A method and a system for priming a tube set in a peritoneal ultrafiltration machine

Abstract

An ultrafiltration system, comprising: an ultrafiltration machine arranged to perform ultrafiltration of a patient. A tube set is arranged in the UF machine and connected to a peritoneal cavity of a patient. The tube set comprises a glucose tube interacting with a metering pump of the UF machine and ending in a connector for connection to a glucose bag. A sensor is arranged for sensing that there is no air in the tube set between the glucose bag and the metering pump. The opening of the glucose bag is facing downwards during priming and operation. Any air inside the glucose bag is gathered in the upwards facing portions of glucose bag. Only air inside the tube set is removed during priming while the air gathered in the upwards facing portions of the glucose bag is left during priming and use. The sensor ensures that no air passes to the patient.

Description

[0001] TITLE:

[0002] METHOD AND A SYSTEM FOR PRIMING A TUBE SET IN A PERITONEAL ULTRAFILTRATION MACHINE

[0003] FIELD OF INVENTION

[0004] The present invention relates to a method and a device for performing peritoneal ultrafiltration of a patient in need thereof. More in details, the invention relates to a method and device for priming a tube set before peritoneal ultrafiltration.

[0005] BACKGROUND

[0006] Renal failure is a disease that affects many people around the world.

[0007] Renal replacement therapy may be dialysis, which means that the patient is connected to an apparatus that performs dialysis, either hemodialysis or peritoneal dialysis. During dialysis, a sufficient amount of fluid is normally removed from the patient, which is called ultrafiltration.

[0008] Some dialysis treatments may be supplemented by removal of fluid in an ultrafiltration treatment separate from or in conjunction with the dialysis treatment.

[0009] A promising ultrafiltration method which does not use extracorporeal blood treatment and circulation is used in peritoneal dialysis, in which the endogenous peritoneal membrane is used for ultrafiltration. A peritoneal ultrafiltration fluid is instilled in the patient’s peritoneal cavity. The fluid comprises an osmotic agent, such as glucose or Icodextrin or other agent causing ultrafiltration. Peritoneal ultrafiltration is gentle to the patient and seldom results in hypotension. In addition, peritoneal ultrafiltration may be used daily outside the hospital without or with limited need for medically trained professionals.

[0010] The osmotic agent may be provided as a concentrated fluid which is diluted before introduction to the peritoneal cavity.

[0011] Such an ultrafiltration apparatus is disclosed in patent documents W02015130205A1, W02016080883A1 and WO2017034452A1.

[0012] Other disease condition may also benefit from ultrafiltration, such as congestive heart failure.

[0013] W02015130205A1 discloses a method and an apparatus for ultrafiltration of a patient being overhydrated, comprising a cassette having four inlets / outlets. A patient tube is connected to a patient connector, intended to be connected to a patient line for access to a peritoneal cavity of the patient. The patient tube comprises a flow pump for addition and removal of a peritoneal fluid between the cassette and the peritoneal cavity. The fluid is introduced into an intermittent bag controlled by an intermittent valve and then returned the same way back to the peritoneal cavity. Glucose is metered into the fluid entering the peritoneal cavity by means of a glucose pump. Glucose is replenished continuously or intermittently for keeping a concentration of the osmotic agent substantially constant in the peritoneal cavity. After treatment, the peritoneal fluid is drained to a drain bag, wherein the drain tube comprises a drain valve and an albumin filter.

[0014] WO20 16080883 Al discloses an apparatus for ultrafiltration of a patient being overhydrated, comprising a tube set including a connector for connection to a patient line for access to the peritoneal cavity of the patient. A flow pump is arranged for addition and removal outflow and inflow (recirculation) of fluid from / to the peritoneal cavity. An osmotic agent peristaltic pump is arranged for replenishment of glucose solution to the fluid added to the peritoneal cavity for promoting ultrafiltration. The glucose is replenished intermittently for keeping a concentration of glucose substantially constant in the peritoneal cavity. The flow pump comprises a pressure chamber with rigid walls and a flexible pump bag arranged therein. An air pump pressurizes the chamber for outflow of fluid from the peritoneal cavity by a sub pressure and inflow of fluid to the peritoneal cavity by an overpressure, which pressures are maintained within safe limits.

[0015] WO2017034452A1 discloses an apparatus for ultrafiltration of a patient being overhydrated. The apparatus comprises a dilution syringe for removal of a portion of peritoneal fluid from the peritoneal cavity. A glucose bag comprises glucose concentrate at a concentration of 30%. A small amount of glucose concentrate is mixed with the dilution fluid in the dilution syringe in order to dilute the glucose concentrate to below 3% concentration. Then, the mixture is filled into the peritoneal cavity from the dilution syringe in order to replenish the glucose in the peritoneal cavity for maintaining a substantially constant glucose concentration in the peritoneal cavity. In addition, peritoneal fluid is intermittently removed from the peritoneal cavity for counteracting increased intraperitoneal fluid volume and increased intraperitoneal pressure due to ultrafiltration. A UF bag is arranged for receiving such surplus peritoneal fluid. A glucose syringe may be arranged for metering the glucose concentrate.

[0016] Such ultrafiltration apparatus comprises a tube set. The tube set is sterilized and comprises tubes or hoses and connectors and bags for performing the desired operation. The tube set is a single use part and the ultrafiltration apparatus is used several times, often several years. The tube set is arranged in the ultrafiltration apparatus before use. Since the ultrafiltration apparatus is to be used by elderly patients with problematic hand and finger dexterity, the handling of the tube set needs to be as simple as possible.

[0017] The tube set is inserted in the ultrafiltration apparatus and is then primed with a priming fluid. The priming fluid is arranged for rinsing the internal volumes of the tube set to remove any debris remaining in the tube set and rinse out any traces of toxic or other agents, that may be left on the internal surfaces of the tube set. The tube set is connected to the peritoneal cavity of the patient. The peritoneal cavity is sensitive to introduction of air inside the peritoneal cavity, which should be avoided. Thus, the priming fluid is arranged to displace all air inside the tube set. For improved usability, the priming time should be as short as possible, so that the treatment may start early.

[0018] The tube set is normally sterilized with ETO sterilization. However, the osmotic agent, such as glucose, is normally not sterilized with ETO but is often heat sterilized. The tube set consists of two parts that need to be connected before use, the osmotic agent bag and the rest of the tube set.

[0019] The tube set is to be arranged in the ultrafiltration apparatus, which arrangement should be as simple as possible.

[0020] Finally, the tube set should be connected to the patient via a patient line.

[0021] These connections and arrangements cause problems for patients with reduced dexterity and need to be as simple as possible.

[0022] With the above problems and requirements in mind, the present invention intends to provide an ultrafiltration device with a tube set that is easy to handle and which can be safely primed with priming fluid in a short time.

[0023] The patients having need for peritoneal ultrafiltration may need a device for performing the ultrafiltration method, which device is transportable and may be carried by the patient, so that the patient is not tied to any stationary equipment. Furthermore, the device should be simple to use.

[0024] In an embodiment, the tube set is to be arranged in a peristaltic pump for metering concentrated glucose. The peristaltic pump should be arranged easily accessible and is therefore arranged at the top of the device. The portion of the tube set interacting with the peristaltic pump ends in the osmotic agent bag, which is arranged at a lower level than the peristaltic pump. When the osmotic agent bag is connected to the rest of the tube set, air is enclosed in the tube set and the top of the osmotic agent bag. The enclosed air should be removed during priming. However, a peristaltic pump is inefficient when pumping air and is more efficient when pumping liquid. This means that it takes long time to remove the enclosed air by the peristaltic pump. In fact, this may be the priming step taking longest time. Therefore, there is a need for reducing the time for this priming step.

[0025] SUMMARY OF THE INVENTION

[0026] Accordingly, an object of the present invention is to mitigate, alleviate or eliminate one or more of the above-identified and other deficiencies and disadvantages singly or in any combination.

[0027] In an aspect there is provided a method for priming a tube set arranged in a peritoneal machine, wherein the tube set comprises: a patient connector for connection to a patient’s peritoneal cavity comprising peritoneal fluid; an intermittent bag for storing a portion of said peritoneal fluid when removed from the peritoneal cavity; a patient tube connecting said patient connector to said intermittent bag; an addition fluid tube, at a first end being connected to the patient line or the intermittent bag and at a second end comprising an addition fluid connector; a waste tube for disposal of peritoneal fluid from the tube set, for example to a waste bag; and wherein the peritoneal machine comprises: a pump member for pumping said peritoneal fluid to and from the patient via said patient tube; a clamp for opening and closing said patient tube and a clamp (26, 66) for opening and closing said waste tube; a peristaltic pump arranged and operating at the addition fluid tube between the first end and the second end thereof; an addition fluid bag having an outlet connected to the second end of the addition fluid tube via said addition fluid connector; whereby the addition fluid bag is arranged at a level below that of the peristaltic pump and said outlet is arranged at or adjacent a bottom portion of the addition fluid bag; said method comprising: operating said pump member, during a priming step when the tube set initially is filled with air, to pump peritoneal fluid from the peritoneal cavity to the intermittent bag when the patient clamp is open and the waste clamp is closed, thereby displacing air into the intermittent bag; operating the pump member to pump the contents of the intermittent bag to the waste tube when the patient clamp is closed and the waste clamp is open; operating the peristaltic pump to remove air inside the addition fluid tube.

[0028] In an embodiment, the method may further comprise: operating the peristaltic pump to remove air inside the addition fluid tube towards the intermittent bag until the addition fluid tube is filled with addition fluid from the addition fluid bag. Alternatively or additionally, the method may further comprise: operating the peristaltic pump to remove air inside the addition fluid tube towards the addition fluid bag for displacing the air inside the addition fluid tube into the top of the addition fluid bag via said outlet. The air may be displaced towards the addition fluid bag by entering a displacement liquid at the peristaltic pump side of the addition fluid tube, which displacement fluid displaces said air inside the addition fluid tube into said space, whereupon the fluid flow direction is reversed to move the displacement fluid back including addition fluid in the addition fluid tube until filled with addition fluid.

[0029] The addition fluid may be concentrated glucose.

[0030] In another aspect, there is provided a system for priming a tube set arranged in a peritoneal machine, wherein the tube set comprises: a patient connector for connection to a patient’s peritoneal cavity comprising peritoneal fluid; an intermittent bag for storing a portion of said peritoneal fluid when removed from the peritoneal cavity; a patient tube connecting said patient connector to said intermittent bag; an addition fluid tube, at a first end being connected to the patient line or the intermittent bag and at a second end comprising an addition fluid connector; waste tube for disposal of peritoneal fluid from the tube set, for example to a waste bag; and wherein the peritoneal machine comprises: a pump member for pumping said peritoneal fluid to and from the patient via said patient tube; a clamp for opening and closing said patient tube and a clamp for opening and closing said waste tube; a peristaltic pump arranged and operating at the addition fluid tube between the first end and the second end thereof; an addition fluid bag having an outlet connected to the second end of the addition fluid tube via said addition fluid connector; whereby the addition fluid bag is arranged at a level below that of the peristaltic pump and said outlet is arranged at or adjacent a bottom portion of the addition fluid bag; wherein the pump member, during a priming step when the tube set initially is filled with air, is operated to pump peritoneal fluid from the peritoneal cavity to the intermittent bag when the patient clamp is open and the waste clamp is closed, thereby displacing air into the intermittent bag, and to pump the contents of the intermittent bag to the waste tube when the patient clamp is closed and the waste clamp is open; and wherein the peristaltic pump is operated to remove air inside the addition fluid tube.

[0031] In an embodiment, the peristaltic pump may be arranged to remove air inside the addition fluid tube towards the intermittent bag.

[0032] In an alternative or additional embodiment, the peristaltic pump may be arranged to remove air inside the addition fluid tube towards the addition fluid bag for displacing the air inside the addition fluid tube into a top of the addition fluid bag.

[0033] The addition fluid may be concentrated glucose.

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further objects, features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the drawings, in which:

[0036] Fig. 1 is an isometric view of an UF machine according to an embodiment of the invention without a tube set installed.

[0037] Fig. 2 is an isometric view similar to Fig. 1 but with a tube set installed.

[0038] Fig. 3 is an isometric view of the tube set according to Fig. 2.

[0039] Fig. 4 is a plan view of the UF machine according to Fig. 1 with an organizer of the tube set installed but with the rest of the tube set removed.

[0040] Fig. 5 is a cross-sectional view according to line A-A of Fig. 4.

[0041] Fig. 6 is an enlarged cross-sectional view of the area encircled by circle C in Fig. 5. Fig. 7 is a partial cross-sectional view taken according to line B-B of Fig. 4.

[0042] Fig. 8 is a schematic drawing corresponding to Fig. 1 in the published Patent Document WO2015130205 Al .

[0043] Fig. 9 is a schematic drawing corresponding to Fig. 8 with an embodiment of the glucose bag.

[0044] Fig. 10 is a schematic drawing similar to Fig. 9 with the glucose bag inverted. DETAILED DESCRIPTION OF EMBODIMENTS

[0045] Below, several embodiments of the invention will be described. These embodiments are described in illustrating purpose in order to enable a skilled person to carry out the invention and to disclose the best mode. However, such embodiments do not limit the scope of the invention. Moreover, certain combinations of features are shown and discussed. However, other combinations of the different features are possible within the scope of the invention.

[0046] A device for performing a peritoneal ultrafiltration method may in principle be constructed similar to an apparatus for performing peritoneal dialysis. Thus, the present invention can be used at a dialysis apparatus or any apparatus for metering a fluid at a low pace.

[0047] It is noted that an apparatus for performing peritoneal dialysis may simultaneously be arranged for performing peritoneal ultrafiltration. However, the task to remove unwanted agents or products, such as urea and creatinine, is normally the focus during peritoneal dialysis. Thus, a peritoneal dialysis apparatus is normally arranged for removing such unwanted products, for example by adsorption, or by dialysis.

[0048] On the other hand, an ultrafiltration device (or shorter UF device) is optimized for providing ultrafiltration, while removal of unwanted products (such as urea) is of secondary importance. In addition, a gentle ultrafiltration is desired in order to avoid complications.

[0049] A peritoneal dialysis / ultrafiltration method is preferred over hemodialysis, since the patient is free from hospitalization and can perform the peritoneal dialysis / ultrafiltration method at home or at any place. In addition, the peritoneal dialysis / ultrafiltration method can be performed often, for example daily.

[0050] Below, several embodiments of an ultrafiltration device will be disclosed. An ultrafiltration device may be constructed having the following precautions in mind:

[0051] 1) Use of heavy mechanical devices such as pumps driven by electric batteries should be avoided or minimized. The patient should be able to carry the device during the treatment time.

[0052] 2) The treatment should be able to be performed by the patient himself.

[0053] 3) For optimizing ultrafiltration and minimizing body absorption of osmotic agent, such as glucose, a low and substantially constant concentration of osmotic agent should be used and a substantially constant volume of fluid should be maintained in the peritoneal cavity.

[0054] 4) High intraperitoneal pressure should be avoided.

[0055] 5) Exposure of the entrance area of the peritoneal cavity from high osmotic agent concentration should be avoided.

[0056] 6) A short priming time is required so that UF treatment can start without undue delay. The peritoneal dialysis method most frequently used today is CAPD. During this method, a predetermined volume of peritoneal dialysis fluid is instilled in the peritoneal cavity, for example four times per day. The peritoneal dialysis fluid is maintained in the peritoneal cavity during for example 2 hours to 4 hours. Then, the peritoneal fluid is removed and discarded and fresh dialysis fluid is instilled, which normally takes about 30 minutes or more. The exchange of peritoneal fluid is performed by gravity forces. The volume of peritoneal fluid instilled each time is normally between 1200 ml and 2400 ml or as much as the patient can take. If an ultrafiltration of 400 ml per exchange should be obtained, the volume removed will be 400 ml larger than the volume installed.

[0057] The use of large volumes may result in high pressure in the peritoneal cavity. Such high pressure counteracts ultrafiltration. In order to reduce the intraperitoneal pressure, it may be advantageous to remove fluid more often than each second or fourth hour, in order to keep the intraperitoneal fluid volume below a specific volume, at which the intraperitoneal pressure increases more rapidly, and in order to reduce back-filtration.

[0058] CAPD often uses glucose as osmotic agent and uses different glucose concentrations in dependence of the need of a patient. The glucose concentrations normally range from 1.5% to 4.25%. However, several reports have indicated that high glucose concentrations may result in compromised peritoneal function, at least during long time exposure. Thus, the present embodiments endeavor to use of a maximum glucose concentration in the peritoneal cavity, which is lower than 4.25%. Below, a maximum concentration of 3.0% will be used as an example. Other maximum concentrations can be used, such as 4.25%, 4.0%, 3.9%, 3,8%, 3.7%, 3.6%, 3.5%, 3.4%, 3.3%, 3.2%, 3.1%, 3.0% 2.9%, 2.8%, 2.7%, 2.6%, 2.5%, 2.4%, 2.3%, 2.2%, 2.1%, 2.0% or even lower. The maximum concentration is experienced when the fluid is introduced into the peritoneal cavity and is then lowered due to dilution in the fluid prevailing in the peritoneal cavity.

[0059] The osmotic agent mentioned above is glucose, which has been shown to work well for ultrafiltration of a peritoneal dialysis patient. However, other osmotic agents may be used such as Icodextrin, which is a glucose polymer. In this case, different concentrations may be used as is well-known to the skilled person.

[0060] With reference to the drawings, first a peritoneal ultrafiltration (UF) device will be described, in which embodiment of the present invention can be used.

[0061] Fig. 1 shows a UF machine according to an embodiment. The UF machine 10 comprises an enclosure 11 closed by a lid 12, which is attached to the enclosure 11 by hinges 13. The lid can be opened to the position shown in Fig. 1 and be closed into a horizontal position (not shown). The lid is locked to the enclosure 11 by a lid lock 14. At the front side of the enclosure there is arranged a display 15. In this specification, positions and directions are related to a normal use of the device and are also used for describing directions in a drawing view. The device may be used in other orientations.

[0062] The enclosure comprises three recesses, a glucose bag recess 21, an intermittent bag recess 22 and a drain bag recess 23 intended to enclose a glucose bag 51, an intermittent bag 52 and a drain bag 53, respectively, of the tube set 50 to be further described below with reference to Fig. 3.

[0063] In addition, the enclosure comprises a peristaltic pump 24 and a patient tube clamp 25 and a drain tube clamp 26. The clamps are electrically controlled and operated. The patient tube clamp 25 is arranged in a patient tube grove 27 and the drain tube clamp 26 is arranged in a drain tube groove 28, see Fig. 4.

[0064] The enclosure further comprises a pressure connector 29 to be connected to a pressure tube connector 54 of the tube set. An organizer sealing 30 is arranged at the periphery of the intermittent bag recess 22. Inside the enclosure 11 there is arranged an air pump 31 (see Fig. 4) connected to an air opening 32 in the intermittent bag recess 22.

[0065] The lid 12 comprises a peristaltic pump recess 41 arranged opposite to the peristaltic pump in the closed position of the lid. There is also an organizer hold arrangement 42 for keeping the organizer 56 in place and two hold arrangements 43, 44 for keeping the patient tube in the patient tube groove 27 and for keeping the drain bag tube in the drain tube groove 28. A sensor tab 33 is arranged to sense and indicate when the lid is in its closed position.

[0066] Fig. 2 shows the UF machine with the tube set installed.

[0067] Fig. 3 shows the tube set separately. The tube set 50 comprises an organizer 56. The organizer comprises a longitudinal tube 57. The organizer is substantially oval to fit the oval intermittent recess.

[0068] A patient tube 60 is connected to the left end of the longitudinal tube 57 as seen in Fig. 3. The patient tube comprises a patient connector 61 at the other end. A patient clamp 62 is arranged to close or open the patient tube.

[0069] A pressure tube 55 is also connected to the left end of the longitudinal tube 57 and hence to the patient tube 60. The pressure tube comprises a pressure connector 54 at the other end. The pressure tube comprises a hydrofobic filter to prevent fluid from entering a pressure meter arranged in the enclosure.

[0070] The intermittent bag 52 is connected to the middle of the longitudinal tube 57 and extends downward as seen in Fig. 3.

[0071] A drain bag tube 58 is connected to the right end of the longitudinal tube 57. The other end of the drain bag tube is connected to a drain bag 53. A drain tube clamp 66 is arranged to close or open the drain bag tube 58.

[0072] A glucose tube 59 is attached to the left end of the organizer without being connected to the longitudinal tube 57 as indicated by flow arrow 67. The glucose tube 59 extends in a semicircle 63 for cooperation with the peristaltic glucose pump. The end of the semicircle glucose tube is connected to the right end of the longitudinal tube 57. The other end of the glucose tube 59 comprises a glucose connector 64 to be connected to a glucose bag 51, which is shown in Fig. 2.

[0073] The organizer comprises several ribs 65 at the right end which are used for keeping the tubes in place during handling.

[0074] In use, the tube set 50 is connected to the glucose bag 51 (see Fig. 2) by means of the glucose connector 64. The glucose bag comprises concentrated glucose at a concentration of for example 50%. The volume of glucose is dependent on the treatment to be performed but a volume of 200 - 250 ml would be suitable for most UF treatments.

[0075] The intermittent bag 52 is placed in the oval intermittent bag recess 22 so that an airtight seal may be obtained of the intermittent bag recess 22. A lip seal 34 is arranged for keeping the seal airtight. Simultaneously, the glucose tube semicircle 63 is arranged at the peristaltic pump 24.

[0076] The drain bag 53 is placed in the drain bag recess 23. The drain bag tube 58 is arranged in the drain tube groove 28. The patient tube 60 is arranged in the patient tube groove 27.

[0077] The pressure tube connector 54 is connected to the pressure connector 29 of the UF machine.

[0078] The glucose bag 51 is arranged in the glucose bag recess 21 with the glucose connector 64 facing downward, as shown in broken lines in Fig. 2. Any air inside the glucose bag is gathered at the top of the glucose bag, as shown by broken line 75 in Fig. 2.

[0079] The lid 12 is pivoted down and locked with the lid lock 14. Now, the UF device is ready for priming and subsequent use.

[0080] The patient comprises a peritoneal fluid in the peritoneal cavity, for example provided in a normal CAPD treatment. Thus, a volume of for example 1200ml - 3000ml of peritoneal fluid is installed in the patient’s peritoneal cavity. The peritoneal cavity of the patient is connected to the patient connector 61.

[0081] Since the tube set is filled with air from the start, it needs to be primed, i.e. be filled with fluid.

[0082] The glucose pump is operated in its normal direction to withdraw air from the glucose tube 59. Since the glucose pump has a low capacity for pumping air, it may take long time to empty the glucose bag tube 59. However, since the air inside the glucose bag 51 is collected at the top 75 of the glucose bag 51 and the outlet from the glucose bag is arranged at the bottom thereof, there is no need to remove the air inside the top 75 of the glucose bag. This will decrease the time for removing air from the glucose bag by at least 50% but normally by 75% or more. By this measure, the emptying of the glucose tube from air takes approximately the same time as the rest of the priming cycle. The air pump 31 is activated and withdraw air from the intermittent bag recess 22 to generate a sub-pressure in the intermittent bag 52. The patient clamp 25 is operated to open the patient tube 60 in order to allow peritoneal fluid from the patient’s peritoneal cavity to flow into the intermittent bag. During this process, drain bag tube clamp 26 is activated to close the drain bag tube 58. During this process, air inside the patient tube 60 and the longitudinal tube 57 are entered into the intermittent bag 52.

[0083] When the intermittent bag is almost full, the air pump is reversed to cause an overpressure in the intermittent bag recess. The patient clamp 25 is closed and the drain clamp 26 is opened to allow the fluid in the intermittent bag to drain to the drain bag 53 inclusive all air.

[0084] A liquid sensor 35 is arranged at the glucose tube adjacent the organizer. The sensor senses when fluid is present in the glucose tube, which is an indication that the removal of air from the glucose tube is finalized.

[0085] The priming is now finalized. The UF treatment can start.

[0086] Optionally, a further session of operating the air pump 31 and fill the intermittent bag with peritoneal fluid from the patient is performed, whereupon the priming is ready.

[0087] Fig. 5 is a cross-sectional view taken according to line A-A in Fig. 4. The organizer 56 and the intermittent bag 52 are shown. Fig. 6 shows the area encircled by the circle C in Fig. 5.

[0088] Fig. 7 is a partial transversal cross-sectional view taken according to line B-B in Fig. 4. The air opening 32 from the air pump to the intermittent bag recess is shown.

[0089] The UF treatment may comprise that the glucose pump is operated continuously or intermittent and meters a predetermined amount of concentrated glucose to the longitudinal tube 57 of the organizer.

[0090] The air pump is operated to generate a sub pressure (lower than the surrounding pressure) in order to remove or suck peritoneal fluid from the peritoneal cavity. When the intermittent bag is almost full, the air pump is reversed and generates an overpressure (higher than the surrounding pressure) in order to infuse the peritoneal fluid from the intermittent bag to the peritoneal cavity. There may be a stop time when the air pump is not operated, for example when the intermittent bag is almost full.

[0091] The glucose pump can provide glucose during the in-flow of peritoneal fluid to the peritoneal cavity or during the out-flow of peritoneal fluid from the peritoneal cavity or both. The glucose pump can also provide glucose to the contents of the intermittent bag when there is no in-flow or out-flow. In an embodiment, the glucose pump operates continuously with a desired flow rate prescribed by a physician. The in-flow fluid is now replenished with glucose to cause ultrafiltration in the peritoneal cavity.

[0092] During the process, the concentrated glucose (such as 50% concentration) is diluted so that the concentration of glucose entering the peritoneal cavity is below a desired limit, in an example below 3%. In this example, the flow of peritoneal fluid removed and infused to the peritoneal cavity of the patient should be at least 16.6 times the flow of concentrated glucose to ensure that the infused glucose concentration is lower than the desired limit, of 3% if a glucose concentration of 50% is used.

[0093] Instead of glucose, another osmotic agent can be used, such as Icodextrin etc.

[0094] The priming of the tube set provided with a bag comprising a liquid to be added to a patient can be used in other types of devices, such as peritoneal dialysis devices, hemodialysis devices, parenteral nutrition devices, devices for entering drugs to the vascular system of a patient, etc.

[0095] The tube set forms a unit which is easy to handle without need for dexterity of the patient. A glucose pump of small dimensions can be used, which saves pump weight and battery weight.

[0096] In an embodiment, the glucose pump is a peristaltic pump, that is arranged at a level above the bags included in the tube set. In particular, the glucose bag is arranged at a level so that a glucose liquid top surface is lower than the peristaltic pump.

[0097] Fig. 8 is a schematic drawing corresponding to Fig. 1 of the published Patent Document W02015130205A1, which shows an ultrafiltration device similar to the one described above. In principle, there is a pump arranged in the patient line and a clamp in the intermittent bag line in Fig. 8, and these components have shifted places in the embodiment described with reference to Fig. 1. The pump in Fig. 8 is indicated to be a peristaltic pump and the corresponding pump in Fig. 1 is pneumatic pump.

[0098] It is noted that a peristaltic pump forms a clamping action in addition to acting as a pump, since the tube is squeezed by the peristaltic pump when the pump is standing still.

[0099] In Fig. 8, a glucose bag 71 comprises a space 72 where air inside the glucose bag is gathered. The air in space 72 needs to be removed during the priming step. A sensor 73 senses when liquid passes from the glucose bag 71 to the organizer 74. The glucose bag 71 is arranged at a level below a peristaltic pump 75.

[0100] The volume of the space 72 is often about 5% of the total volume (e.g. 200 ml) of the glucose bag, for example 10 ml. The volume of the glucose tube 76 between the peristaltic pump and the glucose bag is about 1 ml. Since the glucose pump 75 is dimensioned for the glucose fluid flow, it takes a long time to remove all air in the space 72, which will prolong the priming step and retard the start of the treatment. The time is exaggerated by the fact that a peristaltic pump is inefficient in pumping air compared to pumping liquid, especially at a pressure lower than the atmospheric pressure.

[0101] In Fig. 9, there is shown another design of the glucose bag, which enables that air in the space 72 can be kept in the space 72 even after priming. An outlet 77 from the glucose bag 71 extends down and opens at the bottom of the glucose bag. Consequently, the priming of the glucose tube 76 and the glucose bag 71 can take place much faster since the air at the top space 72 of the glucose bag 71 can be left.

[0102] The removal of air from the glucose tube 76 can take place by operating the glucose pump 75 in the normal operation direction, pumping the air in the glucose tube 76 in the left direction as seen in Fig. 9, until the sensor 73 indicates that there is only liquid in the tube. Now, it is safe to operate the device and the priming may be ended.

[0103] Alternatively, the removal of air can take place in the opposite direction. The glucose pump 75 is operated in the reverse direction and pumps liquid (peritoneal fluid) present in the organizer 74 towards the glucose bag. The sensor 73 may indicate that fluid enters the glucose tube. The air is displaced towards the outlet 77 and bubbles up into the space 72, in which the displaced air is gathered until the end of the treatment. Since the peristaltic pump 75 now pumps liquid (which is efficient), the pump can be operated until a predetermined volume of fluid has been entered into the glucose tube 76 corresponding to its volume, whereby all air has been displaced into the space 72. The priming is now ready.

[0104] The priming steps may be combined.

[0105] In a further optional step, it can be validated that the glucose tube 76 is free from air by operating the glucose pump 76 in its normal direction until a volume corresponding to the (known) volume of the glucose tube has been pumped out of the glucose bag. Thus, the fluid previously entered for displacement of the air is moved back to the organizer 74 and can be discarded. The sensor 73 controls that no air is delivered from the glucose bag during treatment.

[0106] Fig. 10 discloses a further embodiment, similar to the embodiment of Figs. 1 to 3. The priming starts with connecting the glucose connector 79 to the glucose bag 78. Then, the tube set is installed in the ultrafiltration machine with the glucose tube 76 loosely inserted in the peristaltic pump 75. The glucose bag 78 is arranged in its inverted position, as shown in Fig. 10, with the glucose connector 79 facing downwards. The peristaltic pump may not have been closed, which means that the glucose in glucose bag 78 will pass into the glucose tube 76 until the level is equal to the upper level of glucose in glucose bag, as indicated by broken line 70. Then, the peristaltic pump is closed and the patient clamp 85 and the waste bag clamp 86 are open. Now, the lid of the ultrafiltration machine is closed to fix the tube set in position and ensure that the peristaltic pump is closed.

[0107] Then, the patient clamp 85 is closed and the patient connector 91 is connected to the peritoneal cavity of the patient, whereby peritoneal fluid may be removed from or entered to the peritoneal cavity. The waste clamp 86 is opened and the air pump 81 is operated to exert an over pressure to empty any air inside the intermittent bag 82 to the waste bag 83. The peritoneal pump 75 is non-rotating.

[0108] Then, the waste clamp 86 is closed and the air pump 81 is reversed to exert a sub pressure in the intermittent bag 82. The patient clamp 85 is opened and peritoneal fluid from the peritoneal cavity is sucked into the patient tube 90 and displaces air inside the patient tube into the organizer 74 and further to the intermittent bag 82.

[0109] At the same time, in a first step, the peristaltic pump 75 may be operated in the normal direction thereby pumping air inside the glucose tube 76 towards the organizer 74 and the intermittent bag 82. Such pumping is supported by the low pressure in the organizer and intermittent bag. In addition, there is only a small amount of air inside the glucose tube, as is evident from Fig. 10, since glucose fluid has already filled the glucose tube portion below the glucose level in the glucose bag. The liquid sensor 73 will indicate if all air has been removed.

[0110] When the intermittent bag 82 is almost full with air and peritoneal fluid, the patient clamp 85 is closed, the waste claim 86 is opened and the air pump 81 is reversed for exerting an over pressure to expel air and peritoneal fluid to the waste bag 83.

[0111] At the same time, in a second step, the peristaltic pump is operated in its reverse direction to pump peritoneal fluid from organizer 74 and further towards the glucose bag 78. Any air in the glucose tube is displaced towards the glucose bag and bubbles up to the top space 72. The liquid sensor 73 determines that fluid enters the glucose tube. The overpressure in the organizer 74 will support such operation.

[0112] In addition, in a third step, the glucose pump may operate in its normal direction and pump fluid from the bottom of the glucose bag. Initially, the displacement fluid still present in the glucose tube will be returned to the organizer 74. When a volume corresponding to the glucose tube volume has been pumped, the liquid provided to the organizer is the glucose solution. Any air still present in the glucose tube will pass out to the organizer 74, which will be indicated by the liquid sensor 73.

[0113] If the first step results in that all air inside the glucose tube is removed, which is indicated by the liquid sensor, the second and third steps are not required.

[0114] If the first step is insufficient, the second and / or third steps may be used.

[0115] Alternatively, the first step is not used, but instead the second step is used. The third step is optional.

[0116] After priming, the waste clamp 86 is closed, the patient clamp 85 is opened, and normal operation may start.

[0117] The glucose bag in the embodiment of Fig. 9 may be modified so that the passage 77 instead is arranged at the side of the bag.

[0118] The outlet 77 may be arranged as an integral portion of the glucose bag. Alternatively, the outlet 77 is arranged at the end of the glucose connector and is inserted into the glucose bag when the glucose bag is connected to the glucose connector of the glucose tube.

[0119] The peristaltic pump is arranged at the end of the glucose tube 76 that is closest to the organizer as appears from Figs. 3, 8, 9, 10. The length of the glucose tube should be as small as possible, such as about 25 cm. The arrangement of the glucose bag in an inverted position as shown in Fig. 10, and Fig. 2 results in that the glucose tube is partially filled with glucose fluid already before priming, which further reduces the priming time.

[0120] The dimension of the glucose tube is about 1 - 2 mm internal diameter. Thus, the volume of the glucose tube is less than 1 ml.

[0121] In the claims, the term "comprises / comprising" does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit. Additionally, although individual features may be included in different claims or embodiments, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", “first”, “second” etc. do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way. Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and other embodiments than those specified above are equally possible within the scope of these appended claims.

Claims

CLAIMS1. A method for priming a tube set arranged in a peritoneal machine, wherein the tube set comprises: a patient connector (61) for connection to a patient’s peritoneal cavity comprising peritoneal fluid; an intermittent bag (52) for storing a portion of said peritoneal fluid when removed from the peritoneal cavity; a patient tube (60) connecting said patient connector to said intermittent bag; an addition fluid tube (39), at a first end being connected to the patient line or the intermittent bag and at a second end comprising an addition fluid connector (64); a waste tube (58) for disposal of peritoneal fluid from the tube set, for example to a waste bag (53); and wherein the peritoneal machine comprises: a pump member (31, 32, 22) for pumping said peritoneal fluid to and from the patient via said patient tube; a clamp (25, 62) for opening and closing said patient tube and a clamp (26, 66) for opening and closing said waste tube; a peristaltic pump (24) arranged and operating at the addition fluid tube between the first end and the second end thereof; an addition fluid bag having an outlet connected to the second end of the addition fluid tube via said addition fluid connector; whereby the addition fluid bag is arranged at a level below that of the peristaltic pump and said outlet is arranged at or adjacent a bottom portion of the addition fluid bag; said method comprising: operating said pump member, during a priming step when the tube set initially is filled with air, to pump peritoneal fluid from the peritoneal cavity to the intermittent bag when the patient clamp is open and the waste clamp is closed, thereby displacing air into the intermittent bag, operating the pump member to pump the contents of the intermittent bag to the waste tube when the patient clamp is closed and the waste clamp is open; operating the peristaltic pump to remove air inside the addition fluid tube.

2. The method as claimed in claim 1, further comprising: operating the peristaltic pump to remove air inside the addition fluid tube towards the intermittent bag until the addition fluid tube is filled with addition fluid from the addition fluid bag.

3. The method as claimed in claim 1, further comprising: operating the peristaltic pump to remove air inside the addition fluid tube towards the addition fluid bag for displacing the air inside the addition fluid tube into the top of the addition fluid bag via said outlet.

4. The method as claimed in claim 3, further comprising that said air is displaced towards the addition fluid bag by entering a displacement liquid at the peristaltic pump side of the addition fluid tube, which displacement fluid displaces said air inside the addition fluid tube into said space, whereupon the fluid flow direction is reversed to move the displacement fluid back including addition fluid in the addition fluid tube until filled with addition fluid.

5. The method as claimed in any one of the previous claims, wherein the addition fluid is concentrated glucose.

6. A system for priming a tube set arranged in a peritoneal machine, wherein the tube set comprises: a patient connector (61) for connection to a patient’s peritoneal cavity comprising peritoneal fluid; an intermittent bag (52) for storing a portion of said peritoneal fluid when removed from the peritoneal cavity; a patient tube (60) connecting said patient connector to said intermittent bag; an addition fluid tube (39), at a first end being connected to the patient line or the intermittent bag and at a second end comprising an addition fluid connector (64); a waste tube (58) for disposal of peritoneal fluid from the tube set, for example to a waste bag (53); and wherein the peritoneal machine comprises: a pump member (31, 32, 22) for pumping said peritoneal fluid to and from the patient via said patient tube; a clamp (25, 62) for opening and closing said patient tube and a clamp (26, 66) for opening and closing said waste tube; a peristaltic pump (24) arranged and operating at the addition fluid tube between the first end and the second end thereof; an addition fluid bag having an outlet connected to the second end of the addition fluid tube via said addition fluid connector; whereby the addition fluid bag is arranged at a level below that of the peristaltic pump and said outlet is arranged at or adjacent a bottom portion of the addition fluid bag; wherein the pump member, during a priming step when the tube set initially is filled with air, is operated to pump peritoneal fluid from the peritoneal cavity to the intermittent bagwhen the patient clamp is open and the waste clamp is closed, thereby displacing air into the intermittent bag, and to pump the contents of the intermittent bag to the waste tube when the patient clamp is closed and the waste clamp is open; and wherein the peristaltic pump is operated to remove air inside the addition fluid tube.

7. The system as claimed in claim 6, further comprising that the peristaltic pump is arranged to remove air inside the addition fluid tube towards the intermittent bag.

8. The method as claimed in claim 6, further comprising that the peristaltic pump is arranged to remove air inside the addition fluid tube towards the addition fluid bag for displacing the air inside the addition fluid tube into a top of the addition fluid bag.

9. The method as claimed in claim 6, 7 or 8, wherein the addition fluid is concentrated glucose.

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