Dialysis system and method

Abstract

The dialysis system being disclosed provides dialysis treatment to patients while they are in their own homes. [Solution] The dialysis system is configured to prepare purified water from a tap water source in real time, which is used to produce the dialysate solution. The dialysis system described also includes features that facilitate patient self-administration therapy. For example, the dialysis system includes a patient tube set and a disposable cartridge that is easily installed in the dialysis system and automatically arranges the tube set, sensors, intravenous drip chamber and other features with the corresponding components of the dialysis system. The method of use is also provided, including steps of automatically priming the sequence, blood return sequence, and dynamic balancing method that controls the fluid transfer rate between different types of dialysis, including hemodialysis, ultrafiltration, and hemodiafiltration.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 722,119, filed Aug. 23, 2018, entitled “Dialysis System and Method,” and incorporates it herein by reference in its entirety. This application is related to U.S. Patent No. 9,504,777, entitled “Dialysis System and Method,” and incorporates it herein by reference.

[0002] Incorporation by Reference All publications and patent applications mentioned in this specification are hereby incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference.

[0003] The present disclosure generally relates to dialysis systems. More specifically, the present disclosure relates to dialysis systems that include a number of features that reduce the requirements that technicians be involved in the preparation and administration of dialysis treatment.

Background Art

[0004] Currently, there are hundreds of thousands of end - stage renal disease patients in the United States. Most of them need dialysis to survive. Many patients undergo dialysis treatment at dialysis centers with demanding, restrictive, and tiring schedules. Patients receiving in - center dialysis usually have to travel to the center at least three times a week and sit in a chair for three to four hours each time while toxins and excess fluid are filtered from their blood. After treatment, patients have to wait for the bleeding to stop at the needle site and their blood pressure to return to normal, which requires more time away from other enriching activities in their daily lives. Further, in - center patients usually have to adhere to uncompromising schedules such that the center treats patients in three to five shifts during the day's progress. As a result, many people who dialyze three times a week complain of feeling tired for at least several hours after a session.

[0005] Many dialysis systems on the market require considerable input and attention from technicians before, during, and after dialysis treatment. Before treatment, technicians are often required to manually install the patient's blood tubing set into the dialysis system, connect the tubing set to the patient and the dialysis machine, and manually prime the tubing set to remove air before treatment. During treatment, technicians are usually required to monitor venous pressure and fluid level and administer bolus doses of saline and / or heparin to the patient. After treatment, technicians are often required to return the blood in the tubing set to the patient and drain it from the dialysis system. The inefficiencies of most dialysis systems and the considerable technical involvement required in the process make it even more difficult for patients to receive dialysis treatment away from large treatment centers.

[0006] Given the demanding nature of in-center dialysis, many patients have opted for home dialysis as an alternative. Home dialysis offers patients scheduling flexibility, allowing them to choose treatment times to fit into other activities, such as going to work or caring for family. Unfortunately, current dialysis systems are generally not suitable for use at patients' homes. One reason for this is that current systems are too large and bulky to fit into a typical home. Current dialysis systems are also energy inefficient, as they use a lot of energy to heat the water necessary for proper use. While some home dialysis systems are available, they are generally difficult to set up and use. As a result, most dialysis treatment for chronic patients is performed at a dialysis center.

[0007] Hemodialysis is also performed in acute care hospital settings for currently hospitalized dialysis patients or patients suffering from acute kidney injury. In these care settings, typically in hospital rooms, water of sufficient purity to produce dialysate is not readily available. Therefore, hemodialysis machines in acute settings rely on large bags of pre-mixed dialysate, which is difficult for staff to handle. Instead, hemodialysis machines are connected to portable RO (reverse osmosis) machines or other similar water purification devices. This introduces another independent component of the equipment that must be managed, transported, and sterilized. [Overview of the project]

[0008] A method for priming a dialysis system tubing set and dialysis machine is provided, comprising the steps of: connecting the arterial lines of the tubing set to the venous lines of the tubing set to form a continuous loop of the tubing set; pumping air from the tubing set with an air pump; drawing a fluid flow from a fluid source to the tubing set with an air pump; operating the blood pump of the dialysis system in forward operation mode to allow fluid to flow from the fluid source to the tubing set in a first direction; and operating the blood pump in backward operation mode to allow fluid to flow through the tubing set in a second direction opposite to the first direction.

[0009] In some examples, the pulling step further comprises pulling the fluid into the tubing set with an air pump until the fluid is detected by a first fluid level sensor in the intravenous drip chamber.

[0010] In one embodiment, the step of operating the blood pump in forward operation mode further includes operating the blood pump in forward operation mode until the fluid is detected by a second fluid level sensor in the intravenous infusion chamber, thereby allowing the fluid to flow from the fluid source into the tubing set.

[0011] In some examples, the method of the present invention includes a step after the pulling step that allows the fluid level in the intravenous infusion chamber to fall below the first fluid level sensor.

[0012] In one embodiment, the step of operating the blood pump in forward operation mode further comprises operating the blood pump in forward operation mode until fluid is detected by a first fluid level sensor in the intravenous infusion chamber, thereby allowing fluid to flow from the fluid source to the tubing set.

[0013] In another example, the method of the present invention comprises a step of drawing air from the tube set with an air pump during the operation step.

[0014] The dialysis system is also provided, comprising: a fluid source; a patient tubing set fluidly coupled to the fluid source, the patient tubing set including an intravenous infusion chamber; an air pump coupled to the intravenous infusion chamber, configured to pump air into or out of the intravenous infusion chamber; a blood pump coupled to the patient tubing set, configured to pump fluid through the patient tubing set; at least one sensor coupled to the intravenous infusion chamber and configured to monitor the fluid level in the intravenous infusion chamber; and an electronic controller communicating with at least one sensor, the blood pump, and the air pump, the electronic controller being configured to control the air pump to pump air from the tubing set, to control the air pump to pull fluid flow from the fluid source to the patient tubing set, to control the blood pump in the forward direction to pump fluid from the fluid source to the tubing set, and to control the blood pump in the backward direction to pump fluid through the tubing set.

[0015] A method for testing for leakage of a dialysis system tube set is provided, comprising the steps of: pressurizing a first portion of the tube set; measuring a reference pressure of the first portion of the tube set; exposing a second portion of the tube set to the pressurized first portion; measuring the pressure of the second portion of the tube set; and comparing the measured pressure of the second portion with the reference pressure of the tube set to confirm leakage of the second portion.

[0016] In some embodiments, the step of exposing the second portion comprises the step of opening one or more pinch valves of the tube set.

[0017] In one example, the method of the present invention includes the step of monitoring the pressure of a second portion for a pressure decay rate that exceeds a pressure decay threshold to confirm leakage of the second portion.

[0018] A method for priming a tubing set of a dialysis system is provided, comprising the steps of: removing the tubing set from a sterile transport container; installing the tubing set in a dialysis system; priming the tubing set with a fluid flow from the dialysis system to remove air from the tubing set; and discharging the fluid from the tubing set into a transport container.

[0019] In some examples, the method of the present invention further comprises the step of attaching the transport container to the dialysis system.

[0020] In one embodiment, the step of attaching the transport container further comprises engaging the transport container attachment mechanism with the corresponding mechanical mechanism of the dialysis system.

[0021] In some examples, the mechanical mechanism of a dialysis system is angled relative to one another to impose a bend on one or more surfaces of the transport container, thereby enlarging the opening of the transport container.

[0022] In another embodiment, the method of the present invention includes the step of discharging fluid from the tube set to a transport container through a connecting fitting that connects the arterial lines of the tube set to the venous lines of the tube set.

[0023] A method for improving the durability and operation of one or more positive displacement pumps includes connecting one or more positive displacement pumps to a pump power fixture to form a closed-loop flow path between the one or more positive displacement pumps and the pump power fixture, increasing the temperature and pressure of the fluid within the closed-loop flow path, and operating the one or more positive displacement pumps to flow fluid through the closed-loop flow path for a predetermined period to reduce surface defects inside the one or more positive displacement pumps.

[0024] In one embodiment, the increasing step further includes increasing the temperature and pressure of the fluid to a level higher than the level encountered during normal operation of the one or more positive displacement pumps.

[0025] In another embodiment, the method of the present invention includes increasing the temperature above 25 °C.

[0026] In another embodiment, the method of the present invention includes increasing the pressure of the fluid above 100 psi.

[0027] The pump power fixture includes a housing, a fluid source, one or more connection ports in or on the housing, one or more positive displacement pumps coupled to the one or more connection ports to form a closed-loop flow path between the fluid source, the one or more positive displacement pumps, and the one or more connection ports, a heating element configured to heat the fluid within the closed-loop flow path to a temperature higher than the normal operating temperature of the one or more positive displacement pumps, and an electronic controller configured to control the operation of the one or more positive displacement pumps with the hot fluid for a predetermined time to reduce surface defects inside the one or more positive displacement pumps.

[0028] In some examples, a method of providing dialysis treatment to a patient includes combining a dialysate concentrate and water in a dialysate system to create dialysate in real time, providing a first flow of dialysate through a dialysis system at a first dialysate flow rate, monitoring consumption of the dialysate concentrate by the dialysis system, determining whether sufficient dialysate concentrate remains to complete the dialysis treatment at the first dialysate flow rate, and if not, providing a second flow of dialysate through the dialysis system at a second dialysate flow rate at which the dialysis treatment can be completed.

[0029] In one embodiment, the method of the present invention includes calculating a second dialysate flow rate at which the dialysis treatment can be completed before the step of providing the second flow.

[0030] In some embodiments, the dialysis system houses a finite supply of dialysate concentrate.

[0031] In one embodiment, the second dialysate flow rate is lower than the first dialysate flow rate.

[0032] In one example, the first dialysis flow rate is about 300 ml / min and the second dialysis flow rate is about 100 ml / min.

[0033] In another embodiment, the determining step further comprises determining whether sufficient dialysate concentrate remains based on the first dialysate flow rate, the amount of dialysate concentrate remaining, and the total treatment time.

[0034] In one example, the method of the present invention further comprises maintaining the pressure within the dialysis system when the second flow of dialysate is provided.

[0035] Novel features of the present invention are described in detail in the following claims. A better understanding of the features and advantages of the present invention can be obtained by referring to the following detailed description and accompanying drawings, which describe embodiments that are useful in explaining how the principles of the present invention are utilized. [Brief explanation of the drawing]

[0036] [Figure 1] This shows one embodiment of a dialysis system. [Figure 2] This diagram illustrates one embodiment of a water purification system for a dialysis system. [Figure 3] This diagram illustrates one embodiment of a dialysis supply system for a dialysis system. [Figure 4] This shows one example of a front panel for a dialysis supply system. [Figure 5] This illustration depicts one embodiment of a cartridge, including a set of tubes mounted in a storage case. [Figure 6] This illustration depicts one embodiment of a cartridge, including a set of tubes mounted in a storage case. [Figure 7] This shows a flow chart of the water purification system included in the dialysis system. [Figure 8] This is a schematic diagram showing the water supply subsystem, filtration subsystem, preheating subsystem, RO filtration subsystem, and pasteurization subsystem of the water purification system in a dialysis system. [Figure 9] This diagram illustrates the mechanism of the water supply subsystem in a water purification system. [Figure 10] This shows one embodiment of the filtration subsystem of a water purification system. [Figure 11] One embodiment of the preheating subsystem of a water purification system is shown. [Figure 12] This document illustrates one embodiment of the RO filtration subsystem of a water purification system. [Figure 13] This diagram illustrates one embodiment of the pasteurization subsystem of a water preparation system. [Figure 14] Draw a schematic diagram of the mixing subsystem of the dialysis supply system. [Figure 15] One embodiment of the mixing chamber is shown. [Figure 16] The ultrafiltration subsystem of the dialysis supply system, which receives dialysate prepared from the mixing subsystem, is depicted. [Figure 17] A schematic diagram illustrating the flow of saline solution through the tube set while blood is being returned to the user is shown. [Figure 18] One embodiment of a connecting joint configured to connect the venous and arterial lines of a patient tube set during the priming sequence is shown. [Figure 19A] One embodiment of a waste container for discarding priming saline following a priming sequence is depicted. [Figure 19B] One embodiment of a waste container for discarding priming saline following a priming sequence is depicted. [Figure 19C] One embodiment of a waste container for discarding priming saline following a priming sequence is depicted. [Figure 20] This flowchart illustrates an example of a method for storing dialysis fluid during treatment. [Figure 21] This shows an example of a pump energization system to prevent fine particles from the pump from entering the dialysis system. [Figure 22] This shows an example of a pump energization system to prevent fine particles from the pump from entering the dialysis system. [Figure 23] This shows an example of a pump energization system to prevent fine particles from the pump from entering the dialysis system. [Figure 24] This shows an example of a pump energization system to prevent fine particles from the pump from entering the dialysis system. [Figure 25] This shows an example of a pump energization system to prevent fine particles from the pump from entering the dialysis system. [Figure 26] An embodiment of a container for discarding the priming solution is shown. [Figure 27] An embodiment of a container for discarding the priming solution is shown. [Figure 28]This is a schematic diagram of the ultrafiltration system that will be implemented in place of the pasteurization subsystem shown in Figure 13. [Figure 29A] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29B] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29C] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29D] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29E] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29F] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29G] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29H] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29I] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29J] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29K] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 29L] Describe another sequence for priming the patient tube set before dialysis treatment. [Figure 30] This flowchart describes one method for automatically controlling the fluid level in the intravenous infusion chamber during dialysis treatment. [Modes for carrying out the invention]

[0037] This disclosure describes systems, apparatus, and methods relating to dialysis treatment, including dialysis systems that include automated features that make them easy to use and eliminate or reduce the need for technician involvement during dialysis treatment. In some embodiments, the dialysis system is a home dialysis system. Embodiments of the dialysis system include various features that automate and improve the performance, efficiency, and safety of dialysis treatment.

[0038] In some embodiments, a dialysis system capable of providing a user with acute and chronic dialysis treatment is described. The system includes a water purification system configured to prepare water for use in dialysis treatment in real time using an available water source, and a dialysis supply system configured to prepare dialysate for dialysis treatment. The dialysis system includes a disposable cartridge and tubing set that connects to the user during dialysis treatment to collect and supply blood from the user.

[0039] Figure 1 illustrates one embodiment of a dialysis system 100 configured to provide dialysis treatment to a user in a clinical or non-clinical setting, such as the user's home. The dialysis system 100 comprises a water purification system 102 and a dialysis supply system 104, both located within a housing 106. The water purification system 102 is configured to purify a water source in real time for dialysis treatment. For example, the water purification system is connected to a residential water source (e.g., tap water) and prepares pasteurized water in real time. The pasteurized water is then used for dialysis treatment (e.g., together with the dialysis supply system) without the need to heat and cool large quantities of water, which would normally be associated with water purification methods.

[0040] The dialysis system 100 also includes a cartridge 120 detachably coupled to the system housing 106. The cartridge includes a patient tubing set mounted in a storage case, which is further described in detail below. The cartridge and tubing set, which are sterilized, disposable, single-use parts, are configured to be connected to the dialysis system before treatment. This connection ensures that the corresponding parts between the cartridge, tubing set, and dialysis system are properly aligned before dialysis treatment. For example, the tubing set is automatically associated with one or more pumps (e.g., peristaltic pumps), clamps, and sensors for drawing and pumping the user's blood through the tubing set when the cartridge is coupled to the dialysis system. The tubing set is also associated with the saline source of the dialysis system for automatic priming and with air to be removed before treatment. In some embodiments, the cartridge and tubing set are connected to a dialysis machine 126 of the dialysis system. In other embodiments, the cartridge and tubing set include a built-in dialysis machine pre-installed on the tubing set. The user or patient interacts with the dialysis system by a user interface 113, which includes a display device.

[0041] Figures 2 and 3 depict a water purification system 102 and a dialysis supply system 104, respectively, of one embodiment of the dialysis system 100. The two systems are depicted and described separately for the sake of brevity, but both systems should be understood to be contained within a single housing 106 of the dialysis system. Figure 2 depicts one embodiment of the water purification system 102 contained within the housing 106, including a front door 105 (shown in the open position). The front door 105 provides access to the water purification system and associated mechanisms, including one or more filters, for example, a precipitate filter 108, a carbon filter 110, and a reverse osmosis (RO) filter 112. The filters are configured to assist in purifying water from a water source (e.g., tap water) that is in fluid communication with the water purification system 102. The water purification system includes heating and cooling elements, including a heat exchanger configured to pasteurize and control the fluid temperature of the system, as will be further described in more detail below. The system optionally includes a chlorine sample port 195 to provide a sample of the fluid to measure its chlorine content.

[0042] In Figure 3, the dialysis supply system 104 contained within the housing 106 includes a top cover 109 and a front door 111, both shown in the open position. The top cover 109 opens to provide access to various mechanisms of the dialysis system, such as a user interface 113 (including an electronic controller, a display device such as a touchscreen, e.g., a computer device) and a dialysate container 117. The front door 111 opens and closes to provide access to a front panel 210, which includes various mechanisms configured to interact with the cartridge 120 and its associated tubing set, including an arrangement and mounting mechanism configured to connect the cartridge 120 to the dialysis system 100. The dialysis machine 126 is mounted on the front door 111 or the front panel and includes wires or ports for connecting the dialysis machine to the prepared dialysate and cartridge tubing set.

[0043] In some embodiments, the dialysis system 100 also includes a blood pressure cuff to provide real-time monitoring of the user's blood pressure. The system (i.e., the system's electronic controller) is configured to monitor the user's blood pressure during dialysis treatment. If the user's blood pressure falls below a threshold (e.g., a blood pressure threshold indicating the user is hypotonic), the system alerts the user with a hypotonic alarm and stops the dialysis treatment. If the user ignores a configurable number of hypotonic alarms from the system, the system is configured to automatically stop the dialysis treatment, in which case the system informs the user that the user's blood (blood remaining in the tubing set and dialysis machine) needs to be returned to the user's body. For example, the system is pre-programmed to automatically stop treatment if the user ignores three hypotonic alarms. In other embodiments, the system provides the user with a bolus dose of saline to restore the user's fluid level before resuming dialysis treatment. The amount of saline supplied to the patient is tracked and documented during the ultrafiltration fluid exclusion.

[0044] The dialysis supply system 104 in Figure 3 is configured to automatically prepare dialysate with purified water supplied by the water purification system 102 in Figure 2. Furthermore, the dialysis supply system degass the purified water and mixes the acid and bicarbonate concentrate from the dialysate container 117. The resulting dialysate fluid undergoes one or more ultrafiltration processes (described below) to ensure that the dialysate fluid conforms to certain regulatory limits for microbial and endotoxin contaminants.

[0045] Dialysis is performed in the dialysis supply system 104 of the dialysis system 100 by passing the user's blood and dialysate through the dialyzer 126. The dialysis system 100 includes an electronic controller configured to manage various flow control devices and mechanisms for adjusting the flow of dialysate and blood to and from the dialyzer in order to achieve different types of dialysis, including hemodialysis, ultrafiltration, and hemodiafiltration.

[0046] Figure 4 shows one embodiment of the front panel 210 of the dialysis supply system 104 of Figure 3, which includes several mechanisms to assist in positioning and mounting the cartridge 120 and its associated tubing set to the dialysis system 100 and to monitor and control the fluid flow along the cartridge's tubing set. During the installation of a new sterile cartridge into the dialysis system, the cartridge placement mechanism (e.g., the hole 125 through which the cartridge passes, shown in Figure 5) is lined up with positioning pegs 260. The positioning pegs also help to align the cartridge and tubing set with the mechanisms of the front panel used in dialysis treatment, which include a blood pump 213, spring wires 22, positioning mechanism 212, venous and arterial pressure sensors 182a and 182b, venous air sensor 2161, arterial air sensor 216, pinch valves 180a-d, and venous infusion chamber holder 179. The blood pump 213 is, for example, a peristaltic pump. Holders or slots 215 for infusion pumps or syringes are also shown.

[0047] The cartridge is pressed into place on the front panel using these positioning pegs 260, ensuring that all the mechanisms of the cartridge and tube set are aligned and properly installed in the corresponding mechanisms on the front panel 210. In some embodiments, the cartridge can be easily installed with one hand, and the cartridge can be mounted on the system by closing the system door. As shown in Figure 1, the dialysis system includes wheels to facilitate transport. In one particular embodiment, the force applied to mount the cartridge horizontally on the front panel 210 by closing the door with a downward rotational motion of the door lever does not tend to move the dialysis system 100 on its wheels.

[0048] Pinch valves are used for many functions before, during, and after dialysis treatment. Pinch valves 180a-d are controlled by an electronic controller of the dialysis supply system. Pinch valves 180a and 180b are configured to control the flow of saline from a saline source (e.g., a saline bag) to the tubing set. In some embodiments, the pinch valves open, and the blood pump 213 operates to pump saline into the tubing set, remove air during the priming sequence, flush impurities from the dialysis machine before treatment, and return blood to the user at the end of treatment. Pinch valves 180a and 180b are also used to supply a therapeutic bolus of saline to the user during treatment to maintain blood pressure or regulate the patient's electrolyte or fluid levels. In other embodiments, a pump, such as a peristaltic pump, is configured to supply a therapeutic bolus of saline to the user.

[0049] Pinch valves 180c and 180d are configured to close the arterial and venous lines of a tubing set connected to the user. They also facilitate multiple closing and openings before, during, and after treatment, such as acclimatization tubing of the tubing set, to achieve proper compliance for priming, discarding priming saline, returning blood to the patient, and / or draining from the dialysis machine after treatment. In one embodiment, the system takes information from the system's venous air sensor 2161, arterial air sensor 216, or other air sensors and closes pinch valves 180c and 180d if air bubbles are found in the lines, particularly the venous lines. In a further embodiment, the system is configured to remove detected air bubbles by reversing the operation of the blood pump and to endeavor to remove air bubbles through the intravenous infusion chamber.

[0050] The pinch valve 180a-d also operates to perform a series of self-tests on the tubing set before each treatment. The tubing set is pressurized by a blood pump, and the pressure is maintained in the tubing set by closing the pinch valve. Arterial and venous pressure sensors are then used to look for any pressure decay in the tubing set.

[0051] Figure 4 also depicts an intravenous infusion chamber holder 179, which includes a pair of intravenous fluid level sensors 181a and 181b. When the cartridge is coupled to the dialysis supply system, the intravenous infusion chamber (described in further detail below) engages with the intravenous infusion chamber holder 179. During dialysis treatment, the intravenous fluid level sensors 181a and 181b monitor the fluid level in the intravenous infusion chamber. If the fluid level rises above sensor 181a, the dialysis supply system then automatically pumps air into the intravenous infusion chamber to lower the fluid level. Conversely, if the fluid level falls below sensor 181b, the dialysis supply system then automatically pumps air out of the intravenous infusion chamber (or releases air from the chamber instead) to raise the fluid level. Automatic fluid level control reduces the number of workers because the periodic adjustment of the fluid level is done by machine instead of by clinic staff or patients.

[0052] In other embodiments, the system features algorithmic characteristics that protect itself from one or more failures of the venous fluid level sensors 181a or 181b and can further automatically control the fluid level. During treatment, the venous infusion chamber 361 is filled with blood. Detecting the fluid level of the blood in the infusion chamber is hindered by the blood's tendency to clot. These conditions cause the venous fluid level sensor to fail to accurately sense the true fluid level of the blood, causing the system to erroneously raise or lower the fluid level. This can lead to an excessive drop in the fluid level, resulting in the air detector generating a warning, or an excessive rise in the fluid level, causing blood to enter the line 363, clogging the venous transducer protector 371 and interfering with the pressure reading.

[0053] In these embodiments, algorithmically improved automatic fluid level control within the intravenous infusion chamber is maintained under unfavorable conditions of coagulation and foaming. The algorithmically improved automatic fluid level control utilizes the ideal gas method to determine a set amount of air (air volume) for the air pump 250 to inject or remove, and lowers or raises the fluid level based on the pressure detected in the chamber by the venous pressure sensor 182a. This is possible because the geometric gas volume and tubing connections of the infusion chamber are known. At high pressure, air is volumetrically compressed, and therefore the straight-line distance over substantially straight walls that raises or lowers the fluid level in the chamber is small for a given amount of air to be injected or removed. If the fluid level sensor 181b detects air (or a blood clot formed that is perceived as air), the algorithm begins to raise the fluid level. For a given venous pressure, the pump removes air until the air allocation is reached. The allocation is determined to place the fluid level between two fluid level sensors and is dynamically calculated using the ideal gas method as described above. If the system actually detects air instead of a blood clot, the fluid rises, and as a result, the low-level sensor 181b detects fluid again. In this regard, the algorithm initializes the amount of air available for use when the low-level sensor 181b next detects air. However, if the low-level sensor 181b is mistakenly detected by a blood clot or other event, the air pump will not detect any further air after removing the air and raising the fluid level. In this regard, the algorithm begins to control the fluid level dynamically based on the pressure in the infusion chamber. If the pressure increases, the gaseous space over the fluid compresses, raising the fluid level. Conversely, if the pressure decreases, the gaseous space over the fluid expands, lowering the fluid level. Pressure increases or decreases are detected by the venous pressure sensor 182a. If a sufficiently large pressure change is detected, the control algorithm uses the pressure / volume relationship of the ideal gas method to calculate the amount of air and add or remove it using the air pump 250 to counteract the rise or fall of the fluid level. In some embodiments, the pressure change threshold is 20 mmHg. In some embodiments, the pressure change threshold is 50 mmHg.In some embodiments, the pressure change threshold is 100 mmHg. The amount of air to be removed or injected is dynamically calculated using both the magnitude and change of the venous pressure. In a further embodiment, if the pressure in the chamber remains unchanged and the upper liquid level sensor 181a senses fluid, the control algorithm drives the air pump 250 to inject a calculated allocation of air into the chamber and lower the liquid level.

[0054] Figure 30 shows a flowchart 3000 illustrating the automatic fluid level control process described above. In step 3002 of flowchart 3000, the dialysis system automatically controls the fluid level in the intravenous infusion chamber during treatment as described above (for example, by measuring the fluid level with low-level and high-level sensors in the intravenous infusion chamber and automatically raising or lowering the fluid level based on the sensed level). During dialysis treatment, in step 3004, if the low-level sensor detects air (instead of fluid), then in step 3006, the dialysis system determines the “amount of air” for the system’s air pump and injects or removes it from the intravenous infusion chamber. This “amount of air” is dynamically calculated based on the measured pressure in the intravenous infusion chamber to set the fluid level between the upper and lower fluid level sensors. In some embodiments, the pressure in the intravenous infusion chamber is measured by a venous pressure sensor in the dialysis system. Next, in step 3008, the dialysis system raises the fluid level by removing volume air from the intravenous infusion chamber with an air pump equal to the calculated “volume of air”. After the volume of air has been removed from the intravenous infusion chamber, if the low fluid level sensor detects fluid in step 3010, then the “volume of air” is initialized in step 3012.

[0055] Referring again to step 3010, in some cases, the low fluid level sensor detects more air even after the allocated air in step 3008 has been removed. This is caused, for example, by a blood clot in the intravenous infusion chamber or by another event. In this event, in step 3014, a failure is detected and the dialysis system switches to controlling the fluid level in the intravenous infusion chamber based on the measured pressure. In step 3016, the system continuously measures the pressure in the intravenous infusion chamber. If a pressure change exceeding a pressure threshold is detected (e.g., a pressure change greater than 20-50 mmHg), then in steps 3018 / 3022, the system determines the "amount of air" based on the pressure change and the magnitude of the pressure. In step 3020, the fluid level is lowered by adding the allocated air, and in step 3024, the fluid level is raised by adding the allocated air.

[0056] In other embodiments, the system includes a single analog or non-binary digital fluid level sensor instead of two venous fluid level sensors to detect the actual fluid level in the infusion chamber. The dialysis supply system is then configured to perform similar adjustments as described above based on the fluid level detected by this single sensor. The single sensor may be, for example, an ultrasonic, optical, or capacitive fluid level sensor.

[0057] Referring further to Figure 4, in one embodiment, mounting the cartridge on the front panel 210 causes the cartridge to properly engage with a cartridge presence detector 214, which is a switch or sensor configured to communicate with the dialysis system (e.g., the system's controller) on which the cartridge is installed on the front panel. As a safety precaution, the system does not allow the pinch valves 180a-d to close until the cartridge presence detector 214 indicates that the cartridge is properly installed. The presence detector also initiates automatic loading of the blood pump portion of the blood pump tubing set. In one embodiment, the blood pump includes a spring wire 22 which is actuated to grip and pull the blood pump portion of the blood pump tubing set when the presence detector 214 is pressed down. Furthermore, the connection of the cartridge and tubing set to the front panel also initiates a self-check at each portion of the tubing set to ensure that all tubing is leak-free.

[0058] Figures 5 and 6 illustrate one embodiment of a cartridge 120 including a tube set 122 mounted in a storage case 124. Most of the tube set 122 is obscured from the viewpoint in Figure 5 by the storage case, but the arterial line 230, venous line 232, saline line 233, and infusion line 234 are visible. Referring to Figure 5, the user ensures proper placement of the cartridge relative to the front panel comprising the storage case 124 by positioning holes 125 of the storage case, which are equipped with positioning pegs 260 on the front panel. Figure 5 shows multiple positioning holes 125 near the top of the storage case, but it should be understood that any number and arrangement of positioning holes and positioning pegs can be used to align and mount the cartridge 120. Furthermore, the storage case 124 ensures proper placement of the tube set 122 relative to one or more mechanisms of the dialysis system, including valves (e.g., the pinch valves 180a-d described above), sensors (e.g., pressure and air sensors), a blood pump, and an intravenous infusion chamber. Furthermore, as shown in Figure 5, the cartridge includes multiple access holes 2165 for accessing mechanisms of the dialysis supply system, such as gaining access to a pinch valve or blood pump when the cartridge is installed in the system.

[0059] Figure 6 shows the rear view of a storage case 124 configured to connect to the front panel 210 of the dialysis supply system and the cartridge 120, including the tube set 122. The tube set 122 of the cartridge 120 includes an arterial line 230, a venous line 232, and a blood pump section 2167 configured to connect to the blood pump 213 of the front panel 210. The blood pump 213 is configured to draw blood from the user through the arterial line 230, pass the blood through the dialysis machine, and return the treated blood to the patient through the venous line 232. The tube set 122 is also connected to the intravenous infusion chamber 361 to remove air from the lines during treatment and priming. A continuous pathway through which blood circulates and is dialyzed is created by connecting one end of the arterial line 230 and the other end of the venous line 232 of the tube set 122 to the user's blood vessels, for example, by access points (e.g., fistula needles and catheters). The opposite ends of the arterial and venous lines are attached to the dialysis machine (described below) by color-coded connectors (e.g., red for arteries and blue for veins).

[0060] The tubing set further includes saline connections 353a and 353b to a saline solution, such as a saline bag, via a saline line 233. As shown in Figure 6, saline connection 353a connects to the tubing set proximal to the blood pump portion of the tubing set. Tube set 353b exits the cartridge and connects to the tubing set of arterial line 230 near where the arterial line is connected to the user. By connecting saline connection 353b near the arterial connection to the user, all the blood in the arterial line is returned to the user, thus improving blood return after dialysis treatment. The tubing set also includes a connection to an infusion pump or syringe via an infusion line 234. The infusion pump and infusion line are connected to the tubing set in a non-pulsating position, such as at the top of the intravenous infusion chamber, to prevent backflow of blood to the heparin line. In some embodiments, the infusion pump is essential to the system. In other embodiments, the infusion pump is separate from the system. The connection at the top of the intravenous infusion chamber is in a non-pulsating position due to the gap created between the heparin gland and the fluid in the intravenous infusion chamber.

[0061] The flow of fluid, such as blood, through the tubing set 122 is described below. As described above, the blood pump interacting with the blood pump portion 2167 of the tubing set 122 is a peristaltic pump. The blood pump operates in two modes of operation. One mode of operation is the "forward" mode of the blood pump, used during dialysis treatment, which moves blood from the patient to the tubing set and back to the patient. The other mode of operation is the "backward" mode of the blood pump, used during the priming sequence, which moves saline through the tubing set. The fluid flows through the tubing set in the "forward" mode, opposite to the fluid flowing through the tubing set in the "backward" mode. During dialysis treatment, blood is pumped from the patient through the arterial line 230 to the tubing set 122 by the blood pump 213, which interacts with the tubing set in the "forward" mode. The arterial pressure pod 355 connects to a pressure sensor (arterial pressure sensor 182b in Figure 4) or transducer on the front panel of the dialysis supply system to measure the pressure of the arterial line during treatment. The arterial pressure pod 355 is equipped with a diaphragm that allows pressure to be transmitted without the transmission of blood in the system. Blood continues through the tubing set, past the saline connection 353a, through the blood pump section of the tubing set, and through the tubing section 357 to the dialysis machine. As soon as the blood proceeds through the dialysis machine, it continues through the tubing section 359 to the tubing set 122, returns to the cartridge, and enters the intravenous infusion chamber 361 at the bottom of the infusion chamber at the inlet port 365. As the blood flows into the intravenous infusion chamber 361, air is separated from the blood into the intravenous infusion chamber and removed from the system (e.g., through a vent or port at the top of the infusion chamber). The intravenous infusion chamber is connected to the venous pressure sensor or transducer of the dialysis supply system by line 363 and venous transducer protector 371 to prevent blood or other fluids from contaminating the pressure sensor. Blood entering the intravenous infusion chamber then exits the chamber through outlet port 367 and continues to flow through the tubing set until it returns to the patient via venous line 232.

[0062] As shown in Figure 6, the intravenous infusion chamber includes inlet and outlet ports 365 and 367 through which blood can enter and exit the chamber from the bottom. Any air bubbles trapped in the blood or vein are removed from the blood before they permeate the chamber and are returned to the patient. This configuration allows the fluid flow through the tubing set to be reversed during priming of the dialysis machine, pushing air up and out of the dialysis machine. The blood flow can also be reversed in the tubing set if air is detected in the venous lines of the tubing set.

[0063] Priming and priming disposal

[0064] Before treatment, the tubing set is primed with saline solution to remove air from the lines and prepare the system for dialysis treatment. During the priming sequence, the arterial and venous lines of the tubing set are connected together to form a continuous loop of the tubing set. Figure 18 shows one embodiment of a connecting joint 256 configured to attach an arterial line 230 to a venous line 232. In some embodiments, the connecting joint 256 is made into a "T" or "Y" shape or other forms having at least three connecting tubing pathways: 1) arterial line, 2) venous line, and 3) a conduit for priming and discharging fluid from the tubing set. This third tubing pathway is selectively open or closed, i.e., includes an external cap 258. This connecting fitting has only one exposed open surface during the priming and disposal procedure, providing improved infection control than having two exposed patient connection points.

[0065] During the priming sequence to remove air from the tubing set and prepare the system for treatment, saline is pumped into the tubing set through saline connections 353a and / or 353b by operating the blood pump in "forward" and "backward" operating modes, causing the blood pump to interact with the tubing set and move saline from the saline source to the tubing set. When the pump operates in this "backward" operating mode, saline moves from the saline source to the tubing set and the blood side of the dialysis machine, filling the tubing set and the dialysis machine with fluid, and removing air from the tubing set by the dialysis infusion chamber. In this "backward" operating mode, saline flows through the tubing set in the opposite direction to the blood flow during dialysis treatment. Therefore, saline flows through the intravenous infusion chamber before flowing through the blood side of the dialysis machine. Air in the intravenous infusion chamber is monitored by a venous fluid level sensor. Any air in the system is pushed out into the intravenous infusion chamber by saline.

[0066] When the venous fluid level sensor no longer detects any change in the fluid level in the venous infusion chamber, or when the air sensor no longer detects air circulation through the tubing set, the tubing set is then primed and ready for treatment. The blood pump is then operated in “forward” mode, moving the saline solution in a direction other than those described above and discharging it from the tubing set. In “forward” mode, the saline solution passes through the blood side of the dialysis machine and through the venous line 232 to the patient before passing through the venous infusion chamber. In some embodiments, the saline solution used during the priming sequence is supplied to the patient at the start of the dialysis treatment. The amount of saline solution supplied is monitored and monitored during the dialysis treatment according to the patient’s individual fluid removal needs. In another embodiment, some or all of the saline solution is pumped up from the tubing set before treatment and discharged.

[0067] To complete the priming sequence, the dialysate is pumped or moved through the dialysate side of the dialyzer by a dialysate pump (described below). The dialysate is pumped through the dialysate side of the dialyzer in the same direction as the saline is pumped through the blood side of the dialyzer. The direction of the saline and dialysate through the dialyzer is from bottom to top through the dialyzer, allowing bubbles to be naturally purged through the top of the dialyzer. Thus, the priming sequence of this disclosure removes air from both the blood side and dialysate side of the dialyzer without physically manipulating or "reversing" the orientation of the dialyzer, as required by other conventional systems, because the priming sequence flows the fluid through both sides of the dialyzer in the same direction.

[0068] During treatment, blood in the tubing set typically flows through the blood side of the dialysis machine in a top-down direction. However, during priming, the blood pump operates in a "reverse" direction, pushing saline solution from bottom to top through the dialysis machine, more efficiently removing air from the dialysis machine. Due to the inherent configuration of the tubing set and intravenous infusion apparatus, the fluid can flow through the tubing set in a "reverse" direction, as it enters and exits the intravenous infusion chamber at the lower connection point of the chamber. Conventional intravenous infusion chambers, where tubing connections are made at the top and bottom of the chamber, only allow fluid flow through the chamber in one direction. The inherent configuration of this disclosure allows priming of both the blood and dialysate sides of the dialysis machine without the need to physically replace the dialysis machine. During priming, any air generated in the intravenous infusion chamber is removed by exhausting it from the system or by priming it from the system. In one embodiment, a pinch valve in the system is operated periodically to open and close the saline line of the tubing set, depending on the timing of the priming sequence, to "tap" and release bubbles in the dialysis machine. For example, the pinch valve is opened and closed every 4-8 seconds, creating a pulsed effect of saline in the line.

[0069] Figures 29A–29L illustrate another sequence for priming a patient tubing set before dialysis treatment. As shown in Figure 29A, the patient tubing set and dialysis system 2900 includes a blood pump 2902, a dialysis machine 2904, an intravenous infusion chamber 2906, an arterial line 2908, an intravenous line 2910, and a saline source 2912. The tubing set further includes an arterial pressure sensor 2914 configured to sense the pressure in the arterial line, and one or more fluid level sensors 2916 and 2918 coupled to the intravenous infusion chamber. One or more fluid level sensors are configured to detect the fluid in the intravenous infusion chamber during priming and during dialysis treatment. While two fluid level sensors are shown in the depicted embodiment, it should be understood that one or more sensors than two may also be implemented to achieve the same or similar functionality described herein. The system includes multiple pinch valves, such as first and second saline pinch valves 2920 and 2922, an arterial pinch valve 2924, and a venous pinch valve 2926, which are operated by an electronic controller (described herein but not illustrated) that can change and alter the fluid flow path within the tubing set. Finally, the patient tubing set and treatment system include an air pump 2928 and a pressure sensor 2930, both located upstream of the intravenous infusion chamber.

[0070] Figure 29B depicts the starting conditions of the tubing set and dialysis system before initiating the priming sequence. In Figure 29, the first and second saline pinch valves 2920 and 2922 are closed, and the arterial pinch valve 2924 and venous pinch valve 2926 are open. Connector 2932 is also used to connect the venous and arterial lines and create a closed-loop flow path in the patient tubing set. In this starting state, the blood pump 2902 is turned off, and the air pump 2928 operates to begin pulling air from the tubing set. As the first and second saline pinch valves close in this step, the patient tubing set forms a closed loop, and the air pump begins to create a vacuum in the tubing set.

[0071] Next, as shown in Figure 29C, the first saline pinch valve 2920 opens while the air pump 2928 continues to operate, drawing saline from the saline source into the patient tubing set. This step is performed for a predetermined period of time. For example, the air pump is used to draw saline into the tubing set for 2–20 seconds. In the depicted embodiment, the saline level rises to the arterial pressure sensor during this step.

[0072] Next, as shown in Figure 29D, the first saline pinch valve 2920 closes and the second saline pinch valve 2922 opens, and the air pump 2928 continues to pull saline into the tubing set. This operation continues until the fluid level in the tubing set reaches a predetermined level. In one embodiment, the air pump pulls saline into the tubing set until the saline or fluid level is detected in the intravenous infusion chamber by one or more fluid level sensors. In the depicted embodiment, this operation stops when the fluid is detected by the lower fluid level sensor 2916. However, it should be understood that this operation continues until detection by the upper fluid level sensor 2918. In embodiments with a single fluid level sensor, the operation stops when the fluid is detected by that single sensor.

[0073] Referring here to Figure 29E, both the first and second saline pinch valves are closed, and the blood pump 2902 operates in a “forward” direction (e.g., the same direction as during dialysis treatment) while the air pump 2928 continues to operate. This lowers the fluid level in the intravenous infusion chamber, as indicated by arrow 2901. Then, as shown in Figure 29F, while the blood pump and air pump continue to operate, the first saline pinch valve 2920 opens and the venous pinch valve 2926 closes, raising the fluid level again in the patient tubing set. This operation continues until one or more of the fluid level sensors detect fluid in the intravenous infusion chamber. In the embodiment depicted, this operation continues until the upper fluid level sensor 2918 detects fluid in the intravenous infusion chamber. In Figure 29G, the blood pump and air pump continue to operate as in Figure 29F, but the patient tubing set is vented through vent 2930. This allows air bubbles to be extracted from the patient tubing set through the intravenous infusion chamber.

[0074] Next, as shown in Figure 29H, the blood pump 2902 operates in a "reverse" direction (e.g., opposite to the direction of dialysis treatment) while the air pump 2928 continues to operate. This continues the process of filling the entire surface of the tube set with saline while priming, removing, and dislodging air bubbles from the tube set.

[0075] Figures 29I-29L depict one embodiment that includes individual pressure test portions of a patient tubing set after a priming sequence to check for localized leakage of the patient tubing set. The pressure test sequence includes steps of successively opening and closing various pinch valves and steps of changing the operation of the blood pump to evaluate different portions of the patient tubing set. For example, in Figure 29I, all pinch valves are closed and the blood pump continues to operate in “forward” operation mode. This pressurizes the portion of the patient tubing set between the blood pump 2902 and the venous pinch valve 2926. As soon as the portion of the patient tubing set is pressurized, the pressurization within the portion of the patient tubing set is measured as a reference pressurization value and stored. Next, referring to Figure 29J, the blood pump 2902 is turned off and the arterial pinch valve 2924 is opened. By opening the arterial pinch valve 2924, a new portion of the tubing set between the blood pump and the venous pinch valve 2926 is exposed to the pressurized fluid from the first portion of the tubing set. The pressure within the patient tubing set is measured again, compared to the reference pressurization value, and has a calculated pressure decay rate. If the measured pressure in this step is below the reference pressure value or shows a pressure decay rate exceeding a certain threshold, it indicates leakage of the patient tubing set between the blood pump and the venous pinch valve, including through the saline pinch valve 2922. In Figure 29K, the blood pump is turned off and the venous pinch valve 2926 is opened. By opening the venous pinch valve 2926, a new portion of the patient tubing set between the venous pinch valve and the arterial pinch valve is exposed to the pressurized fluid from the first tubing set portion. The pressure in this portion of the patient tubing set is again measured and compared to the reference pressure value or has a calculated pressure decay rate. If the measured pressure in this step is below the reference pressure value or shows a pressure decay rate exceeding a certain threshold, it indicates leakage of the patient tubing set between the venous pinch valve and the arterial pinch valve, including through the saline pinch valve 2920. Finally, in Figure 29L, the arterial pinch valve is opened and the blood pump operates again. In this step, the measured pressure is compared to a reference pressure, or it is determined that the pressure decay rate exceeds a certain threshold, indicating leakage through the saline pinch valve 2922.

[0076] After the priming sequence, when saline solution is present in the tubing set, the system performs a further self-test to check for leaks in the tubing set. In one embodiment, the pinch valve of the venous line is closed by the blood pump, and air is pumped into the venous infusion chamber. Next, the arterial pinch valve closes and the venous pinch valve opens, and the system checks for pressure stabilization. If there is no pressure decay, it is confirmed that there are no leaks in the system.

[0077] In one embodiment, the dialysis machine is flushed before initiating dialysis treatment on a patient. The system flushes the dialysis machine with up to 500 ml of saline solution. Upon completion of the priming procedure, the priming fluid used is discarded. Typically, there are two different types of destinations for the priming fluid used: 1) a container or fluid connection that leads to the inside of the dialysis machine itself, sending it to a drain, and 2) an external container that is usually reusable, manually discharged into a sink, and cleaned. Both of these approaches present challenges in terms of maintaining cleanliness and sterility of internal or external surfaces. Furthermore, the open end of a tubing set, often used in conjunction with a disposable container, is the same end that will later connect to the patient during treatment. Infection control is critical during hemodialysis treatment and assembly, and there is a risk of infection by exposing the open end of the tubing set during the priming disposal procedure, especially since the tubing set is handled by the user to ensure it is properly positioned for fluid disposal.

[0078] As described above, the tubing set is filled with saline solution during the priming sequence. During this priming, the arterial and venous lines are connected to each other at the connecting joint 256 shown in Figure 18. In the first priming waste embodiment, after priming, the tubing set is placed on a waste bucket after the patient removes the cap 258 from the connecting joint 256. The dialysis system is then placed on a priming waste sequence, ensuring that valves 180b and 180c (from Figure 17) are closed first, and valves 180a and 180d (from Figure 17) are opened. The blood pump is operated forward, pumping saline solution into the tubing set until the desired amount of priming waste has been pumped through the system and drained through the connecting joint 256 in Figure 18. Valve 180d is then closed and valve 180c is opened, allowing the saline solution to be drained by gravity through the connecting joint until an appropriate amount of saline solution (e.g., 40 ml of saline solution in one embodiment) is delivered through the connecting joint.

[0079] In another priming disposal embodiment, the sterile package for the cartridge and tube set is also used as a post-priming waste container. The cartridge and tube set is supplied sterilized and typically packaged in a disposable bag that serves as a sterilization barrier. In the first embodiment shown in Figure 19A, the sterile container 1900 is used as a sterile package for carrying and maintaining the cartridge and tube set in a sterile state before treatment. In the second embodiment shown in Figure 19B, the sterile container 1900 serves as a disposable priming waste container for discharging the priming saline. During operation, the user removes the cartridge and tube set from the sterile bag that later serves as a priming waste container. The cartridge and tube set is connected to a dialysis machine including a saline source and a dialysis machine as described above. The arterial and venous lines of the cartridge and tube set are pre-connected to connecting joints, and the cartridge and tube set is primed with saline as described above. After priming the tubing set, the user attaches the sterile container to the dialysis system, removes the cap from the connecting joint, and the dialysis system can transfer saline solution from the tubing set to the sterile container 1900. The saline solution can flow into the container through both the arterial and venous lines because the arterial and venous lines are in contact at the connecting joint. After priming and disposal are complete, the user removes and discards the sterile container. Finally, the user cuts the connecting joint from the arterial / venous lines, connects the lines to the patient's access site, and discards the connecting joint. At this point, the dialysis treatment is ready to begin.

[0080] The sterile container 1900 includes a mounting mechanism 1902, such as a notch, tab, or other mounting mechanism, as shown in Figure 19B, to connect with a dialysis system and hold the container in place during priming and disposal. For example, in one embodiment, the mounting mechanism 1902 includes a notch, and the dialysis system includes a tab extending through the notch and holding the container to the dialysis system.

[0081] Furthermore, the dialysis system includes a mounting mechanism to hold a coupling joint in place of the dialysis system relative to the mounting container. The mounting mechanism of the dialysis system includes a snap-fit ​​mechanism, a spring-grip mechanism, a semicircular cup mechanism, a hole and shaft mechanism, or other similar mounting mechanisms. For example, the container includes a straight slit cut into one of the sheets that connects to a straight extrusion whose cross-section is hook-shaped, which is positioned in the dialysis system. In one particular embodiment, the hook-shaped mechanism is mounted on surfaces that are not coplanar with each other but are in contact at a slight angle, and the hook-shaped mechanism gives a slight bend to the sheets of the bag. This forces the other sheet welded to the first sheet at the edge of the first sheet to bend in the opposite direction, and widens the opening between the sheets at the top of the bag.

[0082] In some embodiments, the sterile container consists of two thin sheets welded together at the ends, and is opened by delaminating the weld at one end of the bag. If the user completely delaminates both sheets, the bag will not be able to hold any liquid volume and will therefore not be used as a priming waste container. Figure 19C shows a design drawing of the sterile container 1900, including a mounting mechanism 1902, a first joint 1904, and a second joint 1906. In this embodiment, the weld of the two sheets is configured to allow the user to open the bag and remove its contents, while preventing the user from opening the bag beyond a certain point so that it cannot serve as a waste container without holding a sufficient volume. As shown, the first joint 1904 along the side of the container is thinned to a point and then, as shown by the second joint 1906, becomes very thick, providing very high resistance to opening the bag beyond the point of resistance. This ensures that the user can open the container and remove the cartridge and tube set, but can still use the container for priming waste saline.

[0083] As shown in Figure 26, an alternative embodiment may include a cartridge and tube set having a container (i.e., not a sterile container at the time of shipment) pre-attached to the tube set. That embodiment includes a coupling joint 256 as described above, which includes connection to the patient line as described above. That embodiment may optionally include a clip as shown to secure the container and patient line on the console during treatment. In this embodiment, the user attaches to and detaches the patient line from the vascular access without having to manage the other side of the tube.

[0084] As shown in Figure 27, in yet another embodiment, the coupling joint 256 includes a three-way stopcock with two female luers for connecting to the patient's arterial and venous lines and a male luer for connecting to a pre-attached waste container. The coupling joint is used to guide the flow of saline solution to the waste container after the priming sequence. The container includes a floating cap for closing and sealing the bag after use.

[0085] In another embodiment, a pre-installed container is coupled to a priming waste valve controlled by the dialysis system. In this embodiment, priming is performed as described above, and upon completion of priming, the dialysis system controls the priming waste valve to send the priming saline to the pre-installed container. Alternatively, the dialysis system itself includes a waste container, and the tube set is configured to be automatically discarded into the waste container by the priming waste valve upon completion of the priming sequence. In some embodiments, the connection between the dialysis system's waste container and the blood tube set is made automatically when the blood tube set is installed in the system as made possible by the sorting case configuration described above. In these embodiments, the flow from the blood tube set to the waste container is automatically controlled by a pinch valve that engages the tubes of the blood tube set connector. In further embodiments, the dialysis system's waste container is sterilized by the system's automatic sterilization sequence.

[0086] At the completion of dialysis treatment, blood still remains inside the tubing set. The blood pump 213 is controlled to pump saline solution from the tubing set and push the remaining blood back to the patient. This blood return mechanism is highly controlled by the system controller and the blood pump. For example, during dialysis treatment and blood return, the system controller monitors and tracks the correct number of rotations made by the blood pump when the pinch valve controlling saline administration opens, so as to know exactly how much saline solution has been pushed out. The blood pump then stops or becomes inactive when the desired volume of saline solution has been pumped into the tubing set. This allows the system to know exactly how much saline solution has been used and how much remains in the saline source or bag. At the end of dialysis treatment, the amount of blood in the tubing set is known (typically about 250 ml), and the system accurately measures the correct amount of saline solution in the tubing set and pushes the blood back to the user. The expected amount of saline solution for use in blood reversion (typically 300-600 ml depending on the degree of change in the perfection of blood reversion) is integrated into the overall fluid removal target in ultrafiltration so that the patient's target weight is achieved after blood reversion. If the required amount of saline solution does not remain in the saline source before blood reversion, the system will alert the user that the saline source needs to be replenished or replaced.

[0087] In one embodiment, the dialysis machine is flushed before initiating dialysis treatment on a patient. In some cases, outpatient clinics disregard this labeling and do not flush the dialysis machine. The system is configured to flush the dialysis machine with up to 1000 ml of saline solution.

[0088] The system also automatically drains all fluid from the dialysis machine after dialysis treatment. In one embodiment, a blood pump operates backward with a grasped venous line to pull fluid from the dialysate chamber of the dialysis machine, through the dialysis machine's microtube wall against gravity, through the dialysis machine to a saline source or bag.

[0089] Figure 7 shows a flow diagram of the water purification system 102 contained within the dialysis system 100. Water entering, for example from a tap, flows through multiple filters, including one or more sediment filters 108 and one or more carbon filters 110. A chlorine sample port 195 is located between the carbon filters 110 to provide a fluid sample for measuring chlorine content. Redundant or double carbon filters are used to protect the system and users in the event of carbon filter failure. The water then passes through a reverse osmosis (RO) supply heater 140, an RO supply pump 142, one or more RO filters 112 (indicated as RO1 and RO2), and a heat exchanger (HEX) 144. The filtration products from the RO filters 112 are supplied to the HEX 144, while the excess filtration products are passively recirculated and pass through the RO supply pump and RO filters again. Recirculation assists the operation of the water purification system by diluting the incoming tap water with RO water to achieve higher salt removal from the incoming water. After passing through HEX144, the purified water is sent to the dialysis supply system 104 to prepare the dialysate and support dialysis treatment. Furthermore, during the water purification process, the concentrate from the RO filter is sent to the drain 152.

[0090] Referring to Figure 8, the water purification system 102 of the dialysis system includes one or more subsystems as described above in Figure 7, including a water supply subsystem 150, a filtration subsystem 154, a preheating subsystem 156, an RO filtration subsystem 158, and a pasteurization or ultrafiltration subsystem 160. Each of the subsystems above produces products into the drain 152. The water purification system 102 is configured to purify the water source in real time for dialysis treatment. For example, the water purification system is connected to a residential water source (e.g., tap water) and prepares purified water in real time. The purified water is then used for dialysis treatment (e.g., in a dialysis supply system) without the need to heat and cool large amounts of water, as is usually associated with water purification methods.

[0091] Figure 9 shows the mechanism of the water supply subsystem 150 of the water purification system, including various valves (e.g., three-way valves, control valves, etc.) for controlling the fluid passing through the water purification system. For example, at least one valve 2169 is open, allowing water to flow into the water purification system for purification. The incoming water flows from, for example, a water source 2171. The fluid return from the water purification system is guided through one or more valves to a drain 152. Furthermore, the subsystem includes a supply regulator 183 that can adjust the water supply pressure to a set value. A drain pressure sensor 153 measures the pressure in the drain. The water flows from the water supply subsystem 150 to the filtration subsystem described below.

[0092] Figure 10 shows one embodiment of the filtration subsystem 154 of the water purification system. The filtration subsystem receives water from the water supply subsystem 150, as shown in Figure 9. The water passes through a supply pressure sensor 2173 configured to first measure the water pressure and a supply temperature sensor 2175 configured to sense the temperature of the incoming water supply. The filtration subsystem includes a sediment filter 155, such as a 5-micron polypropylene cartridge filter. The filter typically requires replacement every six months. Based on the high capacity of the sediment filter and the relatively low flow rate through the filter, the average lifespan is estimated to be more than one year based on average domestic water quality in the United States. The six-month replacement interval provides high confidence that premature clogging of the sediment filter is rare. Failure resulting in unfiltered water passing through the filter is also expected to be a rare occurrence based on the filter's structure and materials. A supersediment pressure sensor 2177 measures the pressure drop across the sediment filter and monitors and confirms when the sediment filter needs to be replaced. If water that has not been filtered through the sediment filter passes through, it results in clogging of the carbon filter, which is detected by a pressure drop in the supersediment pressure sensor 2177. If this pressure drop is a significant factor when the sensor drops to 5 psig, the system needs to replace both the carbon filter and the sediment filter before initiating treatment.

[0093] The water then flows through one or more carbon filters 110 (indicated as CF-1 and CF-2) configured to filter out materials such as organic chemicals, chlorine, and chloramines from the water. For example, the carbon filter 110 includes a granular carbon block cartridge with a 10-micron filter. The carbon filters are connected in series with a chlorine sample port 195 located in the flow path between the carbon filters. The chlorine sample port provides the user with access to the flowing water (e.g., through the system's front panel) for quality control purposes, ensuring that the total chlorine concentration level of the water is below a certain threshold (e.g., less than 0.1 ppm). Furthermore, an excess carbon pressure sensor 2179 is installed after the carbon filters to monitor the fluid pressure in the line after sediment and carbon filtration. Also, as shown in Figure 10, an optional air separator 187 is installed between the sediment filter and the carbon filters to remove excess air and bubbles from the line. In some embodiments, each carbon filter is specified to have a service life of 2500 gallons of produced water with free chlorine and chloramine levels below 0.5 ppm when operating under high chlorine conditions and at higher flow rates supported by the equipment, so an expected life greater than 2500 gallons is expected. Based on a maximum treatment flow rate of 400 mL / min through the carbon filter, the expected lifespan for a single carbon filter is approximately 6 months to over 1 year, depending on the incoming water quality. The system typically requires replacement of both filters every 6 months. Most carbon filters cannot tolerate heat or chemical sterilization, and therefore, recirculation / sterilization channels implemented by the water supply and discharge systems do not include carbon filters (or sediment filters). Since the chlorine absorption capacity of the carbon filter is finite and dependent on the incoming water quality, water samples are taken from chlorine sample port 195 to ensure that the free chlorine concentration level of the water is below 0.1 ppm. Using a two-stage carbon filtration process and ensuring that free chlorine is "equally absent" after the first carbon filter ensures that the second carbon filter maintains full capacity while being fully redundant to the first carbon filter.When the first carbon filter expires, both filters are typically replaced. Water flows from the filtration subsystem to the preheating subsystem described below.

[0094] Figure 11 shows one embodiment of a preheating subsystem 156 of a water purification system. The preheating subsystem is configured to control the temperature of the water in the line to optimize RO filtration performance. The preheating subsystem includes one or more RO supply heaters 186, which include thermoelectric devices such as Peltier heaters / coolers. The RO supply heaters 186 are configured to regulate or adjust the temperature of the water before RO filtration. In one embodiment, the target temperature for reverse osmosis is 25°C for optimal RO filter performance. If the water is too cold, the RO filter will have insufficient flow and the system will not produce enough water. If the water is too hot, the RO filter will be able to flow further, but salt removal will be reduced. In one embodiment, 25°C is the point where flow and removal are balanced to provide enough water that is properly removed. The RO supply heaters can be used to both heat or cool the fluid flowing through the heater. For example, in some embodiments, the RO supply heaters recover heat from wastewater or spent dialysate by the Peltier effect. In other embodiments, for example, during a thermal sterilization cycle, the RO supply heater is configured with opposing polarities to neutralize the Peltier effect. During water treatment, incoming water flows through titanium plates attached to the hot sides of the two thermoelectric wafers of the RO supply heater. Wastewater is guided through a separate titanium plate attached to the cold side of the wafer. Thus, heat is transferred from the wastewater to the incoming water by the Peltier effect. At maximum power when the preheating system achieves two performance coefficients, half of the power used to heat the incoming water is recovered from the wastewater, and the other half is recovered from the electric heating of the wafer. At lower power levels, the performance coefficient increases, meaning that a higher proportion of heat is recovered from the wastewater flow. During thermal sterilization, the thermoelectric wafers of the RO supply heater are configured with opposing polarities. In this way, both titanium plates are heated, and the Peltier effect is neutralized. This ensures that the water is only heated and is always at a higher temperature than the incoming water on either side of the heater.

[0095] As shown in Figure 11, the preheating subsystem 156 includes a process supply valve 188 and a spent dialysate return valve 190 that send spent dialysate to the drain between the filtration subsystem and the RO supply heater. The RO supply heater includes a pair of temperature sensors 192 and 194 to measure the temperature of the fluid on either side of the heater. Water flows from the preheating subsystem to the RO filtration subsystem described below.

[0096] Figure 12 shows one embodiment of the RO filtration subsystem 158 of the water purification system. The RO filtration subsystem receives preheated water from the preheating subsystem described above. The RO filtration subsystem includes an RO supply pump 142 that drives the water through one or more RO filters 112 (indicated as RO-1 and RO-2) to produce a filtration product flow and a concentrated flow. The concentrated flow is filtered by two or more RO filters. Furthermore, the filtration product flow is combined with the excess filtration products and mixed with the incoming water that is returned to the recirculation. In addition, each RO filter 112 includes a recirculation pump 200 to maintain a high fluid velocity on the RO filter. The recirculation pump operates at a constant speed and returns the flow from the concentrated flow to the inlet of the RO filter. Using a separate recirculation pump instead of recirculating through the RO supply pump can reduce overall power consumption, maintain a high flow velocity on the RO membrane, reduce contamination, and increase the rate of water production. In some embodiments, the RO supply pump is a high-pressure but relatively low-flow pump, compared to a recirculation pump, which is a low-pressure but high-flow pump.

[0097] The pressure generated by the RO supply pump and the RO concentrate flow restrictor 2181 controls the flow rate of waste to the drain. To ensure that the restrictor does not become contaminated or clogged, the flow through the RO concentrate flow restrictor is periodically reversed by the operating valve 180. Furthermore, to improve filter life and performance, a recirculation pump is used to increase the fluid flow rate in the RO filter housing. This increase in flow rate helps reduce the boundary layer effect, which occurs near the surface of the RO filter where water does not flow near the filter membrane. The boundary layer forms on the surface of the RO filter, creating areas with high concentrations of total dissolved solids that accumulate and clog the RO filter.

[0098] The RO filtration subsystem includes one or more conductivity sensors 196 configured to measure the conductivity of the water flowing through the subsystem in order to measure the solute purification value or rate, a pressure sensor 198 configured to monitor the fluid pressure, and an air separator 187 configured to separate and remove air and air bubbles from the fluid. Furthermore, the RO filtration subsystem includes various valves 180, including a check valve, and a fluid pump that controls the flow through the RO filter to the pasteurization subsystem, back through the RO filtration subsystem for further filtration, or to the drain. The water flows from the RO filtration subsystem to the pasteurization subsystem described below.

[0099] Figure 13 illustrates one embodiment of the pasteurization subsystem 160 of the water preparation system. The pasteurization subsystem is configured to minimize patient exposure to microbial contamination by heating the fluid and to eliminate microbial contamination and endotoxins from the system. The pasteurization subsystem includes a heat exchanger (HEX) 145 configured to heat the water to a pasteurization temperature, allowing the water to remain at a high temperature, and then to cool and return the water to a safe temperature for dialysate production.

[0100] In some embodiments, the HEX145 heats water received by the pasteurization subsystem to a temperature of approximately 148°C. The heated water is held in the HEX's retention chamber for a sufficient period to eliminate and kill bacteria and denature endotoxins. Endotoxins can be described as dead bacterial remains characterized by long lipid chains. During the preparation of water and dialysate, endotoxins, along with bacteria, are monitored to determine the purity of the dialysate. Endotoxins in dialysate can cause an undesirable inflammatory response for the user. Therefore, it is desirable to minimize the level of endotoxins in the dialysate. Endotoxins are not readily captured by the pore size of typical ultrafilters. Instead, endotoxins are stopped by the ultrafilter at surface adsorption where the endotoxins are saturated, at which point further endotoxins begin to pass through. Heating the endotoxins in superheated water to a temperature of around 130°C has been shown to denature the endotoxins, but the required retention time is very long (several minutes). During these heating stages, water remains in the liquid phase, and water, normally considered a polar solvent, begins to act as a nonpolar solvent to denature the lipid chains of endotoxins. When the temperature is raised to 220°C or higher, the denaturation of endotoxins occurs in seconds. The HEX of this disclosure operates at 220°C or higher while maintaining the pressure at which water remains in liquid form (approximately 340 psi at 220°C, but the HEX can withstand pressures exceeding 1000 psi). In one embodiment, the preferred temperature and pressure range for the HEX is 145–340 psi at 180–220°C. The water is then cooled while present in the retention chamber. The HEX145 is a self-contained countercurrent heat exchanger that simultaneously heats incoming water and cools outgoing water to reduce energy consumption.

[0101] The pasteurization subsystem includes a HEX pump 193 configured to maintain fluid pressure in the fluid line to prevent the water from boiling. After the water has passed through the HEX 145, a water regulator 197 reduces the water pressure for use in the dialysis supply system. One or more pressure sensors 182 or temperature sensors 184 are included to measure the pressure and temperature of the water flowing through the pasteurization subsystem, respectively. In addition, an air separator 187 further removes air and air bubbles from the water. In one embodiment, a flow restrictor 189 and a valve 180 are used to limit the water discharged into the drain when the HEX 145 is heating. As soon as the water has passed through the pasteurization subsystem, it proceeds through the total water purification system and is clean and pure enough to be used for dialysate preparation and supply by the dialysis supply system.

[0102] Figure 28 illustrates different embodiments of an ultrafiltration subsystem used in a given location in the sterilization subsystem of Figure 13. This ultrafiltration subsystem removes microbial contamination and endotoxins from the system using a nanometer-scale filter (ultrafilter). In some embodiments, the pore size of the ultrafilter is 5 nm. In some embodiments, the ultrafilter is made of any material known in the prior art that is formed into a sufficiently porous filter structure, but the material of the ultrafilter is polysulfone. The ultrafiltration subsystem includes a booster pump to provide sufficient pressure to drive the flow of water through the ultrafilter. The pressure across the filter is monitored by upstream and downstream pressure sensors that alert when the filter is clogged and needs to be replaced. The flow may be diverted to a drain through a drain valve and restrictor as needed. The ultrafiltration subsystem also includes a sample port accessible from outside the system to pump water to verify the proper functionality of the ultrafilter. In some embodiments, the ultrafiltration subsystem includes a flow through a heat exchanger somewhere in the system structure to facilitate cooling and heating of the flow path.

[0103] Figure 14 schematically illustrates the mixing subsystem 162 of the dialysis supply system. Purified water from the water purification system is sent to the dialysis supply system and flows through a heater 220 in preparation for final degassing of the degassing chamber 221. In one embodiment, the water flowing into the heater 220 is approximately 43-47°C, and the heater heats the water to a maximum of 50°C or higher. The degassing chamber is, for example, a spray chamber containing a pump sprayer 222. During degassing, a spray chamber recirculation pump 225 pumps fluid up from the bottom of the degassing chamber at a high flow rate. The heated water entering from the heater 220 then enters the degassing chamber at a higher liquid level through the pump sprayer 222. The temperature of the water as it enters and leaves the heater is monitored by a temperature sensor 184. This limited spray head, combined with the high flow rate of the spray chamber recirculation pump 225, creates a vacuum in the degassing chamber ranging from -7 psig to -11 psig. The combination of vacuum pressure and heating efficiently degasses the incoming water. When air accumulates at the top of the deaeration chamber and the water level falls below the liquid level sensor 2183, the deaeration pump 191 turns on and operates quickly to remove the accumulated air from the top of the deaeration chamber. The deaeration pump 191 removes the combination of air and liquid from the deaeration chamber.

[0104] After degassing and subsequent cooling to near body temperature in heater 220, the acid and bicarbonate concentrates are distributed by volumetric analysis into the flow path by concentrate pump 223 to achieve the desired dialysate composition. The water and concentrates are mixed in a series of mixing chambers 224, which smooth the introduction of the fluid by utilizing time-delayed or volumetric mixing instead of in-line mixing. Figure 15 shows one embodiment of the mixing chamber 224, which includes an inlet 236a and an outlet 236b. The mixing chamber includes a number of channels 238 connecting the inlet to the outlet. The channels are arranged such that some channels have longer paths from the inlet to the outlet than others. Thus, the fluid traveling through the channels of the mixing chamber is separated and divided along the varying channel lengths before being recombined to achieve more complete mixing of the incoming fluid, which is "rough" by the time it takes to exit the mixing chamber.

[0105] Smartflow

[0106] During dialysis treatment, users have the ability to adjust the dialysate flow rate from the dialysis system to suit the patient's prescription. Often, this setting is switched once at the start of treatment, and the flow rate is maintained throughout the entire treatment period. Although studies have shown that clearance rates experience diminishing benefits at higher flow rates, dialysis providers typically set the maximum dialysate flow rate to maximize waste clearance. Since most dialysis machines operate in a central water loop using a central dialysis concentrate, there is usually little incentive to conserve dialysate during treatment.

[0107] The dialysis system of this disclosure is unique in that it distributes dialysate during operation as described above, using a finite volume of concentrates. In one embodiment, the dialysis system of this disclosure conserves dialysate concentrates by adjusting the dialysate flow rate, actively monitoring the amount of dialysate used between treatments to reduce the consumption of acid and bicarbonate concentrates. The overall pressure ratio of the dialysis machine (e.g., venous pressure, dialysis pressure, etc.) is automatically maintained by the dialysis system, while the dialysate flow is reduced to ensure an appropriate ultrafiltration profile.

[0108] Depending on the treatment goals, it may be appropriate to perform dialysis at a low dialysate flow rate. For example, performing long treatments at low dialysate and blood flow rates has a milder physiological effect on the body and is suitable for patients undergoing dialysis at night or patients with impaired physiological function. Laissez-faire dialysis treatment can be performed while maintaining appropriate device efficiency through onboard monitoring of dialysate consumption and real-time dialysate flow rate control.

[0109] Figure 20 is a flowchart 2000 illustrating one embodiment of a method for monitoring dialysate consumption and adjusting dialysate flow rate during treatment to conserve dialysate. In step 2002 of flowchart 2000, a dialysis treatment is initiated in the dialysis system. In step 2004 of flowchart 2000, the dialysis system includes an option to perform a “smart flow” configuration in which the dialysis system monitors dialysate consumption during treatment. If smart flow is not selected or turned off, the treatment or therapy is performed normally with the dialysate flow rate selected for the course of treatment, as shown by step 2006 of flowchart 2000.

[0110] However, if the "Smart Flow" option is enabled in step 2004, then in step 2008 of flowchart 2000, the treatment begins at the initially selected treatment flow rate (e.g., 300 ml / min). The dialysis system monitors dialysate consumption in real time, and in step 2010 of flowchart 2000, the dialysis system calculates and determines whether the remaining amount of dialysate (or dialysate concentrate) is sufficient to complete the planned treatment. Step 2010 is performed continuously throughout the treatment, and is performed and repeated at scheduled intervals (e.g., every 30 seconds, every 1 minute, every 5 minutes, etc.) throughout the treatment.

[0111] In step 2010, if there is enough dialysate remaining to complete the treatment, then in step 2012, the dialysis system completes the treatment at the original dialysate flow rate (e.g., 300 ml / min). However, if there is not enough dialysate to complete the treatment, then in step 2014 of flowchart 2000, the dialysate flow rate is reduced to a flow rate that allows the treatment to be completed with the available amount of dialysate (e.g., 100 ml / min). The dialysis system is configured to maintain the pressure within the dialysis system when the flow rate is reduced. The treatment continues at the flow rates of steps 2006, 2012, or 2014 until the completion of the treatment in step 2016.

[0112] The smart flow calculation in the dialysis system determines the amount of dialysate remaining in the concentrate bottle by comparing it to the amount of dialysate consumed in a single dialysate treatment. Since the dialysis system operates from a fixed volume of dialysate concentrate, it calculates the amount of concentrate consumed in real time and adjusts the dialysate flow rate accordingly to conserve concentrate fluid. The calculation of used and remaining dialysate is determined as follows:

[0113] The total amount of dialysis fluid required for treatment is calculated by multiplying the sum of the concentrate and water flow rate by the total treatment time.

[0114] Total dialysate required = (acid flow rate + bicarbonate flow rate + water flow rate) × total treatment time (Equation 1)

[0115] Typically, bicarbonate concentrates are a limiting factor due to their higher consumption compared to acid concentrates. Thus, the total dialysate available for any given treatment depends on the bicarbonate content and flow rate.

[0116] The amount of time available for use with bicarbonate = Total volume of bicarbonate / Bicarbonate flow rate (Equation 2)

[0117] Available dialysate = dialysate flow rate × bicarbonate = amount of time available (Equation 3)

[0118] The amount of dialysis fluid consumed during treatment is calculated in real time.

[0119] Dialysis fluid used = Dialysis fluid flow rate × Treatment duration (Equation 4)

[0120] From this point, the dialysis system calculates the dialysate flow rate required to completely use up the concentrate, and thus completes the treatment without user intervention.

[0121] Remaining treatment time = Total treatment time - Elapsed treatment time (Equation 5)

[0122] Required dialysate flow rate = (Available dialysate - Used dialysate) / Remaining treatment time (Equation 6)

[0123] The amount of dialysate required to complete the treatment (Equation 6) decreases from the initial flow rate during the course of treatment. If the calculated required dialysate flow rate falls to a predetermined setpoint, the system immediately adjusts the flow rate to a lower dialysate flow rate appropriate for completing the treatment.

[0124] In one embodiment, the concentrate pump operates at high speed to push out air bubbles from the pump mechanism (e.g., operating at over 30 ml / min compared to ~7 ml / min during normal operation). As soon as the dialysate is mixed, the dialysate pump 226 controls the flow of dialysate through the dialysate supply system. The mixing subsystem 162 includes various pressure sensors 182, a temperature sensor 184, and a conductivity sensor 196 for monitoring the fluid during dialysate preparation. The conductivity sensor is used to measure the fluid ionic properties to verify that the composition is correct.

[0125] The flow paths within the dialysate supply system include one or more bypasses or circulation paths that allow the circulation of the cleaning and / or sterilizing fluid through the flow paths. The circulation path is an open-flow loop, and the fluid flowing through the circulation path can be discarded from the system after use. In another embodiment, the circulation path is a closed-flow loop, and the fluid flowing through the circulation path cannot be discarded from the system.

[0126] A method for providing dialysis treatment to a patient is provided, comprising the steps of: creating a desired dialysis fluid by combining a dialysis fluid concentrate and water in a dialysis fluid system; providing a first flow of dialysis fluid through the dialysis system at a first dialysis fluid flow rate; monitoring the consumption of the dialysis fluid concentrate by the dialysis system; determining whether there is enough dialysis fluid concentrate remaining to complete the dialysis treatment at the first dialysis fluid flow rate; if there is not enough dialysis fluid concentrate remaining to complete the dialysis treatment at the first dialysis fluid flow rate, calculating a second dialysis fluid flow rate that will allow the dialysis treatment to be completed; and providing a second flow of dialysis fluid through the dialysis system at a second dialysis fluid flow rate.

[0127] In some embodiments, the dialysis system houses a finite supply unit for dialysate concentrate. In another embodiment, the second dialysate flow rate is less than or equal to the first dialysate flow rate. In one embodiment, the first dialysis flow rate is approximately 300 ml / min, and the second dialysis flow rate is approximately 100 ml / min.

[0128] In one embodiment, the determining step further comprises determining whether sufficient dialysate concentrate remains based on a first dialysate flow rate, the amount of remaining dialysate concentrate, and the total treatment time. In one embodiment, the method of the present invention further comprises maintaining pressure within the dialysis system when a second flow of dialysate is provided.

[0129] Figure 16 depicts the ultrafiltration subsystem 164 of the dialysis supply system that receives dialysate prepared from the mixing subsystem. The ultrafiltration subsystem is configured to receive dialysate prepared from the mixing subsystem 162. Dialysate pumps 226 and spent dialysate pumps 227 operate to control the flow of dialysate through the ultrafiltration subsystem. Pumps 226 and 227 control the flow of dialysate so that it passes through the ultrafilter 228 and dialysate heater 230 before entering the dialysis machine 126. A temperature sensor 184 measures the temperature of the dialysate before and after passing through the dialysate heater 230. The dialysate heater is user-configurable to heat the dialysate to between 35-39°C, based on user preference. After passing through the dialysis machine, spent dialysate flows through the spent dialysate pump 230 and returns through the dialysate heater 228 before returning to the drain. In one embodiment, a degassing pump, as shown in Figure 14, is used to wet the back of the spent dialysate pump 227. The ultrafiltration subsystem includes one or more actuators or valves 177 controlled to allow dialysate to pass through the dialysis machine 126, or conversely, to prevent dialysate from passing through the dialysis machine in “bypass mode”. A pressure sensor 182c, positioned between the dialysate pump 226 and the used dialysate pump 227, is configured to measure the pressure of the dialysate between the pumps when preventing dialysate from passing through the dialysis machine in “bypass mode”.

[0130] Figure 17 illustrates a blood circuit subsystem 166 configured to draw blood from the patient during dialysis treatment, create blood flow through the dialysis machine, and pass the fluid from the blood side of the dialysis machine to the dialysate side of the dialysis machine or vice versa. As described above, the blood circuit subsystem 166 includes, among other mechanisms described herein, a tubing set 122, a blood pump 213, pinch valves 180a-d, an intravenous infusion chamber 361, a venous fluid level sensor 181, an arterial line 230, an intravenous line 232, a saline source 240, and an infusion pump 242. The blood pump 213 is controlled to operate in first and second modes of operation. During dialysis treatment, the blood pump 213 operates in a first mode of operation in which the pump draws blood from the patient through the arterial line 230, flows through the tubing set in the direction of arrow 244, flows through the dialysis machine 126, flows through the intravenous infusion chamber 361, and returns to the patient through the intravenous line 232. The blood pump also operates in a second operating mode, with the pump direction reversed and the fluid in the line flowing in the direction of arrow 246 (for example, during the priming sequence as described above).

[0131] The blood circuit subsystem also includes a vent circuit 248 configured to automatically control the fluid level in the venous fluid chamber 361 as described above. The vent circuit includes a bidirectional peristaltic pump 250. The system's venous pressure sensor 182a is also located in the vent circuit 248. During dialysis treatment, the venous fluid sensor 181 monitors the fluid level of blood in the venous infusion chamber 361. The electronic controller receives fluid level information from the sensor and automatically maintains the fluid level of blood in the venous infusion chamber by pumping or venting air from the venous infusion chamber with the bidirectional peristaltic pump 250 and / or vent valve 252 if the sensor detects a fluid level rising above a lower threshold, and by pumping air into the venous infusion chamber with the bidirectional peristaltic pump 250 if the sensor detects a fluid level rising above an upper threshold.

[0132] Referring further to Figure 17, the method for returning blood from the tube set to the patient after dialysis treatment is described. First, the user grasps the arterial needle wire (not shown) at the point where the arterial line 230 enters the body. This clamp is positioned between the saline connection 353b and the user's body. The user then ensures that ACLMP, another clamp for the distal arterial line, is open at the saline connection 353b. Next, the electronic controller of the dialysis system opens pinch valves 180b and 180c and closes pinch valve 180a. The electronic controller then guides the blood pump 213 to operate in the "forward" direction to pump saline from the saline source (e.g., saline bag) to the arterial line 230 at the saline connection 353b through pinch valve 180b, which is very close to where the arterial line connects to the patient. The blood pump operates for a specified time, or a predetermined volume of saline solution (e.g., 300-600 ml) is pumped into the tubing set, and the blood from the tubing set and the dialysis machine is returned to the patient through the venous line 232. In some embodiments, the blood return process is stopped based on the color of the tubing set (i.e., the blood pump is stopped when the saline solution becomes clear or pale pink).

[0133] The dialysate pump and used dialysate pump described above are part of an electronic circuit that communicates with the electronic controller of the dialysis system to achieve a controlled ultrafiltration rate, and are also tuned to precisely control the addition of fluid to the patient or the removal of fluid from the patient.

[0134] The dialysate pumps and spent dialysate pumps are controlled with high precision to achieve dynamic equilibrium, periodic equilibrium, and continuous correction. Referring to Figure 16-17, dialysate pump 226 and spent dialysate pump 227 are configured to pump dialysate through the dialysate supply system. The dialysate pumps are controlled to push the dialysate through an ultrafilter and a dialysate heater for heating.

[0135] To calibrate the system flow, the system is controlled to enter a bypass mode in which valve 177 is activated to prevent dialysate from flowing through the dialysis machine. This isolates the patient's tubing set on the blood side of the dialysis machine from the dialysate flow, creating a closed system of dialysate flow that cannot be ultrafiltered. Whenever the system is in bypass mode, the spent dialysate pump is automatically controlled to maintain a constant pressure measured by pressure sensor 182c, which is located between dialysate pump 226 and spent dialysate pump 227. The spent dialysate pumping rate is adjusted, while the dialysate pumping rate is maintained at a constant rate until the pressure measured by pressure sensor 182c stabilizes. As soon as the pressure stabilizes, the spent dialysate pumping rate versus the dialysate pumping rate is recorded as the pumping rate ratio at which ultrafiltration is zero. When the system exits bypass mode and returns to the dialysis machine, the spent dialysate pumping rate is adjusted based on the desired ultrafiltration rate.

[0136] When the dialysis machine is bypassed, the pressure measurement of the dialysate is independent of or affected by the blood side of the dialysis machine. When the dialysate and spent dialysate pumps operate at the same speed, there is no pressure change at the pressure sensor 182c located between the two pumps, and there is no flow imbalance between the pumps. However, if the dialysate and spent dialysate pumps operate at different speeds, then a flow imbalance is created between the pumps, and the pressure change representing this flow imbalance is measured at the pressure sensor 182c. In some embodiments, the flow imbalance is controlled based on the pump stroke of each pump. In other embodiments, the flow imbalance is controlled based on a lookup table that determines the optimal pumping speed based on the measured venous pressure. The system's electronic controller is configured to automatically control the fluid flow across the dialysis machine (i.e., ultrafiltration) by adjusting the pumping speed of the spent dialysate pump 227 relative to the dialysate pump 226 (or conversely, the dialysate pump 226 relative to the spent dialysate pump 227), thereby creating a flow imbalance between the dialysate side and the blood side of the dialysis machine. When a flow imbalance is created on the dialysate side of the dialyzer by operating pumps 226 and 227 at different speeds, the fluid then flows across the dialyzer membrane from the blood side to the dialysate side or vice versa, equalizing the flow imbalance.

[0137] The pumping speeds of the dialysate pump 226 and the spent dialysate pump 227 are fixed by the system based on the desired ultrafiltration rate, and the valve 180 is open in normal operation during dialysis treatment. During treatment, the system continuously monitors the user's venous pressure at the pressure sensor 182a. If the venous pressure changes (e.g., the change is greater than 30 mmHg), the system automatically re-equalizes the pumps using the same technique described above. This allows the pumps to achieve equilibrium and the desired amount of fluid movement through the dialyzer, or conversely, to achieve no fluid movement through the dialyzer. In one particular embodiment, the system detects a change in the user's venous pressure and automatically adjusts the speed of the spent dialysate pump 227 based on a lookup table of speed against venous pressure to maintain the user's ultrafiltration equilibrium. As soon as the system is calibrated, the spent dialysate pumping speed is adjusted to control the rate of fluid removed from the patient. In some embodiments, the pumping rate of the used dialysate pump is instead increased or decreased relative to the dialysate pump to enable hemodialysis filtration (e.g., pushing / pulling the fluid to the patient).

[0138] In some embodiments, there are two stages of operation for the dialysate pump and the spent dialysate pump. In the first stage of operation, the speed of the spent dialysate pump is faster than the speed of the dialysate pump, resulting in a net fluid flow from the blood side of the dialyzer and the dialysate side of the dialyzer. The speed difference is set so that the fluid is removed from the patient's blood at a physiologically tolerable speed for a short period, perhaps a maximum speed of 100 mL / min. To achieve this, for example, the dialysate pump is set to operate at 300 mL / min and the spent dialysate pump is set to operate at 400 mL / min. In this stage, convective removal of solute increases. However, because the volume of fluid circulating through the patient is limited, applying this first stage of operation indefinitely is unsustainable because it would cause hemoconcentration of the blood in the dialyzer. In the second stage of operation, the speed of the dialysate pump is faster than the speed of the spent dialysate pump, resulting in a net fluid flow from the dialysate side of the dialyzer to the blood side of the dialyzer. In the second stage, at least a portion of the fluid removed from the patient's circulation during the first stage is replaced, and the first stage can be repeated. Convective removal of solutes is reduced during the second stage, although further diffusive removal occurs. Current systems used in hemodiafiltration typically inject replacement fluids directly into the patient's extracorporeal circuit, which usually requires very high standards of microbiological purity. These replacement fluids are typically manufactured and supplied in large bags, which are difficult to handle and add considerable cost. In the disclosed invention, the replacement fluids are produced online and further filtered by the dialysis machine before contact with the patient's blood, thereby preventing the need for pre-manufactured fluids and direct connection to the patient's extracorporeal circuit. In some embodiments, the duration and / or net fluid flow of the first stage and the second stage are equal. In some embodiments, the duration and / or net fluid flow of the first and second stages are not equal. In further embodiments, the net fluid flows produced by the two stages are summed to equal the total fluid removal target during treatment. In further embodiments, the present invention comprises a plurality of any number of operating stages having various periods and / or net fluid flows, or a continuum thereof.

[0139] Pump powered on

[0140] The dialysis systems described herein include multiple pumps, including pumps that directly interact with a fluid, such as dialysate, saline solution, or blood supplied to a patient. Impeller pumps include internal graphite components, while gear pumps typically include PEEK material that falls off during pump operation. These particles enter components of the dialysis system, such as filters or regulators, leading to premature failure. By design, impeller pumps and gear pumps operate under a positive alignment principle, where the internal pump components polish against each other to move the fluid. Thus, surface defects in the internal pump components continue to fall off during use. Under high temperature and / or pressure conditions, the stress on the internal pump components increases, thereby increasing the amount of falloff observed. This disclosure provides impeller and gear pump energizing processes designed to reduce particulate falloff during dialysis system operation.

[0141] The intent of the energizing process is to remove any detached particles present in the pump by operating it at high temperature and / or high pressure for the first few hours of its lifespan. For example, the process includes a step of operating the pump at a higher temperature and / or pressure than the pump would encounter during normal operation. When operating the pump under extreme conditions, surface defects in the internal pump are polished, thus creating even flatter surfaces between the parts. As the surface contact between the internal blades and gears becomes smoother, less particle detachment occurs, thereby preventing premature failure of other parts of the system. In one embodiment, operating these pumps at 70°C and 100 psi for 8 hours maximizes the amount of initial detachment, thus leading to reduced detachment during normal operating mode (25°C and 100 psi).

[0142] Figure 21 shows a fluid circuit diagram of a pump energizing fixture. Pump energizing fixtures are used to energize impeller and / or gear pumps and remove loose particles before the pumps are installed in a dialysis system. Several impeller and gear pumps operate in parallel with the pump energizing fixture. In one embodiment, the fixture includes a computer that runs a built-in program to control the pumps. In another embodiment, the energizing fixture is controlled by a voltage-controlled voltage divider. The pump energizing fixture forms a closed-loop flow path with one or more pumps under test when the pumps are connected to the pump energizing fixture. In some embodiments, the pump energizing fixture includes one or more heating elements configured to heat the fluid within the pump energizing fixture to a temperature higher than the temperature to which the pumps are normally exposed during operation. For example, the heating elements are configured to heat the fluid within the pump energizing fixture to temperatures including up to 100°C. In one embodiment, a preferred temperature for the fluid within the pump energizing fixture is 70°C.

[0143] Figures 22 and 24 are diagrams of the pump-powered fixture from Figure 21, including a closed-loop flow path between the pump and the fixture. Figure 22 also depicts a computer or electronic controller (e.g., a laptop) that controls the software that controls the operation of the pump-powered fixture.

[0144] Figures 23 and 25 show additional electronics that drive the energized fixture, including a power supply unit that switches between 24VDC and 48VDC and provides power to a microcontroller and motor drive unit to operate the pump.

[0145] A method for improving the durability and operation of one or more positive displacement pumps comprises the steps of: connecting one or more positive displacement pumps to a pump energizing fixture to form a closed-loop flow path between one or more positive displacement pumps and the pump energizing fixture; increasing the temperature and pressure of the fluid in the closed-loop flow path; and operating one or more positive displacement pumps to allow fluid to flow through the closed-loop flow path for a predetermined period of time to reduce surface defects inside one or more positive displacement pumps.

[0146] In some embodiments, the increasing step further comprises increasing the fluid temperature and pressure to levels higher than those encountered by one or more positive displacement pumps during normal operation. For example, this includes increasing the fluid temperature above 25°C. In another embodiment, the method of the present invention comprises increasing the fluid pressure above 100 psi.

[0147] As described above, both the water purification system and the dialysis supply system include various pumps, valves, sensors, air separators, air sensors, heat exchangers, and other safety mechanisms. All of these features are electronically and automatically controlled by the dialysis system's electronic controller.

[0148] Automatic conductivity calibration

[0149] The dialysis systems described herein include multiple conductivity sensors to monitor the quality of incoming water, the efficiency of the water purification system, and ensure the correct proportion of dialysate fluid produced. Like many sensors, these sensors require periodic recalibration to ensure accuracy. Typically, each conductivity sensor is calibrated separately, the fluid connection to the rest of the system on either side of the sensor is broken, and then it is reconnected to a conductivity calibration fluid source and a calibrated external conductivity meter. This conductivity calibration fluid, having a known conductivity, is passed through the sensor and further validated by an external conductivity meter, which verifies that the sensor is properly calibrated under test or, if it is out of calibration, its calibration constant can be adjusted. The type of calibration fluid used differs for each sensor, as the conductivity range intended to be read differs from that of other conductivity sensors in the system. A method for performing automatic calibration of all conductivity sensors in a system without the need to break the flow path is disclosed herein. In some embodiments, the automatic conductivity calibration method comprises the step of connecting a calibration fluid concentrate to an acid or bicarbonate pump. Optionally, an external conductivity meter is connected to the system's fluid circuit using inlet and outlet connectors, for example, those used to connect to a dialysis machine. Using a distribution pump, the system mixes a calibration fluid concentrate with purified water produced by a water purification module to create a calibration fluid of a typically known conductivity. In this state, the system's flow path is a single-pass flow, and the mixed fluid is sent for discharge. As soon as the conductivity of the mixed calibration fluid stabilizes, the distribution pump is stopped, and the system's flow path is reconfigured to recirculate the fluid instead of sending it for discharge. The system's recirculation path is configured to include all conductivity sensors in the system, including all optional external conductivity meters exposed to the same recirculating fluid. Subsequently, any or all measurements of the conductivity sensors are compared with other sensors, including any external conductivity sensors, and calibration constants are adjusted as necessary. In some embodiments, this process is automatically repeated multiple times with different mixing ratios of the calibration fluid to produce final mixed fluids of different conductivity. In this way, multiple calibration curves are generated.Furthermore, conductivity sensors in different parts of the flow path typically sense fluids within different conductivity ranges. Calibration fluids are assigned to target the different typical operating ranges of the different conductivity sensors. The calibration of each conductivity sensor is then performed exclusively and with greater emphasis on the calibration fluid that represents its original operating range.

Claims

1. A method for priming a dialysis system tube set and a dialysis machine, The steps include connecting the arterial line of the tube set to the venous line of the tube set to form a continuous loop of the tube set, The steps include: using an air pump to draw air from the tube set, The steps include: pulling the fluid flow from the fluid source to the tube set with the air pump, The steps include operating the blood pump of the dialysis system in forward operation mode to flow the fluid from the fluid source to the tube set in a first direction, A method comprising the steps of operating the blood pump in a backward operating mode to cause the fluid to flow through the tube set in a second direction opposite to the first direction.

2. The method according to claim 1, wherein the pulling step further comprises pulling the fluid into the tube set with the air pump until the fluid is detected by a first fluid level sensor of the intravenous drip chamber.

3. The method according to claim 2, wherein the step of operating the blood pump in the forward operating mode further comprises the step of operating the blood pump in the forward operating mode until the fluid is detected by a second fluid level sensor of the intravenous drip chamber, thereby allowing the fluid to flow from the fluid source to the tube set.

4. The method according to claim 2, further comprising the step after the pulling step, allowing the liquid level in the intravenous drip chamber to fall below the first liquid level sensor.

5. The method according to claim 4, wherein the step of operating the blood pump in forward operating mode further comprises operating the blood pump in forward operating mode until the fluid is detected by the first fluid level sensor of the intravenous drip chamber, thereby allowing the fluid to flow from the fluid source to the tube set.

6. The method according to claim 1, further comprising the step of drawing air from the tube set with an air pump during the operation step.

7. A fluid source and A patient tube set fluidly coupled to the fluid source, wherein the patient tube set includes an intravenous infusion chamber, An air pump connected to the intravenous infusion chamber, wherein the air pump is configured to pump air entering or leaving the intravenous infusion chamber, A blood pump connected to the patient tubing set, wherein the blood pump is configured to allow fluid to flow through the patient tubing set, A sensor connected to the intravenous infusion chamber and configured to monitor the fluid level in the intravenous infusion chamber, A dialysis system comprising: an electronic controller communicating with at least one of the sensors, the blood pump, and the air pump, wherein the electronic controller is configured to control the air pump to draw air from the tube set, to control the air pump to draw fluid flow from the fluid source to the patient tube set, to control the blood pump in the forward direction to allow the fluid to flow from the fluid source to the tube set, and to control the blood pump in the backward direction to allow the fluid to flow through the tube set.

8. A method for testing for leakage in a dialysis system tube set, The steps include pressurizing the first portion of the tube set, The steps include measuring the reference pressure of the tube set of the first part, The steps include: exposing the second portion of the tube set to the pressurized first portion; A step of measuring the pressure of the second portion of the tube set, A method comprising the step of comparing the measured pressure of the second part with the reference pressure of the tube set to confirm leakage of the second part.

9. The method according to claim 8, wherein the step of exposing the second portion further comprises the step of opening one or more pinch valves of the tube set.

10. The method according to claim 8, further comprising the step of monitoring the pressure of the second portion for a pressure decay rate that exceeds a pressure decay threshold and confirming leakage of the second portion.

11. A method for priming a tubing set in a dialysis system, The steps include removing the tube set from the sterile transport container, The steps include attaching the tube set to the dialysis system, The steps include priming the tube set with the fluid flow from the dialysis system to remove air from the tube set, A method comprising the step of discharging fluid from the tube set into the transport container.

12. The method according to claim 11, further comprising the step of attaching the transport container to the dialysis system.

13. The method according to claim 12, wherein the step of attaching the transport container further comprises the step of engaging the attachment mechanism of the transport container with the corresponding mechanical mechanism of the dialysis system.

14. The method according to claim 13, wherein the mechanical mechanism of the dialysis system is angled relative to one of the surfaces of the transport container to enlarge the opening of the transport container by imposing a bend on one or more surfaces of the transport container.

15. The method according to claim 11, further comprising the step of discharging fluid from the tube set to the transport container through a connecting fitting that connects the arterial line of the tube set to the venous line of the tube set.

16. A method for improving the durability and operation of one or more positive displacement pumps, The steps include connecting one or more positive displacement pumps to a pump power supply fixture to form a closed-loop flow path between the one or more positive displacement pumps and the pump power supply fixture, The steps include increasing the temperature and pressure of the fluid in the closed-loop channel, A method comprising the steps of operating one or more positive displacement pumps to allow fluid to flow through the closed-loop passage for a predetermined period of time, thereby reducing internal surface defects in one or more positive displacement pumps.

17. The method according to claim 16, wherein the increasing step further comprises increasing the temperature and pressure of the fluid to a level higher than the level encountered by one or more positive displacement pumps during normal operation.

18. The method according to claim 16, further comprising the step of increasing the temperature above 25°C.

19. The method according to claim 16, further comprising the step of increasing the fluid pressure beyond 100 psi.

20. The casing and A fluid source and One or more connection ports inside or on the enclosure, The fluid source, one or more positive displacement pumps, and one or more positive displacement pumps coupled to one or more of the connection ports to form a closed-loop flow path between the one or more connection ports, A heating element configured to heat the fluid in the closed-loop flow path to a temperature exceeding the normal operating temperature of one or more positive displacement pumps, A pump energizing fixture comprising: an electronic controller configured to control the operation of one or more positive displacement pumps with a high-temperature fluid for a predetermined time to reduce internal surface defects in one or more positive displacement pumps.

21. A method of providing dialysis treatment to a patient, The dialysate system involves the steps of creating dialysate in real time by combining dialysate concentrate and water, A step of providing a first flow of dialysate through the dialysis system at a first dialysate flow rate, A step of monitoring the consumption of the dialysate concentrate by the dialysis system, A step of determining whether there is enough dialysate concentrate remaining to complete the dialysis treatment with the first dialysate flow rate, If there is not enough dialysate concentrate to complete the dialysis treatment at the first dialysate flow rate, A method comprising the step of providing a second flow of dialysate through the dialysis system at a second dialysate flow rate that can complete the aforementioned dialysis treatment.

22. The method according to claim 21, further comprising the step of calculating the second dialysate flow rate that can complete the dialysis treatment, prior to the step of providing the second flow.

23. The method according to claim 21, wherein the dialysis system houses a finite supply unit for dialysate concentrate.

24. The method according to claim 21, wherein the second dialysate flow rate is lower than the first dialysate flow rate.

25. The method according to claim 21, wherein the first dialysis flow rate is approximately 300 ml / min.

26. The method according to claim 24, wherein the second dialysis flow rate is approximately 100 ml / min.

27. The method according to claim 21, wherein the determining step further comprises determining whether sufficient dialysate concentrate remains based on the first dialysate flow rate, the amount of remaining dialysate concentrate, and the total processing time.

28. The method according to claim 21, further comprising the step of maintaining pressure within the dialysis system when the second flow of dialysate is provided.

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