixture by injecting air into the blood-compatible and physiologically safe fluid; (iii) during the cleaning sequence, pumping the fluid mixture through the interior and / or exterior of the plurality of hollow fiber membranes of the blood filter (30) so as to remove or detach blood residues, such as blood clots, proteins, and / or biological fluid, wherein the fluid mixture is delivered to the blood filter instead of a drain during at least (ii) and (iii), and wherein the use of the fluid mixture enables the cleaning sequence to be performed after blood processing.

14. A method for cleaning a blood filter according to claim 13, wherein the pumping of the fluid mixture through the interiors and / or exteriors of the membranes comprises at least one of the following: (a) fractionating the air into microbubbles, (b) pumping the fluid mixture from a lower part of the blood filter to an upper part of the blood filter, (c) pumping the fluid mixture in both directions through the membranes, or (d) circulating the fluid mixture through the membranes a plurality of times.

15. A method of cleaning a blood filter according to claim 13, wherein the blood-compatible and physiologically safe fluid is pumped in both directions through the interiors and / or exteriors of the plurality of hollow fiber membranes of the blood filter so as to remove or detach blood residues.

16. A method for cleaning a blood filter according to claim 15, further comprising transferring the fluid mixture with the blood residues removed or detached to the drain after the cleaning sequence, in which the transfer of the fluid mixture to the drain includes the injection of air to push the fluid mixture with the removed or detached blood residues towards the drain.

17. A method of cleaning a blood filter according to claim 16, further comprising at least one of the following: priming the blood filter with at least one dialysis fluid, replacement fluid or saline solution after transfer to the drain; or disinfecting the blood filter with at least one element of hot water or chemical disinfectant after transfer to the drain.

18. A method for cleaning a blood filter according to claim 13, wherein the air injection comprises at least one of the following: (a) filtering the air or (b) pumping the air into the blood filter via a blood pump.

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