Hemodialysis system incorporating dialysate generator

Abstract

To provide a hemodialysis system incorporating a dialysate generator.SOLUTION: A portable hemodialysis system is provided that includes a dialyzer, a closed loop blood flow path which transports blood from a patient to the dialyzer and back to the patient, and a closed loop dialysate flow path which transports dialysate through the dialyzer. The hemodialysis system includes a hemodialysis machine and a dialysate generator which are physically connectable to and disconnectable from one another. To connect the hemodialysis machine and the dialysate generator together, both the hemodialysis machine and the dialysate generator possess connectable and disconnectable electrical connectors and fluid connectors which are positioned and constructed to allow both a fluid and electrical connection between the two machines. The hemodialysis machine includes a processor and a user interface preferably in the form of a touchscreen that is capable of controlling both the functions of the hemodialysis machine and the dialysate generator.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an artificial kidney system for use in providing dialysis. More particularly, the present invention is directed to a hemodialysis system incorporating a machine for generating dialysate.

[0002] Applicants hereby incorporate by reference all patents and published patent applications cited or referred to in this application. [Background technology]

[0003] Hemodialysis is a medical procedure used to achieve extracorporeal removal of waste products, including creatine, urea, and free water, from a patient's blood, involving diffusion of solutes across a semi-permeable membrane. Failure to adequately remove these waste products can lead to renal failure.

[0004] During hemodialysis, the patient's blood is removed through an arterial line, treated by a dialysis machine, and returned to the body through a venous line. The dialysis machine includes a dialyzer, which contains a number of hollow fibers that form a semi-permeable membrane through which the blood is transported. In addition, the dialysis machine utilizes a dialysate liquid that contains the appropriate amount of electrolytes and other vital components (such as glucose) and is pumped through the dialyzer.

[0005] Dialysis solutions, commonly referred to as dialysis fluids, are aqueous electrolyte solutions similar to those found in extracellular fluids, except for the buffers bicarbonate and potassium. Dialysis solutions are nearly isotonic, with an osmolality of approximately 300±20 milliosmoles per liter (mOsm / L). To ensure patient safety and prevent red blood cell destruction by hemolysis or acanthosis, the osmolality of the dialysate must be close to that of plasma, which is 280±20 mOsm / L. Dialysis solutions typically contain six electrolytes: sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), and bicarbonate. Dialysis solutions also contain a seventh component, the non-electrolyte glucose or dextrose. The dialysate concentration of glucose is typically 100-200 mg / dL.

[0006] Typically, dialysis fluid is prepared by mixing purified water with the appropriate proportions of acid and bicarbonate concentrates. Preferably, the acid and bicarbonate concentrates are separated until final mixing immediately prior to use in the dialyzer, since the calcium and magnesium in the acid concentrate will precipitate when in contact with the high bicarbonate levels in the bicarbonate concentrate. Purified water for use in making dialysis fluid should be relatively pure, such as by treating municipal drinking water through a water purification system to an acceptable level of purification.

[0007] Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water to reduce the concentration of particulate matter, including suspended particles, parasites, bacteria, algae, viruses, and fungi, and to reduce the concentration of a range of dissolved particulate matter. Water purification methods used include physical processes such as filtration, sedimentation, and distillation, biological processes such as slow sand filtration or biological activated carbon, chemical processes such as flocculation and chlorination, and the use of electromagnetic radiation such as ultraviolet light.

[0008] The dialysis process across the membrane is accomplished by a combination of diffusion and convection. Diffusion involves the migration of molecules by random motion from areas of high concentration to areas of low concentration, while convection typically involves the movement of solutes in response to differences in hydrostatic pressure. The fibers that form the semipermeable membrane separate the plasma from the dialysate, allowing waste products including urea, potassium, and phosphate to permeate into the dialysate while providing a larger surface area for diffusion to occur, preventing the transport of larger molecules such as blood cells, polypeptides, and certain proteins into the dialysate.

[0009] Typically, the dialysate flows in the extracorporeal circuit in a countercurrent direction to the blood flow. The countercurrent flow maintains a concentration gradient across the semi-permeable membrane to improve the efficiency of dialysis. In some cases, hemodialysis can provide fluid removal, also referred to as ultrafiltration. Ultrafiltration is generally accomplished by lowering the hydrostatic pressure in the dialysate compartment of the dialyzer, thus allowing water containing dissolved solutes, including electrolytes and other osmotic substances, to move from the plasma across the membrane to the dialysate. In more rare circumstances, the fluid in the dialysate flow path portion of the dialyzer is higher than the blood flow portion, causing fluid to move from the dialysis flow path to the blood flow path. This is generally referred to as reverse ultrafiltration. Because ultrafiltration and reverse ultrafiltration can increase risks to the patient, ultrafiltration and reverse ultrafiltration are typically performed while being supervised by highly trained medical personnel.

[0010] Unfortunately, hemodialysis suffers from a number of drawbacks. Among the drawbacks is that large quantities of clean dialysate must be available. Typically, this is done by preparing the dialysate on-site at a hospital or dialysis center that treats a large patient population. Unfortunately, hospital and in-center dialysis treatments require patients to leave their homes for treatments three times a week, with each treatment typically taking about 3-4 hours. Furthermore, patients must make appointments for these treatments, requiring their schedules to be set up long in advance, which impacts their standard of living. Moreover, hemodialysis treatments often leave patients plagued with nausea, cramps, dizziness, and headaches that they must then condition and endure to return home and recover.

[0011] To a lesser extent, patients perform hemodialysis at home, which reduces scheduling concerns and the burden of travel to and from clinics. However, home hemodialysis requires more frequent treatments, typically performed for two hours, six days a week. These treatments require large volumes of heavy dialysate to be shipped to the patient. Alternatively, the patient's home must be equipped with a water purification system and the patient must prepare the dialysate themselves. Unfortunately, the water purification systems suitable for preparing dialysate are expensive, often noisy, and occupy a significant amount of living space.

[0012] Home hemodialysis still suffers from additional drawbacks: The home dialysis systems are large, complex, intimidating, and difficult to operate. The equipment requires significant training. Home hemodialysis systems are currently too large and non-portable, thereby discouraging hemodialysis patients from traveling. Home hemodialysis systems are expensive and require a high initial financial investment, especially compared to in-center hemodialysis, where patients are not required to pay for the machines. The home hemodialysis systems do not adequately provide for reuse of consumables, making home hemodialysis less economically viable for medical supply providers. As a result of the drawbacks stated above, there are very few patients motivated to undergo the drudgery of home hemodialysis.

[0013] Thus, there is a significant need for a hemodialysis system that is portable, lightweight, easy to use, and patient friendly, thus allowing for in-clinic or in-home use.

[0014] It would also be desirable to provide a hemodialysis system that incorporates a water purification system.

[0015] Additionally, it would be desirable to provide a hemodialysis system that generates dialysate.

[0016] Aspects of the present invention fulfill these needs and provide further related advantages, as described in the following summary. Summary of the Invention [Means for solving the problem]

[0017] According to a first aspect of the present invention, a hemodialysis system includes a hemodialysis machine and a dialysate generator. The hemodialysis machine and the dialysate generator each include their own housing and are connectable and disconnectable from each other by electrical and fluid connectors. It is also desirable that the hemodialysis machine and the dialysate generator can be operated together and that the hemodialysis machine and the dialysate generator can operate and function independently of each other.

[0018] A hemodialysis machine includes an arterial blood line for connecting to a patient's artery to collect blood from the patient, a venous blood line for connecting to a patient's vein to return blood to the patient, and a disposable dialyzer. The arterial and venous blood lines may be of typical constructions known to those skilled in the art. For example, the arterial blood line may be conventional flexible hollow tubing connected to a needle to collect blood from the patient's artery. Similarly, the venous blood line may be conventional flexible tubing and needles to return blood to the patient's vein. Various constructions and surgical procedures may be employed to gain access to the patient's blood, including intravenous catheters, arteriovenous fistulas, or synthetic grafts.

[0019] Preferably, the disposable dialyzer has a construction and design known to those skilled in the art, including a blood flow path and a dialysate flow path. The term "flow path" is intended to refer to one or more fluid conduits, also referred to as passageways, for transporting fluids. The conduits may be constructed in any manner as may be determined by those skilled in the art, including flexible medical tubing or non-flexible hollow metal or plastic housings, etc. The blood flow path transports blood in a closed loop system by connecting to arterial and venous blood lines for transporting blood from the patient to the dialyzer and back to the patient. Meanwhile, the dialysate flow path transports dialysate in a closed loop system from a dialysate supply to the dialyzer and back to the dialysate supply.

[0020] Preferably, the hemodialysis system contains one or more reservoirs for storing dialysis solution. In one embodiment of the hemodialysis system, the one or more reservoirs are located in the hemodialysis machine. For this embodiment, the reservoir connects to the dialysate flow path of the hemodialysis machine and forms a closed loop system for conveying the dialysate from the reservoir to the dialyzer of the hemodialysis machine and back to the reservoir. More preferably, the hemodialysis machine holds two (or more) dialysate reservoirs, which may alternatively be placed in the dialysate flow path. When one reservoir holds contaminated dialysate, the dialysis treatment can continue using the other reservoir while the reservoir with the contaminated dialysate is emptied and refilled. The reservoirs may be of any size as required by the clinician to perform a proper hemodialysis treatment. However, it is preferred that the two reservoirs are identical in size and small enough to allow the dialysis machine to be easily portable. Acceptable reservoirs are between 0.5 liters and 5.0 liters in size. A preferred reservoir stores approximately 2.0 liters of dialysate.

[0021] The hemodialysis machine preferably has one or more heaters thermally coupled to the reservoir for heating the dialysate stored in the reservoir. In addition, the hemodialysis machine includes a temperature sensor for measuring the temperature of the dialysate in the reservoir. The hemodialysis machine preferably has a fluid level sensor for detecting the level of the fluid in the reservoir. The fluid level sensor may be any type of sensor for determining the amount of fluid in the reservoir. Acceptable level sensors include magnetic or mechanical float type sensors, conductivity sensors, ultrasonic sensors, optical interfaces, and gravimetric sensors such as scales or load cells for measuring the weight of the dialysate in the reservoir.

[0022] Preferably, the hemodialysis machine includes three primary pumps. Two of the pumps are a first and a second "dialysate" pump connected to the dialysate flow path to pump dialysate through the dialysate flow path from the reservoir to the dialyzer and back to the reservoir. Preferably, the first pump is positioned in the dialysate flow path "upwards" from the dialyzer (meaning "earlier in the flow path"), while the second pump is positioned in the dialysate flow path "downwards" from the dialyzer (meaning "later in the flow path"). Meanwhile, the third primary pump of the hemodialysis machine is connected to the blood flow path. This "blood" pump pumps blood from the patient through the arterial blood line, through the dialyzer, and through the venous blood line for return to the patient. It is preferred that the third pump is positioned in the blood flow path upwards from the dialyzer.

[0023] The hemodialysis machine may also contain one or more sorbent filters to remove toxins that permeate from the plasma through the semi-permeable membrane into the dialysate. Filter materials for use in the filter are well known to those skilled in the art. For example, suitable materials include resin beds, including zirconium-based resins. Acceptable materials are also described in U.S. Pat. No. 8,647,506 and U.S. Patent Publication No. 2014 / 0001112. Other acceptable filter materials can be developed and utilized by those skilled in the art without undue experimentation. Depending on the type of filter material, the filter housing may include a vapor membrane that is capable of releasing gases, such as ammonia.

[0024] Preferably, the hemodialysis machine includes two additional flow paths in the form of a "drain" flow path and a "fresh dialysate" flow path. The drain flow path includes one or more fluid drain lines for draining a reservoir of contaminated dialysate, and the fresh dialysate flow path includes one or more fluid fill lines for conveying fresh dialysate from a supply of fresh dialysate to the reservoir. One or more fluid pumps may be connected to the drain flow path and / or the fresh dialysate flow path for conveying the fluids to their intended destinations.

[0025] In addition, the hemodialysis machine includes a plurality of fluid valve assemblies for controlling the flow of blood through the blood flow path, the flow of dialysate through the dialysate flow path, and the flow of used dialysate through the filter flow path. The valve assemblies may be any type of electromechanical fluid valve construction, including, but not limited to, conventional electromechanical two-way and three-way fluid valves, as may be determined by those skilled in the art. A two-way valve is any type of valve with two ports, including an inlet port and an outlet port, and the valve simply allows or blocks the flow of fluid through a fluid path. Conversely, a three-way valve possesses three ports and functions to open the flow of fluid in one fluid path while blocking the flow of fluid in another path. In addition, the valve assembly of the dialysis machine may include a safety pinch valve, such as a pinch valve connected to the venous blood line, for selectively allowing or blocking the flow of blood through the venous blood line. A pinch valve is provided which reduces the cross-section of the venous blood line, thereby preventing the flow of blood back to the patient if an unsafe condition is detected.

[0026] Preferably, the hemodialysis machine contains sensors for monitoring hemodialysis. To achieve this goal, the dialysis machine preferably has at least one flow sensor connected to the dialysate flow path for detecting the fluid flow (volume and / or velocity) in the dialysate flow path. In addition, it is preferred that the dialysis machine contains one or more pressure sensors for detecting the pressure in the dialysate flow path, or at least an occlusion sensor for detecting whether the dialysate flow path is blocked. Preferably, the dialysis machine also has one or more sensors for measuring the pressure and / or fluid flow in the blood flow path. The pressure and flow rate sensors may be separate components, or pressure and flow rate measurements may be performed by a single sensor.

[0027] Additionally, it is preferred that the hemodialysis machine includes a blood leak detector ("BLD") that monitors the flow of dialysate through the dialysate flow path and detects whether blood is inappropriately diffusing through the dialyzer's semi-permeable membrane into the dialysate flow path. In a preferred embodiment, the hemodialysis machine includes a blood leak sensor assembly that incorporates a light source that emits light through the dialysate flow path and a light sensor that receives the light being emitted through the dialysate flow path. After passing through the dialysate flow path, the received light is then analyzed to determine whether the light has been altered to reflect possible blood in the dialysate.

[0028] The dialysis machine preferably includes additional sensors, including an ammonia sensor for detecting the levels of ammonia and pH in the dialysate, and a pH sensor. Preferably, the ammonia sensor and the pH sensor are in the dialysate flow path immediately downstream of the filter. In addition, the dialysis machine has an air bubble sensor connected to the arterial blood line and an air bubble sensor connected to the venous blood line to detect whether gaseous bubbles are forming in the blood flow path.

[0029] The hemodialysis machine possesses a processor that contains dedicated electronics for controlling the hemodialysis system. The hemodialysis machine's processor contains power management and control circuitry connected to the pump motors, valves, and dialysis machine sensors for controlling the proper operation of the hemodialysis machine. In addition, the hemodialysis machine includes a user interface connected to the processor for allowing a human to control the hemodialysis machine's software and hardware. The user interface may include any electromechanical device that allows a user to interact with the processor, such as a display screen, keyboard, and / or mouse. In a preferred embodiment, the user interface is a graphical user interface in the form of a touch screen. In addition, the hemodialysis machine may include simple electromechanical switches and / or mechanical valves, such as for turning the machine on / off or for manually disabling any of the fluid conduits.

[0030] In addition, the hemodialysis system includes a machine for generating dialysate, referred to herein as a dialysate generator. The dialysate generator may utilize any known method and / or device for purifying water, such as filtration, sedimentation, and distillation, or a combination thereof. In a preferred embodiment, the dialysate generator incorporates a combination of carbon filtration, ultraviolet sterilization, and reverse osmosis (RO) filtration. Additionally, the dialysate generator includes conduits that provide a fluid path that carries water from a water inlet through various filters, valves, heaters, mixers, pumps, ultraviolet sterilization units, sensors, and sources of reagents for production. Fresh dialysate is discharged from the dialysate generator outlet directly into one of the hemodialysis machine reservoirs.

[0031] In a preferred embodiment, water enters the dialysate generator through a water inlet. The water is then conveyed through the dialysate generator flow path, which includes an inlet flow path, a main filtration loop, and an outlet flow path. The dialysate generator inlet flow path, in turn, includes a pressure regulator, a one-way valve, a first carbon and sediment filter, a sample port, and a second carbon filter, referred to herein as a carbon polisher. The carbon filtered water is then directed through the main filtration loop, which includes an ultraviolet (UV) sterilizer, a water descaler, a temperature sensor, a pressure sensor, a conductivity sensor, a pump (preferably a membrane), and an additional pressure sensor, to the reverse osmosis membrane. The reverse osmosis membrane outputs a "clean water" and a "reject" effluent. The waste effluent from the reverse osmosis membrane is split by a bypass valve, with a portion of the waste effluent being discarded and another portion of the waste effluent being sent to a pair of parallel variable flow restrictor orifices that controllably restrict the water flow and create back pressure within the reverse osmosis membrane. The waste effluent can be directed back to the head of the main filtration loop through a check valve.

[0032] The purified water from the reverse osmosis membrane undergoes further processing and testing. To achieve this goal, the purified water is directed through a flow meter, a heater, a temperature sensor, and a conductivity sensor. If the tested water is determined to be acceptable for the purpose of producing dialysate, concentrated reagents are introduced into the purified water by a pair of pumps to produce the dialysate. The concentrated reagents may contain one or more of the following: a bicarbonate solution, an acid solution, a lactate solution, and a salt solution. An additional conductivity sensor is provided to verify whether the appropriate amount of reagent is introduced into the water.

[0033] Before the dialysate is delivered to the hemodialysis machine, where it passes through an additional ultraviolet sterilizer to kill any remaining bacteria, and through a sub-micron filter to remove any endotoxins that may remain from the dead bacteria. The sterilized dialysate is delivered to the hemodialysis machine through the fluid outlet of the dialysate generator. Preferably, the dialysate generator possesses multiple bypass flow paths and controllable valves for controlling various functions of the dialysate generator.

[0034] In another embodiment of the hemodialysis system, the one or more reservoirs are located in the dialysate generating machine, not in the hemodialysis machine. For this embodiment, the one or more reservoirs are in the flow path of the dialysate generating machine, forming a closed loop system for conveying dialysate from the one or more reservoirs to the hemodialysis machine of the hemodialysis machine and back to the reservoir. More preferably, the dialysate generator holds two (or more) dialysate reservoirs, which may alternatively be placed in the flow path of the dialysate generator. When one reservoir holds contaminated dialysate, the dialysis treatment can continue using the other reservoir while the reservoir with the contaminated dialysate is emptied and refilled. As in the embodiment where the reservoir is located in the hemodialysis machine, the reservoir may be any size as required by the clinician to perform a proper hemodialysis treatment. However, it is preferred that the two reservoirs are the same size and small enough to allow the dialysis machine to be easily portable. Acceptable reservoirs are between 0.5 liters and 5.0 liters in size. A preferred reservoir stores approximately 2.0 liters of dialysate.

[0035] The hemodialysis machine and the dialysate generator are stand-alone machines that can be connected or disconnected from each other. To achieve this goal, the hemodialysis machine preferably includes a housing for encapsulating and protecting the various components that provide hemodialysis treatment. In addition, the housing of the hemodialysis machine includes electrical and fluid connectors for connecting to the dialysate generator. Similarly, the dialysate generator includes a housing for encapsulating and protecting the various components that generate fresh dialysate. Also, like the hemodialysis machine, the housing of the dialysate generator includes electrical and fluid connectors for connecting to the hemodialysis machine. More specifically, in addition to the fluid connectors and fluid conduits that carry fresh dialysate to the hemodialysis machine and the fluid conduits and fluid connectors that receive used dialysate from the hemodialysis machine, the hemodialysis machine and the dialysate generator include electrically wired and engageable (and disengageable) electrical terminals that connect the processor of the hemodialysis machine to all of the electrical and electromechanical components of the dialysate generator. These include all of the dialysate generator's pumps, sensors, heaters, UV sterilizers, variable orifices, and valves to allow the hemodialysis machine's processor to control the operation of the dialysate generator. Advantageously, mechanically and electrically connecting the dialysate generator to the hemodialysis machine allows a user of the hemodialysis system to control the operation of both the hemodialysis machine and the dialysate generator using only the hemodialysis machine's user interface.

[0036] The hemodialysis machine housing and the dialysate generator housing can be constructed in a myriad of shapes and sizes to physically join together. However, in a preferred embodiment, the hemodialysis machine has a generally hexahedral shape and a size and shape like a moderately sized suitcase. Because it has a generally hexahedral shape, the hemodialysis machine housing has six sides, preferably including a generally parallel top side, a bottom side, a generally parallel left side, a generally parallel right side, a generally parallel front side, and a rear side. On the other hand, the preferred dialysate generator has a housing with a generally "L" shaped construction, including a horizontally extending base unit constructed to rest on a surface, and a vertically extending rear unit extending vertically from the rear of the base unit. Preferably, the processor and pump of the dialysate generator are located in the base unit, and the filters and concentrated reagents of the dialysate generator are located in the rear unit. It is also preferred that the carbon filter and reverse osmosis membrane are located in an elongated cylindrical container that is positioned vertically within the rear unit of the dialysate generator. Also, the rear side of the rear unit preferably has an openable rear panel that allows a person to access all of the disposable components (including the carbon filter, reverse osmosis membrane, and concentrated reagent container) so that they can be easily removed and replaced when depleted. The dialysate reservoir may be located either within the hemodialysis machine or within the housing of the dialysate generator.

[0037] Additionally, the hemodialysis machine housing and the dialysate generator housing are constructed so that the hemodialysis machine can be engaged and placed on the base unit of the dialysate generator with the rear side of the hemodialysis machine engaging with the rear unit of the dialysate generator to form a stable combination.

[0038] The hemodialysis system (including the hemodialyzer and dialysate generator) is portable, lightweight, easy to use, patient friendly, and suitable for in-home use.

[0039] Additionally, the present hemodialysis system provides an extraordinary amount of control and monitoring not previously provided by a hemodialysis system so as to provide improved patient safety.

[0040] Other features and advantages of the present invention will become apparent to those skilled in the art upon reading the detailed description that follows, and upon reference to the drawings. The present invention provides, for example, the following items. (Item 1) 1. A hemodialysis system comprising: A hemodialysis machine, comprising: A dialysis machine; a blood flow path for carrying blood through the dialyzer, the blood flow path including an arterial blood line connected to a patient's artery and a venous blood line connected to a patient's vein; a dialysate flow path isolated from the blood flow path and carrying dialysate through the dialyzer, the dialysate flow path including a dialysate flow path inlet for receiving fresh dialysate and a dialysate flow path outlet for discharging used dialysate; a blood pump for pumping blood through the blood flow path; a dialysis fluid pump for pumping the dialysis fluid through the dialysis fluid flow path; a primary processor connected to the first and second pumps; a user interface connected to the primary processor; an electrical terminal of the hemodialysis machine electrically connected to the primary processor; Including hemodialysis machines Equipped with The hemodialysis system further includes a dialysate generating machine, the dialysate generating machine comprising: a dialysate generator flow path, the dialysate generator flow path including a dialysate generator outlet connected to the dialysate flow path inlet and a dialysate generator inlet connected to the dialysate flow path outlet; a water source connected to the dialysate generator flow path; a water purification system connected to the dialysate generator flow path for purifying the water; a chemical reagent source connected to the dialysate generator flow path, the chemical reagent source forming a dialysate when mixed with the water; at least one chemical reagent pump, the at least one chemical reagent pump controlling the flow of the chemical reagent into the dialysate generator flow path and then mixing with the water to form dialysate; at least one dialysate generator pump that controls the flow of dialysate through the dialysate generator flow path to the dialysate flow path inlet; a dialysate generator electrical terminal electrically connected to the at least one chemical reagent pump and the at least one dialysate generator pump; Equipped with the hemodialysis machine is mechanically and electrically connectable to and disconnectable from the dialysate generating machine, the dialysate flow path inlet is connectable to and disconnectable from the dialysate generator outlet, the dialysate flow path outlet is connectable to and disconnectable from the dialysate generator inlet, and electrical terminals of the hemodialysis machine are electrically connectable to and disconnectable from electrical terminals of the dialysate generator; A hemodialysis system, wherein the hemodialysis machine user interface and primary processor controls the operation of both the hemodialysis machine and the dialysate generator, including the user interface and primary processor controlling the operation of the blood pump, the dialysate pump, the at least one chemical reagent pump, and the at least one dialysate generator pump. (Item 2) a hemodialysis machine housing, the dialysate pump, the blood pump, and the primary processor being located within the hemodialysis machine housing; The user interface is attached to the hemodialysis machine housing. Item 2. The hemodialysis system according to item 1. (Item 3) a hemodialysis machine housing, the dialysate pump, the blood pump, and the primary processor being located within the hemodialysis machine housing; a dialysate generator housing, wherein the water source, the water purification system, the chemical reagent source, the at least one chemical reagent pump, and the at least one dialysate generator pump are located within the dialysate generator housing; 2. The hemodialysis system of claim 1, further comprising: (Item 4) a hemodialysis machine housing, the dialysate pump, the blood pump, and the primary processor being located within the hemodialysis machine housing; a dialysate generator housing, wherein the water source, the water purification system, the chemical reagent source, the at least one chemical reagent pump, and the at least one dialysate generator pump are located within the dialysate generator housing; Further equipped with 2. The hemodialysis system of claim 1, wherein the electrical terminals of the hemodialysis machine are affixed to the exterior of the hemodialysis machine housing, the electrical terminals of the dialysate generator are affixed to the exterior of the dialysate generator housing, and the hemodialysis machine housing and the dialysate generator housing are constructed such that the hemodialysis machine housing can engage and mate with the dialysate generator housing with the electrical terminals of the dialysate machine mating with the electrical terminals of the dialysate generator. (Item 5) 4. The hemodialysis system of claim 3, wherein the user interface is affixed to the hemodialysis machine housing. (Item 6) The hemodialysis system according to item 1, wherein the hemodialysis machine further comprises a first reservoir having a volume of 0.5 liters to 5.0 liters, the first reservoir being within the dialysate flow path, receiving dialysate from the dialysate generator, and supplying dialysate to the dialyzer. (Item 7) The hemodialysis system according to item 3, wherein the hemodialysis machine further comprises a first reservoir having a volume of 0.5 liters to 5.0 liters located within the hemodialysis machine housing, the first reservoir being located within the dialysate flow path, receiving dialysate from the dialysate generator, and supplying dialysate to the dialyzer. (Item 8) 2. The hemodialysis system of claim 1, wherein the dialysate generator further comprises a first reservoir having a volume of 0.5 liters to 5.0 liters, the first reservoir being within the dialysate generator flow path and supplying dialysate to the dialysate flow path inlet. (Item 9) 4. The hemodialysis system of claim 3, wherein the dialysate generator further comprises a first reservoir located within the dialysate generator housing and having a volume between 0.5 liters and 5.0 liters, the first reservoir being within the dialysate generator flow path and supplying dialysate to the dialysate flow path inlet. [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is a flow chart illustrating a hemodialysis system, including a hemodialysis machine.

[0042] [Diagram 2] FIG. 2 is a flow chart illustrating the dialysate generator checking the water at its inlet, with the thicker dashed lines illustrating the water that is allowed to move within the flow path.

[0043] [Diagram 3] FIG. 3 is a flow chart illustrating a dialysate generator producing dialysate, with the thicker dashed lines illustrating water that may travel within the flow path.

[0044] [Figure 4] FIG. 4 is a flow chart illustrating a dialysate generator delivering dialysate to a hemodialysis machine, with the thicker dashed lines illustrating water that may travel within the flow path.

[0045] [Diagram 5] FIG. 5 is a flow chart illustrating a dialysate generator draining dialysate from a hemodialysis machine, with the thicker dashed lines illustrating water that may travel within the flow path.

[0046] [Figure 6] FIG. 6 is a flow chart illustrating a dialysate generator using fresh water to pump dialysate from the dialysate generator, with the thicker dashed lines illustrating the water that is allowed to move within the flow path.

[0047] [Figure 7] FIG. 7 is a flow chart illustrating a dialysate generator that sterilizes itself using hot water, with the thicker dashed lines illustrating the water that can travel within the flow path.

[0048] [Figure 8] FIG. 8 is a flow chart illustrating a dialysate generator sterilizing the waste fluid pathway from a hemodialysis machine, with the thicker dashed lines illustrating water that is allowed to travel within the flow path.

[0049] [Figure 9] FIG. 9 is a flow chart illustrating a dialysate generator sterilizing one of its drain passages, with the thicker dashed lines illustrating water that is allowed to travel within the flow path.

[0050] [Figure 10] FIG. 10 is a flow chart illustrating a dialysate generator sterilizing one of its drain passages, with the thicker dashed lines illustrating water that is allowed to travel within the flow path.

[0051] [Figure 11] FIG. 11 is a front perspective view of the hemodialysis system.

[0052] [Figure 12] FIG. 12 is an exploded front perspective view of the hemodialysis system.

[0053] [Figure 13] FIG. 13 is an exploded rear perspective view of the hemodialysis system.

[0054] [Figure 14] FIG. 14 is a rear perspective view of the hemodialysis system.

[0055] [Figure 15] FIG. 15 is a front elevation view of a hemodialysis system.

[0056] [Figure 16] FIG. 16 is a rear elevation view of the hemodialysis system.

[0057] [Figure 17] FIG. 17 is a side elevation view of a hemodialysis system.

[0058] [Figure 18] FIG. 18 is a top plan view of the hemodialysis system.

[0059] [Figure 19] FIG. 19 is a bottom plan view of the hemodialysis system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] Detailed Description of the Invention While the present invention is capable of embodiments in various forms, as illustrated in the drawings, presently preferred embodiments of the invention will be described hereinafter, with the understanding that the present disclosure is to be regarded as an exemplification of the invention, and that it is not intended to limit the invention to the specific embodiments illustrated.

[0061] As illustrated in Figures 1 and 11-19, the hemodialysis system includes a hemodialysis machine 100 and a dialysate generator 201 that are physically connectable to each other and disconnectable therefrom. With particular reference to Figures 12 and 13, to connect the hemodialysis machine 100 and the dialysate generator 201 together, the hemodialysis machine 100 has an electrical connector 108 and fluid connectors 109 and 110, and the dialysate generator 201 has an electrical connector 325 and fluid connectors 321 and 323. Separate electrical and fluid connectors are positioned and constructed to allow both fluid and electrical connections between the two machines. Advantageously, the electrical and fluid connectors are disconnectable to allow decoupling of the dialysate generator from the hemodialysis machine 100. (Hemodialysis machine)

[0062] 1, hemodialysis machine 100 includes a blood flow path 53 and a dialysate flow path 54. Blood flow path 53 includes an arterial blood line 1 for connecting to a patient's artery to collect blood from the patient, and a venous blood line 14 for connecting to a patient's vein to return blood to the patient. Arterial blood line 1 and venous blood line 14 may be of typical construction known to those skilled in the art.

[0063] The blood flow path 53 carries blood in a closed loop system by connecting to the arterial blood line 1 and from the venous blood line 14 to the patient for carrying blood from the patient through the dialyzer 8 and back to the patient. Preferably, the hemodialysis machine includes a supply of heparin 6 and a heparin pump connected to the blood flow path 1. The heparin pump delivers small amounts of heparin anticoagulant into the bloodstream to reduce the risk of blood clotting within the machine. The heparin pump can take the form of a linearly actuated syringe pump, or the heparin pump may be a bag connected to a small peristaltic or infusion pump.

[0064] The hemodialysis machine includes within the dialysate flow path 54 a dialyzer 8 of construction and design known to those skilled in the art. Preferably, the dialyzer 8 includes a number of hollow fibers forming a semi-permeable membrane. Suitable dialyzers can be obtained from Fresenius Medical Care, Baxter International, Inc., Nipro Medical Corporation, and other manufacturers of hollow fiber dialyzers. Both the blood flow path and the dialysate flow path proceed through the dialyzer 8, which possesses an inlet for receiving dialysate, an outlet for draining dialysate, an inlet for receiving blood from the patient, and an outlet for returning blood to the patient. Preferably, the dialysate flows in a counter-direction to the blood flowing through the dialyzer, with the dialysate flow path isolated from the blood flow path by a semi-permeable membrane (not shown). 1-6 and described in more detail below, the dialysate flow path 54 carries dialysate in a closed loop system in which the dialysate is pumped from a reservoir (17 or 20) to the dialyzer 8 and back to the reservoir (17 or 20). Both the blood flow path 53 and the dialysate flow path 54 pass through the dialyzer 8, but the flow paths are separated by the dialyzer's semi-permeable membrane. The reservoirs 17 and 20 may be located within the hemodialysis machine 100, or the reservoirs 17 and 20 may be located external to the hemodialysis machine, such as in a dialysate generator 201.

[0065] Preferably, the hemodialysis machine includes three primary pumps (5, 26, and 33) for pumping blood and dialysate. For the purposes of this specification, the term "pump" is meant to refer to both the pump actuator, which uses suction or pressure to move the fluid, and the pump motor, which moves the actuator mechanically. Suitable pump actuators may include impellers, pistons, diaphragms, lobes of a lobe pump, screws of a screw pump, rollers, or linearly movable fingers of a peristaltic pump, or any other mechanical construct for moving the fluid as can be determined by one skilled in the art. The motor of the pump, on the other hand, is an electromechanical device for moving the actuator. The motor may be connected to the pump actuator by a shaft or the like. In a preferred embodiment, the dialysate and / or blood flows through conventional flexible tubing, and the pump actuators each consist of a peristaltic pump mechanism including a rotor with several cams attached to the periphery of the rotor, each in the form of a "roller", "shoe", "wiper", or "lobe", which compress the flexible tubing. As the rotor turns, the portion of the tube that is under compression is reduced in cross section (i.e., "blocked") into a closed state, forcing fluid to be pumped through the tube. In addition, fluid flow is induced through the tube as the tube opens to its natural state after the passage of the cam.

[0066] A first and a second primary pump (26 and 33) are connected to the dialysate flow path to pump the dialysate from the reservoir (17 or 20) through the dialysate flow path to the dialysate 8 and back to the reservoir (17 or 20). The first pump 26 is connected to the dialysate flow path "upstream" (meaning "forward in the flow path") from the dialysate 8, while the second pump 33 is connected to the dialysate flow path "downstream" (meaning "backward in the flow path") from the dialysate 8. Meanwhile, the third primary pump 6 of the hemodialysis machine is connected to the blood flow path. The third pump 6, also referred to as the blood pump, pumps blood from the patient through the arterial blood line, through the dialysate 8, and through the venous blood line to return to the patient. It is preferred that the third pump 6 is connected to the blood flow path upstream from the dialyzer. The hemodialysis machine may contain more or less than three primary pumps. For example, the dialysate may be pumped through the dialysate 8 utilizing only a single pump. However, it is preferred that the hemodialysis machine contains two pumps, including a first pump 26 upstream from the dialyzer 8 and a second pump 33 downstream from the dialyzer 8 .

[0067] In one embodiment illustrated in FIG. 1, the hemodialysis machine 100 contains two or more reservoirs (17 and 20) for storing dialysis solution. Both reservoirs (17 and 20) may be connected simultaneously to the dialysate flow path 54 to form one large source of dialysate. However, this is not considered preferred. Instead, the hemodialysis system includes a valve assembly 21 that introduces either of the two reservoirs (17 or 20), but not both, into the dialysate flow path 54 and forms a closed-loop system for conveying dialysate from one of the two reservoirs to the dialyzer and back to the reservoir. After the dialysate in the first reservoir 17 has been used and is no longer sufficiently clean or does not possess the appropriate chemical properties, the valve 21 of the hemodialysis machine is controlled to remove the first reservoir 17 from the dialysate flow path and replace the second reservoir 20 with fresh dialysate in the dialysate flow path. Thus, when one reservoir holds contaminated dialysis fluid and the reservoir needs to be emptied and refilled with freshly generated dialysis fluid 75, dialysis treatment can continue using the other reservoir.

[0068] In this manner, the hemodialysis machine may switch between each reservoir 17 and 20 multiple times over the course of treatment. Additionally, the presence of two reservoirs, as opposed to one, allows for measurement of flow rates for pump calibration or ultrafiltration measurements while isolating the other reservoir while it is drained or filled. Although the reservoirs may be of any size as required by the clinician to perform a proper hemodialysis treatment, preferred reservoirs have a volume between 0.5 liters and 5.0 liters.

[0069] For the embodiment illustrated in Figures 1-9, the hemodialysis system includes a drain flow path 55 for disposing of waste dialysate from the reservoirs (17 and 20). In the embodiment illustrated in Figures 1-4, the drain flow path 55 is connected to both reservoirs (17 and 20). Waste dialysate may be drained through the drain flow path 5 through a gravity feed, or the hemodialysis system may include any type of pump, as may be selected by one of skill in the art, to pump the used dialysate to be discarded.

[0070] Still referring to FIG. 1, the hemodialysis machine preferably has a heater 23 thermally connected to the dialysate flow path or reservoir for heating the dialysate to a desired temperature. For example, in one embodiment illustrated in FIG. 1, a single heater 23 is thermally coupled to the dialysate flow path downstream of both reservoirs (17 and 20). However, the hemodialysis machine may include additional heaters, and the one or more heaters may be in different locations. For example, in an alternative embodiment, the hemodialysis system includes two heaters, with a single heater thermally coupled to each reservoir. The one or more heaters preferably include resistors that are electrically activated and produce heat upon passage of electrical current.

[0071] In addition, the hemodialysis machine 100 possesses various sensors for monitoring the hemodialysis, in particular the blood flow path 53 and the dialysate flow path 54. To achieve this goal, the hemodialysis machine 100 preferably has one or more flow sensors 25 connected to the dialysate flow path for monitoring the fluid flow (volume and / or velocity) in the dialysate flow path 54. In addition, it is preferred that the hemodialysis machine contains one or more pressure sensors or occlusion sensors (9 and 27) for detecting the pressure in the dialysate flow path. Preferably, the hemodialysis machine also possesses one or more sensors for measuring the pressure (4 and 7) and / or the fluid flow 11 in the blood flow path.

[0072] Preferably, the hemodialysis machine includes temperature sensors (22, 24, and 28) for measuring the temperature of the dialysate throughout the dialysate flow path. One of the temperature sensors, such as temperature sensor 24, may be a conductivity / temperature sensor. In addition, the hemodialysis system possesses level sensors for detecting the level of fluid in the reservoirs (17 and 20). Preferred level sensors may include either capacitive fluid level sensors, ultrasonic fluid level sensors, or load cells. In a preferred embodiment, the level of each reservoir is measured by a pair of redundant load cells 15, 16, 18, and 19. In addition, it is preferred that the hemodialysis machine includes a blood leak detector 31 that monitors the flow of dialysate through the dialysate flow path and detects whether blood is improperly diffusing into the dialysate flow path through the semi-permeable membrane of the dialyzer.

[0073] Preferably, the hemodialysis machine also contains a first pinch valve 2 connected to the arterial blood line 1 for selectively allowing or blocking the flow of blood through the venous blood line, and a second pinch valve 13 connected to the venous blood line 14 for selectively allowing or blocking the flow of blood through the venous blood line. The pinch valves are provided to reduce the cross-section of the arterial blood line 1 and the venous blood line 14 and prevent the flow of blood back to the patient if any of the sensors detect an unsafe condition. Still subject to additional safety features, the hemodialysis machine includes blood line air bubble sensors (3 and 12) to detect if an air bubble is traveling backwards through the arterial line (blood leak sensor 3) or the venous line (blood leak sensor 12). Additionally, the blood flow path 53 may include an air bubble trap 10 with a pocket of pressurized air inside a plastic housing. Air bubbles rise to the top of the air bubble trap while blood continues to flow to the lower outlet of the trap. This component reduces the risk of air bubbles progressing into the patient's blood.

[0074] Preferably, the level of fluid in the bubble trap is measured by one or more level sensors 78. Additionally, in a preferred embodiment, the hemodialysis machine 100 includes a device for increasing or decreasing the pressure in the bubble trap 10. As illustrated in FIG. 1, the preferred hemodialysis machine 100 includes an air release flow path, including a transducer protector 79, a pressure sensor 80, and a variable air release valve 81. The transducer protector 79 allows air to pass, but not fluid, and prevents blood from being released through the air release flow path. The variable air release valve 81 can be opened or closed. When closed, blood moving through the blood flow path 53 will increase the pressure in the blood flow path 53 and the bubble trap 10. This pressure can be controllably reduced (down to ambient pressure) by opening the air release valve 81 and releasing air through the air release flow path. By modulating the valve between a fully open condition and a fully closed condition, the hemodialysis machine can control and maintain the fluid pressure in the blood flow path 53.

[0075] To control the flow and direction of blood and dialysate through the hemodialysis system, the hemodialysis system includes various fluid valves for controlling the flow of fluids through the various flow paths of the hemodialysis system. The various valves include pinch valves and two-way valves, which must be opened or closed, and three-way valves, which redirect the dialysate through the desired flow path as intended. In addition to the valves identified above, the hemodialysis system includes a three-way valve 21, located at the outlet of the reservoir, which determines from which reservoir (17 or 20) the dialysate passes through the dialyzer 8. An additional three-way valve 42 determines the reservoir from which the used dialysate is delivered. Finally, two-way valves 51 and 52 (which may be pinch valves) are located at the inlet of the reservoirs and allow or block the supply of fresh dialysate to the reservoirs (17 and 20). Of course, alternative valves may be employed, as can be determined by one skilled in the art, and the present invention is not intended to be limited to the specific two-way or three-way valves identified.

[0076] Although not shown in the figures, the hemodialysis machine 100 includes a processor and a user interface. The processor contains dedicated electronics for controlling the hemodialysis system, including power management circuitry connected to the pump motors, sensors, valves, and heaters for controlling the proper operation of the hemodialysis machine. The processor monitors each of the various sensors and ensures that the hemodialysis treatment proceeds according to a pre-programmed procedure entered into the user interface by medical personnel. The processor may be a general purpose computer or microprocessor, including hardware and software, as may be determined by one skilled in the art, for monitoring the various sensors and providing automated or directed control of the heaters, pumps, and pinch valves. The processor may be located in the electronics of a circuit board or in an aggregate processor of multiple circuit boards.

[0077] Although not shown, the hemodialysis machine includes a power supply for providing power to the processor, user interface 111, pump motors, valves, and sensors. The processor is connected by conventional electrical circuitry to the dialysis machine sensors (including reservoir level sensors (15 and 18), blood leak sensor 31, pressure and flow rate sensors (4, 7, 9, 11, 25, and 27), temperature / conductivity sensors (22, 24, and 28), and blood line air bubble sensors (3 and 12)), pumps (5, 6, 26, 33, 40, 44, 47, and 49), and pinch valves (2 and 13).

[0078] In operation, the processor is electrically connected to the first, second, and third primary pumps (5, 26, and 33) for controlling the activation and rotational speed of the pump motors, which in turn controls the pump actuators, which in turn controls the pressure and fluid velocity of blood through the blood flow path and the pressure and fluid velocity of dialysate through the dialysate flow path. By independently controlling the operation of the dialysate pumps 26 and 33, the processor can maintain, increase, or decrease the pressure and / or fluid flow in the dialysate flow path in the dialyzer. Also, by independently controlling all three pumps, the processor can control the pressure difference across the semi-permeable membrane of the dialyzer to maintain a predetermined pressure difference (zero, positive, or negative) or to maintain a predetermined pressure range. For example, most hemodialysis is performed with zero or near-zero pressure difference across the semi-permeable membrane, and to achieve this goal, the processor can monitor and control the pumps to maintain this desired zero or near-zero pressure difference. Alternatively, the processor may monitor a pressure sensor and control a pump motor, and thus a pump actuator, to increase and maintain a positive pressure in the blood flow path in the dialyzer relative to the pressure in the dialysate flow path in the dialyzer. Advantageously, this pressure differential can be influenced by the processor to provide ultrafiltration and the transport of free water and dissolved solutes from the blood to the dialysate.

[0079] In a preferred embodiment, the processor monitors blood flow sensor 11 and controls the flow rate of the blood pump. It uses dialysate flow sensor 25 to control the flow rate of dialysate from the upstream dialysate pump. The processor then uses reservoir level sensors (15, 16, 18, and 19) to control the flow rate from the downstream dialysate pump 33. A change in fluid level (or volume) in the dialysate reservoir is the same as a change in patient volume. By monitoring and controlling the level in the reservoir, forward, reverse, or zero ultrafiltration can be accomplished.

[0080] The processor also monitors all of the various sensors to ensure that the hemodialysis machine is operating efficiently and safely, and if an unsafe or unspecified condition is detected, the processor corrects the fault or stops further hemodialysis treatment. For example, if the venous blood line pressure sensor 9 indicates unsafe pressure, or if the air bubble sensor 12 detects gaseous bubbles in the venous blood line, the processor signals an alarm, the pump is deactivated, and the pinch valve is closed to prevent further blood flow back to the patient. Similarly, if the blood leak sensor 31 detects that blood is permeating the semi-permeable membrane of the dialyzer, the processor signals an alarm and stops further hemodialysis treatment.

[0081] The dialysis machine's user interface may include a keyboard or touch screen 111 to allow the patient or medical personnel to enter commands for the treatment or to allow the patient or medical personnel to monitor the performance of the hemodialysis machine. The processor may also include Wi-Fi or Bluetooth connectivity for the transfer of information or control to remote locations.

[0082] In what follows, the various components of the preferred hemodialysis machine are identified and numbers correspond to the components illustrated in the figures. [Table 1-1] [Table 1-2] [Table 1-3] (Hemodialysis treatment options)

[0083] The hemodialysis system provides increased flexibility of treatment options based on the required frequency of dialysis, patient characteristics, availability of dialysate or water, and desired portability of the dialysis machine. For all treatments, the blood flow path 53 carries blood in a closed loop system by connecting the arterial blood line 1 to the patient and the venous blood line 14 to carry blood from the patient to the dialyzer and back to the patient.

[0084] 1, a first method of providing hemodialysis involves introducing dialysate from a water supply 46, such as water supplied through reverse osmosis (RO), into the hemodialysis machine through a fresh dialysate flow path 56. The mixed dialysate is then introduced into reservoirs 17 and 20. For this treatment, dialysate from the first reservoir is recirculated across the dialyzer 8, through bypass passage 35, and back to the same reservoir. Once the reservoir volume has been recirculated, the reservoir is emptied through drain flow path 55 and the reservoir is refilled through fresh dialysate flow path 56.

[0085] Meanwhile, hemodialysis treatment continues using the second reservoir (17 or 20) while the first reservoir is emptied and refilled. Once the processor determines that all of the dialysate has been recirculated once, or that the dialysate has become contaminated, the processor switches all relevant valves (21, 42, 43, 51, and 52) to remove the first reservoir 20 from the patient treatment and insert the second reservoir 17 into the dialysate flow path 54. Dialysate from the second reservoir 17 is recirculated back to the same reservoir 17 through the bypass passage 35, past the dialyzer 8. This switching back and forth between reservoir 17 and reservoir 20 continues until the dialysis treatment is completed. This operation is similar to, but not identical to, a conventional single-pass system, since no sorbent filter is used.

[0086] As illustrated in FIG. 4, once the processor determines that continued use of the reservoir 17 for dialysis treatment is not appropriate, the processor switches the various valve assemblies (21, 42, 43, 51, and 52) to remove the reservoir 17 from the dialysate flow path 54 and instead insert the reservoir 20 into the dialysis flow path for dialysis treatment. Clean dialysate is recirculated back through the dialyzer 8 to the same reservoir 20. Again, this recirculation continues using the reservoir 20 until a switch to the reservoir 17, a switch back to the reservoir 17, or until the dialysis treatment is completed, as determined by the processor. While the dialysis treatment continues using the reservoir 20, contaminated fluid in the reservoir 17 is drained through the drain flow path. The reservoir 17 is then refilled using the fresh dialysate flow path 56. As with other treatment methods, this switching back and forth between the reservoir 17 and the reservoir 20 continues until the dialysis treatment is completed.

[0087] In yet an additional embodiment, during treatment, dialysate 75 from the first reservoir is recirculated across the dialyzer 8 and directed back to the same reservoir. As with the previous embodiment, dialysis treatment is implemented by alternating between reservoir 17 and reservoir 20. The dialysis treatment uses clean dialysate in reservoir 17, but the various valve assemblies (21, 42, 43, 51, and 52) are switched to insert the second reservoir 20 into the closed-loop filter flow path 55 and 56. Contaminated water is drained from reservoir 20.

[0088] 1, the processor continues to monitor the output of various sensors, including those in the dialysate flow path 54. Once the water in the reservoir 17 becomes contaminated, it is removed from the dialysate flow path and the reservoir 20 is replaced in its place by again switching all of the associated valve assemblies (21, 42, 43, 51, and 52). Dialysate 75 from the second reservoir 20 is recirculated in the closed-loop dialysate flow path 54 past the dialyzer 8 and directed back to the same reservoir. Meanwhile, the now contaminated water in the reservoir 17 is drained and fresh dialysate is introduced into the reservoir 17. (Dialysis fluid generator)

[0089] 1-10, a preferred dialysate generator 201 includes an inlet 205 for introducing water, such as tap water, into the various fluid flow paths of the system. The inlet flow path 203 includes a pressure regulator 207, a one-way valve 209, a first carbon and sediment filter 211, a sample port 213, and a second carbon filter 215. The pressure regulator 207 ensures that the water pressure does not get high for the dialysate generator. The first carbon and sediment filter 211 removes sediment, chlorine, and chloramines, while the second carbon filter 215 acts as a backup to the upflow filter 211. The filtered water is then directed to a second fluid path that includes an ultraviolet (UV) sterilizer 221, a water descaler 223, a temperature sensor 225, a pressure sensor 227, a conductivity sensor 229, a pump 231, which is preferably a membrane pump, and an additional pressure sensor 233. An ultraviolet (UV) sterilizer kills any bacteria that has entered the system. A descaler removes dissolved calcium from the water. Temperature sensor 225, pressure sensor 227, and conductivity sensor 229 ensure that the incoming water meets certain requirements for temperature (TPi), pressure (PPi), and conductivity (CPi). After passing pressure sensor 233, the water proceeds to a reverse osmosis membrane 235.

[0090] The ultraviolet sterilizer 221 may include any UV light producing light source capable of killing bacteria. In a preferred embodiment, the ultraviolet sterilizer 221 is a short fluid conduit incorporating LEDs that produce UV light with intense short wavelength (250-280 nm) radiation. Suitable fluid conduits incorporating LEDs can be purchased from Acuva Technologies Inc. and Crystal IS, Inc. The descaler 223 can be any construction for reducing or expelling calcium scale buildup resulting from dissolved calcium carbonate or other calcium salts in the water. Preferably, the descaler does not employ the introduction of chemicals to provide water softening. Instead, the preferred descaler 223 is a mechanical device that provides water pressure and a drop in a magnetic field provided by a stationary magnet to convert the dissolved calcium salts into calcium crystals. The calcium crystals may then be removed from the water by a filter located within the descaler or, more preferably, by a separate downstream filter in the dialysate generator. A suitable descaler is sold by Dime Water, Inc. of Vista, California, and is described in US Pat. No. 6,221,245, which is incorporated herein by reference in its entirety.

[0091] The reverse osmosis membrane 235 outputs "clean water" and "reject" effluent. The reject effluent from the reverse osmosis membrane is split by bypass valve 237, with a portion of the reject effluent being discarded and another portion being sent to a pair of parallel flow restrictor orifices 239 and 241, which controllably restrict the water flow and create back pressure within the reverse osmosis membrane. These restrictor orifices 239 are constructed to balance the flow through and across the membrane. A portion of the water that flows across the reverse osmosis membrane 235 must be discarded through three-way valve 243. Alternatively, a portion of the water is recirculated through three-way valve 245. Check valve 219 ensures that the recirculated water does not enter the flow path with the inlet water and not vice versa.

[0092] When the fluid is forced through the reverse osmosis membrane 235, the resulting purified water undergoes further processing and testing. To achieve this goal, the fluid flow rate is measured by a flow rate meter 251. The water is heated to body temperature by a heater 253, with a temperature sensor 255 provided to control the heater 253. The conductivity of the water is measured by a conductivity sensor 257 to ensure that the reverse osmosis membrane has sufficiently purified the water. If the tested water is determined to be acceptable, two chemical concentrates 259 and 267 are added to the water to create the final dialysate composition. The concentrated reagents are introduced into the purified water by a pair of pumps 261 and 269 to produce the dialysate. Preferably, the pumps 261 and 269 are piston pumps that meter the chemical concentrates into the pure water stream. Again, the conductivity of the water is measured by conductivity sensors 265 and 273 to ensure that the reverse osmosis membrane 235 has sufficiently cleaned the water, and to confirm that the proper amounts of chemical reagents 259 and 267 have been introduced into the water. Finally, the dialysate is pumped over another ultraviolet (UV) sterilizer 275 to kill any remaining bacteria, and a sub-micron ultrafilter 277 then captures any endotoxins remaining from the dead bacteria. The sterilized dialysate is delivered from the fluid outlet of the dialysate generator to the hemodialysis machine, into the fresh dialysate flow path 56 of the hemodialysis machine.

[0093] Preferably, the dialysate generator 201 possesses a plurality of bypass flow paths 289, controllable valves 209, 237, 243, 245, and 279, and pumps 231, 261, 267, and 285 for controlling various operations of the machine. For example, as illustrated in Figs. 1-10, the dialysate generator 201 preferably includes a pump 285, a pressure sensor 283, and a check valve 281 connected to the drainage flow path 55 of the hemodialysis machine for controlling the drainage of waste dialysate from the reservoirs 17 or 20. The reservoirs 17 and 20 may be located either in the hemodialysis machine 100 or in the dialysate generator 201. However, in the preferred embodiment illustrated in Figs. 4 and 5, the reservoirs 17 and 20 are located in the dialysate generator 201, as are the control valves 21, 42, 43, and 51. Further, the dialysate generator 201 preferably includes an additional three-way valve 279 that redirects dialysate from the fresh dialysate flow path 56 through the three-way valve 245 and back to the drain line 249. In addition, and referring to Figures 1-10, the dialysate generator 201 preferably includes a bypass flow path 289 that connects the fresh dialysate flow path 56 of the hemodialysis machine with the waste dialysate flow path 55 of the hemodialysis machine.

[0094] The hemodialysis system includes at least one processor containing power management and control circuitry connected to pump motors, valves, and sensors for controlling the proper operation of the hemodialysis system, including the hemodialysis machine and the dialysate generator. A preferred hemodialysis system includes two processors, with a first processor located in the hemodialysis machine 100 and a secondary processor located in the dialysate generator 201. However, it is preferred that the primary control processor for the entire hemodialysis system is located in the hemodialysis machine 100, and the dialysate generator 201 is preferably electrically connected to and controlled by this primary processor in the hemodialysis machine 100, as described below. However, it is preferred that the dialysate generator 201 includes a secondary processor for control and cycling through various cleaning and disinfecting modes, but preferably the dialysate generator includes only a single on / off button 327. The preferred dialysate generator 201 does not include any additional buttons, knobs, switches, or other control interfaces. Instead, preferably, the dialysate generator 201 is controlled exclusively through the hemodialysis machine's user interface 111, and if the dialysate generator is disconnected from the hemodialysis machine, the dialysate generator's only function is to cycle through the cleaning and disinfecting modes. Preferably, the dialysate generator is equipped with one or more status or warning lights that may indicate a fault condition or a requirement to replace disposable items such as filters or consumable concentrates. In a preferred embodiment, the dialysate generator 201 includes only a single LED light 329 that provides three different colors to indicate powered, cleaning mode, or error detected.

[0095] Preferably, the hemodialysis machine 100 is capable of operating without the dialysate generator 201, such as by obtaining dialysate from a source other than the dialysate generator described herein. However, because the preferred dialysate generator 201 does not have a user interface, other than operating in a clean mode, the preferred dialysate generator is constructed to operate only with the hemodialysis machine 100 described herein.

[0096] In what follows, the various components of the preferred dialysate generator are identified and numbers correspond to the components illustrated in the figures. [Table 2-1] [Table 2-2] [Table 2-3] (Dialysis fluid generator operation)

[0097] The dialysate generator can perform various operations. In the first mode illustrated in Figure 2, the inlet water source is tested to determine if it meets the quality requirements and requirements related to temperature, pressure, and conductivity. The product water is heated to the target dialysate temperature and the water is tested by various sensors. This mode requires that valves, heaters, pumps, and UV sterilizers are activated as follows: [Table 3]

[0098] In a second mode, illustrated in Figure 2, the dialysate generator 201 produces clean, rather than dialysate, for monitoring of reverse osmosis product water. It also heats the water produced by reverse osmosis to a target dialysate treatment temperature and tests the water for temperature suitability. This mode requires the valves, heaters, pumps, and UV sterilizer to be activated as follows: [Table 4]

[0099] In the third mode illustrated in Figure 3, the dialysate generator 201 generates dialysate. Chemical concentrates are added to clean water produced by reverse osmosis to produce dialysate of the correct composition. However, the dialysate is not provided to the hemodialysis machine 100. Instead, the dialysate is tested to ensure that it meets quality requirements. This mode requires that valves, heaters, pumps, and UV sterilizers are activated as follows: [Table 5-1] [Table 5-2]

[0100] In the fourth mode illustrated in Figure 4, the dialysate generator 201 generates dialysate and delivers the dialysate to the hemodialysis machine. The hemodialysis machine diverts the produced dialysate to one of the other reservoirs (17 or 20). This mode requires the valves, heater, pump, and UV sterilizer to be activated as follows: [Table 6-1] [Table 6-2]

[0101] In the fifth mode illustrated in Figure 5, the dialysate generator 201 drains waste dialysate from one of the hemodialysis reservoirs (17 or 20). While the dialysate is being drained, no new dialysate is being produced and additional chemical concentrates stop. The hemodialysis machine determines which reservoir to drain, which is reservoir 20 as shown in Figure 5. This mode requires the valves, heater, pump, and UV sterilizer to be activated as follows: [Table 7-1] [Table 7-2]

[0102] In the sixth mode, illustrated in Figure 6, the dialysate generator 201 pumps dialysate through its fluid paths. This mode requires that the valves, heaters, pumps, and UV sterilizers be activated as follows: [Table 8]

[0103] In an additive mode, the dialysate generator 201 sterilizes itself. Sterilization activates the heater 253, which heats the water in the system to 85° C. Water is recirculated through the various flow paths of the system. The different paths are staggered and balanced so that the entire system is heated evenly. At times, fluid will be directed to drain, sterilizing the line to the drain. As fluid is directed to drain, new fluid is drawn into the system. During sterilization, valve 237-VBf is opened to prevent high pressure across the reverse osmosis membrane.

[0104] In a first sterilization mode, illustrated in Figure 7, hot water is recirculated throughout the fluid paths of the system to sterilize it. This mode requires that valves, heaters, pumps, and UV sterilizers be activated as follows: [Table 9]

[0105] In a second disinfection mode, the dialysate generator 201 disinfects the "waste" fluid pathways by recirculating hot water through selected pathways, as illustrated in Figure 8. This mode requires that valves, heaters, pumps, and UV sterilizers be activated as follows: [Table 10]

[0106] In a third disinfection mode, as shown in Figure 9, the dialysate generator 201 disinfects the "drain" path leading from valve 245 by recirculating hot water through a selected path. This mode requires that the valves, heater, pump, and UV sterilizer be activated as follows: [Table 11]

[0107] In a fourth disinfection mode, as shown in Figure 10, the dialysate generator 201 disinfects the "drain" path leading from valve 243 by recirculating hot water through a selected path. This mode requires that the valves, heater, pump, and UV sterilizer be activated as follows: [Table 12-1] [Table 12-2] (Combination of hemodialysis machine and dialysis fluid generator)

[0108] As illustrated in Figures 1, 4, 5, and 11-19, the hemodialysis machine 100 and the dialysate generator 201 are stand-alone machines that can be connected or disconnected from each other. To achieve this goal, the hemodialysis machine includes a housing 101 for encapsulating and protecting the various components that provide hemodialysis treatment. The hemodialysis machine housing 101 can be constructed in a myriad of shapes and sizes to physically engage the dialysate generator 201. However, in a preferred embodiment, the hemodialysis machine has a substantially hexahedral shape including a top side 102, a bottom side 103, a left side 104, a right side 105, a front side 106, and a back side 107. In addition, the hemodialysis machine 100 includes one or more electrical connectors 108 for transmitting and receiving electrical signals (and, optionally, power) between the hemodialysis machine 100 and the dialysate generator. 1, 4, 5, and 13, the hemodialysis machine 100 includes at least one fluid connector 109 for receiving clean dialysate from the dialysate generator 201 and at least one fluid connector 110 for draining used dialysate back to the dialysate generator. Preferably, the hemodialysis machine includes a touch screen 111 that is integrated into or hingedly affixed to the housing 101 of the machine.

[0109] Similarly, the dialysate generator 201 includes a housing 301 for encapsulating and protecting the various components that generate fresh dialysate. The preferred dialysate generator 201 has a housing 301 having a generally "L" shaped construction including a horizontally extending base unit 303 and a vertically extending rear unit 305 that extends vertically from the rear of the base unit 303. This construction provides a dialysate generator housing 301 with a top 307, a bottom 309, a left side 311, a right side 313, a front side 315, and a rear side 317. Additionally, the horizontally extending base unit 303 provides a resting surface 319 on which the hemodialysis machine 100 sits when the hemodialysis machine is mated to the dialysate generator. Preferably, the dialysate generator processor and pumps are located in the hemodialysis base unit 100, and the dialysate generator filters and concentrated reagents are located in the dialysis generator back unit 201. These chemical reagents may include six electrolytes, namely, sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), and bicarbonate, as well as glucose and / or dextrose. The reservoirs 17 and 20 may either be in the hemodialysis machine, as illustrated in FIG. 1, or the reservoirs may be located in the dialysate generator housing. It is also preferred that the carbon filter 211 and reverse osmosis membrane 235 are located in an elongated cylindrical container (not shown) that is positioned vertically in the dialysate generator back unit 305. 13, preferably the rear side 317 of the back unit is an openable rear panel 318 that allows a person access to all of the disposable components, including the carbon filter 211, secondary filter 215, reverse osmosis membrane 235, and concentrated reagent containers 259 and 267. The openable rear panel 318 may be completely removed or fold back on a hinge so that the disposable components can be easily removed and replaced when depleted.

[0110] The dialysate generator 201 includes one or more electrical connectors 325 for mating with the electrical connector 108 of the hemodialysis machine, which are constructed and positioned on the dialysate generator housing 301. In addition, the dialysate generator 201 includes a first fluid connector 321 that is positioned and passes through the dialysate generator housing to provide clean dialysate to the fluid connector 109 of the hemodialysis machine, and the dialysate generator includes a second fluid connector 323 that is positioned and passes through the dialysate generator housing 301 to receive used dialysate from the fluid connector 110 of the hemodialysis machine.

[0111] In closing, it should be understood that a hemodialysis system is disclosed with respect to the exemplary embodiments of the invention as shown and described herein. It should be understood that the principles of the invention may be practiced in several configurations other than those shown and described, and therefore the invention is not limited in any way by the exemplary embodiments, but is generally directed to hemodialysis systems, and may take many forms to do so without departing from the spirit and scope of the invention. It will also be understood by those skilled in the art that the invention is not limited to the specific geometries and materials of construction disclosed, but instead may involve other functionally equivalent structures or materials now known or later developed without departing from the spirit and scope of the invention. Furthermore, it is intended that the various features of each of the embodiments described above may be combined in any logical manner and still fall within the scope of the invention.

[0112] The grouping of alternative embodiments, elements, or steps of the invention shall not be construed as limiting. Each group member may be referred to and claimed individually or in any combination with other group members disclosed herein. It is anticipated that one or more members of a group may be included in or deleted from a group for convenience and / or patentability reasons. When any such inclusion or deletion occurs, the specification shall be considered as containing the group as amended.

[0113] Unless otherwise indicated, all numerical values ​​expressing properties, items, quantities, parameters, characteristics, terms, etc. used in the specification and claims should be understood as being modified in all instances by the term "about". As used herein, the term "about" means that the property, item, quantity, parameter, characteristic, or term so qualified contains a range of ±10 percent above and below the value of the stated property, item, quantity, parameter, characteristic, or term. Thus, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical indication should be construed at least in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and values ​​setting forth the broad scope of the invention are approximations, the numerical ranges and values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical range or value inherently contains certain errors that necessarily result from the standard deviation found in their respective testing measurements. The recitation of numerical ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each separate numerical range falling within the range, and unless otherwise stated herein, each individual value of a numerical range is incorporated herein as if it were individually recited herein.

[0114] The terms "a," "an," "the," and similar referents used within the context of the description of the present invention (particularly in the context of the claims below) should be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. All of the methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended only to more clearly illuminate the invention and does not impose limitations on the scope of the invention as otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0115] Specific embodiments disclosed herein may be further limited in the claims using the phrases "consisting of" or "consisting essentially of." When used in the claims, whether as filed in an amendment or as added, the transitional term "consisting of" excludes any element, step, or ingredient not recited in the claim. The transitional term "consisting essentially of" limits the scope of the claim to those materials or steps recited and which do not materially affect the basic and novel characteristics. The embodiments of the invention so claimed are essentially or explicitly described and enabled herein.

[0116] It should be understood that the logical code, programs, modules, processes, methods, and order in which the individual elements of each method are implemented are purely illustrative. Depending on the implementation, they may be implemented in any order or in parallel, unless otherwise indicated in this disclosure. Furthermore, the logical code is not related to or limited to any particular programming language, and may comprise one or more modules executing on one or more processors in a distributed, non-distributed, or multi-processing environment.

[0117] While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and invention of the invention. Accordingly, it is not intended that the invention be limited, except as by the following claims.

Claims

[Claim 1] The invention described in this specification.

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