Control architecture and method for blood treatment systems

Abstract

The object of the present invention is to provide various systems and methods that enable hemodialysis to be performed more efficiently, easily, and / or at a lower cost. [Solution] The dialysis system comprises a plurality of actuators that cooperate to perform dialysis functions and a plurality of sensors that cooperate to monitor dialysis functions. In one embodiment, the hemodialysis system comprises a user interface model layer, a treatment layer below the user interface model layer, and a machine layer below the treatment layer. The user interface model layer is configured to manage the state of a graphical user interface and to receive input from the graphical user interface. The treatment layer is configured to run a state machine that generates treatment commands based on input from the graphical user interface, at least in part. The machine layer is configured to provide commands to the actuators based on the treatment commands.

Description

【Technical Field】 【0001】 The present invention relates to hemodialysis systems and similar dialysis systems, i.e., systems for treating blood and other body fluids outside the body. In aspects, the system includes various systems and methods that can perform hemodialysis more efficiently, easily, and / or at lower cost. 【Background Art】 【0002】 Hemodialysis is inefficient, difficult, and costly due to many factors. The above elements include the complexity of hemodialysis, the safety related to hemodialysis, and the large amount of dialysate required for hemodialysis. Furthermore, hemodialysis usually requires skilled professionals and is performed at a dialysis center. Therefore, improving the ease and efficiency of the dialysis process affects the cost of the treatment and the outcome of the patient. 【0003】 FIG. 1 is a schematic diagram showing a hemodialysis system. The system 5 includes two flow paths, i.e., a blood flow path 10 and a dialysate flow path 20. Blood is drawn from a patient. The blood pump 13 causes the blood to flow around the blood flow path 10, draws blood from the patient, thereby passing the blood through the dialysis device 14, and returns the blood to the patient. Optionally, the blood passes through other elements such as at least one of a filter and an air trap 19 prior to returning to the patient. Additionally, in the example, an anticoagulant is supplied from the anticoagulant supplier 11 through the anticoagulant valve 12. 【0004】 The dialysate pump 15 draws dialysate from the dialysate supplier 16 and passes the dialysate through the dialysis device 14. Thereafter, the dialysate passes through the drain valve 18 and / or returns to the dialysate supplier through the dialysate pump 15. The dialysate valve 17 controls the flow of dialysate from the dialysate supplier 16. The dialysis device is configured such that blood from the blood flow circuit flows through a small tube and the dialysate circulates around the outside of the tube. The treatment is performed by allowing excretory molecules (e.g., urea, creatinine, etc.) and water to reach the dialysate from the blood through the tube wall. At the end of the treatment, the dialysate is discharged out. [Prior art documents] [Patent Documents] 【0005】 [Patent Document 1] U.S. Patent Application Publication No. 2002 / 056672 [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 The object of the present invention is to provide various systems and methods that enable hemodialysis to be performed more efficiently, easily, and / or at a lower cost. [Means for solving the problem] 【0007】 The present invention relates to hemodialysis systems and similar dialysis systems. In the examples, the subject matter of the present invention includes related products, alternatives to given problems, and / or multiple different uses of one or more systems or products. Although the various systems and methods disclosed herein are described in relation to hemodialysis, the various systems and methods disclosed herein are suitable for other dialysis systems and / or any extracorporeal systems capable of treating blood or other body fluids, such as hemofiltration, hemodiafiltration, etc. 【0008】 In one embodiment, the system includes four channels: one for blood, one for dialysate to the inside, one for dialysate to the outside, and one for a mixture of dialysate. In one embodiment, these four channels are connected in a single cassette. In another embodiment, these four channels are each located in a corresponding cassette. In yet another embodiment, two or more channels are included in a single cassette. In one embodiment, a hemodialysis system is provided having at least two channels, these two channels being integrally provided in 1) a blood flow pump cassette, 2) an internal dialysate cassette, 3) an external dialysate cassette, and 4) a mixing cassette. The cassettes are in communication with each other. In one embodiment, one or more embodiments of these cassettes are incorporated into a single cassette. In yet another embodiment, a hemodialysis system is provided that includes a blood channel through which untreated blood is drawn from the patient, passes through a dialysis machine, and treated blood is returned to the patient. The blood channel includes at least one blood flow pump provided in a removable cassette. The hemodialysis system may further include a first receiving structure for receiving a cassette of blood flow channels, a dialysate flow channel through which dialysate flows from a dialysate supply unit through a dialysis machine, a second receiving structure for receiving the dialysate flow channel, and a control fluid path for sending control fluid from a drive mechanism to the cassette to drive each blood flow pump and dialysate pump. In the embodiment, the dialysate flow channel may include at least one dialysate pump provided on a removable cassette. 【0009】 Further alternative examples of hemodialysis systems are disclosed. In these embodiments, the hemodialysis system includes a blood flow path through which untreated blood is drawn from the patient, passes through a dialysis machine, and treated blood is returned to the patient. The blood flow path includes at least one blood valve. The hemodialysis system further comprises a blood valve, a dialysate mixing system communicating with a dialysis machine (including at least one dialysis machine valve), and a control fluid passage that delivers a control fluid from a drive mechanism to the blood valve to drive a heating means or heater for heating the dialysate. 【0010】 In a further example, a hemodialysis system is disclosed that includes a blood channel through which untreated blood is drawn from a patient, passes through a dialysis machine, and treated blood is returned to the patient. The blood channel includes at least one blood flow pump. The hemodialysis system further includes a dialysate channel through which dialysate flows from a dialysate supply to a dialysis machine. The dialysate channel includes at least one pneumatic pump. In one embodiment, the present invention relates to a hemodialysis system. In an embodiment, the hemodialysis system includes a blood channel, a first cassette forming an internal dialysate channel, a dialysis machine communicating with the blood channel and the internal dialysate channel, a second cassette forming an external dialysate channel, and a membrane connecting the first cassette to the second cassette. 【0011】 In yet another example, a hemodialysis system comprises a blood channel, an internal dialysate channel, a dialysis device communicating with the blood channel and the internal dialysate channel, an external dialysate channel, a membrane connecting the internal dialysate channel and the external dialysate channel, a first dialysate pump for pumping dialysate from the internal dialysate channel, and a second dialysate pump for pumping dialysate from the external dialysate channel, wherein the second dialysate pump and the first dialysate pump are operably connected so that the flow in the internal dialysate channel is approximately equal to the flow in the external dialysate channel. 【0012】 In yet another example, the dialysate system includes a blood channel through which blood is drawn from the patient and passes through the dialyzer, and a dialysate channel through which dialysate flows from a dialysate supply to the dialyzer. In this embodiment, the dialysate channel includes an equilibrium cassette that controls the amount of dialysate passing through the dialyzer, a mixing cassette that forms dialysate from water, and an orientation cassette that sends water from the water supply to the mixing cassette and then sends the dialysate from the mixing circuit to the equilibrium circuit. 【0013】 In a further example, the hemodialysis system comprises a cassette system consisting of an orientation cassette, a mixing cassette, and an equilibrium cassette. In this embodiment, the orientation cassette can distribute water from the water supply to the mixing cassette and the dialysate from the mixing cassette to the equilibrium cassette. The mixing circuit can mix the water from the orientation cassette with the dialysate from the dialysate supply to form a precursor. The equilibrium cassette can control the amount of dialysate passing through the dialysis machine. 【0014】 In the embodiment, the hemodialysis system includes a blood channel through which blood is drawn from the patient and passes through the dialysis machine, a blood channel including a blood flow pump, and a dialysis fluid channel through which dialysate flows from a dialysate supply body through the dialysis machine, the dialysis fluid channel including a dialysis fluid pump and a control fluid channel through which a control fluid drives the blood flow pump and the dialysis fluid pump. 【0015】 In yet another example, the hemodialysis system includes a blood channel through which blood is drawn from the patient and passes through the dialysis machine, and a dialysis fluid channel through which dialysate flows from a dialysate supply and through the dialysis machine. In this embodiment, the dialysis fluid channel includes at least one pneumatic pump. 【0016】 In yet another example, the hemodialysis system includes a first pump comprising a pump chamber and a drive chamber, a second pump comprising a pump chamber and a drive chamber, a control fluid communicating with the drive chambers of the first and second pumps, and a controller capable of pressurizing the control fluid and controlling the operation of the first and second pumps. 【0017】 In yet another example, the hemodialysis system includes a first valve comprising a valve chamber and a drive chamber, a second valve comprising a valve chamber and a drive chamber, a control fluid communicating with the drive chambers of the first and second valves, and a controller capable of pressurizing the control fluid and controlling the drive of the first and second valves. 【0018】 In this embodiment, the hemodialysis system comprises a blood channel through which blood is drawn from the patient and passes through the dialysis machine, a cassette containing at least a portion of the blood channel, and a spike integrally formed with the cassette, the spike being capable of receiving a vial of fluid, and the integrally formed spike communicating with the blood channel in the cassette. 【0019】 In another example, a hemodialysis system includes a blood channel through which blood is drawn from the patient and passes through the dialysis machine, a dialysate channel through which dialysate flows from a dialysate supplier through the dialysis machine, and a gas supplier that communicates with the dialysate channel and, when activated, provides gas from a gas supplier to cause the dialysate to pass through the dialysis machine and return the blood in the blood channel to the patient. The dialysis machine causes the dialysate to flow from the dialysate channel into the blood channel. 【0020】 In yet another example, a hemodialysis system comprises a blood channel through which untreated blood is drawn from the patient and passes through the dialysis machine, a dialysate channel through which dialysate flows from a dialysate supply to the dialysis machine, a fluid supply, a chamber communicating with the fluid supply and the dialysate channel, and a pressurizing device that pressurizes the fluid supply, pressing a partition against the dialysate in the chamber, thereby causing the dialysate to pass through the dialysis machine and return the blood in the blood channel to the patient. The dialysate flows from the dialysate channel to the blood channel by the dialysis machine. The chamber has a partition that separates the fluid from the fluid supply from the dialysate in the dialysate channel. 【0021】 In yet another example, a hemodialysis system includes a blood channel through which untreated blood is pumped to the patient and passes through the dialysis machine, a dialysate channel through which dialysate flows from a dialysate supply unit through the dialysis machine, and a pressurizing device that pressurizes the dialysate in the dialysate channel to flow into the blood channel. The dialysate channel and the blood channel are in communication with each other. 【0022】 In this embodiment, the hemodialysis system comprises a first housing including a positive displacement pump driven by a control fluid, a flow path connecting the positive displacement pump to the control fluid pump, and a second housing including the control fluid pump, the second housing being detachable from the first housing. 【0023】 In another example, the hemodialysis system comprises a housing consisting of a first compartment and a second compartment separated by an insulating wall, the first compartment being sterilizable at a temperature of at least about 80°C, and the second compartment containing electrical elements that are not heated to a temperature of 60°C or higher when the first compartment is heated to at least about 80°C. 【0024】 In a further example, a hemodialysis system comprises a blood flow path including at least one blood valve through which untreated blood is drawn from a patient and passes through a dialysis machine; a control fluid path that sends control fluid from a drive mechanism to the blood valve to drive the blood valve; a dialysate mixing system communicating with the dialysis machine and including at least one dialysate device valve; and a heater for heating the dialysate. Another aspect of the present invention relates to a valve system. In an embodiment, the valve system includes a valve housing including a plurality of valves. At least two of the valves each consist of a valve chamber and a drive chamber. At least two of the valves are driven by control fluid in the drive chamber. The valve system further comprises a control housing having a plurality of fluid interface ports for communicating with control fluid from a base unit, and a plurality of tubes extending between the valve housing and the control housing. Each tube communicates one of the fluid interface ports with at least one of the drive chambers, so that the base unit can drive the valve by pressurizing the control fluid in the fluid interface port. In an embodiment of the present invention, the valve includes a first plate, a second plate, a third plate, and a partition wall. The second plate has a recess on the side facing the first plate, the recess has a groove formed inside, and the groove is open in the direction facing the first plate. The second plate is provided between the first plate and the third plate. A partition wall is provided in the recess between the first plate and the second plate. The partition wall has a rim, which is held in the groove. The second plate is equipped with a valve seat. The partition wall is pressed by pneumatic pressure to seal and tightly close the valve seat. The groove surrounds the valve seat. In this embodiment, the valve inlet and valve outlet are formed between the second plate and the third plate. In this embodiment, a passage for generating pneumatic pressure is provided between the first plate and the second plate. 【0025】 In a further aspect of the present invention, a pump system is disclosed. In an embodiment, the pump system comprises a pump housing that includes a plurality of pumps. At least two of the pumps each include a pump chamber and a drive chamber. At least two of the pumps are each drivable by a control fluid within the drive chamber. The pump housing comprises a control housing having a plurality of fluid interface ports for communicating with the control fluid from a base unit, and a plurality of tubes extending between the pump housing and the control housing. The tubes each communicate between one of the fluid interface ports and at least one of the drive chambers, whereby the base unit can drive the pumps by pressurizing the control fluid within the fluid interface ports. 【0026】 In another aspect of the present invention, a pump cassette is disclosed. In an embodiment, the pump cassette comprises at least one fluid inlet, at least one fluid outlet, a flow path connecting the at least one fluid inlet and the at least one fluid outlet, and a spike for attaching a vial to the cassette. The spike communicates with the flow path in an embodiment. 【0027】 In one aspect of the present invention, a pump cassette is disclosed that balances the flow reciprocating through a target site. In an embodiment, the pump cassette includes a cassette inlet, a supply line to the target site, a return line from the target site, a cassette outlet, a pump mechanism that flows fluid from the cassette inlet to the supply line and from the return line to the cassette outlet, and a balance chamber. In an embodiment, the pump mechanism includes a pod pump comprising a rigid curved wall that defines a pump volume and has an inlet and an outlet, a partition provided within the pump volume, and a drive port that connects the pod pump to a pneumatic drive system and thereby drives the partition to allow fluid to enter and exit the pump volume. The pump partition separates the fluid from the gas in communication with the pneumatic drive system. In an embodiment, the balance chamber includes a rigid curved wall that defines a balance volume and a balance partition provided within the balance volume. The balance partition separates the balance volume into a supply side and a return side. The supply side and the return side each have an inlet and an outlet. In an embodiment, the fluid from the cassette inlet flows into the supply side inlet, the fluid from the supply side outlet flows into the supply line, the fluid from the return line flows into the return side inlet, and the fluid from the return side outlet flows into the cassette outlet. In an alternative embodiment, a pump system includes a system inlet, a supply line to the target site, a return line from the target site, a system outlet, a pump mechanism that flows fluid from the system inlet to the supply line and from the return line to the system outlet, and a balance chamber. 【0028】 In the embodiment, the pump mechanism comprises a pod pump consisting of a rigid ellipsoidal wall defining a rigid pump capacity and having an inlet and outlet, a pump partition wall provided within the ellipsoidal wall and leading to the ellipsoid, and a port connecting the pod pump to a pneumatic drive system to drive the partition wall and allow fluid to enter and exit the pump capacity. In the embodiment, the pump partition wall separates the fluid from the gas communicating with the pneumatic drive system. In the embodiment, the equilibrium chamber comprises a rigid ellipsoidal wall defining an equilibrium capacity, and an equilibrium partition wall provided within the ellipsoidal wall and leading to the ellipsoid. In the embodiment, the equilibrium partition wall separates the equilibrium capacity into a supply side and a return side, with the supply side and return side having an inlet and an outlet, respectively. In the embodiment, fluid from the system inlet flows to the supply side inlet. Fluid from the supply side outlet flows to the supply line. Fluid from the return line flows to the return side inlet. Fluid from the return side outlet flows to the system outlet. The pump mechanism further comprises valve mechanisms provided at the inlets and outlets of the supply side and return side, respectively. The valve mechanism is driven by air pressure. A cassette is disclosed in a further embodiment of the present invention. In this embodiment, the cassette comprises a first channel connecting a first inlet to a first outlet, a second channel connecting a second inlet to a second outlet, a pump capable of pumping fluid to pass at least a portion of the second channel, and at least two balancing chambers. Each balancing chamber comprises a rigid vessel, the rigid vessel including a partition separating the rigid vessel into a first compartment and a second compartment. The first compartment of each balancing chamber communicates with the first channel, and the second compartment communicates with the second channel. 【0029】 In an alternative example, the cassette includes a first channel connecting a first inlet to a first outlet, a second channel connecting a second inlet to a second outlet, a control fluid channel, at least two pumps, and a balancing chamber capable of maintaining balance between the flow between the first and second channels. Each pump consists of a rigid vessel including a partition separating the rigid vessel into a first and second compartment. The first compartment of each pump communicates with the control fluid channel, and the second compartment communicates with the second channel. In yet another example, the cassette comprises a rigid vessel including a first channel connecting a first inlet to a first outlet, a second channel connecting a second inlet to a second outlet, and a partition separating the rigid vessel into a first and second compartment. In this example, the first compartment communicates with the first channel, and the second compartment communicates with the second channel. 【0030】 A pump is disclosed in a further embodiment of the present invention. In an embodiment, the pump comprises a first rigid element, a second rigid element, and a partition wall having an edge. The second rigid element has a groove provided internally on the side facing the first plate. The groove opens in a direction facing the first rigid element. The edge is held in the groove by frictional fitting into the groove, but the first rigid element does not contact the edge. In an embodiment, the first and second rigid elements form a pod pump chamber, at least partially separated into separate chambers by the partition wall, and further at least partially forming a flow path to the pod pump chamber. The groove surrounds the pod pump chamber. In another embodiment, the pump comprises a substantially spherical container including a flexible partition wall that separates the rigid container into a first compartment and a second compartment. The first and second compartments do not communicate with each other. The movement of the partition wall by fluid entering the first compartment causes the fluid to be pumped out of the second compartment. 【0031】 In another example, the pump is a reciprocating positive displacement pump. In this embodiment, the pump comprises a rigid chamber wall and a flexible partition wall attached to the rigid chamber wall. The flexible partition wall and the rigid chamber wall form a pump chamber. The pump further comprises an inlet for distributing fluid from the rigid chamber wall into the pump chamber, an outlet for discharging fluid from the pump chamber through the rigid chamber wall, and a limiting wall that restricts the movement of the rigid partition wall and limits the maximum capacity of the pump chamber. The rigid limiting wall forms a drive chamber. The pump further comprises a pneumatic drive system that intermittently applies a control pressure to the drive chamber. In this embodiment, the pneumatic drive system comprises a drive chamber pressure transducer for measuring the pressure in the drive chamber, a gas tank having a first pressure, a variable valve mechanism for variably limiting the flow of gas between the drive chamber and the gas tank, and a controller that receives pressure information from the drive chamber pressure transducer and controls a variable valve, thereby generating a control pressure in the drive chamber. The control pressure is less than or equal to the first pressure. Further aspects of the present invention disclose methods. In the embodiment, the method includes the steps of providing a first pump consisting of a pump chamber and a drive chamber, and a second pump consisting of a pump chamber and a drive chamber; sending a common fluid to the respective drive chambers of the first and second pumps; and pressurizing the common fluid and passing the fluid through the respective first and second pumps. 【0032】 In another example, the method includes the steps of providing a first valve comprising a valve chamber and a drive chamber, and a second valve comprising a valve chamber and a drive chamber; sending a common fluid to the respective drive chambers of the first and second valves; and pressurizing the common fluid to at least partially pass the fluid through the first and second valves. 【0033】 In a further example, the method is a method for measuring the cleaning rate of a dialysis machine. The dialysis machine is installed in a blood flow path. Untreated blood is drawn from the patient, passes through the blood flow path, and is sent to the dialysis machine. In the dialysis fluid flow path, through which the dialysis fluid flows from the dialysis fluid supply to the dialysis machine, the blood flow path is separated from the dialysis fluid flow path by a membrane inside the dialysis machine. In the example, the method includes the steps of passing a liquid through the dialysis fluid flow path to the dialysis machine and keeping the membrane moist, thereby preventing gas from flowing through the membrane; passing a gas through the blood flow path path to the dialysis machine and filling the blood flow path inside the dialysis machine with gas; measuring the volume of gas inside the dialysis machine; and calculating the cleaning rate based on the volume of gas measured in the dialysis machine. In a further example, the method is a method for measuring the cleaning rate of a dialysis machine. In the example, the method includes the steps of applying a pressure difference across the dialysis machine; measuring the flow velocity of the dialysis machine; and determining the cleaning rate of the dialysis machine based on the pressure difference and flow velocity. In a further example, the method is a method for measuring the cleaning rate of a dialysis machine. In the example, the method includes the steps of passing water through a dialysis machine, measuring the amount of ions collected by the water after it has passed through the dialysis machine, and determining the cleaning rate of the dialysis machine based on the amount of ions collected by the water after it has passed through the dialysis machine. In another example, the method includes the steps of passing water through a dialysis machine, measuring the conductivity of the water, and determining the cleaning rate of the dialysis machine based on the change in the conductivity of the water. 【0034】 The method in the embodiment is a method for guiding a fluid into blood. The method in the embodiment includes the steps of: providing a cassette that includes an integrally formed spike for receiving a fluid vial and a valve mechanism for controlling the flow of fluid from the vial to the cassette; attaching the fluid vial to the spike; drawing blood through the cassette; and guiding the fluid from the vial into the blood. 【0035】 In one example, the method includes the steps of: providing a hemodialysis system comprising a blood channel through which untreated blood is drawn from a patient and passes through a dialysis machine, and a dialysis fluid channel through which dialysate passes from a dialysate supply to the dialysis machine; connecting the blood channel and the dialysis fluid channel; and passing the dialysate through the dialysis fluid channel to deliver the blood in the blood channel to the patient. In another example, the method includes the steps of: providing a hemodialysis system comprising a blood channel through which untreated blood is drawn from a patient and passes through a dialysis machine, and a dialysis fluid channel through which dialysate passes from a dialysate supply to the dialysis machine; connecting the blood channel and the dialysis fluid channel; and sending gas into the dialysis fluid channel to cause the blood in the blood channel to flow. 【0036】 In a further example, the method is a method for hemodialysis. In the example, the method includes the steps of: providing a blood channel through which untreated blood is drawn from a patient and passes through a dialysis machine; providing a dialysis fluid channel through which dialysate passes from a dialysate supply to a dialysis machine; providing raw materials to prepare a total volume of dialysate; providing water to be mixed with the raw materials for the dialysate; and mixing a volume of water with a portion of the raw materials to prepare a first partial volume of dialysate. The first partial volume is less than the total volume. The method further includes the steps of: pumping a partial volume of dialysate through a dialysate channel and passing through a dialysis machine; and pumping blood through a blood channel and passing through a dialysis machine. The first partial volume of dialysate is sent to the dialysis machine by the pump. The method further includes the steps of: mixing a volume of water with a portion of the raw materials to prepare a second partial volume of dialysate; and storing the second partial volume of dialysate in a container. Blood and a first partial volume of dialysate are pumped out and pass through the dialyzer. 【0037】 In another example, the method includes the steps of passing blood and dialysate from a patient through a dialyzer contained within a hemodialysis system at a first speed, and forming dialysate within the hemodialysis system at a second speed different from the first speed, wherein excess dialysate is stored in a container contained within the hemodialysis system. 【0038】 Another aspect of the present invention relates to a hemodialysis system comprising a dialysis unit and a user interface unit. The dialysis unit comprises an automated computer and a dialyzer. The user interface unit comprises a user interface computer and a user interface, the user interface being configured to display information and receive input. The automated computer is configured to receive requests for safety-critical information from the user interface computer and to access the safety-critical information on behalf of the user interface computer. The user interface computer is configured to use the safety-critical information to display information about the dialysis process via the user interface. 【0039】 Another aspect of the present invention relates to a method for managing a user interface in a hemodialysis system. The method includes receiving inputs relating to the dialysis process at a user interface that is linked to a user interface computer, and, in response to the inputs, transmitting a request for safety-critical information from the user interface computer to an automated computer linked to a dialyzer. The method further includes accessing safety-critical information on behalf of the user interface computer, and using the safety-critical information to display information relating to the dialysis process via the user interface. 【0040】 A further aspect of the present invention relates to a computer storage medium encoded with instructions that, when executed, perform a method. The method includes the steps of receiving input relating to a dialysis process from a user interface linked to a user interface computer, and in response to the input, transmitting a request for safety-critical information from the user interface computer to an automated computer linked to a dialyzer. The method further includes the steps of accessing safety-critical information on behalf of the user interface computer, transmitting safety-critical information to the user interface computer, accessing screen design information stored in the user interface computer, and using the safety-critical information and screen design information to display information relating to the dialysis process on the user interface. 【0041】 Another embodiment of the present invention discloses, for example, a method for forming one or more hemodialysis systems. Further embodiments of the present invention disclose, for example, a method for using one or more hemodialysis systems. 【0042】 In yet another embodiment, the present invention relates to a control architecture for a dialysis system, the control architecture comprising a user interface model layer, a treatment layer below the user interface model layer, and a machine layer below the treatment layer. The user interface model layer is configured to manage the state of a graphical user interface and to receive input from the graphical user interface. The treatment layer is configured to run a state machine that generates treatment commands, at least in part, based on input from the graphical user interface. The machine layer is configured to provide commands to actuators based on the treatment commands. 【0043】 Another aspect of the present invention relates to a disinfection method for disinfecting a fluid pathway in a dialysis system. The method includes the step of storing disinfection parameters, including a disinfection temperature and a disinfection time, in at least one storage medium. The method further includes the steps of circulating a fluid through the fluid pathway, monitoring the temperature of the fluid with each of a plurality of temperature sensors, and determining that disinfection of the fluid pathway is complete when the temperature of the fluid at each of the plurality of temperature sensors remains above the disinfection temperature for at least the disinfection time. 【0044】 Another aspect of the present invention relates to at least one computer-readable medium encoded with instructions for performing a disinfection method to disinfect a fluid path in a dialysis system when executed by at least one processing apparatus. The method includes the step of electronically receiving disinfection parameters, including a disinfection temperature and a disinfection time. The method further includes the steps of controlling a plurality of actuators to circulate a fluid in the fluid path, monitoring the temperature of the fluid at each of the plurality of temperature sensors, and determining whether the temperature of the fluid at each of the plurality of temperature sensors remains above the disinfection temperature for at least the disinfection time. 【0045】 Another aspect of the present invention relates to a control method for controlling the administration of an anticoagulant in a dialysis system. The method includes the steps of: storing an anticoagulant protocol, including a maximum dose of the anticoagulant, in at least one storage medium; automatically administering the anticoagulant according to the anticoagulant protocol; and prohibiting further administration of the anticoagulant after determining that the maximum dose of the anticoagulant has been administered. 【0046】 Another aspect of the present invention relates to at least one computer-readable medium encoded with instructions for a control method that controls the administration of an anticoagulant in a dialysis system when executed by at least one processing apparatus. The method includes the steps of: electronically receiving an anticoagulant protocol including a maximum dose of the anticoagulant; controlling a plurality of actuators to administer the anticoagulant according to the anticoagulant protocol; and prohibiting further administration of the anticoagulant after determining that the maximum dose of the anticoagulant has been administered. 【0047】 Another aspect of the invention relates to a method for determining the fluid level in a dialysate tank of a dialysis system. The method includes the steps of tracking a first number of strokes that deliver fluid to the dialysate tank, tracking a second number of strokes that discharge fluid from the dialysate tank, and determining the fluid level in the dialysate tank based at least in part on the first number of strokes, the second number of strokes, and the volume per stroke. 【0048】 Another aspect of the present invention relates to a method for determining the fluid level in a dialysate tank of a dialysis system. The method includes the steps of filling a reference chamber of known capacity with a predetermined pressure and evacuating the reference chamber into a dialysate tank. The method further includes determining the pressure in the dialysate tank after evacuating the reference chamber into the dialysate tank. In addition, the method includes, at least in part, determining the fluid level in the dialysate tank based on the determined pressure in the dialysate tank. 【0049】 Another aspect of the present invention relates to a method for returning blood to a patient in the event of a power outage in a dialysis system that uses compressed air to drive a pump and / or valves during the dialysis process. In this method, the dialysis system comprises a dialysis apparatus having a membrane that separates a blood flow path from a dialysate flow path. The method includes the step of identifying a power outage in the dialysis system. The method further includes the step of releasing compressed air from a tank associated with the dialysis system in response to the identification of the power outage. In addition, the method includes the step of returning blood in the blood flow path to the patient by using the released compressed air to increase the pressure in the dialysate flow path. 【0050】 Another aspect of the present invention relates to a method for returning extracorporeal blood to a patient using a compressed gas source in an extracorporeal treatment system in the event of a power outage. The extracorporeal treatment system includes a filter having a semipermeable membrane that separates a blood flow path from an electrolyte solution flow path. The compressed gas communicates with an electrolyte solution container via a valve, and the electrolyte solution container communicates with an electrolyte solution flow path via a valve. The method includes the steps of: causing one or more first electrooperated valves to open a first fluid path between the compressed gas and the electrolyte solution container in response to the termination of power to one or more electrooperated valves that control the dispersion of compressed gas or the dispersion of the electrolyte solution flow in the extracorporeal treatment system; causing one or more second electrooperated valves to open a second fluid path between the electrolyte solution container and the filter; causing one or more third electrooperated valves to close the alternative fluid path of the electrolyte solution flow path when the alternative fluid path diverts the electrolyte solution from the filter; and returning the blood in the blood flow path to the patient by increasing the pressure in the electrolyte solution flow path using compressed gas. 【0051】 Another aspect of the present invention relates to a method for returning extracorporeal blood to a patient using a compressed gas source in an extracorporeal treatment system in the event of a power outage. The extracorporeal treatment system includes a filter having a semipermeable membrane that separates a blood flow path from an electrolyte solution flow path. The compressed gas communicates with an electrolyte solution container via a valve, and the electrolyte solution container communicates with an electrolyte solution flow path via a valve. The method includes causing one or more electrically operated valves to open a fluid path between the compressed gas and the electrolyte solution container in response to the termination of power to one or more electrically operated valves that control the dispersion of compressed gas or the dispersion of the electrolyte solution flow in the extracorporeal treatment system, and using the compressed gas to cause a flow of electrolyte solution from the electrolyte solution container to the filter, thereby returning the blood in the blood flow path to the patient. 【0052】 Further effects and novel features of the present invention will become apparent in the various embodiments of the invention described below, in conjunction with the accompanying drawings. These embodiments are not limited to those described below. The specification and cited documents contain conflicts and inconsistencies, but the specification prevails. Two or more cited documents contain conflicts and inconsistencies with each other, but the later-published document prevails. [Brief explanation of the drawing] 【0053】 [Figure 1] A schematic diagram showing a hemodialysis system. [Figure 2A] High-level schematic diagrams illustrating various implementations of dialysis systems. [Figure 2B] High-level schematic diagrams illustrating various implementations of dialysis systems. [Figure 3A] A schematic diagram showing an example of fluids in a dialysis system. [Figure 3B] A schematic diagram showing an example of fluids in a dialysis system. [Figure 4A] A schematic diagram showing the blood flow circuit used in a hemodialysis system in one embodiment. [Figure 4B] A schematic diagram showing the blood flow circuit used in a hemodialysis system in one embodiment. [Figure 4C]Figure 4A is a perspective view of the air trap. [Figure 4D] Figure 4A is a side view of the air trap. [Figure 5] A schematic diagram showing the equilibrium circuit used in a hemodialysis system in one embodiment. [Figure 6] A schematic diagram showing the orientation circuit used in a hemodialysis system. [Figure 7A] A schematic diagram showing the mixing circuit used in a hemodialysis system. [Figure 7B] A schematic diagram showing the mixing circuit used in a hemodialysis system. [Figure 8A] A diagram showing the phase relationship. [Figure 8B] A diagram showing the phase relationship. [Figure 8C] A diagram showing the phase relationship. [Figure 9] A cross-sectional view showing a valve incorporated into a fluid control cassette in the embodiment. [Figure 10] A cross-sectional view of the pod pump incorporated into the fluid control cassette in the embodiment. [Figure 11A] A schematic diagram illustrating various pneumatic control systems for pod pumps. [Figure 11B] A schematic diagram illustrating various pneumatic control systems for pod pumps. [Figure 12] A graph showing how the pressure applied to the pod pump is managed. [Figure 13A] A diagram illustrating the detection of an obstruction. [Figure 13B] A diagram illustrating the detection of an obstruction. [Figure 14] A diagram showing the control algorithm in one embodiment. [Figure 15] A diagram showing a typical separate PI regulator in one embodiment of the controller. [Figure 16] A diagram showing a double-housing cassette structure in one embodiment. [Figure 17A] A diagram relating to the priming of a part of the system in one embodiment of the invention. [Figure 17B]A diagram relating to the priming of a part of the system in one embodiment of the invention. [Figure 17C] A diagram relating to the priming of a part of the system in one embodiment of the invention. [Figure 18A] A diagram showing the flow rate of dialysate from the dialysate tank, through the dialyzer, and discharged from the drain pipe in one embodiment of the invention. [Figure 18B] A diagram showing the flow rate of dialysate from the dialysate tank, through the dialyzer, and discharged from the drain pipe in one embodiment of the invention. [Figure 19] A diagram showing the emptying of the dialysate tank in another embodiment of the invention. [Figure 20] A diagram showing the cleaning of the system with air at the end of a procedure in one embodiment of the invention. [Figure 21A] A diagram showing the pumping of air from an anticoagulant pump in another example of the invention. [Figure 21B] A diagram showing the pumping of air from an anticoagulant pump in another example of the invention. [Figure 21C] A diagram showing the pumping of air from an anticoagulant pump in another example of the invention. [Figure 22A] A diagram illustrating a integrity test in an embodiment of the invention. [Figure 22B] A diagram illustrating a integrity test in an embodiment of the invention. [Figure 22C] A diagram illustrating a integrity test in an embodiment of the invention. [Figure 22D] A diagram illustrating a integrity test in an embodiment of the invention. [Figure 23] A diagram showing a recirculation channel in another example of the invention. [Figure 24A] A diagram illustrating the priming of a system with dialysate in a further example of the invention. [Figure 24B] A diagram illustrating the priming of a system with dialysate in a further example of the invention. [Figure 24C] A diagram illustrating the priming of a system with dialysate in a further example of the invention. [Figure 24D] A diagram illustrating the priming of a system with dialysate in a further example of the invention. [Figure 25] A diagram illustrating the priming of an anticoagulant pump in a further example of the invention. [Figure 26A] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 26B] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 26C] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 26D] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 26E] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 26F] A diagram showing the removal of dialysate from a blood flow circuit in one embodiment of the invention. [Figure 27A] A diagram illustrating the delivery of anticoagulant pills to a patient in another embodiment of the invention. [Figure 27B] A diagram illustrating the delivery of anticoagulant pills to a patient in another embodiment of the invention. [Figure 27C] A diagram illustrating the delivery of anticoagulant pills to a patient in another embodiment of the invention. [Figure 28] A diagram showing solution injection in one embodiment of the invention. [Figure 29A] A schematic diagram illustrating how an emergency cleaning process is feasible. [Figure 29B] A schematic diagram illustrating how an emergency cleaning process is feasible. [Figure 30A] Equiscale and plan views of the outer top plate of the cassette in the embodiment. [Figure 30B] Equiscale and plan views of the outer top plate of the cassette in the embodiment. [Figure 30C] Equiscale and plan views of the inner top plate of the cassette in the embodiment. [Figure 30D] Equiscale and plan views of the inner top plate of the cassette in the embodiment. [Figure 30E] Side view of the top plate of the cassette in the embodiment. [Figure 31A] Equiscale and plan views of the fluid side of the midplate of the cassette in the embodiment. [Figure 31B] Equiscale and plan views of the fluid side of the midplate of the cassette in the embodiment. [Figure 31C] Equiscale and plan views of the air side of the midplate of the cassette in the embodiment. [Figure 31D] Equiscale and plan views of the air side of the midplate of the cassette in the embodiment. [Figure 32A] Equiscale and plan views of the inside of the bottom plate of the cassette in the embodiment. [Figure 32B] Equiscale and plan views of the inside of the bottom plate of the cassette in the embodiment. [Figure 32C] Equiscale and plan views of the outside of the bottom plate of the cassette in the embodiment. [Figure 32D] Equiscale and plan views of the outside of the bottom plate of the cassette in the embodiment. [Figure 32E] Side view of the bottom plate of the cassette in the embodiment. [Figure 33A] A plan view of the cassette assembled with the small bottle attached in the embodiment. [Figure 33B] A bottom view of the cassette assembled with the small bottle attached in the embodiment. [Figure 33C] An exploded view of the cassette assembled with the small bottle attached in the example. [Figure 33D] An exploded view of the cassette assembled with the small bottle attached in the example. [Figure 34A] An equiscale bottom view showing the midplate of the cassette in the embodiment. [Figure 34B] An equiscale plan view showing the midplate of the cassette in the embodiment. [Figure 34C] An equiscale bottom view showing the midplate of the cassette in the embodiment. [Figure 34D] A side view showing the midplate of the cassette in the embodiment. [Figure 35A] Equiscale and plan views of the top plate of the cassette in the embodiment. [Figure 35B] Equiscale and plan views of the top plate of the cassette in the embodiment. [Figure 35C] Equiscale view of the top plate of the cassette in the embodiment. [Figure 35D] Equiscale view of the top plate of the cassette in the embodiment. [Figure 35E] Side view of the top plate of the cassette in the embodiment. [Figure 36A] An equiscale bottom view of the bottom plate of the cassette in the embodiment. [Figure 36B] An equiscale bottom view of the bottom plate of the cassette in the embodiment. [Figure 36C] Equiscale plan view of the bottom plate of the cassette in the embodiment. [Figure 36D] Equiscale plan view of the bottom plate of the cassette in the embodiment. [Figure 36E] Side view of the bottom plate of the cassette in the embodiment. [Figure 37] Equiscale front view showing the drive side of the midplate of a cassette equipped with a valve, as shown in the embodiment, corresponding to Figure 36. [Figure 38A] A schematic diagram showing the outer top plate of the cassette in the embodiment. [Figure 38B] A schematic diagram showing the top plate inside the cassette in the embodiment. [Figure 38C] A side view showing the top plate of the cassette in the embodiment. [Figure 39A] A schematic diagram showing the fluid side of the midplate of the cassette in the example. [Figure 39B] A front view showing the air side of the midplate of the cassette in the embodiment. [Figure 39C] A side view showing the midplate of the cassette in the embodiment. [Figure 40A] A side view of the inside of the bottom plate of the cassette in the embodiment. [Figure 40B] A schematic diagram showing the outside of the bottom plate of the cassette in the embodiment. [Figure 40C]A side view showing the midplate of the cassette in the embodiment. [Figure 41A] Equiscale and front views showing the outer top plate in an embodiment of the cassette. [Figure 41B] Equiscale and front views showing the outer top plate in an embodiment of the cassette. [Figure 41C] Equiscale and front views of the top plate inside the cassette in the embodiment. [Figure 41D] Equiscale and front views of the top plate inside the cassette in the embodiment. [Figure 41E] A side view showing the top plate of the cassette in the embodiment. [Figure 42A] Equiscale and front views showing the fluid side of the midplate of the cassette in the embodiment. [Figure 42B] Equiscale and front views showing the fluid side of the midplate of the cassette in the embodiment. [Figure 42C] Equiscale and front views showing the air side of the midplate of the cassette in the embodiment. [Figure 42D] Equiscale and front views showing the air side of the midplate of the cassette in the embodiment. [Figure 42E] A side view showing the midplate of the cassette in the embodiment. [Figure 43A] Equiscale and front views of the inside of the bottom plate of the cassette in the embodiment. [Figure 43B] Equiscale and front views of the inside of the bottom plate of the cassette in the embodiment. [Figure 43C] Equiscale and front views showing the outside of the bottom plate of the cassette in the embodiment. [Figure 43D] Equiscale and front views showing the outside of the bottom plate of the cassette in the embodiment. [Figure 43E] A side view showing the bottom plate of the cassette in the embodiment. [Figure 44A] A plan view showing the cassette assembled in the embodiment. [Figure 44B] A bottom view showing the cassette assembled in the embodiment. [Figure 44C] An exploded view showing the cassette assembled in the example. [Figure 44D] An exploded view showing the cassette assembled in the example. [Figure 45] A cross-sectional view showing the assembled cassette system in the embodiment. [Figure 46A] A front view showing the assembled cassette system in the embodiment. [Figure 46B] A large-scale diagram showing the assembled cassette system in the embodiment. [Figure 46C] A large-scale diagram showing the assembled cassette system in the embodiment. [Figure 46D] An exploded view showing the assembled cassette system in the embodiment. [Figure 46E] An exploded view showing the assembled cassette system in the embodiment. [Figure 47A] A large diagram showing the cassette system pod in the embodiment. [Figure 47B] A large diagram showing the cassette system pod in the embodiment. [Figure 47C] A side view showing the pod of the cassette system in the embodiment. [Figure 47D] A large-scale diagram showing half of the cassette system pod in the embodiment. [Figure 47E] A large-scale diagram showing half of the cassette system pod in the embodiment. [Figure 48A] A diagram showing an image of the membrane of the cassette system pod in the example. [Figure 48B] A diagram showing an image of the membrane of the cassette system pod in the example. [Figure 49] An exploded view showing the cassette system pod in the embodiment. [Figure 50A] An exploded view showing the fluid lines of the inspection valve of a cassette system in one embodiment. [Figure 50B] An exploded view showing the fluid lines of the inspection valve of a cassette system in one embodiment. [Figure 50C] A large-scale diagram showing the fluid lines of the cassette system in the embodiment. [Figure 51A] A schematic diagram showing the fluid flow path of a cassette system integrally formed in one embodiment. [Figure 51B] A schematic diagram showing the fluid flow path of a cassette system integrally formed in one embodiment. [Figure 52A] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 52B] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 52C] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 52D] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 52E] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 52F] Various schematic diagrams showing blocks for connecting a pneumatic pipe to a manifold in a system according to one embodiment of the present invention. [Figure 53] A schematic diagram showing a sensor manifold as an alternative example. [Figure 54] Figure 53 shows the flow path within the sensor manifold. [Figure 55] Figure 53 is a side view showing the sensor manifold. [Figure 56A] A cross-sectional view of the sensor manifold shown in Figure 53 along line AA in Figure 56B. [Figure 56B] Figure 53 is a front view showing the sensor manifold. [Figure 57] Figure 53 is an exploded view showing the sensor manifold. [Figure 58]Figure 53 shows the printed circuit board and media edge connectors corresponding to the sensor manifold. [Figure 59] Fluid design diagram for a hemodialysis system. [Figure 60] A perspective view showing the combination of the user interface and the treatment device in the embodiment. [Figure 61] Figure 60 is a schematic diagram showing the hardware configuration of the display unit and the user interface unit, respectively. [Figure 62] A schematic diagram showing a software process that may be executed on the automated computer and user interface computer shown in Figure 61. [Figure 63] A schematic diagram illustrating the flow of information between hardware and software components in user interface computers and automation computers. [Figure 64] A schematic diagram showing a hierarchical state machine (HSM) that may be used in the UI controller shown in Figure 63. [Figure 65] A schematic diagram showing a normal screen display and an alarm screen display, which may be shown in the user interface shown in Figure 61. [Figure 66] A schematic diagram illustrating how the treatment layer interfaces with other layers, such as the machine layer and the user interface model layer. [Figure 67] A schematic diagram showing an example of machine layer implementation, as shown in Figure 66. [Figure 68] A schematic diagram showing an example implementation of a recycling preparation application. [Figure 69A] A schematic diagram illustrating an example implementation of a blood tract cleaning application. [Figure 69B] A schematic diagram illustrating an example implementation of a blood tract cleaning application. [Figure 70A] A schematic diagram showing an example of a disinfection application implementation. [Figure 70B] A schematic diagram showing an example of a disinfection application implementation. [Figure 71] A schematic diagram illustrating an example implementation of an endotoxin cleansing application. [Figure 72] A schematic diagram showing an example implementation of a treatment preparation application. [Figure 73A] A schematic diagram showing an example implementation of a patient linking application. [Figure 73B] A schematic diagram showing an example implementation of a patient linking application. [Figure 73C] A schematic diagram showing an example implementation of a patient linking application. [Figure 73D] A schematic diagram showing an example implementation of a patient linking application. [Figure 74A] A schematic diagram showing an example implementation of a dialysis application. [Figure 74B] A schematic diagram showing an example implementation of a dialysis application. [Figure 75A] A schematic diagram showing an example implementation of a solvent injection application. [Figure 75B] A schematic diagram showing an example implementation of a solvent injection application. [Figure 75C] A schematic diagram showing an example implementation of a solvent injection application. [Figure 75D] A schematic diagram showing an example implementation of a solvent injection application. [Figure 75E] A schematic diagram showing an example implementation of a solvent injection application. [Figure 76A] A schematic diagram illustrating an example implementation of a rinseback application. [Figure 76B] A schematic diagram illustrating an example implementation of a rinseback application. [Figure 77] A schematic diagram showing an example implementation of a sampling application. [Figure 78A] A schematic diagram showing an example implementation of a parts replacement application. [Figure 78B] A schematic diagram showing an example implementation of a parts replacement application. [Figure 78C] A schematic diagram showing an example implementation of a parts replacement application. [Figure 79A] A schematic diagram showing an example of a chemical application implementation. [Figure 79B] A schematic diagram showing an example of a chemical application implementation. [Figure 80]A diagram showing the pathway between the pressurized air tank and the dialysate tank in a hemodialysis system. [Modes for carrying out the invention] 【0054】 Embodiments of the present invention are disclosed with reference to the accompanying drawings, but are not limited thereto. The drawings are not intended to show dimensions precisely. Identical or substantially identical elements in the drawings are usually indicated by a single reference numeral. Not all elements in all drawings are denoted by reference numerals for clarity, nor are all elements of each embodiment of the present invention shown in order to enable those skilled in the art to understand the invention. 【0055】 The present invention relates to hemodialysis systems and similar dialysis systems, including various systems and methods that enable hemodialysis to be performed more efficiently, easily, and / or at a lower cost. An embodiment of the present invention shows a novel fluid circuit for fluid flow. In the embodiment, the hemodialysis system comprises a blood flow path and a dialysate flow path, the dialysate flow path comprising one or more equilibrium circuits, mixing circuits, and / or orientation circuits. In the embodiment, the pretreatment of the dialysate by the mixing circuit is separated from the patient's dialysis. In the embodiment, the circuit is provided at least partially within one or more cassettes and optionally interconnected with conduits, pumps, etc. In the embodiment, the fluid circuit and at least one of the various fluid flow paths are at least partially spatially and / or thermally isolated from the electrical elements of the hemodialysis system. In the embodiment, a gas supply is provided communicating with at least one of the dialysate flow path and the dialysis machine. When the gas supply is driven, it can facilitate the flow of dialysate through the dialysis machine and the return of blood in the blood flow path to the patient's body. The system is useful, for example, in emergency situations (e.g., power outages) where it is desirable to return as much blood as possible to the patient. In another embodiment of the present invention, the hemodialysis system further includes one or more fluid processing devices, such as pumps, valves, and mixers, which can be driven using a control fluid such as air. In the embodiment, the control fluid is delivered to the fluid processing device using a removable external pump or other device. In the embodiment, one or more fluid processing devices are typically rigid (e.g., spherical) and optionally have partitions within the device to separate the device into a first compartment and a second compartment. 【0056】 Various embodiments of the present invention illustrate novel hemodialysis systems, such as blood filtration systems, hemodialysis filtration systems, and plasma exchange systems. While various systems and methods related to hemodialysis are disclosed, these systems and methods can be applied to other dialysate systems and / or extracorporeal systems capable of treating other body fluids such as blood and plasma. 【0057】 As described above, a hemodialysis system typically comprises a blood flow path and a dialysate flow path. It should be noted that the fluid flow within these flow paths is not necessarily linear, and there can be any number of "branches" within the flow path such that the fluid flows from the inlet to the outlet. Examples of such branching will be described in detail later. In the blood flow path, blood is drawn from the patient and passes through the dialysis machine before returning to the patient. The blood is processed by the dialysis machine, and waste molecules (e.g., urea, creatinine, etc.) and water are removed from the blood and pass through the dialysis machine into the dialysate. The dialysate passes through the dialysis machine via a dialysate flow path. In various embodiments, blood is drawn from the patient through two lines (e.g., an arterial line and a venous line, i.e., a "two-needle" flow), or in some cases, blood is drawn from the patient and returned to the patient through the same needle (e.g., both lines are located within the same needle, i.e., a "one-needle" flow). In further examples, "Y"-shaped branching and "T"-shaped branching are used. Here, blood is drawn from and returned to the patient through a connection point with two branches (one for drawing blood and the other for returning blood). The patient can be any subject requiring hemodialysis or a similar procedure, but the patient is usually a human. However, hemodialysis may be performed on non-human subjects such as dogs, cats, and monkeys. 【0058】 In the dialysate flow path, unused dialysate is prepared and passes through the dialyzer to treat blood from the blood flow path. The dialysate is further homogenized within the dialyzer for blood treatment (i.e., the pressure between the dialysate and blood is made uniform), meaning that the pressure of the dialysate passing through the dialyzer is strictly, usually precisely, matched to the blood pressure passing through the dialyzer, or in some embodiments, within at least about 1% or about 2% of the blood pressure. After passing through the dialyzer, the used dialysate contains excretory molecules (described later). In some embodiments, the dialysate is heated using a suitable heater, such as an electrical resistance heater, prior to blood treatment within the dialyzer. The dialysate is further filtered, for example, using an ultrafiltration device, to remove contaminants, infectious microorganisms, and debris. The ultrafiltration device has a mesh size selected to prevent the passage of the above types. For example, the mesh size may be about 0.3 micrometers or less, about 0.2 micrometers or less, about 0.1 micrometers or less, or about 0.05 micrometers or less. Dialysis fluid is used to draw excretory molecules (e.g., urea, creatinine, potassium ions, phosphates, etc.) and water from the blood into the dialysis fluid through osmosis. Dialysis fluid is well known to those skilled in the art. 【0059】 Dialysis fluid typically contains various ions, such as potassium and calcium, at concentrations similar to those naturally present in healthy blood. In the examples, the dialysis fluid typically contains sodium bicarbonate at higher concentrations than those found in normal blood. Dialysis fluid is usually prepared by mixing one or more materials, namely an "acid" (including various types such as acetic acid, glucose, NaCl, CaCl, KCl, MgCl, etc.), sodium bicarbonate (NaHCO3), and / or sodium chloride (NaCl), with water from the water supply. The preparation of dialysis fluid, including the use of suitable concentrations of salt, osmolality, pH, etc., is well known to those skilled in the art. As will be described in detail later, the dialysis fluid does not need to be prepared at the same concentration used to treat blood. For example, the dialysis fluid can be formed simultaneously with or prior to dialysis and stored in a dialysis fluid storage container, etc. 【0060】 In a dialysis machine, dialysate and blood are not typically in physical contact with each other, but are separated by a semipermeable membrane. These semipermeable membranes are usually made of polymers such as cellulose, polyaryl ethersulfone, polyamide, polyvinylpyrrolidone, polycarbonate, and polyacrylonitrile. These allow ions and small molecules (e.g., urea, water) to pass through the membrane, but do not allow bulky substances to pass through or circulate during blood processing. In the example, even larger particles such as beta-2 microglobulin also pass through the membrane. 【0061】 Dialysis fluid and blood do not physically come into contact with each other within the dialysis machine, but are usually separated by a semipermeable membrane. A typical dialysis machine consists of a "shell-and-tube" design, comprising multiple separate tubes or fibers (through which blood flows) formed from a semipermeable membrane, and a larger "shell" (or, in some embodiments, the reverse configuration) surrounding the tubes or fibers through which the dialysate flows. In some embodiments, the flow of dialysate and blood through the dialysis machine may be parallel or reverse. Dialysis machines are well known to those skilled in the art and are available from a variety of commercial sources. 【0062】 In one embodiment, the dialysate flow path is separated into one or more circuits, namely an equilibrium circuit, a mixing circuit, and / or an orientation circuit. With respect to fluid flow, it should be noted that the circuits do not need to be isolated from the fluid, and the fluid flows in and out of the fluid circuits. Similarly, the fluid flows from one fluid circuit to another if the fluid circuits are in communication or interconnected. As used herein, "fluid" refers to anything having the characteristics of a fluid, and includes, but is not limited to, gases such as air, liquids such as water, aqueous solutions, blood, dialysate, etc. 【0063】 A fluid circuit is typically a distinct module that accepts any number of fluid inputs and performs one or more tasks in response to the fluid inputs before suitably outputting the fluid in an embodiment. As will be described later in embodiments of the present invention, the fluid circuit is formed as a cassette. Specifically, a dialysate flow path includes an equilibrium circuit, an orientation circuit, and a mixing circuit. As an alternative, a blood flow path includes a blood flow circuit. In the equilibrium circuit, the dialysate is guided within the circuit, and a pump acts on the dialysate to maintain equilibrium between the pressure of the dialysate passing through the dialysis machine and the pressure of the blood passing through the dialysate, as described above. Similarly, in the orientation circuit, unused dialysate moves from the mixing circuit to the equilibrium circuit, and used dialysate moves from the equilibrium circuit to the drain pipe. In the mixing circuit, the material and water are mixed to form unused dialysate. The blood flow circuit is used to draw blood from the patient, pass the blood through the dialysis machine, and return the blood to the patient. These circuits will be described in detail later. 【0064】 Figure 2A is a high-level schematic diagram showing an example of a hemodialysis system having the fluid circuit described above. Figure 2A shows a dialysis system 5 comprising a blood flow circuit 10 through which blood is transferred from the patient to the dialysis machine 14 and the treated blood is returned to the patient. The hemodialysis system in this example further comprises an equilibrium circuit or inner dialysate circuit 143, which pumps out the dialysate after it has passed through the ultrafiltration device 73 and the dialysis machine 14. Used dialysate is returned from the dialysis machine 14 to the equilibrium circuit 143. An orientation circuit or outer dialysate circuit 142 processes unused dialysate before it passes through the ultrafiltration device 73. A mixing circuit 25 prepares the dialysate using various raw materials 49 and water, for example, during and / or prior to dialysis, as needed. The orientation circuit 142 further receives water from the water supply 30 and transfers the water to the mixing circuit 25 for the preparation of the dialysate. The orientation circuit 142 further receives used dialysate from the equilibrium circuit 143 and moves it out of the system 5 through the drain pipe 31. Furthermore, a conduit 67 connecting the blood flow circuit 10 and the orientation circuit 142 for sterilization of the hemodialysis system is shown by a dashed line. In the embodiment, one or more of these circuits (e.g., blood flow circuit, equilibrium circuit, orientation circuit, and / or mixing circuit) comprises a cassette containing valves and pumps required to control the flow through the portion. An example of the above system will be described in detail below. 【0065】 Figure 2B is a schematic diagram showing a hemodialysis system in an embodiment of the present invention. In this figure, a blood flow cassette 22 is used to control the flow through the blood flow circuit 10, and a dialysate cassette 21 is used to control the flow through the dialysate circuit. The blood flow cassette includes at least one inlet valve 24 (another embodiment includes one or more inlet valves) to control the flow of blood through the cassette 22. Furthermore, an anticoagulant valve or pump 12 controls the flow of anticoagulant into the blood, and in the embodiment, the blood flow pump 13 comprises a pair of pod pumps. These pod pumps are of the type disclosed in U.S. Patent Application No. 60 / 792073, filed on 14 August 2006, with the title "Extracorporeal Thermal Therapy System and Method," or of the type disclosed in U.S. Patent Application No. 11 / 787212, filed on 13 August 2007, with the title "Fluid Pump System, Apparatus, and Method" (or variations thereof). These specifications are disclosed herein in their entirety. All pumps and valves in the system in this example are controllable by a control system, such as an electronic digital control system, but other control systems are also possible in other examples. 【0066】 By providing two pod pumps, blood can be continuously flowed through the blood flow circuit 10, although in an alternative example, a single pod pump may also be used. The pod pump includes a dynamic inlet valve and a dynamic outlet valve (in place of static check valves at the inlet and outlet), which may reverse the flow in the blood flow circuit 10 under certain conditions. For example, by reversing the flow in the blood flow circuit, the hemodialysis system can verify that the outlet of the blood flow circuit is properly connected to the patient and that the treated blood is correctly returned to the patient. For example, if the connection point to the patient becomes detached, such as by falling, reversing the blood flow pump will draw in air rather than blood. This air is detected by a standard air detector incorporated into the system. 【0067】 In an alternative example, the blood outlet valve 26 and air trap or filter 19 located downstream of the dialysis machine are incorporated into the blood flow cassette 22. The pod pump and all valves (including valves relating to the inlet and outlet of the pod pump) within the blood flow cassette 22 are driven by pneumatics. In the embodiment, the source of positive and negative gas pressure is provided by a base unit holding the cassette or other device holding the cassette. However, in an alternative example, the source of positive and negative gas may be provided by an external device connected in communication with the cassette or by a device incorporated within the system. The pump chamber is driven as disclosed in U.S. Patent Application No. 60 / 792073, filed on August 14, 2006, with the title "Extracorporeal Thermal Therapy System and Method," and U.S. Patent Application No. 11 / 787212, filed on August 13, 2007, with the title "Fluid Pump System, Apparatus, and Method." For example, the pump is controlled as described later to detect the end of the stroke. The blood flow cassette 22 further includes a spike integrally formed to receive a vial of anticoagulant. 【0068】 In the embodiment, the anticoagulant pump comprises three fluid valves (controlled by a control fluid) and one pump compartment (one or more pump compartments may be provided in other embodiments). The valves connect the compartment to a filtered vent, to an anticoagulant vial (or other anticoagulant supply such as a bag or bottle), or to a blood flow path. The anticoagulant pump can be driven by sequentially opening and closing the fluid valves, for example, by controlling the pressure in the pump compartment with a control fluid. When the anticoagulant is removed from the vial, it is replaced by an equal volume of air, for example, to maintain a relatively constant pressure in the vial. As described above, replacing the anticoagulant with air is carried out by, for example, (i) opening a valve from a filtered vent to the pump compartment, (ii) supplying air into the compartment by connecting a negative pressure source to the chamber, (iii) closing the vent valve, (iv) opening the valve connecting the compartment to the vial, and (v) supplying air into the vial by connecting a positive pressure source to the compartment. The anticoagulant is pumped from the vial into the blood flow channel in a similar order using valves to the vial and the blood flow channel rather than valves to the vent and the vial. 【0069】 Figure 3A is a schematic diagram showing an embodiment of the configuration shown in Figure 2A. Figure 3A shows in detail how the blood flow circuit 141, equilibrium circuit 143, orientation circuit 142, and mixing circuit 25 are arranged in the cassette, relate to each other, and relate to the dialysis machine 14, ultrafiltration machine 73, and / or heater 72 in an embodiment of the present invention. Figure 3A shows the only possible hemodialysis system in the embodiment of Figure 2A, but other fluid circuits, modules, flow paths, layouts, etc., are possible in other examples. Examples of the above system will be described in detail later. Furthermore, these include U.S. Patent Application No. 60 / 903582, filed on February 27, 2007, with the title of the invention "Hemodialysis System and Method", U.S. Patent Application No. 60 / 904024, filed on February 27, 2007, with the title of the invention "Hemodialysis System and Method", U.S. Patent Application No. 11 / 871680, filed on October 12, 2007, with the title of the invention "Pump Cassette", and U.S. Patent Application No. 11 / 871680, filed on October 12, 2007, with the title of the invention "Pump Cassette". The invention is disclosed in Japanese Patent Application No. 11 / 871712, U.S. Patent Application No. 11 / 871787, filed on October 12, 2007, with the title of the invention "Pump Cassette", U.S. Patent Application No. 11 / 871793, filed on October 12, 2007, with the title of the invention "Pump Cassette", or U.S. Patent Application No. 11 / 871803, filed on October 12, 2007, with the title of the invention "Cassette System Integrated Device", and the entirety thereof is disclosed herein. 【0070】 The elements shown in Figure 3A will be described later. Briefly, the blood flow circuit 141 comprises an anticoagulant dispenser 11 and a blood flow pump 13 that pumps blood from the patient to the dialysis machine 14. The illustrated anticoagulant dispenser 11 is located in the blood flow path to the dialysis machine, but in other examples it may be located in the blood flow path to the patient or in another preferred location. The anticoagulant dispenser 11 is located downstream of the blood flow pump 13. The equilibrium circuit 143 includes a dialysate pump 15 that pumps two similar dialysates to the dialysis machine 14, and a bypass pump 35. The orientation circuit 142 includes a dialysate pump 159 that pumps dialysate from the dialysate tank 169 through a heater 72 and / or an ultrafiltration device 73 to the equilibrium circuit. The orientation circuit 142 pumps wastewater from the equilibrium circuit 143 to a drain pipe 31. 【0071】 In this embodiment, the blood flow circuit 141 is connected to the orientation circuit 142 via a conduit 67, for example, for sterilization, as will be described later. The dialysate flows from the dialysate supply to the dialysate tank 169. As shown in Figure 3A, in this embodiment, the dialysate is formed in the mixing circuit 25. Water from the water supply 30 flows into the mixing circuit 25 through the orientation circuit 142. Dialysate raw materials 49 (e.g., bicarbonate and acid) are further added into the mixing circuit 25, and a series of mixing pumps 180, 183, 184 are used to form the dialysate. The dialysate is then transported to the orientation circuit 142. 【0072】 In this example system, one of the fluid circuits is the blood flow circuit, i.e., the blood flow circuit 141 shown in Figure 3A. In the blood flow circuit, blood from the patient is pumped through the dialysis machine and returned to the patient. As will be described later, in this embodiment the blood flow circuit is provided in a cassette, but this is not required. In this embodiment the blood flow through the blood flow circuit is in equilibrium with the flow of dialysate flowing through the dialysate channel, particularly through the dialysis machine and the equilibrium circuit. 【0073】 Figure 4 shows an example of a blood flow circuit. Normally, blood flows from the patient through arterial line 203 to the dialysis machine 14 via blood flow pump 13 (the direction of flow in normal dialysis is indicated by arrow 205; however, in another mode of operation, the flow is in a different direction). Optionally, an anticoagulant is introduced into the blood from an anticoagulant dispenser via an anticoagulant pump 80. As shown in Figure 4, the anticoagulant enters the blood flow path after the blood has passed through blood flow pump 13. However, in another example, the anticoagulant is added at a suitable location along the blood flow path. In another example, the anticoagulant dispenser 11 is located downstream of the blood flow pump. After passing through the dialysis machine 14 and undergoing dialysis, the blood returns to the patient through venous line 204. Optionally, it returns to the patient through an air trap or a blood sample port 19. 【0074】 As shown in Figure 4, the blood flow cassette 141 further includes one or more blood flow pumps 13 to move blood through the blood flow cassette. The pumps are driven by a control fluid, for example, as described later. In this embodiment, for example, the pump 13 consists of two (or more) pod pumps, i.e., the pod pumps 23 shown in Figure 4. In this embodiment, each pod pump includes a rigid chamber with a flexible partition or membrane that separates each chamber into a fluid compartment and a control compartment. These compartments are provided with four inlet or outlet valves, two in the fluid compartment and two in the control compartment. The valves in the control compartment of the chamber are bidirectional proportional valves, one connected to a first control fluid source (e.g., a high-pressure air source) and the other connected to a second control fluid source (e.g., a low-pressure air source) or a vacuum sink. The fluid valves in the compartments are openable and closable to allow fluid to flow when the pod pumps are driven. Examples of these pod pumps are disclosed, but are not limited to, U.S. Patent Application No. 60 / 792073, filed on 14 August 2006, with the title "Extracorporeal Thermal Therapy System and Method," and U.S. Patent Application No. 11 / 787212, filed on 13 August 2007, with the title "Fluid Pump System, Apparatus, and Method." These are disclosed herein in their entirety. Further details of the pod pumps will be described below. When one or more pod pumps are provided, they can be operated in a preferred manner, for example, synchronously or asynchronously, in phase or out of phase. 【0075】 In this embodiment, for example, two pumps may be rotated in different phases to affect the pump period, i.e., one pump chamber may be filled and the second pump chamber may be empty. The phase relationship between 0° (pod pumps drive in the same direction) and 180° (pod pumps drive in opposite directions) can be selected to obtain the desired pump period. 【0076】 A 180° phase relationship creates a continuous flow inside and outside the pod pump. This is suitable, for example, when a continuous flow is required, i.e., when used with a double needle flow or with a "Y" or "T" shaped connection. However, setting a 0° phase relationship is useful in the single-needle flow in the embodiment, or in other examples. In the 0° relationship, the pod pump is initially filled from the needle and the same needle is used to return blood to the patient through the blood flow path. Additionally, in the embodiment, drives between 0° and 180° can be used to obtain a push-pull relationship (hemodiafiltration or continuous backflow) across the dialysis machine. Figures 8A to 8C illustrate examples of such phase relationships. In these figures, the volume and flow of each pod pump, the volume of each pod pump, and the total volume of both pod pumps are shown on the time axis. These times and fluid velocities are arbitrarily selected and shown to illustrate the relationship between pod pumps at different phases. As shown in Figure 8B, for example, in the 180° phase relationship, the total volume is approximately constant. 【0077】 In the embodiment, as shown in Figure 4, an anticoagulant (e.g., heparin or other anticoagulants well known to those skilled in the art) is mixed with the blood in the blood flow cassette 141. For example, the anticoagulant is contained in a vial 11 (or other anticoagulant dispenser such as a tube or bag), and the blood flow cassette 141 is capable of receiving the vial of anticoagulant together with an integrally formed spike 201 (which is a needle in one embodiment) that can puncture the seal of the vial. The spike is formed from plastic, stainless steel, or other suitable material, and in the embodiment is a sterilizable material. For example, the material is sufficiently resistant to high temperatures or radiation to sterilize the material. As an example, as shown in Figure 4, the spike 201 is integrally formed with the blood flow cassette 141, the vial 11 is positioned on the spike, and the spike punctures the seal of the vial. The anticoagulant is then mixed with the blood in the blood flow channel and flows into the blood flow cassette to be mixed with the dialysate, as may be described later. 【0078】 In the embodiment, a third pump 80, which functions as a measurement chamber in the blood flow cassette 141, can be used to control the flow of anticoagulant into the blood in the cassette. The third pump 80 is of the same design as pump 13 or a different design. For example, the third pump 80 is a pod pump and / or the third pump 80 is driven by a control fluid such as air. For example, as shown in Figure 4, the third pump 80 includes a rigid chamber with a flexible partition separating the chamber into a fluid compartment and a control compartment. A valve in the control compartment of the chamber is connected to a first control fluid source (e.g., a high-pressure air source), and the other compartment is connected to a second control fluid source (e.g., a low-pressure air source) or a vacuum sink. A valve in the fluid compartment of the chamber is opened and closed according to the control compartment, thereby controlling the flow of anticoagulant into the blood. Further details of the pod pump described above will be described later. As described later in the embodiment, air is guided into the blood flow path through a filter 81. 【0079】 Fluid Management System (FMS) measurements are used to measure the volume of fluid pumped through the pump chamber during a membrane stroke, or to detect air within the pump chamber. Fluid management system methods are described in U.S. Patents 4,808,161, 4,826,482, 4,976,162, 5,088,515, and 5,350,357, which are incorporated herein by reference in their entirety. In some examples, the volume of fluid transported by an anticoagulant pump, dialysate pump, or other membrane-based pump is determined using a fluid management system algorithm that uses changes in chamber pressure to calculate volume measurements at the end of the filling stroke and the end of the transport stroke. The difference between the calculated volumes at the end of the filling stroke and the end of the transport stroke is the actual stroke volume. This actual stroke volume can be compared to the expected stroke volume for a chamber of given dimensions. If the actual volume differs significantly from the expected volume, the stroke is not properly completed, and an error message is generated. 【0080】 When stroke capacity is collected by scale, calculations are performed in the background to determine the calibration value relative to the reference chamber. The fluid management system vents to the atmosphere for measurements of the fluid management system. Alternatively, the system may vent to a high-pressure positive source and a low-pressure negative source for measurements of the fluid management system. This provides the following effects: (1) If the high-pressure source is a pressure tank with controlled pressure, there is an opportunity to cross-check the pressure sensors of the tank and chamber to see if the chamber is similar to when it is open to the tank. These can be used to detect pressure sensor failures or valve failures. (2) By using high or low pressure for ventilation, a large pressure difference is created for measurements of the fluid management system, thus providing better answers. 【0081】 The blood flow circuit 141 includes an air trap 19 incorporated into the blood flow circuit 141 in the embodiment. The air trap 19 is used to remove air bubbles from the blood flow path. In the embodiment, the air trap 19 can separate air generated from the blood by gravity. In the embodiment, the air trap 19 further includes a port for blood sample extraction. Air traps are well known to those skilled in the art. 【0082】 According to another aspect of the present invention, the air trap 19 is provided in the blood flow path after blood has been discharged from the dialysis machine and before it returns to the patient. As shown in Figures 4C and 4D, the air trap 19 has a spherical or ellipsoidal container 6, with its inlet port 7 located near the top of the container, offset from its vertical axis, and its outlet 9 located at the bottom of the container. The curved shape of the inner wall 4 of the trap thus guides the blood to circulate along the inner wall as it descends to the bottom of the container due to gravity, making it easier to remove air bubbles from the blood. Air present in the blood discharged from the outlet 9 of the dialysis machine 14 enters the top of the air trap 19 and remains at the top of the container as the blood exits the outlet at the bottom and enters the venous blood line 204. By providing the inlet port 7 near the top of the trap 19, it is also possible to circulate blood through a trap with little or no air present in the container (as a "run-full" air trap). It is advantageous to eliminate the air-blood interface for normal blood circulation within the trap. By positioning the inlet port 7 at or near the top of the container, it is also possible to remove most or all of the air present in the trap by reversing the flow of fluid through the blood tube (i.e., from the bottom to the top of the trap 19, and discharged from the inlet port of the trap 19). In the embodiment, a self-sealing port 3, such as a self-sealing stopper with a divided partition or membrane, or another configuration, is provided at the top of the trap so that air can be discharged from the container (e.g., by a syringe). The blood-side surface of the self-sealing membrane can be positioned at approximately the same height as the top inside the trap to facilitate cleaning of the self-sealing port during disinfection. The self-sealing port 3 can also function as a blood sample extraction site and / or for introducing liquids, drugs or other compounds into the blood circuit. If needle access is anticipated, a sealing rubber type stopper can be used. Using a self-sealing stopper with a divided partition allows for sample extraction and fluid transport using a needleless system. 【0083】 The blood flow circuit 10 is also connected to the patient by an additional fluid connector 82 and / or to a fluid source for priming or sterilizing the system including the blood flow circuit 10. During normal sterilization, the arterial line 203 and venous line 204 are directly connected to the orientation circuit 142 via conduits 67, thereby returning the sterilization fluid (for example, hot water or a combination of hot water and one or more chemicals in the embodiment) to the orientation circuit 142 for recirculation through the dialysis machine 14 and the blood flow circuit 141. This sterilization is similar to that disclosed in U.S. Patent No. 5,651,898 by Kenley et al., which is disclosed in whole here. These are further described below. 【0084】 The pressure within the arterial line 203 is maintained below atmospheric pressure in the embodiment to draw blood from the patient. When a pod pump is used, the pressure within the blood flow pump 13 is inherently limited to the pressure available from the positive and negative pressure tanks used to drive the pump. In the event of a failure of the pressure tank or valve, the pressure in the pump chamber approaches the tank pressure. This causes the fluid pressure to rise to match the tank pressure up to the septum in the "bottom" of the pod pump (i.e., it is immobile as it comes into contact with the surface). The fluid pressure does not exceed safe limits and equilibrium with natural body fluid pressure. This failure causes the pod pump to stop operating spontaneously without special intervention. 【0085】 Examples of blood flow cassettes are shown in Figures 30 to 33, but are not limited to these. Figures 30A and 30B show the outside of the top plate 900 of the cassette in an embodiment. The top plate 900 contains half of the pod pumps 820 and 828. This half is half of the fluid through which the source fluid flows. Two channels 818 and 812 are shown. These channels are guided to the respective pod pumps 820 and 828. 【0086】 The pod pumps 820,828 include raised channels 908,910. The raised channels 908,910 allow fluid to flow continuously through the pod pumps 820,828 after a bulkhead (not shown) has reached the end of its stroke. Thus, the raised channels 908,910 minimize bulkheads that trap air or fluid in the pod pumps 820,828, or bulkheads that block the inlet or outlet of the pod pumps 820,828, preventing continuous flow. In one embodiment, the raised channels 908,910 have predetermined dimensions, which are equivalent to those of the fluid channels 818,812. However, in another embodiment, the raised channels 908,910 are narrower, and in yet another embodiment, the raised channels 908,910 may have any dimensions, as the objective is to control the fluid to obtain a desired fluid velocity or action flow rate. In the embodiment, the raised channels 908, 910 and fluid channels 818, 812 may have different dimensions. Therefore, the dimensions shown herein with respect to the raised channels, pod pumps, valves, and other embodiments are merely illustrative and alternative examples. Other embodiments are also apparent. 【0087】 In one embodiment of this cassette, the top plate includes a spike 902 in addition to the container's base 904. The spike 902 is empty in this example and is connected to a fluid in the flow path. In this embodiment, a needle is attached to the spike. In another embodiment, the needle is connected to an accessory of the container. 【0088】 Figures 30C and 30D show the interior of the top plate 900. The raised channels 908 and 910 connect to the inlet channels 912 and 916 and the outlet channels 914 and 918 of the pod pumps 820 and 828. The raised channels are described in detail above. 【0089】 The metering pump (not shown) includes a connection to the vent 906 as well as a connection to the spike's air passage 902. In one embodiment, the vent 906 includes an air filter (not shown). In the embodiment, the air filter is a particulate air filter. In the embodiment, the filter is a somicron hydrophobic air filter. In various embodiments, the dimensions of the filter vary and depend on the required results. The metering pump is driven by drawing in air through the vent 906, pumping the air through the spike's air passage 902 to a container of a second fluid (not shown), and then pumping a volume of the second fluid from the container (not shown) through the spike's air passage 902 to point 826 into the fluid line. This fluid passage for the metering pump is indicated by an arrow in Figure 30C. 【0090】 Figures 31A and 31B show the fluid side of the midplate 1000. They show supplementary areas of the flow path in the internal top plate. These areas are slightly raised trajectories indicating a conductive surface finish achieved by laser welding, one mode of manufacturing in this embodiment. Other modes of cassette manufacturing are described above. The fluid inlet 810 and fluid outlet 824 are also shown in these figures. 【0091】 Figures 31C and 31D show the air side of the midplate 1000 in one embodiment. As shown in Figure 31A, the air side of valve holes 808, 814, 816, and 822 corresponds to the fluid side holes of the midplate. As shown in Figures 33C and 33D, partition wall 1220 completes valves 808, 814, 816, and 822, and partition wall 1226 completes pod pumps 820 and 828. Metering pump 830 is completed by partition wall 1224. Valves 808, 814, 816, 822, 832, 834, and 836 are driven by air. The partition walls are stretched and removed from the holes, drawing in the liquid. When the partition walls are pressed toward the holes, the liquid is pushed and passes through. The fluid flow is directed by opening and closing valves 808, 814, 816, 822, 832, 834, and 836. 【0092】 Figures 31A and 31C show that the metering pump includes three holes 1002, 1004, and 1006. Hole 1002 draws air into the metering pump. The second hole 1004 pushes and moves the air into the spike or source container and further draws liquid from the source container. The third hole 1006 pushes and moves the second fluid from the metering pump 830 to point 826 in the fluid line. 【0093】 Valves 832, 834, and 836 drive the second fluid metering pump. Valve 832 is the second fluid or spike valve. Valve 834 is an air valve, and valve 836 controls the flow of fluid into region 826 of the fluid line. 【0094】 Figures 32A and 32B show the interior of the bottom plate 1100. The interiors of the pod pumps 820 and 828, the metering pump 830, and the drives or air chambers of the valves 808, 814, 816, 822, 832, 834, and 836 are shown. The pod pumps 820 and 828, the metering pump 830, and the valves 808, 814, 816, 822, 832, 834, and 836 are driven by an air source. Figures 32C and 32D show the exterior of the bottom plate 1100. The air source is mounted on this side of the cassette. In one embodiment, the tubing is connected to the surface of the valves and pump 1102. In the embodiment, the valves are interlocked, and one or more valves are driven by the same air line. 【0095】 Figures 33A and 33B show an assembled cassette 1200 with a second fluid container (or other source) 1202. The container 1202 contains the source of the second fluid and is attached to a spike (not shown) by a container accessory 1206. The spike is mounted inside the container accessory 1206 and faces upward so as to penetrate the top of the container 1202. The container 1202 is held on the opposite side from the container accessory 1206. The spike communicates with the liquid channel as well as the recessed air passage shown in Figures 30C and 30D. In the illustration, an air filter 1204 is mounted to a vent (not shown, shown as 906 in Figure 30A). Not shown in Figure 33A, a container basin (shown as 904 in Figure 30A) is located below the container accessory 1206. 【0096】 In some examples, the metering pump is a fluid management system pump that works in conjunction with a reference chamber and can be monitored by a pressure transducer to determine the volume of fluid being transported. The fluid management system algorithm uses the change in pressure to calculate volume measurements at the end of the filling stroke and the end of the transport stroke. The difference between the calculated volumes at the end of the filling stroke and the end of the transport stroke is the actual stroke volume. This actual stroke volume can be compared to the expected stroke volume for a chamber of given dimensions. If the actual volume and the expected volume differ significantly, the stroke is not properly completed and an error message is generated. The fluid management system is connected to the atmosphere for fluid management system measurements. Alternatively, the system may be connected to a high-pressure positive source and a low-pressure negative source for fluid management system measurements. In some embodiments, the metering pump (e.g., an anticoagulant pump) is primed. Priming the pump removes air from the metering pump and flow path, ensuring that the pressure in the fluid container (e.g., a vial of anticoagulant) is acceptable. 【0097】 A metering pump can be designed so that air in the pump chamber flows into the vial. The test involves closing all fluid valves of the metering pump and measuring the volume outside, evacuating the pump's fluid management system chamber, opening the valves to introduce fluid from the vial into the pump chamber, and then measuring the volume outside again, applying pressure to the fluid management system chamber, opening the valves to push the fluid back into the vial, and then measuring the volume outside again. The change in volume outside resulting from the fluid flow should correspond to the known volume of the pump chamber. If the pump chamber cannot be filled with fluid, the pressure in the vial is too low, and air must be pumped in. Conversely, if the contents of the pump chamber cannot be completely transferred to the vial, the pressure in the vial is too high, and some of the anticoagulant must be pumped out of the vial. The anticoagulant pumped out of the vial during the test can be discarded, for example, through a drain pipe. 【0098】 The pressure inside the vial can be measured periodically while heparin or other medications are being normally delivered through the bloodstream. When the pressure inside the vial approaches a predetermined threshold, for example, below atmospheric pressure, the metering pump can first introduce air into the vial through the metering pump vent, helping to restore the pressure inside the vial to normal and ensure that a reasonably accurate amount of medication is dispensed from the vial. When the pressure inside the vial approaches a predetermined threshold, above atmospheric pressure, the metering pump can refrain from blowing any more air into the vial before dispensing the next dose of medication from it. 【0099】 Figures 33C and 33D are exploded views of the assembled cassette 1200 shown in Figures 33A and 33B, respectively. In these figures, the pod pump partition 1226 in the embodiment is shown. The partition gasket seals between the liquid chamber (of the top plate 900) and the air or drive chamber (of the bottom plate 1100). The domed recessed texture of the partition 1226 provides additional space for air and fluid to escape the chamber, particularly at the end of the stroke. 【0100】 The system of the present invention further includes an equilibrium circuit, for example, an equilibrium circuit 143 shown in Figure 3A. A blood flow circuit is provided in the cassette, even if it is not necessary in the embodiment. Within the equilibrium circuit, the flow of dialysate entering and leaving the dialysis machine is such that equal amounts of dialysate enter and leave the dialysis machine (however, this equilibrium may be altered in certain cases by the use of a bypass pump, as will be described later). Additionally, in the embodiment, the flow of dialysate is maintained in equilibrium by the dialysis machine such that the pressure of the dialysate in the dialysis machine is equal to the pressure of the blood passing through the blood flow circuit. 【0101】 In addition, in some examples, the flow of dialysate is balanced by the dialyzer so that the pressure of the dialysate within the dialyzer is approximately equal to the pressure of the blood passing through the blood circuit. In some examples, the flow of blood through the blood flow circuit 141 and the dialyzer is synchronized with the flow of dialysate in the dialysate channel through the dialyzer. Because fluid can pass through the semipermeable membrane of the dialyzer, and because the pumps of the balancing circuit operate under positive pressure, the pumps of the balancing circuit can use pressure and control data from the blood flow pump to time the transport stroke to the dialyzer to synchronize with the transport stroke of the blood pump. 【0102】 Figure 5 shows an example of a balance circuit, but it is not limited to this. In the balance circuit 143, dialysate flows from an optional ultrafiltration membrane 73 to one or more dialysate pumps 15 (two as shown in Figure 5). The dialysate pumps 15 in this figure include two pod pumps 161, 162, two balance chambers 341, 342, and a pump 35 for bypassing the balance chambers. The balance chamber is formed from a rigid chamber with a flexible partition that divides the chamber into two separate fluid compartments, configured such that fluid entering one compartment causes fluid to be discharged from the other compartment, and vice versa. Examples of pumps that can be used as pod pumps or equilibrium chambers are disclosed, but are not limited to, U.S. Patent Application No. 60 / 792,073, filed on April 14, 2006, with the title "Extracorporeal Thermotherapy System and Method," or U.S. Patent Application No. 11 / 787,212, filed on April 13, 2007, with the title "Fluid Pump System, Apparatus, and Method." These are disclosed herein in their entirety. Additional examples of pod pumps will be described in detail later. As shown in Figure 5, many of the valves are "interlocked" or synchronized as a set, so that all valves in the set open and close simultaneously. 【0103】 More specifically, in one embodiment, flow equilibrium operates as follows. Figure 5 shows that in the first synchronized and controlled valves 211, 212, 213, 241, 242, valves 211, 212, 213 are linked, and valves 241 and 242 are linked. Similarly, in the second synchronized and controlled valves 221, 222, 223, 231, 232, valves 221, 222, 223 are linked, and valves 231 and 232 are linked. At a first point in time, the valves 211, 212, 213, 241, 242 of the first linked set are open, and the valves 221, 222, 223, 231, 232 of the second linked set are closed. Unused dialysate flows into the equilibrium chamber 341, and used dialysate flows from the dialyzer 14 into the pod pump 161. Unused dialysate does not flow into the equilibrium chamber 342 because valve 221 is closed. When unused dialysate flows into the equilibrium chamber 341, the used dialysate in the equilibrium chamber 341 is forcibly pushed out and discharged from the equilibrium circuit 143 (used dialysate cannot enter the pod pump 161 because valve 223 is closed). At the same time, the dialysate in the pod pump 162 is forcibly drawn into the equilibrium chamber 342 by the pod pump 162 (through the open valve 213. Valves 242 and 222 are closed, ensuring that used dialysate flows into the equilibrium chamber 342). As a result, the unused dialysate contained in the equilibrium chamber 342 is discharged from the equilibrium circuit 143 and enters the dialysis machine 14. Furthermore, the pod pump 161 draws used dialysate from the dialysis machine 14 into the pod pump 161. This is further illustrated in Figure 18A. 【0104】 When the pod pump 161 and the balancing chamber 341 are filled with dialysate, the first set of valves 211, 212, 213, 241, and 242 close, and the second set of valves 221, 222, 223, 231, and 232 open. Unused dialysate flows into the balancing chamber 342 instead of the balancing chamber 341 because valve 212 is closed and valve 221 is open. Once the unused dialysate flows into the balancing chamber 342, the used dialysate in the chamber is forcibly discharged from the balancing circuit by the closing of valve 213. Valve 232 closes and valve 222 opens, preventing the used dialysate from flowing into the pod pump 161. As a result, the unused dialysate contained in the balancing chamber 341 is directed into the dialysis machine (because valve 241 is open and valve 212 is closed). At the end of this process, the pod pump 162 and the balancing chamber 342 are filled with dialysate. This returns the system state to the initial state described herein, the cycle repeats, and ensures that the dialysate circulating through the dialyzer remains in a constant flow. This is further illustrated in Figure 18B. 【0105】 In a specific example, a vacuum (e.g., a vacuum of 4 psi (approximately 27.586 kPa)) acts on the valves of the first interlocking pair, and a positive pressure (e.g., atmospheric pressure of 20 psi (approximately 137.931 kPa) (1 psi = 6.89475 kPa)) acts on the valves of the second interlocking pair, thereby closing (or vice versa) these valves. Each pod pump pumps dialysate into one of the volumes of the equilibrium chambers 341, 342. By forcing dialysate into the volumes of the equilibrium chambers, an equal amount of dialysate is compressed in the equilibrium chamber from the other volume by the partition. In each equilibrium chamber, one volume is occupied by unused dialysate going to the dialysis machine, and the other volume is occupied by used dialysate from the dialysis machine. Thus, the volumes of dialysate entering and leaving the dialysis machine are kept approximately equal. 【0106】 It should be noted that any valve connected to the equilibrium chamber can be opened and closed at any appropriate pressure. However, it would be advantageous to apply a pressure lower or more controlled than the pressure that will ultimately maintain the valve in a closed state ("holding pressure") from the time the valve begins to close until it is fully closed. Applying a pressure equal to the holding pressure to cause the valve to close can cause a transient pressure rise in the fluid line, leading to leakage in already closed downstream valves and negatively impacting the equilibrium of the dialysate flow in and out of the dialysate machine. Closing the dialysate pump and the inlet and / or outlet valves of the equilibrium chamber at a lower or more controlled pressure can improve the equilibrium of the dialysate flow in and out of the dialysate machine. In the embodiment, this can be achieved, for example, by employing pulse width modulation ("PWM") to apply pressure to the fluid control line of the valve. Using a moderate or controlled pressure on a "soft-close" valve would be effective for reasons such as, for example, the following, though not limited to the theory below: (1) In some cases, the pressure in the equilibrium chamber may transiently exceed the holding pressure of the closed outlet valve of the equilibrium chamber (for example, when excessive pressure is applied to close the inlet valve of the equilibrium chamber against the mass of fluid behind the valve partition). The transient pressure rise in the fluid line can overcome the holding pressure of the closed outlet valve, causing fluid to leak between the two sides of the equilibrium chamber and resulting in an imbalance in fluid transport. (2) Furthermore, the presence of air or gas between the equilibrium chamber and the valve of the equilibrium chamber, combined with rapid valve closure, may cause excess fluid to be pushed into the equilibrium chamber without being balanced by the fluid from the other side of the equilibrium chamber. 【0107】 As the partition approaches the wall of the equilibrium chamber (causing one volume of the equilibrium chamber to approach its minimum and the other volume to approach its maximum), positive pressure acts on the valves of the first set of interlocking mechanisms, thereby closing these valves. Vacuum acts on the valves of the second set of interlocking mechanisms, thereby opening these valves. The pod pump delivers dialysate to one of the other volumes of the equilibrium chambers 341, 342. The same amount of dialysate is again forced into the volume of the equilibrium chamber, compressed by the partition from the other volume of the equilibrium chamber. In each equilibrium chamber, one volume is occupied by unused dialysate going to the dialysis machine, and the other volume is occupied by used dialysate from the dialysis machine. Thus, the volume of dialysate entering and leaving the dialysis machine is maintained equal. 【0108】 Furthermore, Figure 5 shows a bypass pump 35 capable of directing the flow of dialysate from the dialysis machine 14 through the equilibrium circuit 143 without passing through either the pod pump 161 or 162. In this figure, the bypass pump 35 is a pod pump similar to those described above, and comprises a rigid chamber and a flexible partition separating each chamber into a fluid compartment and a control compartment. This pump is the same as or different from the other pod pumps and equilibrium chambers described above. For example, this pump is the same as the pump described in U.S. Patent Application No. 60 / 792,073, filed on April 14, 2006, titled “Extracorporeal Thermotherapy System and Method,” or in U.S. Patent Application No. 11 / 787,212, filed on April 13, 2007, titled “Fluid Pump System, Apparatus and Method,” each of which is disclosed in its entirety here. The pod pump will be described in more detail later. 【0109】 When a control fluid is used to drive this pump, the dialysate is pumped through the dialyzer without being in equilibrium with the blood flow through the dialyzer. This causes a fluid flow from the patient through the dialyzer towards the drain pipe. The above bypass is useful, for example, to reduce the amount of fluid the patient has, which usually increases because the patient cannot reduce fluid (mainly water) through the kidneys. As shown in Figure 5, the bypass pump 35 is controlled by a control fluid (e.g., air) independently of the driving of the pod pumps 161 and 162. This configuration makes it easy to control the removal of fluid from the patient without driving the equilibrium pump so that fluid is discharged from the patient. 【0110】 To obtain a balanced flow across the dialysis machine, the blood flow pump, the balance circuit pump, and the orientation circuit pump (described later) are driven in cooperation to ensure that the flow to the dialysis machine is equal to the flow from the dialysis machine. When ultrafiltration is required, the ultrafiltration pump (if there is one) is driven independently of some or all of the other blood pumps and dialysate pumps to obtain the desired ultrafiltration rate. 【0111】 To prevent gas release from the dialysate, the equilibrium circuit pump is always held at a pressure greater than atmospheric pressure. In contrast, the blood flow pump and orientation circuit pump use a pressure lower than atmospheric pressure to stretch the septum toward the chamber wall for the filling stroke. Potentially, for the fluid to move across the dialyzer, and because the equilibrium circuit pump is driven by positive pressure, the equilibrium circuit pump can use information from the blood flow pump to operate in a mode of balanced flow. 【0112】 In the embodiment, when driven in the mode that maintains the balance described above, if there is no transport pressure from the blood flow pump, the partition of the balance circuit pump will press and move fluid across the dialysis machine into the blood, so the pods in the balance circuit will not be fully filled. Therefore, the blood flow pump reports when there is a stroke. The balance pump is driven when the blood flow pump is stroking. When the blood flow pump is not transporting blood, the valves that control the flow from the dialysis machine to the balance pump (and other balance valves that work in conjunction with these valves as described above) are closed to prevent fluid movement from the blood side to the dialysate side. When the blood flow pump is not transporting, the balance pump is effectively frozen, and the stroke continues when the blood flow pump starts transporting again. The filling pressure of the balance pump is set to the minimum positive value to ensure that the pump is driven above atmospheric pressure with minimum impedance. Furthermore, the transport pressure of the balance pump is typically set to the blood flow pump pressure to match the pressure on both sides of the dialysis machine, minimizing the flow across the dialysis machine during the internal pump stroke. 【0113】 In some cases, it may be advantageous to have the dialysate pump deliver dialysate to the dialyzer at a pressure higher than that of the blood pump. This helps, for example, to ensure that clean dialysate is delivered to the dialyzer throughout the entire chamber. In some embodiments, the delivery pressure on the dialysate pump is set high enough to complete the internal pump's stroke, but not high enough to stop the blood flow in the dialyzer. Conversely, in some cases, when the dialysate pump is receiving used dialysate from the dialyzer, it may be advantageous to set the pressure inside the dialysate pump lower than the outlet pressure on the blood side of the dialyzer. This helps ensure that the receiving dialysate chamber is always filled, that is, that enough dialysate is available to complete a full stroke in the equilibrium chamber. The flow through the semipermeable membrane created by such a pressure difference tends to cancel each other out. Otherwise, the pump algorithm will attempt to match the average pressure on the dialysate and blood sides of the dialyzer. 【0114】 The convection that occurs across the membrane of the dialysis machine, while not achieving net ultrafiltration, is beneficial because the constant, repetitive shift of fluid entering and leaving the machine, does help prevent the formation of blood clots in the blood vessels and within the dialysis machine. This, in turn, allows for reduced heparin dosage, extends the lifespan of the dialysis machine, and facilitates its cleaning and reuse. Backflushing also has the additional benefit of further promoting solute removal by convection. In another embodiment, a kind of continuous backflushing across the membrane of the dialysis machine can also be achieved by slightly adjusting the synchronization of the blood transport stroke and the dialysate transport stroke through the dialysis machine. 【0115】 In treatment, stagnant blood flow can cause blood clots, so it is preferable to maintain blood flow as constant as possible. Additionally, if the velocity of the fluid being transported by the blood flow pump is discontinuous, the balance pump will need to frequently pause its strokes, which will result in discontinuous and / or low velocity of the dialysate fluid. 【0116】 However, the flow through the blood flow pump becomes discontinuous for various reasons. For example, the pressure is limited to +600 mmHg (approximately 79.993 kPa) to -350 mmHg (approximately -46.662 kPa) within the blood flow pump to provide a safe pumping pressure for the patient. For example, in a double needle flow, the two pod pumps of the blood flow pump can be programmed to drive 180° apart from each other. This phase can always be achieved if there is no pressure limit. However, these pressures are limited to provide a safe blood flow for the patient. If the impedance is high during the filling stroke (due to a small needle, very viscous blood, difficulty accessing the patient, etc.), the negative pressure limit is reached, and the fluid velocity of the filling becomes slower than the desired fluid velocity. Therefore, the transport stroke must wait for the previous filling stroke to complete, pausing the transport fluid velocity of the blood flow pump. Similarly, in a single needle flow, the blood flow pumps are driven at a 0° phase, and the pod pumps of both blood flow pumps are emptied and refilled simultaneously. When both pod pumps are refilled, the volumes of both pod pumps are transported. Therefore, a single needle flow is discontinuous. 【0117】 One way to control the pressure saturation limit is to restrict the desired fluid velocity to the slowest of the filling and transport strokes. This makes the velocity of the blood transport flow slower, but the flow velocity becomes known, always continuous, and provides a more accurate and continuous dialysate flow velocity. Another way to make the blood flow velocity more continuous in driving a single needle is to use the maximum pressure to fill the pod so that the filling time is minimized. The desired transport time can be set by subtracting the time taken for the filling stroke from the total time of the desired stroke. However, if the blood flow velocity cannot be kept constant, the dialysate flow velocity is adjusted and compensated by a set value for the time the dialysate pump stops when the blood flow pump is filling, when the blood flow velocity transporting the dialysate flow is high. If this is done at the correct timing, the average of the dialysate flow velocity over multiple strokes can match the desired dialysate flow velocity. 【0118】 Figures 34 to 36 show, but are not limited to, examples of balanced cassettes. In one cassette structure shown in Figure 34A, the valves are interlocked to be driven simultaneously. In one embodiment, four interlocking valves 832, 834, 836, and 838 are provided. In this embodiment, the interlocking valves are driven by the same airline. However, in another embodiment, each valve has a corresponding airline. As shown in the embodiment, the interlocking valves generate the fluid flow as described above. In this embodiment, the interlocking valves further ensure that the appropriate valve is opened and closed, forming the required fluid path. 【0119】 In this embodiment, the fluid valve is a volcanic valve, as disclosed in detail here. While an outline of the fluid path in various embodiments is disclosed with respect to a specific flow path, the flow path changes based on the operation of the valve and pump. Additionally, the terms inlet and outlet, as well as first fluid and second fluid, are used only for descriptive purposes (in this cassette and other cassettes described later). In other examples, the inlet may be an outlet, and furthermore, the first fluid and second fluid may be different types of fluids, or the same type and configuration of fluids. 【0120】 Figures 35A to 35E show the top plate 1000 of the cassette in the embodiment. Figures 35A and 35B are plan views of the top plate 1000. In this embodiment, the pod pumps 820, 828 and the equilibrium pods 812, 822 of the top plate are formed in the same manner. In this embodiment, the pod pumps 820, 828 and the equilibrium pods 812, 822 have a total capacity of 38 ml when assembled with the bottom plate. However, in various embodiments, the total capacity may be larger or smaller than that of this embodiment. The first fluid inlet 810 and the second fluid outlet 816 are shown. 【0121】 Figures 35C and 35D are bottom views of the top plate 1000. The flow paths are shown in these figures. These flow paths correspond to the flow paths of the mid-plate 900 shown in Figure 34B. The tops of the top plate 1000 and the mid-plate form the liquid side or fluid side of the cassette for the pod pumps 820, 828 and one side of the equilibrium pods 812, 822. Thus, most of the fluid flow paths are located in the top plate and the mid-plate. The opposite side of the equilibrium pods 812, 822 is located inside the bottom plate, as shown in Figures 36A and 36B, but not shown here. 【0122】 Figures 35C and 35D further show that the pod pumps 820, 828 and the equilibrium pods 812, 822 also include the groove 1002. The illustrated groove 1002 has a predetermined shape. However, in another example, the shape of the groove 1002 may be any preferred shape. Figures 35C and 35D show the shape in an embodiment. In the embodiment, the groove 1002 forms a passage between the fluid inlet side and the fluid outlet side of the pod pumps 820, 828 and the equilibrium pods 812, 822. 【0123】 The groove 1002 forms a flow path, and because there is a flow path between the inlet and outlet when the partition wall is at the end of the stroke, no pockets of fluid or air are trapped in the pod pump or balance pod. The groove 1002 is included on both the liquid side and the air side of the pod pumps 820, 828 and the balance pods 812, 822 (see Figures 36A, 36B, which relate to the air side of the pod pumps 820, 828 and the opposite side of the balance pods 812, 822). 【0124】 In one embodiment, the liquid side of the pod pumps 820, 828 and the equilibrium pods 812, 822 is characterized by having continuous inlet and outlet flow paths and a continuous outer ring 1004. This feature allows for the formation of a seal (not shown) on the partition wall to be held. 【0125】 Figure 35E is a side view of the top plate 1000 in the embodiment. It shows the continuous outer ring 1004 of the pod pumps 820, 828 and the equilibrium pods 812, 822. Figures 36A to 36E show the bottom plate 1100. Figures 36A and 36B show the inner surface of the bottom plate 1100. The inner surface is the side that contacts the bottom surface of the midplate (not shown) shown in Figure 34E. The bottom plate 1100 is attached to the airline (not shown). The corresponding inlet holes 1106 for air that drive the pod pumps 820, 828 and valves (not shown) shown in Figure 34E are provided in the midplate. Holes 1108 and 1110 correspond to the second fluid inlet 824 and the second fluid outlet 826, respectively, shown in Figure 34C. The corresponding halves of the pod pumps 820, 828 and the equilibrium pods 812, 822 are further shown, such as the groove 1112 for the flow path. Unlike the top plate, the bottom plate halves corresponding to the pod pumps 820, 828 and the equilibrium pods 812, 822 clearly distinguish between the pod pumps 820, 828 and the equilibrium pods 812, 822. The pod pumps 820, 828 have an air passage in the second half of the bottom plate, while the equilibrium pods 812, 822 have the same structure as the top plate half. Furthermore, the equilibrium pods 812, 822 maintain fluid equilibrium, and thus both sides of a partition (not shown) contain liquid flow paths, while the pod pumps 820, 828 are pressure pumps that pump liquid, and thus one side contains a liquid flow path, and the other side, shown on the bottom plate 1100, contains an air-driven chamber or air-fluid passage. 【0126】 In one embodiment of the cassette, sensor elements are incorporated into the cassette to detect various properties of the fluid pumped by the pump. In one embodiment, three sensor elements are included. In one embodiment, the sensor elements are provided in a sensor cell 1114. Cell 1114 houses the three sensor elements in sensor element housings 1116, 1118, and 1120. In one embodiment, two of the sensor housings 1116 and 1118 house conductivity sensor elements, and the third sensor element housing 1120 houses a temperature sensor element. The conductivity sensor elements and temperature sensor elements may be any conductivity sensor elements or temperature sensor elements in the art. In one embodiment, the conductivity sensor element is a graphite post. In another embodiment, the conductivity sensor element is formed from stainless steel, titanium, platinum, or other metals that are coated for corrosion protection but still possess electrical conductivity. The conductivity sensor element may include wires that transmit probe information to a controller or other device. In one embodiment, the temperature sensor is a thermistor embedded in a stainless steel probe. In alternative embodiments, the cassette may not have a sensor, may only have a temperature sensor, may have one or more conductivity sensors, or may have one or more other types of sensors. In embodiments, the sensor element may be located outside the cassette, on a separate cassette, or connected to the cassette by a fluid line. 【0127】 Figures 36A and 36B further show the drive side of the metering pump 830, as well as the corresponding air inlet hole 1106 for the air that drives the pump. Figures 36C and 36D show the outside of the bottom plate 1100. The valve, the pod pumps 820, 828, and the airline connection point 1122 for the metering pump 830 are shown. Again, the equilibrium pods 812, 822 do not have airline connection points and are therefore not driven by air. Furthermore, the corresponding openings in the bottom plate 1100 for the second fluid outlet 824 and the second fluid inlet 826 are also shown. 【0128】 Figure 36E is a side view of the bottom plate 1100. In the side view, the edge 1124 surrounds the inner bottom plate 1100. The edge 1124 is raised and continuous, and serves as a connection point for a bulkhead (not shown). The bulkhead rests on this continuous raised edge 1124, thereby sealing between the pod pumps 820, 828 and equilibrium pods 812, 822 of the bottom plate 1100 and the pod pumps 820, 828 and equilibrium pods 812, 822 of the top plate (not shown) shown in Figures 35A to 35D. 【0129】 As described above, the dialysate flows from the orientation circuit through a heater and / or an ultrafiltration membrane to the equilibrium circuit. In the embodiment, the orientation circuit is provided in the cassette, although it is not essential. Figure 3A shows an example of an orientation circuit, 142. The orientation circuit 142 can perform several different functions in this embodiment. For example, dialysate flows from the dialysate supply (e.g., from the mixing circuit as described later) through the orientation circuit to the equilibrium circuit, and used dialysate flows from the equilibrium circuit to the drain pipe. The dialysate flows by driving one or more pumps contained within the orientation circuit. In the embodiment, the orientation circuit includes a dialysate tank, which contains dialysate prior to moving it to the equilibrium circuit. The dialysate tank ensures that in the embodiment, the rate of dialysate production differs from the rate of dialysate use of the dialysate in the dialysis machine in the system. The orientation circuit further orientations water from the water supply to the mixing circuit (if there is one). Additionally, as described above, the blood flow circuit communicates with the orientation circuit for operations such as disinfection. 【0130】 Therefore, in this embodiment, since the dialysate is formed on demand, there is no need to store large quantities of dialysate. For example, the dialysate is held in the dialysate tank 169 after it has been prepared. The dialysate valve 17 controls the flow of dialysate from the tank 169 to the dialysate circuit 20. The dialysate is filtered and / or heated before being sent to the dialysis machine 14. A contaminant removal valve 18 is used to control the flow of used dialysate from the dialysate circuit 20. 【0131】 Figure 6 shows an example of an orientation circuit, but it is not limited to this. In this figure, the orientation circuit 142 connects the dialysate from the dialysate supply to the dialysate tank 169 before it enters the equilibrium circuit through the dialysate pump 159, heater 72, and ultrafiltration membrane 73, as described above. As shown in the figure, the dialysate in the dialysate flow path flows from the dialysate supply to the dialysate tank, pump, heater, and ultrafiltration membrane (in this order), but other orders are possible in other examples. The heater 72 is used to heat the dialysate to body temperature and / or so that the blood in the blood flow circuit is heated by the dialysate and the blood returned to the patient is at body temperature. The ultrafiltration membrane 73 is used to remove pathogens, pyrogens, etc., from the dialysate, as will be described later. The dialysate flows into the equilibrium circuit and is orientationd to the dialysis machine. 【0132】 The dialysate tank 169 is made of a suitable material and may have any suitable dimensions for storing dialysate prior to use. For example, the dialysate tank 169 may be made of plastic, metal, etc. The dialysate tank may be made of a material similar to the material used to form the pod pump as described above. 【0133】 The flow of dialysate through the orientation circuit 142 is controlled (at least partially) by the operation of the dialysate pump 159. Additionally, the dialysate pump 159 controls the flow through the equilibrium circuit. For example, as described above in Figure 5, unused dialysate from the orientation circuit flows into the equilibrium chambers 341 and 342 of the equilibrium circuit 143. Pump 159 is used to deliver the unused dialysate to these equilibrium chambers. In this embodiment, the dialysate pump 159 comprises a pod pump similar to that described above. The pod pump includes a rigid chamber with a flexible partition that divides each chamber into a fluid compartment and a control compartment. The control compartment is connected to a control fluid source, such as an air source. Examples of pumps used as pod pumps or equilibrium chambers are disclosed, but are not limited to, U.S. Patent Application No. 60 / 792,073, filed on April 14, 2006, with the title "Extracorporeal Thermotherapy System and Method," or U.S. Patent Application No. 11 / 787,212, filed on April 13, 2007, with the title "Fluid Pump System, Apparatus and Method." These are disclosed herein in their entirety. Pod pumps will be described in further detail later. 【0134】 After passing through pump 159, the dialysate flows to a heater, for example, heater 72 in Figure 6. The heater is a heating device suitable for heating the dialysate, such as an electrical resistance heater, which is well known to those skilled in the art. The heater is provided separately from the orientation circuit as shown in Figure 3A, or the heater is incorporated into the orientation circuit or into another circuit (for example, the balancing circuit). 【0135】 In the embodiment, the dialysate is heated to a temperature such that the blood passing through the dialyzer does not cool down. For example, the temperature of the dialysate is controlled so that the dialysate is at or above the temperature of the blood passing through the dialyzer. In the above example, the blood is heated as described above to offset the heat loss caused by the blood passing through various elements of the blood flow circuit. Additionally, as will be described later, in the embodiment, a heater is connected to the control system so that any dialysate that is incorrectly heated (i.e., dialysate that is too hot or too cold) is recirculated (for example, returned to the dialysate tank) instead of passing through the dialyzer via line 731. The heater may be integrally formed as part of a fluid circuit such as an orientation circuit or an equilibrium circuit, or, as shown in Figure 3A, the heater may be a separate element in the dialysate flow path. 【0136】 In the examples, the heater is also used for disinfection or sterilization. For example, water passes through the hemodialysis system and is heated to a temperature suitable for disinfection or sterilization using the heater. The temperature is, for example, at least about 70°C, at least about 80°C, at least about 90°C, at least about 100°C, at least about 110°C, etc. In the examples, as will be described later, the water recirculates through various elements and / or heat loss within the system is minimized by the heater heating the water to the disinfection or sterilization temperature (as will be described later). 【0137】 The heater includes a control system that can control the heater as described above (for example, heating the dialysate to body temperature for dialysis of a patient, and heating the water temperature to a disinfection temperature for purifying the system). 【0138】 Examples of heater controllers are described below, but are not limited to them. The controller is selected to handle pulsating flow velocities and various fluid velocities, in addition to the fluid temperature at various inlets. Additionally, the heater control needs to function properly when the flow is oriented to different channels (dialysis, disinfection, recirculation, etc.). In one embodiment, the heater controller is used on a SIP1 substrate and includes an IR (infrared) temperature sensor on the ultrafiltration membrane and an infrared temperature sensor on the tank. In another example, the substrate is housed in a box with less heat loss and uses a conductivity sensor for the inlet temperature sensor. In another example, a simple proportional controller is used as the controller, using the temperatures of both the tank (heater inlet) and the ultrafiltration membrane (heater outlet). For example: powerHeater=massFlow*((tankPGain*errorTank)+(UFPGain*errorUF)PowerHeater=Heater utilization command (0 to 100%);MassFlow=Fluid mass flow velocity;TankPGain=Proportional gain for the tank or inlet temperature sensor;ErrorTank=Difference between the tank or inlet temperature sensor and the desired temperature;UFPGain=Proportional gain for the ultrafiltration membrane or outlet temperature sensor;ErrorUF=Difference between the uf or outlet temperature sensor and the desired temperature. 【0139】 A PWM command is generated from the heater usage rate command (0 to 100%). In this embodiment, the controller reduces the mass flow velocity when the heater becomes saturated because the predetermined temperature is not maintained. 【0140】 The heater control described above is merely illustrative, and other heater control systems and other heaters are possible in other examples of the present invention. The dialysate is further filtered to remove contaminants, infectious organisms, pathogens, pyrogens, debris, etc., for example, using an ultrafiltration membrane. The filter is positioned in a suitable location in the dialysate flow path between the orientation circuit and the equilibrium circuit, as shown in Figure 3A, and / or the ultrafiltration membrane is incorporated into either the orientation circuit or the equilibrium circuit. When an ultrafiltration membrane is used, it is selected to have a mesh size that prevents the above types from passing through the filter. For example, the mesh size may be about 0.3 micrometers or less, about 0.2 micrometers or less, about 0.1 micrometers or less, or about 0.05 micrometers or less. Those skilled in the art will recognize that filters such as ultrafiltration membranes are often readily available on the market. 【0141】 In the embodiment, the ultrafiltration membrane is operated so that contaminants from the filter (e.g., the flow of unpermeated material) are moved to a contaminant flow such as the contaminant line 39 in Figure 6. In the embodiment, the amount of dialysate flowing into the flow of unpermeated material is controllable. For example, if the unpermeated material is too cold (i.e., the heater 72 does not operate or the heater 72 does not heat the dialysate to a sufficient temperature), the entire dialysate flow (or at least a portion of the dialysate) is diverted to the contaminant line 39 and optionally recirculated to the dialysate tank 169 using line 48. The flow from the filter is further monitored for various reasons using temperature sensors (e.g., sensors 251 and 252), conductivity sensors (for checking the concentration of dialysate, e.g., sensor 253), etc. Examples of the above sensors will be described later. Other examples are disclosed, but are not limited to, in U.S. Patent Application No. 12 / 038,474, titled “Sensor Instrument System, Apparatus and Method” (Case No. F63). The entire document is hereby disclosed. 【0142】 The ultrafiltration membrane and dialysis machine can be considered redundant sorting methods for removing contaminants, infectious organisms, pathogens, pyrogens, and debris (in other cases, the ultrafiltration membrane is not provided). Therefore, contaminants must pass through both the ultrafiltration membrane and the dialysis machine in order to reach the patient from the dialysate. Even if one fails to filter, the other can still sterilize, preventing the contaminants from reaching the patient's blood. 【0143】 The orientation circuit 142 can further guide used dialysate through the equilibrium circuit to the drain pipe, for example, through the contaminant line 39 in Figure 6 to the drain pipe 31. The drain pipe is, for example, a local drain pipe or a separate container for containing contaminants (e.g., used dialysate) to be preferably located. In the embodiment, one or more inspection valves or "one-way" valves (e.g., inspection valves 215 and 216) are used to control the flow of contaminants from the orientation circuit and the system. In the embodiment, a blood leak sensor (e.g., sensor 258) is used to determine whether blood is leaking through the dialysate flow path through the dialyzer. 【0144】 Additionally, the orientation circuit 142 receives water from a water supply 30, for example, from a water container such as a bag, and / or from a device capable of producing water, such as a commercially available reverse osmosis device. As will be known to those skilled in the art in the embodiments, the water entering the system is set to a predetermined purity and has, for example, an ion concentration below a predetermined value. The water entering the orientation circuit 142 moves to various locations, for example, to a mixing circuit for producing unused dialysate and / or to a contaminant line 39. As will be described later in the embodiments, valves to the drain pipe 31 and various recirculation lines are opened, and a conduit 67 is connected between the orientation circuit 142 and the blood flow circuit 141 so that water flows continuously throughout the system. If a heater 72 is also driven, the water passing through the system is continuously heated to a temperature sufficient to disinfect the system. The disinfection method will be described in detail later. 【0145】 Examples of equilibrium cassettes are shown in Figures 41 to 45, but are not limited to these. Figures 41A and 41B show the outside of the top plate 900 of a cassette in one embodiment. The top plate 900 contains half of the pod pumps 820, 828. This half is half of the fluid or liquid source through which the source flow passes. Inlet and outlet pod pump channels are shown. These channels guide to each of the pod pumps 820, 828. 【0146】 The pod pumps 820,828 include raised channels 908,910. The raised channels 908,910 allow the fluid to continue flowing through the pod pumps 820,828 after a partition (not shown) has reached the end of its stroke. Thus, the raised channels 908,910 minimize the partitions that trap air or fluid in the pod pumps 820,828, and the partitions that block the inlet and outlet of the pod pumps 820,828, preventing flow. In this embodiment, the raised channels 908,910 have predetermined dimensions. In alternative embodiments, the raised channels 908,910 are larger or narrower. In further alternative embodiments, the raised channels 908,910 may be of any dimensions, as the purpose is to control the flow rate to obtain a desired fluid velocity or a desired drive of the fluid. Accordingly, the dimensions disclosed herein for the lifted flow path, pod pump, valve, or other embodiments are illustrative and merely alternative embodiments. Other embodiments are clearly described. Figures 41C and 41D show the inside of the top plate 900 of the cassette in this embodiment. Figure 41E is a side view of the top plate 900. 【0147】 Figures 42A and 42B show the fluid or liquid side of the midplate 1000. Figures 41C and 41D show regions that supplement the flow paths of the inner top plate. These regions are slightly raised trajectories indicating a conductive surface finish achieved by laser welding, one mode of manufacturing in this embodiment. Other modes of cassette manufacturing are described above. 【0148】 Figures 42C and 42D show the air side of the midplate 1000 in this embodiment, or the side facing the bottom plate (not shown here) shown in Figures 43A to 43E. The valve holes 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, and 856 on the air side correspond to the fluid side holes of the midplate 1000 shown in Figures 42A and 42B. As shown in Figures 44C and 44D, the partition wall 1220 completes the pod pumps 820 and 828, and the partition wall 1222 completes the valves 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, and 856. Valves 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, and 856 are driven by pneumatic pressure, and when the partition wall is stretched from the hole, liquid or fluid flows. When the partition wall is pressed toward the hole, the fluid flow is prevented. The fluid flow is directed by opening and closing valves 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, and 856. Figures 43A and 43B show the inside of the bottom plate 1100. The interior of the pod pumps 820 and 828, and the drive or air chamber of valves 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, and 856 are shown. Pod pumps 820, 828, and valves 802, 808, 814, 816, 822, 836, 838, 840, 842, 844, 856 are driven by an air source. Figures 43C and 43D show the outside of the bottom plate 1100. The air source is mounted on this side of the cassette. In one embodiment, the tubing connects to the tubing of the valves and pump 1102. In the embodiment, the valves are interlocked, and multiple valves are driven by the same air line. 【0149】 Figures 44A and 44B show the assembled cassette 1200. Exploded views of the assembled cassette 1200 shown in Figures 44A and 44B are shown in Figures 12C and 12D. In these figures, the pod pump partition 1220 in the embodiment is shown. The partition gasket seals between the liquid chamber (of the top plate 900) and the air or drive chamber (of the bottom plate 1100). In the embodiment, the dome texture of the partition 1220 provides additional space for air and liquid to escape the chamber, particularly at the end of the stroke. In the cassette in an alternative embodiment, the partition includes a double gasket. A feature of the double gasket in the preferred embodiment is that both sides of the pod pump contain liquid, or it is desirable to seal both sides of the chamber. In these embodiments, a rim is added to the internal bottom plate 1100 that complements the gasket and other features (not shown), so that the gasket seals the pod pump chamber of the bottom plate 1100. 【0150】 Figure 45 is a cross-sectional view of the cassette pod pump 828. Details of the accessories of the bulkhead 1220 are shown. Again, in this embodiment, the gasket of bulkhead 1220 is sandwiched between the midplate 1000 and the bottom plate 1100. The edge of the midplate 1000 is characterized in that the gasket can seal the chamber of the pod pump 828 to which the top plate 900 is attached. 【0151】 Figure 45 is a cross-sectional view of the assembled cassette valves 834 and 836. It shows that in this embodiment, the partition wall 1220 is assembled and positioned between the mid plate 1000 and the bottom plate 1100. Furthermore, the cross-sectional view of Figure 45 shows the assembled cassette valve 822. It shows that the partition wall 1222 is positioned between the mid plate 1000 and the bottom plate 1100. 【0152】 In the embodiment, the dialysate is prepared separately and transported to the system for use in the orientation circuit. However, in the embodiment, the dialysate is prepared in the mixing circuit. The mixing circuit is driven to form the dialysate at a suitable time. For example, the dialysate is produced during and / or prior to the patient's dialysis (for example, the dialysate is contained in a dialysate tank). To form the dialysate in the mixing circuit, water (for example, optionally supplied to the mixing circuit from the water supply by the orientation circuit) is mixed with various dialysate ingredients. For example, those skilled in the art know of suitable dialysate ingredients such as sodium bicarbonate, sodium chloride, and / or acids, as described above. Since the dialysate is formed on demand, it is contained in a dialysate tank in certain cases, but it does not need to be contained in large quantities. 【0153】 Figure 7A shows, but is not limited to, an example of a mixing circuit provided in a cassette in an embodiment. In Figure 7A, water from the orientation circuit flows to the mixing circuit 25 by the drive of pump 180. In the embodiment, a portion of the water is transported to the raw material 49 for use in transporting the raw material, for example, through the mixing circuit. As shown in Figure 7A, water is transported to the bicarbonate source 28 (which further includes sodium chloride in the embodiment). In the embodiment, sodium chloride and sodium bicarbonate are moved by the action of water and are provided in powder or granular form. The bicarbonate from the bicarbonate source 28 is transported to the mixing line 186 by the bicarbonate pump 183, and water from the orientation circuit also flows through the mixing line 186. Acid (in fluid form) from the acid source 29 is also pumped to the mixing line 186 by the acid pump 184. The raw materials (water, bicarbonate, acid, sodium chloride, etc.) are mixed in the mixing chamber 189 to form the dialysate that flows from the mixing circuit 25. Conductivity sensors 178 and 179 are provided along the mixing line 186 to ensure that each raw material is added to the mixing line at a suitable concentration. 【0154】 In the embodiment, pump 180 is comprised of one or more pod pumps similar to those described above. A pod pump includes a rigid chamber with a flexible partition dividing each chamber into a fluid compartment and a control compartment. The control compartment is connected to a control fluid source, such as an air source. Examples of pod pumps are disclosed, but are not limited to, U.S. Patent Application No. 60 / 792,073, filed April 14, 2006, with the title “Extracorporeal Thermotherapy System and Method,” or U.S. Patent Application No. 11 / 787,212, filed April 13, 2007, with the title “Fluid Pump System, Apparatus and Method.” These documents are hereby disclosed in their entirety. Similarly, in the embodiment, pumps 183 and / or 184 are each pod pumps. Further details of the pod pumps will be described later. 【0155】 In the embodiment, one or more pumps have a pressure sensor that monitors the pump pressure. This pressure sensor ensures that the pump compartment is completely filled and conveyed. For example, to ensure that the pump makes a full stroke of fluid, (i) the compartment is filled, (ii) both fluid valves are closed, (iii) pressure is applied to the compartment by opening the valve between the positive air tank and the compartment, (iv) this positive pressure valve is closed, leaving pressurized air in the passage between the valve and the compartment, (v) the fluid valve is opened, allowing the fluid to flow out of the pump compartment, and (vi) the pressure drop in the compartment is monitored as the fluid flows out of the pump compartment. The pressure drop corresponding to a full stroke is consistent and depends on the initial pressure, the volume occupied between the valve and the compartment, and / or the stroke volume. However, in another embodiment of the pod pump disclosed herein, a reference volume compartment is used, and the volume is defined by pressure and volume data. 【0156】 The volume transported by water pumps and other pumps is directly related to conductivity measurements and is therefore used as a cross-check of the dialysate composition in which volume measurements are formed. This ensures that the dialysate composition is safely maintained even if conductivity measurements are inaccurate during treatment. 【0157】 Figure 7B is a schematic diagram showing another example of a mixing circuit provided in the cassette in the embodiment. The mixing circuit 25 in this figure includes a pod pump 181 that pumps water from the feedwater along line 186. Various raw materials for making dialysate are guided into the water. Another pump 182 pumps from the feedwater to a source 28 (e.g., a container) holding sodium bicarbonate and / or to a source 188 holding sodium chloride. A third pump 183 guides the decomposed bicarbonate into the mixing line 186 (to be mixed in the mixing chamber 189), and a fourth pump 185 guides the decomposed sodium chloride into line 186 (to be mixed in the mixing chamber 191). A fifth pump 184 guides the acid into the water before passing through the first pump 181. Mixing is monitored using conductivity sensors 178, 179, and 177. Each conductivity sensor measures conductivity after a predetermined raw material has been added to the mixing line 186, and detects that the appropriate amount and concentration of the raw material has been added. Examples of the above sensors will be described later. Further examples are disclosed, but are not limited to, in U.S. Patent Application No. 12 / 038,474, Case Summary No. F63, Title of Invention, “Sensor Apparatus Systems, Apparatus and Methods.” The above document is hereby disclosed in its entirety. 【0158】 Figure 3B shows that in this embodiment, the mixing circuit 25 uses two sources, an acid concentrate source 27, and a combined source of sodium bicarbonate (NaHCO3) and sodium chloride (NaCl) to compose the dialysate. In the embodiment shown in Figure 3B, the dialysate compiling system 25 includes multiples of each source. In the manner in which the system operates continuously in this embodiment, the system can function continuously by having extra dialysate sources, so when one set of sources is depleted, the system can use the extra sources and the first set of sources is replaced. This process is repeated as needed, for example, until the system is interrupted. 【0159】 Examples of equilibrium cassettes are shown in Figures 34 to 36, but are not limited to these. In the fluid flow channel cassette shown in Figure 37, the valves are open. In this embodiment, the valves are opened by air pressure. Furthermore, in this embodiment, the fluid valves are volcanic valves as disclosed in detail herein. 【0160】 Figures 38A and 38B show the top plate 1100 of a cassette in one embodiment. In this embodiment, the pod pumps 820, 828 and the mixing chamber 818 of the top plate 1100 are formed similarly. In this embodiment, the pod pumps 820, 828 and the mixing chamber 818, when assembled with the bottom plate, have a total capacity of 38 ml. However, in another embodiment, the mixing chamber may be of any required dimensions. 【0161】 Figure 38B is a bottom view of the top plate 1100. The flow paths are shown in this figure. These flow paths correspond to the flow paths of the mid-plate 1200 shown in Figures 39A and 39B. The tops of the top plate 1100 and the mid-plate 1200 form the liquid or fluid side of the cassette for the pod pumps 820, 828 and for one side of the mixing chamber 818. Thus, most of the fluid flow paths are located in the top plate 1100 and the mid-plate 1200. Figure 39B shows the first fluid inlet 810 and the first fluid outlet 824. 【0162】 Figures 38A and 38B show that the pod pumps 820 and 828 include a groove 1002 (in alternative embodiments, this is a groove). The illustrated groove 1002 has predetermined dimensions and shape, but in alternative embodiments, the dimensions and shape of the groove 1002 may be any preferred dimensions and shape. Figures 38A and 38B show the dimensions and shape in one embodiment. In all embodiments, the groove 1002 forms the fluid inlet and fluid outlet passages of the pod pumps 820 and 828. In alternative embodiments, the groove 1002 is a groove in the wall of the internal pump chamber of the pod pump. 【0163】 The groove 1002 forms a flow path, so that even when the partition is in the final stroke, the flow path is still positioned between the inlet and outlet so that no pocket of fluid or air is trapped in the pod pump. The groove 1002 is included on both the liquid or fluid side and the air or drive side of the pod pumps 820, 828. In some embodiments, the groove 1002 is further included in the mixing chamber 818 (see Figures 40A, 40B relating the air or drive side of the pod pumps 820, 828 and the opposite side of the mixing chamber 818). In alternative embodiments, the groove 1002 is included on only one side of the pod pumps 820, 828, or is not included at all. 【0164】 In an alternative embodiment of the cassette, the liquid or fluid side of the pod pumps 820, 828 includes the feature (not shown) that the inlet and outlet flow paths are continuous, and a rigid outer ring (not shown) molded around the pump chamber is further continuous. This feature maintains a seal formed with a partition (not shown). Figure 38E is a side view of the top plate 1100 in this embodiment. 【0165】 Figures 39A and 39B show the midplate 1200 in the embodiment. The midplate 1200 is further shown in Figures 37A to 37F, which correspond to Figures 39A to 39B. Accordingly, Figures 37A to 37F show the locations of various valves and valve passages. The location of the mixing chamber 818 is also shown, as well as the location of the partitions (not shown) for each pod pump 820, 828. 【0166】 Figure 39A shows that in one embodiment, sensor elements are incorporated into a cassette to detect various characteristics of the fluid pumped by the pump. In one embodiment, three sensor elements are included. However, in this embodiment, six sensor elements (two sets of three) are included. The sensor elements are provided in sensor cells 1314 and 1316. In this embodiment, sensor cells 1314 and 1316 are included as areas of the cassette for the sensor elements. In one embodiment, the three sensor elements of the two sensor cells 1314 and 1316 are housed in sensor element housings 1308, 1310, 1312 and 1318, 1320, 1322, respectively. In one embodiment, two sensor element housings 1308, 1312 and 1318, 1320 house conductivity sensor elements, and the third sensor element housing 1310, 1322 houses temperature sensor elements. The conductivity sensor element and temperature sensor element may be any conductivity or temperature sensor element in the art. In one embodiment, the conductivity sensor is a graphite post. In another embodiment, the conductivity sensor element is formed from stainless steel, titanium, platinum, or other metals that are coated for corrosion protection but still possess electrical conductivity. The conductivity sensor element may include wires that transmit probe information to a controller or other device. In one embodiment, the temperature sensor is a thermistor embedded in a stainless steel probe. However, in alternative embodiments, a combination of temperature sensor element and conductivity sensor element similar to that disclosed in U.S. Patent Application (DEKA-024XX), filed October 12, 2007, with the title "Sensor Apparatus Systems, Apparatus and Methods," is used. 【0167】 In alternative embodiments, the cassette sensor is either not used, only one temperature sensor is used, only one or more conductivity sensors are used, or one or more other types of sensors are used. 【0168】 FIG. 39C is a side view of the midplate 1200 in this embodiment. FIGS. 40A and 40B show the bottom plate 1300. FIG. 40A shows the inside or inner surface of the bottom plate 1300. The inside or inner surface is the surface that contacts the lowermost surface of a midplate (not shown). The bottom plate 1300 is attached to air or a drive line (not shown). Corresponding inlet holes for air to drive the pod pumps 820, 828 and valves (not shown here, see FIGS. 37A to 37F) of the midplate 1300 are shown. The holes 810, 824 correspond to the first fluid inlet 810 and the first fluid outlet 824 shown in FIG. 39B respectively. Grooves 1002 for the corresponding other flow paths of the pod pumps 820, 828 and the mixing chamber 818 are shown. Holes for driving the pumps are also shown. Unlike the top plate, the corresponding halves of the bottom plate 1300 of the pod pumps 820, 828 and the mixing chamber 818 clarify the differences between the pod pumps 820, 828. The pod pumps 820, 828 include air or drive paths of the bottom plate 1300, and the mixing chamber 818 has the same structure as half at the top plate. The mixing chamber 818 does not include a partition (not shown) and neither air nor drive paths because it mixes liquids. Sensor cells 1314, 1316 with three sensor element housings 1308, 1310, 1312 and 1318, 1320, 1322 are also shown. 【0169】 FIG. 40B shows the drive ports 1306 on the outside of the bottom plate 1300 or outside the bottom plate 1300. The drive source is connected to these drive ports 1306. Also, since it is not driven by air, the mixing chamber 818 is not provided with drive ports. FIG. 40C is a side view of the bottom plate 1300 in the embodiment. 【0170】 As described above, in various aspects of the invention, one or more fluid circuits, such as a blood flow circuit, a balance circuit, an orientation circuit, and / or a mixing circuit, are provided in the cassette. Another cassette, for example a sensing cassette, is disclosed in an invention with the title "Sensor Instrument System, Device and Method" (Case Summary No. F63, U.S. Patent Application No. 12 / 038,474), the entire content of which is hereby incorporated by reference. In embodiments, some or all of these circuits are coupled in one cassette. In alternative embodiments, these circuits are formed in each cassette respectively. In yet another example, two or more fluid circuits are included in one cassette. In embodiments, two, three, or more cassettes are provided in non-relative movement, and optionally the cassettes communicate with each other. For example, in one embodiment, two cassettes are connected by a pump such as a pod pump as described above. The pod pump includes a rigid chamber with a flexible partition wall that divides each chamber into a first side and a second side, and as described above, each side is used for various purposes. 【0171】 Examples of cassettes used in the present invention are disclosed in U.S. Patent Application No. 11 / 871,680, filed on October 12, 2007, with the title "Pump Cassette"; U.S. Patent Application No. 11 / 871,712, filed on October 12, 2007, with the title "Pump Cassette"; U.S. Patent Application No. 11 / 871,787, filed on October 12, 2007, with the title "Pump Cassette"; U.S. Patent Application No. 11 / 871,793, filed on October 12, 2007, with the title "Pump Cassette"; U.S. Patent Application No. 11 / 871,803, filed on October 12, 2007, with the title "Cassette System Integration Device"; and a U.S. Patent Application (Case Summary No. F62) with the title "Cassette System Integration Device", but are not limited thereto. The entire content of each of these is hereby incorporated by reference. 【0172】 The cassette further includes various features such as pod pumps, fluid lines, and valves. The cassettes in the embodiments disclosed herein include various alternative embodiments. However, cassettes with similar functions are conceivable. The cassettes in the embodiments disclosed herein are implementations of the illustrated fluid design, and in other examples the cassette includes various flow path and / or valve arrangements and / or pod pump arrangements and numbers, which are within the scope of the invention. 【0173】 In one embodiment, the cassette includes a top plate, a mid plate, and a bottom plate. Various embodiments exist for each plate. Typically, the top plate includes the pump chamber and fluid lines, the mid plate includes supplemental fluid lines and metering pumps and valves, and the bottom plate includes the drive chamber (and in embodiments, the top and bottom plates include the balancing chamber or supplemental portion of the pod pump). 【0174】 Typically, the partition wall is located between the midplate and the bottom plate, but for equilibrium chambers and pod pumps, a portion of the partition wall is located between the midplate and the top plate. In embodiments, the partition wall is attached to the cassette, and this attachment is performed by overmolding, capture, bonding, press-fitting, welding, or any other process or method, but in embodiments, the partition wall is separated from the top plate, midplate and bottom plate until the plates are assembled. 【0175】 The cassette is assembled from a variety of materials. Typically, in various embodiments, the materials used are solid and non-flexible. In one embodiment, the plate is formed from polysulfone, while in another embodiment, the cassette is formed from other solid materials. In some embodiments, it is formed from thermoplastic or thermosetting materials. 【0176】 In one embodiment, the cassette is formed by positioning partitions in precise locations (for example, for one or more pod pumps, if any), assembling plates in sequence, and connecting the plates. In one embodiment, the plates are connected using laser welding technology. However, in another embodiment, the plates are bonded, mechanically fixed, tied together with string, welded by ultrasound, or connected using other methods for connecting plates. 【0177】 In the embodiment, the cassette is used to pump various types of fluids from a source to a location. The types of fluids include those containing nutrients, those without nutrients, inorganic chemicals, organic chemicals, body fluids, or any other type of fluid. Additionally, in the embodiment, the fluid may include gases; therefore, in the embodiment, the cassette is used to pump gases. 【0178】 The cassette functions to pump and orient fluid from one preferred position to another. However, in the embodiment, the external pump pumps fluid into the cassette, and the cassette pumps the fluid out. However, in the embodiment, the pod pump draws fluid into the cassette and pumps the fluid out of the cassette. 【0179】 As described above, the flow path is controlled by the position of the valve. Therefore, valves may be provided in different positions, or additional valves may be provided in the cassette in other examples. Additionally, the illustrated fluid lines and flow paths described above are merely examples of fluid lines and flow paths. In other examples, more or fewer and / or different flow paths may be provided. In yet another example, no valves may be provided in the cassette. 【0180】 The number of pod pumps (when pod pumps are provided within a cassette) varies depending on the embodiment. For example, the various embodiments described above include two pod pumps, while in another embodiment, the cassette includes one pod pump. In yet another embodiment, the cassette includes two or more pod pumps, or no pod pumps are provided. The pod pump may be a single pump or a number of pod pumps arranged to work together to form a continuous flow. Either or both cassettes can be used in various embodiments. However, as described above, in the embodiments, the cassette does not have a pod pump, or a pod pump is included between two or more cassettes. Examples of the above system are disclosed, but are not limited to, in U.S. Patent Application No. F62, titled “Cassette System Integration Device”. The entire document is disclosed herein. 【0181】 The various fluid inlets and outlets disclosed herein are fluid ports in the embodiments. In implementation, by valve configuration and control, the fluid inlet is also the fluid outlet. Therefore, referring to a fluid port as a fluid inlet or fluid outlet is for the purposes of description only. Interchangeable fluid ports are provided in various embodiments. The fluid ports are provided to give the cassette a specific flow path. These fluid ports do not necessarily all need to be used at all times. Instead, the use of various fluid ports allows for flexible use of the cassette in implementation. 【0182】 Figure 46 shows another example of a cassette, but it is not limited to this. Figure 46A shows an integrally formed and assembled cassette system. The mixing cassette 500, intermediate cassette 600, and balancing cassette 700 are connected by fluid lines or conduits. Pods are provided between the cassettes. Figures 46B and 46C show the effect of the integrally formed cassette system by various diagrams. Figures 50A, 50B, and 50C show the fluid lines, i.e., conduits 1200, 1300, and 1400, respectively. The fluid flows between the cassettes through these fluid lines, i.e., conduits. Figures 50A and 50B show the fluid lines of the inspection valve, with the larger fluid line, i.e., conduit 1300, and the smaller fluid line, i.e., conduit 1200. In this embodiment, the inspection valve is a duck-claw valve, but any inspection valve can be used in other examples. Figure 50C shows that the fluid line, or conduit, 1400 is a fluid line, or conduit, that does not include an inspection valve. For the purposes of this description, the terms “fluid line” and “conduit” are used interchangeably with respect to 1200, 1300, and 1400. 【0183】 Figures 46B and 46C, and 51A, show the fluid flow through various cassettes in one embodiment. For ease of description, the fluid flow starts from the mixing cassette 500. Figures 46B and 51A show the fluid side of the mixing cassette 500. The fluid side includes a number of ports 8000, 8002, 8004, 8006, 8008, and 8010 to 8026, which are either fluid inlets or fluid outlets. In various embodiments, one or more fluid inlets and outlets include one or more fluid inlets for reverse osmosis ("RO") water 8004, bicarbonate, acid, and dialysate 8006. Furthermore, one or more fluid outlets, including drainage pipes, include at least one ventilation outlet as an outlet for acid 8002 and dialysate tanks. In one embodiment, a pipe (not shown) is provided behind the outlet and is an outlet (to prevent contamination). Further outlets are included for water, bicarbonate and water mixtures, and dialysate mixtures (bicarbonate with added acid and water). 【0184】 Next, the dialysate flows from the mixing cassette 500 to the dialysate tank (not shown here; shown as 1502 in Figure 51A) and through conduits into the dialysate cassette 700 (pumped by the outer dialysate cassette 600, pod pumps 602 and 604) (604 is not shown here; shown in Figures 46D and 46E). The flow path within the cassette changes. Therefore, the positions of various inlets and outlets vary depending on the flow path of the different cassettes. 【0185】 Figure 51B shows that in one embodiment of the cassette system, the chondrocyte, conductivity sensor, and temperature sensor are contained in a separate outer cassette 1504 of the cassette system shown in Figures 46A to 46C. This outer sensor cassette 1504 is disclosed in U.S. Patent Application No. 12 / 038,474, Case Statement F63, titled "System, Apparatus, and Method of Sensors," and the entirety thereof is disclosed herein. 【0186】 Figure 51B shows the fluid flow path in this embodiment. In the mixing step for the dialysate in this embodiment, the bicarbonate mixture separates from the mixing cassette 500, flows to the outer sensor cassette, and then returns to the mixing cassette 500. When the bicarbonate mixture reaches a predetermined threshold, the acid is added to the bicarbonate mixture. Next, when the bicarbonate and acid are mixed in the mixing chamber 506, the dialysate flows from the cassette to the sensor cassette and then returns to the mixing cassette 500. 【0187】 Figure 46D shows that the mixing cassette 500 includes a pneumatic drive side. Multiple valves and two pump chambers 8030, 8032 are provided in the cassette 500 in the region indicated by reference numeral 500 to pump or measure the acid or bicarbonate. In the embodiment, additional or fewer metering pumps are included. The metering pumps 8030, 8032 may be of any required dimensions. In the embodiment, the pumps are different dimensions relative to each other, but in another embodiment, the pumps are the same dimensions relative to each other. For example, in one embodiment, the acid pump is smaller than the bicarbonate pump. This is advantageous and effective when using high concentrations of acid. Reasons for this include the preference for using a smaller pump for accuracy, and the preference for using a smaller pump so that a full stroke rather than a partial stroke can be used for control. 【0188】 Conduits 1200 and 1300 include inspection valves. These conduits 1200 and 1300 allow unidirectional flow. In this embodiment, all of these conduits 1200 and 1300 are guided to the drain pipe. The location of these inspection valve conduits is clear from the schematic flow path in Figure 51A. In the illustrated embodiment, the fluid directed to the drain pipe passes through the mixing cassette 500. Figure 46B shows that the fluid drain pipe port 8006 is provided on the fluid side of the cassette 500. 【0189】 After the dialysate is mixed and flows to the sensor cassette indicated by reference numeral 1504 in Figure 51B, it is determined whether the dialysate is within a predetermined parameter or threshold. Subsequently, the dialysate is pumped back to the mixing cassette 500, passes through the flat conduit 1400, is sent to the outer dialysate cassette 600, passes through the inspection valve conduit 1200 to the mixing cassette 500, and moves to the drain pipe fluid outlet. 【0190】 Figures 46D and 46E show various pods 502, 504, 506, 602, 604, 702, 704, 706, 708. Each of the pod housings is assembled similarly, but the interior of the pod housing varies depending on whether the pod is a pod pump 502, 506, 602, 604, 702, 704, a balance chamber pod 706, 708, or a pod 504 of the mixing chamber. 【0191】 Figures 46D and 46E, together with Figures 51A and 51B, show various pods provided in both the fluid flow path and the cassette system. Pod 502 is a water pod pump, and 504 is a bicarbonate water pod pump (sending water to bicarbonate) of the mixing cassette 500. Pod 506 is a mixing chamber. When the dialysate is mixed in the mixing chamber 506, it flows from the mixing cassette 500 to the sensor cassette 1504, and it is determined whether the dialysate is suitable for reception. The dialysate then flows through the outlet of the mixing cassette dialysate tank to the dialysate tank 1502. However, if it is determined that the dialysate cannot be received, the fluid is returned to the fluid cassette 500, pumped through the conduit 1400 to the outer dialysate cassette 600, passed through the mixing cassette 500 through the inspection valve conduit 1200, and discharged from the outlet of the drain pipe. 【0192】 Figures 46A through 46C, together with Figures 51A and 51B, show the outer dialysate cassette 600 between the mixing cassette 500 and the inner dialysate cassette 700. The pod pumps 602, 604 pump the dialysate from the dialysate tank 1502 and send it to the balance chambers 706, 708 of the inner dialysate cassette 700 (the driving force of the dialysate). The outer dialysate cassette 600 presses the dialysate into the inner dialysate cassette (i.e., the pump of the inner dialysate cassette 700 does not suck out the dialysate). Thus, the dialysate from the outer dialysate cassette 600 is pumped through the heater 1506 from the dialysate tank 1502, through the ultrafiltration membrane 1508, and into the inner dialysate cassette 700. 【0193】 Furthermore, Figures 46D and 46E, along with Figures 51A and 51B, show that the internal dialysate cassette 700 includes a metering pod 8038 (i.e., an ultrafiltration metering pod), equilibrium pods 706, 708, and pod pumps 702, 704. The internal dialysate cassette 700 further includes fluid outlets and fluid inlets. These inlets and outlets include an outlet to the dialysis machine 1510, an inlet from the dialysis machine 1510, and a dialysate inlet (the ultrafiltration membrane 1508 connects to a port on the internal dialysate cassette). The fluid inlets and outlets are further included for the DCA and DCV relationships in priming and disinfection. Various conduits (1200, 1300, 1400) function to allow fluid to flow to connect cassettes 500, 600, and 700, and to allow fluid to flow through the mixing cassette 500 for drainage. The largest inspection valve 1300 (also shown in Figure 50B) is used during disinfection. This pipe is large to accommodate blood clots and other contaminants flowing through the waterway during disinfection in a preferred embodiment. 【0194】 In the embodiment, the valves and pumps of the cassette system are driven by air pressure. The air pressure source is added to the cassette by a separate pipe. Thus, each pump, balance pod, or valve is individually connected to an air-driven manifold (not shown). Figures 52A to 52F show that in the embodiment, the pipes are connected to at least one block 1600. Multiple blocks are used in the embodiment to connect various pipes. Block 1600 drops into the manifold and is then preferably connected to a pneumatic actuator. This allows the pneumatic pipes to be easily connected to the manifold. 【0195】 Figure 46D shows that in one further embodiment, the cassette system includes a spring 8034 to assist in holding the system together. The spring 8034 is hooked onto the mixing cassette 500 and the inner dialysate cassette 700 by a capture device 8036. However, in other examples, other means and devices may also be used to assist in holding the appropriate orientation of the system, including, but not limited to, latching means, elastic means, etc. 【0196】 Figures 47A to 47C show the pod in an embodiment. The pod includes two fluid ports 902, 904 (inlet and outlet), and the pod is assembled differently in various embodiments. Structures in various embodiments are disclosed, but are not limited to, U.S. Patent Application No. E78, 11 / 787,212, filed on April 13, 2007, with the title of the invention, “Fluid Pump System, Apparatus and Method.” The entirety of that specification is disclosed herein. 【0197】 Figures 47A, 47D, and 47E show the groove 906 in the chamber. The groove 906 is included in each half of the pod housing. In other examples, the groove is not included, and in some embodiments, the groove is included in only one half of the pod. 【0198】 Figures 48A and 48B show the membranes used in pod pumps 502, 504, 602, 604, 702, and 704 in the embodiment. These membranes were described above in Figure 5A. In an alternative example, the membranes shown in Figures 5B to 5D are used. Figure 49 is an exploded view of the pod pump in the embodiment. 【0199】 In various embodiments of the invention, one or more "pod pumps" are used for various purposes. Although described above, the structure of the pod pump will be described later. This structure is modified according to various uses such as pumps, balancing chambers, mixing chambers, etc. Additionally, the pod pump can be placed at any position in the system, for example, in a cassette or between two or more cassettes. 【0200】 Typically, a pod pump includes a rigid chamber (of a suitable shape, such as spherical or elliptical), and the pod pump includes a flexible partition dividing each chamber into a first and second half. In the embodiment, the rigid chamber is a spheroid. The term “spheroid” as shown herein refers to a three-dimensional shape, which corresponds to an ellipse rotated around one of the principal, major, or minor axes, and typically includes three-dimensional egg shapes, flattened and oblong spheroids, spheres, and substantially similar shapes. 【0201】 Each half of the pod pump has at least one inlet valve and typically (but not required) at least one outlet valve (in embodiments, the same port is used for both the inlet and outlet). For example, the valves are on-off valves or bidirectional proportional valves. For example, the valve on one side of the chamber is a bidirectional proportional valve, one end connected to a high-pressure source and the other to a low-pressure (or vacuum) sink. The valve on the other half is opened and closed to direct the fluid. 【0202】 In the embodiment, the partition wall has varying cross-sectional thicknesses. Thinner partitions, thicker partitions, or partitions with variable thickness are used to provide the rigidity, flexibility, and other properties of the selected partition material. The wall thickness of thin, thick, or variable-thickness partitions is used to control the partition wall, thereby promoting bending in a given area compared to other areas, thereby assisting in the control of pumping action and the flow of the main fluid in the pump chamber. In the illustrated partition wall in this embodiment, the area of ​​the thickest cross-section is closest to the center. However, in another embodiment, partition walls with various cross-sections are provided, and the thickest and thinnest areas may be located anywhere on the partition wall. For example, a thinner cross-section may be located near the center, and a thicker cross-section near the periphery of the partition wall. In one embodiment, the partition wall has a tangential bevel in at least one section, but in another embodiment, the partition wall is completely smooth or substantially smooth. 【0203】 The partition wall is made of a material that has desirable durability and flexibility to accommodate the fluid. The partition wall is formed from a material that bends in response to the pressure of the fluid, liquid or gas acting on the drive chamber, or to a vacuum. The partition wall material is further selected to have biocompatibility, temperature compatibility, and compatibility with various main fluids that are pumped out by the partition wall or guided into the chamber to facilitate the movement of the partition wall. In the embodiment, the partition wall is formed from highly stretchable silicone. However, in the embodiment, the partition wall includes, but is not limited to, silicone, urethane, nitrile, elastomers and rubber including EPDM, or other rubber, elastomer or flexible materials. 【0204】 The shape of the partition wall depends on a variety of conditions. These conditions include, but are not limited to, the shape of the chamber, the dimensions of the chamber, the characteristics of the main fluid, the volume of the main body pumped per stroke, and the means and mode of mounting the partition wall to the housing. The dimensions of the partition wall also depend on a variety of conditions. These conditions include, but are not limited to, the shape of the chamber, the dimensions of the chamber, the characteristics of the main fluid, the volume of the main body pumped per stroke, and the means and mode of mounting the partition wall to the housing. Therefore, in various embodiments, the shape and dimensions of the partition wall will vary depending on these and other conditions. 【0205】 The partition wall can have any thickness. However, in the examples, the thickness ranges from 0.002 inches to 0.125 inches (approximately 0.00508 cm to approximately 0.3175 cm) (1 inch = 2.54 cm). The preferred thickness varies depending on the material used for the partition wall. In one example, highly stretchable silicone is used at a thickness of 0.015 inches to 0.050 inches (approximately 0.0381 cm to approximately 0.127 cm). However, in other examples, the thickness varies. 【0206】 In the embodiment, the partition wall is pre-formed such that at least a portion of the partition wall area includes a substantially dome shape. Furthermore, the dimensions of the dome vary based on some or many of the conditions described above. However, in another embodiment, the partition wall does not include a pre-formed dome shape. 【0207】 In one embodiment, the dome of the partition wall is formed using fluid injection molding. However, in another embodiment, the dome can be formed using compression molding. In an alternative embodiment, the partition wall is substantially flat. In another embodiment, the dimensions, width, or height of the dome vary. 【0208】 In various embodiments, the bulkhead is held by various means and methods. In one embodiment, the bulkhead is fastened with a clamp between parts of the cassette. In an embodiment, the edge of the cassette includes features for gripping the bulkhead. In another embodiment, the bulkhead is fastened with a clamp to the cassette using at least one bolt or other device. In another embodiment, the bulkhead is formed from a plastic part and an overmolding, and the plastic is welded or bonded to the cassette. In another embodiment, the bulkhead is clamped between a midplate and a bottom plate. Although the attachment of the bulkhead to the cassette has been disclosed in the embodiments, other methods and means may be used for attaching the bulkhead to the cassette. In an alternative embodiment, the bulkhead is directly attached to a part of the cassette. In an embodiment, the bulkhead has a thicker edge compared to other areas, and the bulkhead is clamped by a plate. In an embodiment, this thicker area is a gasket, which in an embodiment is an O-ring, a ring, or a gasket of other shape. 【0209】 In the gasket in the embodiment, the gasket is continuous with the partition wall. However, in another embodiment, the gasket is a separate part from the partition wall. In the embodiment, the gasket is formed from the same material as the partition wall. However, in another embodiment, the gasket is formed from a different material than the partition wall. In the embodiment, the gasket is formed by over-molding a ring around the partition wall. The gasket may be a ring or suitable seal of any shape to complement the pod pump housing in the embodiment. In the embodiment, the gasket is a compression type gasket. 【0210】 A pod pump typically has a constant capacity due to its rigid chamber. However, within the pod pump, the first and second compartments have different capacities depending on the position of the flexible partition dividing the chamber. By forcing fluid into one compartment, the fluid in the other compartment of the chamber is discharged. However, the fluids do not directly come into contact with each other within the pod pump, usually due to the flexible partition. 【0211】 Accordingly, in one embodiment, the pod pump used for pumping is configured to receive the control fluid in the first compartment and the fluid to be pumped in the second compartment. The control fluid is a fluid, i.e., a liquid or a gas. In one embodiment, the control fluid is air. By discharging the control fluid from the pod pump (for example, by vacuum or a pressure lower than the pressure inside the pod pump), the pod pump draws fluid (e.g., blood, dialysate, etc.) into the other compartment of the pod pump. Similarly, by forcibly supplying the control fluid to the pod pump (for example, from a high-pressure source), the pod pump discharges fluid. Furthermore, by controlling the valve in the second compartment, the fluid is transported through the first valve and discharged through the second valve by the action of the control fluid. 【0212】 As an alternative, a pod pump is used to maintain equilibrium of a fluid, such as dialysate, as described above. In such cases, instead of a control fluid, the fluid is directed to each compartment of the pod pump. As described above, the volume of the pod pump is usually constant due to a rigid chamber. Therefore, when a first volume of fluid is pumped into the first compartment of the equilibrium pod, an equal volume of fluid is discharged from the second compartment of the equilibrium pod (assuming the fluid is normally incompressible under conditions in which the pod is operating). Thus, equal volumes of fluid are movable using the equilibrium pod. For example, in Figure 5, unused dialysate can enter the first compartment and used dialysate can enter the second compartment via the equilibrium pod. The volumes of unused and used dialysate flow are brought into equilibrium with each other. 【0213】 In the embodiment, a pod pump is used that does not include a flexible partition separating the chambers. In the above example, the pod pump can be used as a mixing chamber. For example, the mixing chamber 189 in Figure 7A is the above-mentioned pod pump. 【0214】 Figure 9 shows, but is not limited to, an example of a pod pump. This figure is a cross-sectional view of a pneumatically controlled valve used in a cassette in an embodiment. The term “pneumatic” as used herein refers to the use of air or other gases to move flexible partitions and other components (the use of air is illustrative only; other control fluids such as nitrogen (N2), carbon dioxide, water, and oil are used in other examples). Three rigid parts are used for the “top” plate 91, the “mid” plate 92, and the “bottom” plate (the terms “top” and “bottom” merely indicate the orientation shown in Figure 9; the valve may be oriented in any direction in the embodiment). The top plate 91 and the bottom plate 93 are flat on both sides, while the mid plate 92 is provided with channels, notches and holes to form various flow paths, chambers and ports. The partition 90 forms the valve chamber 97 along the mid plate 92. Air pressure is applied through the air port 96, and the positive gas pressure forces the partition wall 90 against the valve seat 99 to close the valve, or the negative gas pressure pulls the partition wall away from the valve seat, opening the valve. The control gas chamber 98 is formed by the partition wall 90, the top plate 91, and the mid plate 92. The mid plate 92 has notches on which the partition wall 90 is placed, thereby forming the control gas chamber 98 on one side of the partition wall and the valve chamber 97 on the opposite side. 【0215】 The air port 96 is formed by a channel formed by the "top" surface of the midplate 92 together with the top plate 91. By connecting the multiple valve chambers of the cassette, the valves interlock, and all interlocking valves are opened and closed simultaneously by a single source of air pressure. Channels formed on the "bottom" surface of the midplate 92, together with the bottom plate, form the valve inlet 94 and valve outlet 95. Holes formed through the midplate 92 connect the inlet 94 and the valve chamber 97 (through the valve seat 99) and the valve chamber and outlet 95. 【0216】 The partition wall 90 is provided with a thickened edge 88 that fits firmly into the groove 89 of the midplate 92. Thus, the partition wall 90 is positioned in the groove 88 and held in place by the groove 88 prior to the top plate 91 being ultrasonically welded to the midplate 92. Therefore, the partition wall does not interfere with the ultrasonic welding of the two plates. The partition wall is not dependent on the two plates being precisely ultrasonically joined in place. Thus, the valve can be easily manufactured without ultrasonic welding, which is made very firmly. As shown in Figure 9, the top plate 91 includes additional material extending into the control gas chamber 98, which prevents the partition wall from moving away from the groove 89 and prevents the thickened edge 88 of the partition wall from retracting from the groove 89. 【0217】 Pressure sensors are used to monitor the pressure in the pod. For example, by alternating the application of air pressure to the air side of the chamber, the partition circulates back and forth across the total chamber volume. In each cycle, when air pressure creates a vacuum in the pod, the fluid is pumped out through a valve upstream of the inlet fluid port. When air pressure creates a positive pressure in the pod, the fluid is discharged through the outlet port and downstream valve. 【0218】 Figure 10 is a cross-sectional view of a pod pump in one embodiment, which is incorporated into a fluid control cassette in the embodiment. In the embodiment, the cassette incorporates a plurality of pod pumps and a plurality of valves formed by the technology of the configuration shown in Figures 9 and 10. In the embodiment described above, the pod pump in Figure 10 is formed from different parts of the same three rigid parts used to form the valve in Figure 9. These rigid parts are the “top” plate 91, the mid plate 92, and the “bottom” plate (as mentioned above, the terms “top” and “bottom” only indicate the orientation shown in Figure 9). To form the pod pump, the top plate 91 and the bottom plate 93 typically include hemispherical portions to integrally form a hemispherical pod pump. 【0219】 The partition wall 109 divides the central cavity of the pod pump into a chamber that receives the fluid pumped by the pump (pump chamber) and another chamber that receives the control gas that drives the pump by air pressure (drive chamber). The fluid can enter the pump chamber through the inlet 94 and can be discharged from the pump chamber through the outlet. The inlet 94 and outlet 95 are formed between the mid plate 92 and the bottom plate 93. Air pressure is applied to the partition wall 109 against one wall of the pod pump cavity by positive gas pressure through the air port 106, minimizing the pump chamber volume as shown in Figure 10, or, by negative gas pressure, tensioning the partition wall against the other wall of the pod pump cavity, maximizing the pump chamber volume. 【0220】 In the pod pumps of the embodiments, various structures are used that include grooves in one or more plates exposed to the cavity of the pod pump. In particular, the creation of grooves can prevent partitions from blocking inlet or outlet (or both) passages for fluid or air (or both). 【0221】 The partition wall 109 has a rim 88 with a thickness that allows it to be firmly held in the groove 89 of the mid-plate 92. Thus, as in the valve chamber of Figure 9, the partition wall 109 is positioned in the groove 89 and held in the groove 89 prior to the top plate 91 being ultrasonically welded to the mid-plate 92. Therefore, the partition wall does not interfere with the ultrasonic welding of the two plates. The partition wall is not dependent on the two plates being precisely ultrasonically joined in place. Thus, this valve can be easily manufactured without ultrasonic welding, which is extremely robust. 【0222】 Figure 11A is a schematic diagram showing a pressure-driven system 110 for a pod pump as shown in Figure 10 in an embodiment. In this example, air is used as the control fluid (for example, the pump is driven by pneumatic pressure). As mentioned above, in other examples, other fluids (for example, water) are used as the control fluid. 【0223】 In Figure 11A, the pressure drive system 110 alternately applies positive and negative pressure to the gas in the drive chamber 112 of the pod pump 101. The pneumatic drive system 110 includes a pressure transducer 114 for the drive chamber, a variable positive supply valve 117, a variable negative supply valve 118, a positive pressure gas tank 121, a negative pressure gas tank 122, a pressure transducer 115 for the positive pressure tank, a pressure transducer 116 for the negative pressure tank, and an electronic controller 119. 【0224】 The positive pressure tank 121 applies positive pressure of control gas to the drive chamber 112, pushing and moving the partition wall 109 to the position where the pump chamber 111 has its minimum capacity (i.e., the position where the partition wall is relative to the solid wall of the pump chamber). The negative pressure tank 122 applies negative pressure of control gas to the drive chamber 112, pushing and moving the partition wall 109 to the position where the pump chamber 111 in the opposite direction has its maximum capacity (i.e., the position where the partition wall is relative to the solid wall of the drive chamber). 【0225】 In this example, a valve mechanism is used to control communication between these tanks 121, 122 and the drive chamber 112. In Figure 11A, separate valves are used for each tank. A positive supply valve 117 controls communication between the positive pressure tank 121 and the drive chamber 112, and a negative supply valve 118 controls communication between the negative pressure tank 122 and the drive chamber 112. These two valves are controlled by an electronic controller 119 (alternatively, a single three-way valve is used instead of the two separate valves 117 and 118). In this embodiment, the positive supply valve 117 and the negative supply valve 118 are variable limiting valves for two on / off valves. The advantages of using variable valves will be discussed later. 【0226】 Figure 11A shows that the controller 119 receives pressure information from three additional pressure transducers: the drive chamber pressure transducer 114, the positive pressure tank pressure transducer 115, and the negative pressure tank pressure transducer 116. As the names suggest, these transducers measure the pressures of the drive chamber 112, the positive pressure tank 121, and the negative pressure tank 122, respectively. The controller 119 monitors the pressures of the two tanks 121 and 122, ensuring they are pressurized to a suitable (positive or negative) level. A compressor-type pump or other pump is used to obtain the suitable pressures in these tanks 121 and 122. 【0227】 In one embodiment, the pressure exerted by the positive pressure tank 121 is strong enough under normal conditions to press the partition wall 109 against the solid wall of the pump chamber. Similarly, the negative pressure (i.e., vacuum) exerted by the negative pressure tank 122 is strong enough under normal conditions to press the partition wall against the solid wall of the drive chamber. However, these positive and negative pressures obtained by tanks 121 and 122 in the embodiment are within sufficiently safe limits, which are the same pressures that would open either the positive supply valve 117 or the negative supply valve 118, and the positive and negative pressures exerted on the partition wall 109 are not strong enough to harm the patient. 【0228】 In one embodiment, the controller 119 monitors pressure information from the drive chamber pressure transducer 114, and based on this information, controls the valve mechanism (valves 117, 118) to move the partition wall 109 to the position of the smallest pump chamber capacity, and after reaching this position, tensions the partition wall 109 to move it to the position of the largest pump chamber capacity. 【0229】 The pressure drive system (including the pressure transducer 114 of the drive chamber, the pressure transducer 115 of the positive pressure tank, the pressure transducer 116 of the negative pressure tank, the variable positive supply valve 117, the variable negative supply valve 118, the controller 119, the positive pressure gas tank 121, and the negative pressure gas tank 122) is located entirely outside or nearly outside the insulated capacity indicated by reference numeral 61 in Figure 6. In the embodiment, elements that come into contact with blood or dialysate (i.e., the pod pump 101, the inlet valve 105, and the outlet valve 107) are located within the insulated capacity to facilitate disinfection. 【0230】 Figure 11B shows another example of a pressure drive system 110 for a pod pump. In this example, the pod pump 101 includes a pump chamber 111, a drive chamber 112, and a partition wall 109 that divides it into two sides. Fluid ports 102 and 104 allow access to fluid entering and leaving the pump chamber 111 using fluid valves (not shown). However, within the pod pump 101, the fluid ports 102 and 104 include a “volcano” port 126, which typically has a raised shape, and the partition wall 109 tightly seals the port when it is in contact with the port. Furthermore, Figure 11B shows a three-way valve connecting pressure tanks 121 and 122. The three-way valve 123 communicates with the drive chamber 112 through one port in this example. 【0231】 Figures 11A and 11B demonstrate that, instead of a pneumatic drive system for the two tanks, other types of drive systems are used to move the bulkhead back and forth. 【0232】 As described above, the positive supply valve 117 and the negative supply valve 118 of the air drive system 110 in Figure 11A are variable limiting valves suitable for two types of on / off valves. The use of variable valves allows the pressure acting on the drive chamber 112 and the partition wall 109 to be easily controlled by a small pressure in the tanks 121 and 122, instead of applying the full tank pressure to the partition wall. Therefore, even if the pressure required to drive the pod pumps differs for each pod pump, the same tank or set of tanks can be used for different pod pumps. The tank pressure needs to be greater than the suitable pressure acting on the partition walls of various pod pumps, but one pod pump may be driven by half the tank pressure, and another pod pump may be driven by the same tank but by a quarter of the tank pressure. Thus, even if different pods in the dialysis system are designed to be driven at different pressures, these pod pumps all share the same tank or set of tanks, but are driven at different pressures using various valves. The pressure used in the pod pump changes in response to conditions that arise or change during the dialysis process. For example, if the system's tubing is compressed due to tube deformation, the positive or negative pressure, or both, used in the pod pump will be increased to compensate for the increased limit. 【0233】 Figure 12 is a graph showing how the pressure acting on the pod pump is controlled using a variable valve. The vertical axis shows the pressures in the positive and negative tanks (labeled 121 and 122 in Figure 11A) respectively, using PR+ and PR-. PC+ and PC- represent the positive and negative control pressures acting on the pod pump bulkhead, respectively. As shown in Figure 12, a positive pressure acts on the drive chamber from time T0 to approximately time T1 (to force the fluid out of the pump chamber). By repeatedly increasing and decreasing the flow restriction by the positive variable valve (labeled 117 in Figure 11A), the pressure acting on the drive chamber is maintained at a nearly preferred positive control pressure PC+. The pressure changes in a sinusoidal pattern around the preferred control pressure. A drive chamber pressure transducer (reference numeral 114 in Figure 11A), which communicates with the drive chamber, measures the pressure in the drive chamber and transmits the pressure measurement information to a controller (reference numeral 119 in Figure 11A) that controls a variable valve so that the pressure in the drive chamber changes around a suitable control pressure PC+. If there are no faults, the bulkhead is pressed against the solid wall of the pump chamber, thereby ending the stroke. The controller determines that the stroke has ended when the pressure measured in the drive chamber does not drop even as the limit formed by the variable valve decreases. In Figure 12, the end of the discharge stroke occurs around time T1. When the end of the stroke is detected, the variable valve is completely closed by the controller so that the pressure in the drive chamber does not increase beyond the suitable control pressure PC+. 【0234】 After the positive variable valve closes, the negative variable valve (labeled 118 in Figure 11A) partially opens, and the negative pressure tank draws gas from the drive chamber and fluid into the pump chamber. As shown in Figure 12, negative pressure acts on the drive chamber from time immediately after T1 until time T2. Similar to discharge (positive pressure), the stroke described above can be maintained at a nearly suitable negative control pressure PC- (weaker than the pressure in the negative pressure tank) by repeatedly increasing and decreasing the flow restriction created by the variable valve. The pressure changes in a sinusoidal pattern around the suitable control pressure. The pressure transducer in the drive chamber transmits pressure measurement information to the controller, which controls the variable valve to change the pressure in the drive chamber around the suitable control pressure PC-. In the absence of fault conditions, the bulkhead is stretched against the rigid wall of the drive chamber, thereby ending the stretch (negative pressure) stroke. As described above, the controller determines that the end of the stroke has been reached when the partial vacuum measured in the drive chamber does not drop even as the limit formed by the variable valve decreases. In Figure 12, the end of the tension stroke occurs around time T2. When the end of the stroke is detected, the controller completely closes the variable valve to prevent the vacuum in the drive chamber from rising above the preferred negative control pressure PC-. Once the tension stroke is complete, the positive variable valve partially opens, and the positive pressure initiates a new discharge stroke. 【0235】 Therefore, each pod pump in this example uses two variable-opening valves to restrict the flow from a positive pressure source to a negative pressure. The pressure in the drive chamber is monitored, and the controller uses this pressure measurement to determine the appropriate commands for both valves to obtain the desired pressure in the drive chamber. The advantages of this configuration are that the filling and transport of pressure are precisely controlled, allowing the desired flow velocity to be obtained while taking pressure limits into consideration, and that the pressure is changed by a sinusoidal signature command, which is used to determine when the pump is nearing the end of its stroke. 【0236】 Another advantage of using a variable valve instead of a two-way valve, as described above, is that valve wear is reduced by only partially opening and closing the variable valve. Repeatedly and "aggressively" opening and closing the two-way valve shortens the valve's lifespan. 【0237】 The end of the stroke is detected, and a very small combined value of the correlation function indicates that the stroke was interrupted and not completed. By determining whether it is a filling stroke or a conveying stroke, it is possible to distinguish between downstream and upstream interruptions (this is difficult in the case of interruptions occurring near the end of the stroke where the bulkhead is located near the chamber wall). Figures 13A and 13B show the detection of an interruption (the chamber pressure drops to 0 when an interruption is detected). 【0238】 Under normal operation, the integrated value of the correlation function increases as the stroke progresses. If this value remains small or does not increase (in the case of very low impedance flow or interference), the stroke is either very short or does not follow the sinusoidal pressure pattern required by the valve failure or poor pressure signal. A lack of correlation is detected and used in error handling in these cases. 【0239】 Under normal conditions, when the flow controller is operating, the control loop adjusts the pressure in response to changes in fluid velocity. If the circuit impedance increases dramatically and the pressure limit saturates before the flow has a chance to reach the desired rate, the flow controller may not be able to adjust the pressure high enough to reach the required fluid velocity. These conditions occur when the line is partially blocked, such as when a clot forms in the circuit. These are used in error handling when pressure saturation is detected when the flow fails to reach the desired velocity. 【0240】 When there are problems with the valve or pneumatic pressure, such as fluid valve leakage or noise in the pressure signal, the ripple may continue unclearly throughout the stroke, and the stroke end algorithm may not be able to adequately detect the change in pressure ripple necessary to determine the end of the stroke. Therefore, a safety check is added to detect whether the stroke is being completed longer than necessary. This information can be used for error handling. 【0241】 In a dual pump such as pump 13 shown in Figure 3A, the two pump chambers circulate in opposite directions, affecting the pump cycle. A phase relationship from 0° (both chambers function in the same direction) to 180° (chambers function in opposite directions) is selectable. Since it is impossible to move both chambers in the same direction simultaneously, the phase movement can be changed in the embodiment. If they were to move simultaneously, both the inlet and outlet valves would open, and the end of the stroke would not be properly detected. 【0242】 By selecting a 180° phase relationship, a continuous flow is created in and out of the pod. This is the nominal pump mode when a continuous flow is required. Setting the phase relationship to 0° is useful for single-needle flow. The pod is first filled by the needle and then transported to the same needle. Driving in phases between 0° and 180° can be used to obtain a tension relationship (hemodiafiltration or continuous backflushing) across the dialysis machine. Figures 8A to 8C illustrate the above phase relationships graphically. 【0243】 The pod pump controls the flow of fluid through various subsystems. For example, a sinusoidal pressure waveform is appended to a DC pressure command that constitutes the pressure signal commanded for the pod pump. When the bulkhead is moving, the pod pressure follows the sinusoidal command. When the bulkhead contacts the chamber wall and stops moving, the pod pressure is kept constant and does not follow the sinusoidal input command. Differences in subsequent pressure signal commands for the pod are used to detect the end of a stroke. From the stroke end information, the time of each stroke is calculated. By knowing the pod's capacity and when it completes a stroke, the flow velocity for each pod is determined. The flow velocity is fed back into the PI loop to calculate the required DC pressure for the next stroke. 【0244】 The magnitude of the sinusoidal input is selected to be sufficiently large relative to the actual pressure to suitably track the command, and small enough to be subtracted from the DC pump pressure and applied to the pod so that the pressure is sufficient for the bulkhead to move under the expected driving conditions of fluid viscosity, head height, and circuit resistance. The frequency of the sinusoidal input is selected empirically to ensure reliable detection of the end of the stroke. A higher number of sinusoidal periods per stroke results in a more accurate algorithm for detecting the end of the stroke. 【0245】 To detect a continuous command change in pod pressure, the pod pressure signal is passed through a cross-correlation filter. The sampling window size for the cross-correlation filter is equivalent to the period of the input sine wave. For every sample in the window, the commanded pressure signal is multiplied by the previous sample of the actual pressure and added to the previous correlation value. The window moves by one frame, and the process is repeated. The resulting results are distinguished and passed through a second-order filter with a corner frequency similar to the input sine wave frequency and a damping ratio of 1. The effect of this filter is to function as a bandpass filter that separates the signals correlated at the frequency of the input sine wave. The absolute value of the output of this filter passes through a second-order low-pass filter with the same frequency as the sine wave frequency and a damping ratio of 3.0. This second-order filter is used to integrate the distinguished signal and the resulting signal and reduce noise in the resulting signal. When the two signals are correlated, the resulting value that passes through the filter is large. When the two signals are not correlated (e.g., at the end of a stroke), the resulting value that passes through the filter is small. The end of a stroke can be detected when the cross-correlation signal that has passed through the filter falls below a predetermined threshold or drops to 1 percent of its maximum value over the stroke. To adjust performance for a given pump scenario, this threshold or percentage reduction can be varied as a function of pressure or flow velocity. 【0246】 To detect the end of a stroke, the stroke end algorithm takes approximately one period of the sinusoidal ripple; therefore, by minimizing this period (maximizing the amplitude of the sinusoidal wave), the delay at the end of the stroke is reduced. Low-pressure flows and high-pressure flows are not tracked as closely by the controller. Since low-pressure strokes tend to have low fluid velocities, the delay at the end of the stroke is only a small percentage of the total stroke time. Thus, the frequency is low for low-pressure strokes. The sinusoidal wave frequency can be adjusted as a linear function of the carrier pressure. This ensures that the delay is minimized when the stroke is shortest. If the sinusoidal wave frequency changes for a suitable pressure, the filter for the cross-correlation function needs to be further adjusted. The filter is set to continuously calculate the filter coefficients based on this changing frequency. 【0247】 The pressure in the pod chamber is further controlled using two variable solenoid valves. One solenoid valve connects the plenum to a higher pressure source, and the second solenoid valve connects the plenum to a lower pressure (or vacuum) sink. Because solenoid valves tend to have a large neutral zone, a nonlinear offset term is added to the controller to compensate. 【0248】 Figure 14 shows an example of a control algorithm. The controller in this example is a standard individual PI regulator. The output of the PI regulator is split into two passages: one for the source valve and the other for the sink valve. An offset term is added to each of these passages to compensate for the neutral zone of the valve. The resulting instructions are limited to valves greater than zero (after inversion in the case of a sink valve). 【0249】 The offset term is negative for source valves and positive for sink valves. Therefore, both valves will operate even if the error is zero. These offsets improve the trajectory leading to the controller and the controller's interference rejection performance, but they also cause leakage in both valves in a steady state if the command offset is slightly larger than the actual valve neutral zone. In this case, the valves will have equal leakage mass flow and opposite leakage mass flow in a steady state. 【0250】 To eliminate this leaking mass flow while the control system is in standby mode, a "power saving" block is added to close the valve when the absolute value of the error term remains small for a predetermined period of time. This is similar to the use of a mechanical brake in a servo motor. 【0251】 As shown in Figure 15, the controller in this example uses a standard isolated PI regulator. The circuit of the PI regulator is shown. The integrator can be limited to prevent wind-up when the command saturates. The integrator can always be unwinded. Because the amount of air in the pod is different for the filling stroke and the transport stroke, the pod response will be very different for the filling stroke and the transport stroke. To better accommodate the different pod responses, the proportional gain is adjusted differently for the transport stroke and the filling stroke. 【0252】 The saturation limit of the PI regulator should be determined by taking into account the resulting added offset value. For example, if the valve saturates at 12V and a fixed offset of 5V is added after the PI loop, the saturation limit of the PI loop should be set to 7V. These different positive and negative saturation limits are due to the different dead zones present in the source and downstream valves. 【0253】 During the filling stroke, the upstream fluid valve is closed and the downstream fluid valve is open, allowing fluid to flow into the chamber. During the conveying stroke, the upstream fluid valve is open and the downstream fluid valve is closed, allowing fluid to flow out of the chamber. Both fluid valves remain closed from the end of one stroke until the start of the other. 【0254】 As described in certain embodiments, the pod pump can also be driven by a control fluid, such as air, nitrogen, water, or oil. The control fluid is selected to be relatively incompressible and, in some cases, relatively inexpensive and / or non-toxic. The control fluid is supplied to the system's pump through a series of tubes or other suitable conduits. A controller controls the flow of the control fluid within the tubes or conduits. In embodiments, the control fluid is held at different pressures within the tubes or conduits. For example, part of the control fluid is held at positive pressure (i.e., greater than atmospheric pressure), part of the control fluid is held at negative pressure (less than atmospheric pressure), and even at zero pressure (i.e., vacuum). As shown in Figure 11A, the pod pump is controlled by the control fluid operated by the controller. As previously mentioned, the controller (119) opens and closes valves (e.g., valves 117 and 118) at different points in time during the pump cycle, exposing the pneumatic side of the pod pump to positive pressure (121) or vacuum (122). 【0255】 In a further specific embodiment, the controller is isolated from various fluid circuits (usually electronic), and there is no electrical contact between the controller and the fluid circuits, but the control fluid (e.g., air) is configured to flow between the controller and the various pumps. This configuration has advantages such as ease of maintenance (the controller and various circuits can be repaired separately). In one embodiment, the fluid circuits are heated to disinfection temperatures, or exposed to relatively high temperatures or harsh conditions (e.g., radiation) that are effective for disinfection, while the controller is kept isolated by an insulating wall (e.g., a "firewall") or the like, so that it is not exposed to harsh conditions. 【0256】 Therefore, in one embodiment, the system has a "cold" section (not heated) and a "hot" section that is partially heated for disinfection. The "cold" section is insulated from the "hot" section by an insulating material. In one embodiment, the insulating material can be obtained by forming a foamed material using a mold, but it can also be formed by spraying, or even by cutting a sheet material. 【0257】 In one embodiment, the “hot” section is heated to a relatively high temperature. For example, the “hot” section is heated to a temperature sufficient to sterilize the components within it. Many electronic components lose other functions when heated above 50°C, so it is beneficial to separate electronic components from other components to be disinfected. Therefore, components that may sometimes need to be disinfected are kept in the “hot” section, while components that cannot be heated to such temperatures are kept in the “cold” section. In one embodiment, the “cold” section is provided with a circulation system, such as a fan or grid, that causes air to flow in and out of a cold box. 【0258】 The “hot” section is covered entirely or partially with insulation. In the embodiment, the insulation extends to cover access points to the “hot” section, such as doors, ports, and gaskets. For example, when the “hot” section is sealed, the insulation completely covers the “hot” section. 【0259】 Examples of components located in the "cold" section include power supplies, electronic components, power lines, and air control components. In some embodiments, at least several fluids that enter and exit the "hot" section pass through the "cold" section. However, in other embodiments, the fluids pass only through the "hot" section and not through the "cold" section. 【0260】 Examples of components located within the "hot" section include cassettes, fluid lines, etc. In some embodiments, several electrical components are located within the "hot" section. These include heaters. The heaters heat the hot box itself in addition to the fluid (see heater 72 in Figure 3A). In other embodiments, the heaters heat the entire "hot" section to a desired temperature. 【0261】 In one embodiment, the “hot” section includes some or all of the fluid lines. Furthermore, the “hot” section includes temperature sensors, conductive sensors, blood leak sensors, heaters, other sensors, switches, emergency lights, etc. 【0262】 In one embodiment, the manifold for air or other controlled fluids is moved from a "cold" section to a "hot" section. Dividing components into "hot" and "cold" sections offers several advantages, including improved lifespan, reliability, and efficiency of electrical components. For example, by dividing components into "hot" and "cold" sections, the entire hotbox is heated. This allows for more efficient use of heat to achieve a more energy-efficient system. This enables a more effective use of heat, resulting in a more energy-efficient system. It also allows for the use of standard, stock electronic components to achieve lower costs. 【0263】 In one embodiment, the control fluid used to control pumps, valves, etc., is air, which is introduced into the system by the operation of one or more air compressors. In this embodiment, the air compressors are kept separate from the blood flow path and dialysate flow path systems within the system, and the air from the air compressors is introduced to multiple pumps via multiple pipelines, etc. For example, in one embodiment, an air interface is used, through which air from the air compressors is introduced into pipelines, etc., that communicate with various pumps and chambers. 【0264】 Figure 16 schematically shows the structure of a double housing in one embodiment. This configuration is effective when applied to a cassette containing a number of pneumatically driven pumps and valves. As the number of pumps and valves in the cassette increases sufficiently, the cassette containing these pumps and valves becomes larger, the pressures on these pumps and valves also increase, and it becomes difficult to properly seal and position all the pumps and valves. This difficulty can be mitigated by using two or more different housings. The valves and pumps (pod pump 42) are housed in the main housing 41, with connecting pipes 45 extending from the main housing from the air port 44. The main housing 41 further includes inlet pipes and outlet pipes 43, through which fluid flows into and out of the main housing. The pumps and valves are connected by connecting pipes 45 within the main housing 41 and a small secondary pipe-holding housing 46. The pipe-holding housing 46 is provided with air interfaces corresponding to each pipe. It is easier to properly position and seal each air interface relative to the container's base unit by using the smaller tube-holding housing 46 rather than directly on the larger main housing 42. 【0265】 In some embodiments, the control fluid (e.g., air) is supplied to a system with one or more supply tanks or other pressure sources. For example, if two tanks are used, one supply tank is a positive pressure tank with a set value of 750 mmHg (gauge pressure) (approximately 100 kPa, 1 mmHg is approximately 133.3 Pascals). The other supply tank is a negative pressure, i.e., a vacuum tank, with a set value of 450 mmHg (gauge pressure) (approximately 60 kPa). This pressure difference is used to allow for precise control of a variable valve in the pod pump between the supply tank and the required pod pressure. The supply pressure limit can be set based on a sufficient differential pressure for controlling the variable valve and the maximum pressure that can be set for the patient's blood flow pump. Thus, two tanks are used to supply pressure and control the fluid for the entire system. 【0266】 In one embodiment, two independent compressors supply fluid to a supply tank. For example, the tank pressure is controlled using any suitable technique, such as a simple bang-bang controller (a controller with open and closed states) or a sophisticated control mechanism. An example of a bang-bang controller for a positive pressure tank is that if the actual pressure is the desired pressure minus hysteresis, the compressor managing the positive pressure tank starts. If the actual pressure is the desired pressure plus hysteresis, the compressor servicing the positive pressure tank stops. The same principle applies to vacuum tanks and vacuum compressors, although the hysteresis is reversed. If the pressure tank is not regulated, the compressor stops and the valve closes. 【0267】 Reducing the hysteresis band size allows for more reliable control of the pressure tank. However, this requires increasing the compressor's cycle time. If extremely reliable control of these tanks is required, the bang bang controller may be replaced with a PID controller, and the compressor may use a PWM signal. Other control methods are also possible. 【0268】 However, in other embodiments, other pressure sources are used. That is, multiple positive pressure sources or multiple negative pressure sources are used. For example, to minimize leakage, multiple positive pressure sources are used that supply different positive pressures (e.g., 1000 mmHg and 700 mmHg) (approximately 133.3 kPa and approximately 93.3 kPa). The negative pressure is -400 mmHg (approximately -53.3 kPa). In the embodiments, the negative pressure source is a vacuum pump, and the positive pressure source is an air compressor. 【0269】 In certain aspects of the present invention, various sensors are included. For example, various embodiments of the invention disclose systems and methods for fluid processing using a sensor instrument system comprising a sensor manifold. Such embodiments relate to systems and methods for diagnosis, treatment, or improvement in various medical conditions. These inventions include, as examples, systems relating to the dispensing, measurement, control, and / or analysis of various types of biochemical fluids such as dialysates and therapeutic agents, as well as various forms of in vitro treatment and therapy, and specific examples of methods. Further examples disclose fluid utilization systems including water treatment systems, water distillation systems, and diagnostic, treatment, and improvement systems using fluids such as dialysates. 【0270】 Examples of embodiments of the invention described herein include dialysis systems and methods. More specifically, examples of embodiments of the invention described herein include hemodialysis systems and methods described in U.S. Patent Application No. 11 / 871,680, filed October 12, 2007 (title of invention: pump cassette), or U.S. Patent Application Publication No. 2008 / 0216898 (title of invention: device integrated by cassette system). 【0271】 In such systems and methods, one or more sensor manifolds are used, so the medium moves from one environment to another with higher conductivity in order to perform sensor readings. For example, a cassette manifold is held in an area unaffected by conditions such as temperature and humidity, which are undesirable for sensor instruments such as sensor probes, depending on the conditions of various environments. Also, sensor instruments and sensor systems are sensitive and more prone to malfunction than other parts of the system. Isolating sensor instruments and sensor instrument systems from other parts of the system using a sensor manifold reduces the impact of the sensor instruments and systems on other parts during inspection, measurement, repair, or replacement. To inspect, measure, repair, or replace a sensor manifold with minimal impact on other components of the system, it would be advantageous to use it in conjunction with U.S. Patent Application Publication No. 2008 / 0216898 (Title of Invention: Instruments Integrated by Cassette System). Sensor manifolds are replaced somewhat more frequently than other parts of the system. 【0272】 Figures 53 to 58 show various embodiments of the sensor manifold. In these embodiments, one or more fluids are contained within the set manifold 4100. For example, the fluid enters the cassette manifold 4100 via connector 4101 and exits the cassette manifold via connector 4102. A flow path is formed between connectors 4101 and 4102, passing through the cassette (shown as flow path 4225 in Figure 54). Similarly, flow paths extend between connectors 4103 and 4104; 4105 and 4106, 4107, 4108 and 4109; 4110 and 4111; and 4112 and 4113 (shown as flow paths 4223, 4220, 4222, 4224, and 4221, respectively in Figure 54). In certain embodiments, each flow path contains a fluid with different characteristics. In other embodiments, one or more flow paths contain the same or similar fluids. In a particular embodiment, the same medium flows through multiple channels simultaneously in order to inspect and / or scale a sensor instrument system associated with such channels. 【0273】 Referring to Figure 55, a sensor manifold 4100 used with a sensor device and sensor device system is shown. The cassette includes a top plate 4302 and a base plate 4301. A channel 4225 extending between connectors 4101 and 4102 extends between the base plate and the top plate. The cassette can be assembled from a variety of materials. The materials typically used are rigid and non-flexible. In a preferred embodiment, the cassette is formed of polysulfone, but in other embodiments, the cassette is formed of other rigid or thermoplastic materials. Several embodiments of the sensor manifold 4100 can be manufactured using the systems and methods disclosed in U.S. Patent Application Publication No. 2008 / 0216898 (Title of Invention: Device Integrated by Cassette System). 【0274】 Referring again to Figure 55, the sensor manifold 4100, used with the sensor device and sensor device system, has a printed circuit board 4304 (PCB) and a PCB cover 4305. Various embodiments have a connector 4303 (also shown in Figures 53 and 56B) which mechanically connects the cassette manifold 4100 to a system such as a hemodialysis system. The cassette manifold 4100 employs various methods to integrally hold the layers of the sensor manifold 4100. In various embodiments, as shown in Figure 43, 4306 (also shown in Figure 56B), screws, screws used in other embodiments, welding, clips, clamps, and other chemical and mechanical bonding methods are employed. 【0275】 Figure 56A shows an exemplary embodiment of the sensor manifold 4100. Connector 4401 is used to introduce or remove a medium from the channel 4402. A sensor probe 4404 extending into the channel 4402 is incorporated into the sensor manifold 4100 to determine the characteristics of the medium flowing through a specific channel of the sensor manifold. In one embodiment, a sensor probe is used to sense the temperature or other characteristics of the medium. In another embodiment, a sensor probe is used to detect the temperature, conductivity, or other characteristics of the medium. In further embodiments, three or more sensor probes are used. In one embodiment, one or more combined probes that sense temperature and conductivity are used. In other embodiments, the conductivity sensor and temperature detector may be existing conductivity sensors or temperature detectors. In one embodiment, the conductivity sensor element (or sensor lead) is a graphite post. In other embodiments, the conductivity sensor element is formed from stainless steel, titanium, or any other material commonly used for measuring post conductivity. In certain embodiments, the conductivity sensor includes the sensor mechanism and electrical connections that transmit signals from the sensor to a controller or other device. In various embodiments, the temperature detector may also be a temperature detector that is typically used (or can be used) for temperature detection. 【0276】 Referring to Figure 56A, the sensor probe 4404 is electrically connected to the PCB 4405. In certain embodiments, while a suitable method of electrical connection between the sensor element 4404 and the PCB 4405 known in the art is also used to ensure proper electrical connection, an electrically conductive epoxy is utilized between the sensor element 4404 and the PCB 4405. The PCB 4405 is indicated by an edge connector 4406. In various embodiments, the edge connector 4406 is used to transmit sensor information from the cassette manifold 4100 to the main system. The edge connector 4406 is connected to a medium edge connector (such as the medium edge connector 4601 shown in Figure 58). In various embodiments, the medium edge connector 4601 is attached to a hemodialysis machine (not shown). In such embodiments, guide tracks 4310 and 4311 are used (as shown in Figure 55) to complement the relationship between the edge connector 4406 and the medium edge connector 4601. Various embodiments also include configurations in which the connector 4303 mechanically connects the cassette manifold 4100 to a system, such as a hemodialysis system (as shown in Figures 53, 55, and 56B). 【0277】 Figure 56A shows the air trap 4410. In a particular embodiment, the air trap 4410 is used to capture and purify the air in the system. Specifically, as shown in Figure 54, the medium flows through the channel 4222 between connectors 4107 and 4109 of the sensor manifold 4100. As the flow of the medium lags around the circumferential points of the channel 4222 (near connector 4108), air is removed from the following medium at connector 4108. 【0278】 In Figure 56B, the PCB cover 4305 is shown. The PCB cover 4305 is connected to the sensor manifold 4100 by a connector 4306. An edge connector 4406 is also shown. 【0279】 In certain embodiments, the sensor manifold 4100 is passive with respect to flow rate control. In such embodiments, the sensor manifold 4100 does not include a valve or pump mechanism to control the flow of the medium. In such embodiments, the flow of the medium is controlled by the external surface of the fluid control device to the sensor manifold 4100. In other embodiments, the sensor manifold includes one or more known mechanical valves, air valves or other types. In such embodiments, the sensor manifold includes one or more pump mechanisms, including air pump mechanisms, mechanical pump mechanisms or other types of known pump mechanisms. Examples of such valve and pump mechanisms include those described in U.S. Patent Application No. 11 / 871,680, filed on 12 October 2007 under the title Pump Cassette, or U.S. Patent Application Publication No. 2008 / 0216898 (Title of Invention: Apparatus Integrated by Cassette System). Figure 57 shows the base 4301 of connector 4401. The top plate 4302 is shown together with the connector 4303. The sensor probe 4501 extends into the flow path 4503 via the top plate 4302. The sensor probe 4501 is a sensor of various shapes, including the sensor probes described herein. 【0280】 Sensing probes, such as sensing probe 4501, may all be the same, or they may be individually selected from various sensors based on the type of function to be performed, or the same probe may be individually modified based on the type of function to be performed. Similarly, the configuration of the flow path, such as the length and shape of the flow path, may be selected based on the function to be performed. As an example, a temperature sensor such as a thermistor may be used to detect the temperature of a medium of interest in the flow path. Also as an example, to measure the conductivity of a medium of interest, one sensing probe configured to measure both temperature and conductivity and another sensing probe configured to measure only conductivity may be used. In other embodiments, two or more sensing probes configured to measure both temperature and conductivity may be used. In various embodiments of such configurations, as an example, there may be a second temperature sensor that is not used during normal operation, or the second temperature may be used for overlapping temperature measurements, or may be used for overlapping temperature measurements. 【0281】 Referring again to Figure 57, PCB 4502 is shown with an electrical connector 4503. As further shown in Figure 58, PCB 4602 is shown with an electrical connector 4603 for connection to the sensing probe (shown as 4501 in Figure 45). PCB 4602 also includes an opening 4604 for mounting to a top plate (shown as 4305 in Figure 57). In certain embodiments, the electrical connector 4603 may be mounted on PCB 4602 with a gap 4606, or manufactured together with PCB 4602 with a gap 4606. In such embodiments, the gap 4606 may be used to provide protection to the electrical connector between the sensing probe 4501 and PCB 4602 by allowing the contraction and expansion of various components of the sensor manifold 4100 with less impact on PCB 4602. 【0282】 Referring again to Figure 58, PCB 4602 is also shown together with edge connector 4605. As described herein, edge connector 4605 may interface with receiver 4601 of the edge connector, which can be connected to a system such as a hemodialysis system that interfaces with sensor manifold 4100. 【0283】 Various embodiments of the exemplary sensor manifold 4100 shown in Figures 53 to 58 may be used in combination with the hemodialysis system and method described in U.S. Patent Application No. 11 / 871,680, filed October 12, 2007, titled Pumping Cassette, or the hemodialysis system and method described in U.S. Patent Application Publication No. 2008 / 0216898, titled Cassette System Integrated Apparatus. In a particular embodiment, the sensor manifold 4100 includes all of the temperature and conductivity sensors shown in Figure 59. Figure 59 shows a fluid design diagram according to one embodiment of the invention described in the patent applications referenced above. 【0284】 As an example, in various embodiments, the temperature and conductivity of the medium of interest at position 4701, as shown in Figure 59, may be measured using a sensor manifold 4100. In such embodiments, the medium of interest flows through a channel 4220 (as shown in Figure 54) to a pipe connector 4105 (as shown in Figure 53) and exits at a pipe connector 4106 (as shown in Figure 53). The conductivity of the medium of interest is measured by two sensing probes (not shown) extending into the channel 4220, at least one of which is configured to include a temperature sensing element such as a thermistor. Measurements of the conductivity and temperature of the medium of interest are used to determine and / or relate various practical information to a hemodialysis system. For example, in various embodiments at position 4701 in Figure 59, the medium of interest consists of water to which a bicarbonate-based solution has been added. The conductivity of the medium of interest at position 4701 may be used to determine whether an appropriate amount of bicarbonate-based solution was added before position 4701. In certain embodiments, if the conductivity measurement deviates from a predetermined range, or deviates from a predetermined measurement due to being greater than a predetermined amount, the medium in question may not contain a bicarbonate-based solution of the appropriate concentration. In such an example, in certain embodiments, the hemodialysis system receives a warning. 【0285】 Furthermore, as an example, in various embodiments, as shown in Figure 59, the conductivity of the medium of interest at position 4702 can be measured using a sensor manifold 4100. In such embodiments, the medium of interest flows through a channel 4221 (as shown in Figure 54) to a pipe connector 4112 (as shown in Figure 41) and exits at a pipe connector 4113 (as shown in Figure 53). The conductivity of the medium of interest is measured by two sensing probes (not shown) extending into the channel 4221, at least one of which is configured to include a temperature sensing element such as a thermistor. Measurements of the conductivity and temperature of the medium of interest are used to determine and / or relate various practical information to a hemodialysis system. For example, in various embodiments at position 4702 in Figure 59, the medium of interest consists of water to which a bicarbonate-based solution is added, followed by an acid-based solution. The conductivity of the medium in question at position 4702 is used to determine whether an appropriate amount of the acid-based solution (and the bicarbonate-based solution from the previous step) was added before position 4702. In certain embodiments, if the conductivity measurement deviates from a predetermined range or deviates from a predetermined measurement due to being greater than a predetermined amount, the medium in question may not contain the appropriate concentrations of the acid-based and bicarbonate-based solutions. In such an example, in certain embodiments, the hemodialysis system receives a warning. 【0286】 As a further example, in various embodiments, the temperature and conductivity of the medium of interest at position 4703 may be measured using a sensor manifold 4100, as shown in Figure 59. In such embodiments, the medium of interest flows in and out of a pipe connector 4107 (as shown in Figure 53) and a pipe connector 4109 (as shown in Figure 53) via a channel 4222 (as shown in Figure 54). As described herein, air may be removed from the medium of interest by crossing a bend in the channel 4222. In such an example, a portion of the medium of interest is removed to a drain pipe via a pipe connector 4108, with the air being discharged through the gap along with the portion of the medium. The conductivity of the medium of interest is measured by two sensing probes (not shown) extending into the channel 4222, at least one of which is configured to include a temperature sensing element such as a thermistor. Measurements of the conductivity and temperature of the medium of interest are used to determine and / or relate various practical information to a hemodialysis system. For example, in various embodiments, the measurement of conductivity at position 4703 in Figure 59 may be used to correlate with the cleanliness of the dialysis machine. In such an example, in a particular embodiment, this information is then sent to the hemodialysis system. 【0287】 As a further example, in various embodiments, as shown in Figure 59, the temperature of the medium of interest at position 4704 may be measured using a sensor manifold 4100. In such embodiments, the medium of interest flows through a channel 4223 (as shown in Figure 54) to a pipe connector 4103 (as shown in Figure 53) and exits at a pipe connector 4104 (as shown in Figure 53). The temperature of the medium of interest is measured by one or more sensing probes (not shown) extending into the channel 4223. The measurement of the temperature of the medium of interest at position 4704 is used to determine and / or relate various practical information to the hemodialysis system. For example, in various embodiments at position 4704 in Figure 59, the temperature of the medium of interest is determined downstream of the heating device 4706. If the temperature deviates from a predetermined range or deviates from a predetermined measurement by being greater than a predetermined amount, the hemodialysis system receives a warning. For example, in one embodiment, the medium of interest may be recirculated through the heating device 4706 until the temperature of the medium of interest is within a predetermined range. 【0288】 In further examples, in various embodiments, the temperature and conductivity of the medium of interest at position 4705 may be measured using a sensor manifold 4100, as shown in Figure 59. In such embodiments, the medium of interest flows through a channel 4224 (as shown in Figure 54) to a pipe connector 4110 (as shown in Figure 53) and exits at a pipe connector 4111 (as shown in Figure 53). The conductivity of the medium of interest is measured by two sensing probes (not shown) extending into the channel 4224, at least one of which is configured to include a temperature sensing element such as a thermistor. Measurements of the conductivity or temperature of the medium of interest are used to determine and / or relate various practical information to the hemodialysis system. For example, the temperature and conductivity measurements at position 4705 may be used as a further safety check to determine whether the temperature, conductivity, and their correlations and composition of the medium of interest are within acceptable limits before the medium reaches the dialysis machine 4707, and thus before reaching the patient. In one embodiment, if at least one of the temperature and conductivity measurements deviates from a predetermined range or deviates from a predetermined measurement by being greater than a predetermined amount, the hemodialysis system receives a warning. 【0289】 For the various embodiments described herein, the cassette may be formed from any material, including plastics and metals. The plastic may be flexible plastic, rigid plastic, semi-flexible plastic, semi-rigid plastic, or any combination thereof. In some of these embodiments, the cassette includes one or more heat wells. In some embodiments, at least one of one or more sensing probes and one or more other devices for transferring information about one or more characteristics of such a medium of interest is in direct contact with the medium of interest. In some embodiments, the cassette is designed to hold a fluid having a flow velocity or pressure. In other embodiments, one or more compartments of the cassette are designed to hold a medium that is mostly stagnant, even when the medium is flowing, or a medium that is kept in a conduit. 【0290】 In some embodiments, the sensor device may be used based on the need to separate the medium of interest from the sensing probe. However, in other embodiments, the sensing probe may be used for temperature, conductivity, and / or other detections that directly use the medium of interest. 【0291】 Another aspect of the present invention relates to methods and operations of systems, as generally discussed herein. For example, a hemodialysis system may be primed, have its flow equalized, be emptied, purged with air, disinfected, and so on. 【0292】 One set of embodiments relates to priming a system with a fluid. The fluid to be primed is first introduced into a dialysate tank (for example, dialysate tank 169). Next, the ultrafiltration unit 73 is first primed by pushing the fluid from the dialysate tank 169 for ultrafiltration 73, and then discharged through a drain pipe via line 731 through waste line 39, as shown by the thick black line in Figure 17A. Any air present in the ultrafiltration unit 73 rises naturally to the priming port and is flushed out into the drain pipe. 【0293】 Next, as shown in Figure 17B, the equilibrium circuit and its pump 159 push the fluid, causing it to be discharged through the ultrafiltration device 73 and the equilibrium circuit to the drain pipe and primed. The pump 159 primes the fluid by causing it to flow upward (through the ultrafiltration device to the drain pipe). Air entering the dialysis machine 14 is bubbled up to the top of the dialysis machine and discharged from the outlet of the dialysis machine to the drain pipe. 【0294】 Next, the blood flow pump and tubing are primed by circulating the fluid through the blood flow circuit and air trap back to the orientation circuit via conduit 67. As seen in Figure 17C, the fluid passes through the ultrafiltration and dialysis units, is passed through the air trap, and descends to the drain pipe. The air trap traps air circulating in the blood flow circuit and sends it to the drain pipe. Priming may be stopped when the air sensor stops detecting air (and some further fluid has been allowed into the system as a safety margin). 【0295】 Another set of embodiments relates to adding air to the system, for example, emptying the various fluids in the system. In one operation, for example, the dialysate tank is emptied. The outlet 226 of the dialysate tank 169 is opened, and pump 159 is used to pump the fluid from the dialysate tank to the drain pipe until air is detected by pump 159 (discussed later). This is shown in Figure 19. 【0296】 Air is also pumped into the equilibrium circuit in a particular embodiment, as shown in Figure 20. The outlet 226 of the dialysate 16 is opened to allow air into the dialysate tank. Using pump 159, air is pumped up through the outside of the ultrafiltration unit 73. This air pressure moves the fluid outside the ultrafiltration unit inward, causing it to flow through the dialyzer and down into the drain pipe. During this operation, the area outside pump 159 and the ultrafiltration unit will be filled with air. 【0297】 In addition, air is introduced into the blood flow circuit through the anticoagulant pump 80, as shown in Figure 21A. First, the air is introduced into the pod pump 23 (Figure 21A), and then directed from the pod pump to the arterial line 203 and descended into the drainage tube (Figure 21B), or distributed to the venous line 204 (via the dialysis machine 14) and descended into the drainage tube (Figure 21C). 【0298】 In one embodiment, an integrity test is performed. Since the ultrafiltration and dialysis apparatus are constructed using membrane material that air does not easily pass through when wet, the integrity test can be performed by priming the filter with water and then applying compressed air to one side of the filter. In one embodiment, the air outlet is included in one of the blood flow pumps, and therefore the pump chamber can be used to pump air for use in the integrity test. This embodiment takes advantage of a larger pump. The air pressure forces all the water through the filter and stops the airflow as soon as the water is replaced. However, if the airflow continues, the membrane will rupture and need to be replaced. Therefore, the system is primed with water. First, the mixing circuit is primed to remove air before the dialysate tank. Then the outside of the ultrafiltration apparatus is primed, as it is assumed that the ultrafiltration apparatus will not allow water to pass through to the equilibrium circuit until the outside is primed. The equilibrium circuit and dialysis apparatus are then primed. Finally, water is applied past the dialysis apparatus and primes the blood flow circuit. 【0299】 The mixing circuit is first primed by pump 183 to push water through line 281 and bicarbonate source 28, and then through each of the pumps and line 186 to dialysate tank 169. Dialysate tank 169 is aerated by such air, which is pushed through upward bubbles and discharged through outlet 226. Once air is primed from dialysate tank 169, the tank is filled with water, and the priming flow continues from dialysate tank through ultrafiltration unit 73 to drain pipe, as seen in Figure 22A. Next, water is primed as already described (see Figure 17). Then, as shown in Figure 22C, the equilibrium pump 15 is emptied, while the blood flow pod pump 23 is filled with water from dialysate tank 169, as shown in Figure 22B. 【0300】 The test is carried out using a blood flow pump, which pushes water from each chamber beyond the dialysis machine 14 into the equilibrium pump chamber 15. The equilibrium pump chamber is vented to the atmosphere, starting empty (Figure 22C), so that it exists at atmospheric pressure on the dialysate side of the dialysis machine 14. See Figure 22D. Each of the blood flow circuit chambers is delivered using a specific pressure, and the end of the stroke is determined to determine the flow velocity. 【0301】 Another integrity test is the ultrafiltration flow test. In this test, the dialysate tank is filled with water, and the ultrafiltration is primed by pumping water from the dialysate tank through the ultrafiltration to line 731, and the water is pumped through the ultrafiltration, the flow rate is controlled, and the delivery pressure required to maintain the flow is monitored. 【0302】 Another set of embodiments relates to disinfecting and cleaning the system. This process removes any substances that accumulate during treatment and kills any active pathogens. In some examples, disinfectants are used, but typically heat is used. Water is maintained using a dialysate tank and replenished as needed when water is drained. 【0303】 The recirculation channel is shown in Figure 23. The flow along this channel is essentially continuous, and the blood flow circuit and the orientation circuit are connected using a conduit 67. The main channel is heated using a heater 72, which is used to raise the water temperature in the recirculation channel to a temperature that can kill any active pathogens that may be present. Some of the water flows into the drainpipe, but the majority is recirculated. In this embodiment, it should be noted that lines 48 and 731 are kept open to ensure that they are properly disinfected. In addition, a channel through the ultrafiltration device 73 is periodically selected to remove air from the ultrafiltration device and / or to provide recirculation flow through the same channel. Temperature sensors (e.g., sensors 251 and 252) may be used to ensure that the appropriate temperature is maintained. A non-limiting example of such a sensor is described in U.S. Patent Application No. 12 / 038,474, filed concurrently with this application, titled "Sensor Apparatus Systems, Devices and Methods," which is incorporated herein by reference. 【0304】 In one embodiment, the system is primed with dialysate as shown below. In this operation, the pod pump 280 is filled with water (Figure 24A), and the water is then pushed backward by pump 183, expelling air from the top of the bicarbonate source 28. The air is collected in the pod pump 282. See Figure 24B. The air in the pod pump 282 is then discharged through the pod pump 280 and line 186 to the dialysate tank 169. The outlet 226 of the dialysate tank 169 is left open to allow air to be discharged from the system (Figure 24C). In addition, acid is pumped from the acid source 29. It is then mixed with the bicarbonate concentrate from the bicarbonate source 28 and water. As shown in Figure 24D, pump 183 is used to provide sufficient water pressure to fill the bicarbonate source 28 with water. 【0305】 The acid solution and the bicarbonate solution (and, if another sodium chloride source is present, the sodium chloride solution) are then weighed together with the incoming water to prepare the dialysate. Sensors 178 and 179 are used to ensure that the partial mixture of each component with water is accurate. Dialysate that does not meet the standards is drained into the drain pipe, while good dialysate is injected into the dialysate tank 14. 【0306】 In another embodiment, the anticoagulant pump is primed. By priming the pump, air is removed from the heparin pump and the flow path, ensuring that the pressure in the anticoagulant vial is acceptable. The anticoagulant pump may be designed so that air in the pump chamber flows into the vial. The test is carried out by closing all the fluid valves of the anticoagulant pump, measuring the volume outside, evacuating the fluid management system chamber, opening the valves to introduce fluid from the vial into the pump chamber, measuring the volume outside (again), applying pressure to the fluid management system chamber, opening the valves to return the fluid to the vial, and measuring the volume outside (again). The change in volume outside caused by the fluid flow should correspond to the known volume of the pump chamber. If the pump chamber cannot be filled from the vial, the pressure in the vial is too low, and air needs to be introduced inside. Conversely, if the pump chamber cannot flow into the vial, the pressure in the vial is too high, and some of the anticoagulant needs to be pumped out of the vial. The anticoagulant drawn from the vial during this test can be discarded, for example, via a drainage tube. 【0307】 In yet another set of embodiments, the system is flushed with dialysate while not connected to a patient. This can be performed before or after treatment. Before treatment, the dialysate is moved to prevent the accumulation of sterilizing agents, and a portion of it is sent to the drainage tube. After treatment, this operation flushes the blood flow path with dialysate, pushing any remaining blood into the drainage tube. The flow path used in this operation is similar to the flow path used with water as previously described. 【0308】 The acid concentrate can be pumped out of the mixing chamber. Pump 184 is driven, thereby pumping the pod pump 280 to pump out the acid from pump 184 and the acid source 29, which is mixed in line 186 and sent to the drain pipe. Similarly, bicarbonate can be pumped out of the mixing chamber, as shown in Figure 25. Water is introduced from the bicarbonate source 28 using pump 183, and then the water is passed through line 186 using pod pump 280 and flows to the drain pipe. 【0309】 In yet another set of embodiments, the dialysate prime is removed from the blood flow circuit to prevent the priming fluid from being supplied to the patient. Figures 26A and 26B show the fluid flowing out from each of the equilibrium pump chambers and being discharged into the drainage pipe. Next, while the dialysate side of the dialysis machine 14 is closed, blood is introduced from the patient into the blood flow path (Figure 26C). Next, while the patient connection is closed, the blood flow pump chamber 23 pushes the priming fluid out of the dialysis machine into the equilibrium circuit (Figures 26D and 26E). This fluid is then pushed into the drainage pipe as previously described. This operation is repeated as needed until the priming fluid is sufficiently removed. The equilibrium pump is then refilled with unused dialysate and the patient connection is maintained closed, as shown in Figure 26F. 【0310】 In yet another set of embodiments, an anticoagulant for bolus administration may be delivered to the patient. First, as shown in Figure 27A, the anticoagulant for bolus administration is pumped from a vial (or other anticoagulant source) into one chamber of pump 13. The anticoagulant pump alternately pumps air into the vial and pumps the anticoagulant from the vial, thereby maintaining a relatively constant pressure. Next, the remaining volume is filled with dialysate (Figure 27B). Then, as shown in Figure 27B, the combined fluid is delivered to the patient down the arterial line 203. In some examples, the same pump chamber is again filled with dialysate (see Figure 27B), its volume is delivered to the patient, and it is ensured that all anticoagulants are properly delivered. 【0311】 In further embodiments, the system can also perform push-pull hemodiafiltration. In such cases, the blood flow pump 13 and the equilibrium pump 15 can be synchronized to cause the fluid to reciprocate across the dialysis machine. In hemodiafiltration, hydrostatic pressure is used to transport water and solute from the blood flow circuit to the equilibrium circuit through the membrane of the dialysis machine, where they are discharged. Although not theoretically limited, it is believed that larger solutes are more easily transported to the dialysate used by the convective forces in hemodiafiltration. 【0312】 In a series of embodiments, the injection of the solution is used to deliver fluid to the patient. As shown in Figure 28, the pump 159 of the orientation circuit is used to push fluid from the dialysis machine 14 into the blood flow circuit, thereby delivering fluid (e.g., dialysate) to the patient. 【0313】 According to a series of other embodiments, after repeated use, the dialysis machine may lose its efficiency and ability to function entirely due to the accumulation of compounds on the membrane walls of the dialysis machine. Any standard measurement may be used to determine the cleanliness of the dialysis machine. However, a method for measuring the amount of accumulation in the dialysis machine, i.e., a method for measuring the degree to which the cleanliness of the dialysis machine has decreased, involves pressing gas toward the blood side of the dialysis machine while retaining liquid toward the dialysate side. By measuring the volume of gas in the dialysis machine, the cleanliness of the dialysis machine is determined based on the measured volume of gas in the dialysis machine. 【0314】 Alternatively, in other embodiments, the cleaning rate may be determined by the pneumatic pressure of the system of the present invention as follows: By creating a pressure difference along the dialysis apparatus and measuring the fluid velocity of the dialysis apparatus, the cleaning rate of the dialysis apparatus is correlated / measured or calculated based on the pressure difference and fluid velocity. This is done based on well-known correlations or pre-processed programmed criteria, such as correlation tables, i.e., mathematical relationships. For example, a reference table may be used, or a determined mathematical relationship may be used. 【0315】 The cleanliness of the dialysis machine can also be measured using a conductive probe in the blood tubule plug-back recirculation passage. After the procedure, the patient is connected to a blood tubule that returns to a disinfection port. The fluid in the blood tubule and dialysis machine recirculates through the connections of these disinfection ports, and the conductivity of this solution can be measured as the solution passes through a conductivity measurement cell in this recirculation passage. 【0316】 To measure the cleaning rate of a dialysis machine, pure water may be circulated in the dialysate passages, and the conductivity of the fluid flowing through the blood recirculation passages may be continuously monitored. The pure water removes ions from the solution in the blood flow circuit recirculation passages at a rate proportional to the cleaning rate of the dialysis machine. The cleaning rate of the dialysis machine can be determined by measuring the rate at which the conductivity of the solution in the blood flow circuit recirculation passages changes. 【0317】 The cleaning rate of a dialysis machine can be measured by circulating pure water on one hand and dialysate on the other, and further by measuring the amount of fluid passing through the dialysis machine using conductivity. In a series of embodiments, it is preferable to return as much blood as possible to the patient during a power outage. In one embodiment of the hemodialysis system, compressed gas is used to drive the various pumps and valves used, and in other embodiments, such compressed gas can be used to return the system's blood to the patient during a power outage. Following this method, and referring to Figure 29A, dialysate is injected across the dialysis machine 14 to purify the blood in the blood flow circuit 19 and return it to the patient. Compressed air is used to inject dialysate into the dialysis machine 14. This function is activated when valve 77 releases the compressed air. This method can be used when a power outage or other malfunction prevents the dialysis machine from purifying and returning the patient's blood in the manner it normally does at the end of a procedure. 【0318】 By using compressed air to increase the pressure on the dialysate side of the dialysis machine 14 and sending dialysate from inside the dialysis machine to the blood side, the patient's blood is pushed back into the patient's body. The patient or assistant then monitors the procedure and, once the properly purified blood is returned, secures the tube between the blood flow circuit and the patient. 【0319】 In one embodiment, a tank 70 is incorporated into a hemodialysis system and filled with compressed air before the procedure begins. This tank 70 is connected to the dialysate circuit 20 via a manually operated valve 77. When the procedure is finished or interrupted, this valve 77 is opened by the patient or assistant to initiate the purification-return procedure. The membrane of the dialysis machine 14 allows dialysate to pass through but not air. Compressed air moves the dialysate until the patient-side tubing is secured or until the dialysate side of the dialysis machine is filled with air. 【0320】 In other embodiments, a tank containing compressed air is provided as an accessory to the dialysis machine. If the procedure is stopped prematurely due to a power failure or system malfunction in the dialysis machine, this tank is attached to the dialysate circuit of the machine to initiate the purification-return procedure. As in the embodiments described above, the purification-return procedure ends when the patient-side tube is secured or when the dialysate side of the dialysis machine is filled with air. 【0321】 In another embodiment shown in Figure 29B, the air tank 70 is incorporated into the system and attached to a fluid tank 75 equipped with a flexible partition wall 76 that separates air from the dialysate. In this case, rather than allowing compressed air to enter the dialysate circuit 20, the compressed air presses against the partition wall 76, increasing the pressure in the dialysate circuit 20. The amount of movable dialysate is determined by the volume of the fluid chamber 75. The cleanup-return procedure is completed when the patient-side tubing is secured or all fluid has been drained and the partition wall 76 abuts against the wall of the fluid chamber 75 and reaches the bottom. 【0322】 In any of these embodiments, the operation or method of the system is periodically checked by running the dialysate machine program between procedures. During the check, the user interface prompts the user to perform a clean-return procedure, and the machine monitors the pressure in the dialysate circuit to ensure that the operation is performed correctly. 【0323】 In the system shown in Figures 29A and 29B, blood is drawn from the patient by a blood flow pump 13, passed through a dialysis machine 14, and returned to the patient. These components and the tubing connecting them constitute a blood flow circuit 10. The blood contained in the blood flow circuit 10 must be returned to the patient when the procedure is completed or interrupted. 【0324】 The dialysate is drawn from the dialysate tank 169 by the dialysate pump 159 and heated to body temperature by passing through the heater 72. The dialysate then flows through an ultrafiltration device 73 to remove any pathogens or pyrogens that may be present in the dialysate. Next, the dialysate is treated by passing through the dialyzer and then returned to the dialysate tank. 【0325】 It is also possible to isolate the dialysis machine 14 from the rest of the dialysate circuit 20 using a bypass valve 74. To isolate the dialysis machine 14, two valves connecting the dialysate circuit 20 to the dialysis machine are closed, and one valve that shunts the dialysate around the dialysis machine is opened. 【0326】 This purification-return procedure can be used whether the dialysis machine 14 is isolated or not, and is also used when the procedure is completed or interrupted. When the power to the dialysate machine is turned off and it stops, the pump does not operate. When the patient is ready for the purification-return procedure, the air valve 77 is opened by the patient or an assistant. Air from the compressed air tank 70 flows into the dialysate circuit 20, increasing the pressure on the dialysate side of the dialysis machine 14. This increase in pressure can be achieved by allowing air to enter the dialysate circuit directly, as shown in Figure 29A, or by indirectly pushing the partition wall 76, as shown in Figure 29B. 【0327】 Due to the air pressure on the dialysate side of the dialysis machine, a portion of the dialysate flows from the dialysis machine 14 to the blood flow circuit. This dialysate moves the blood, purifies it, and returns it to the patient. The patient or assistant can observe the purification process by paying attention to the dialysis machine 14 and the blood tubes. The dialysate is started within the dialysis machine to move the blood and make it more purified. This purified solution moves from the dialysis machine towards the patient. Once it reaches the patient, the blood tube is clamped using the blood tube fixing device 71, and the purification-return process is completed. If the purification-return process on one line is faster than on the other line, the faster line may be fixed first, and the slower line may be fixed later. 【0328】 Once the purification and recirculation procedure is complete, the blood lines are secured and the patient is released from the dialysis machine. An embodiment of the system and method is shown in Figure 29A, in which the hydrophilicity of the material used is utilized to form a narrow tube within the dialysis machine 14. When this material is wet, dialysate can pass through, but air cannot. When the embodiment shown in Figure 29A is implemented, air can enter the dialysis machine 14, but it cannot pass beyond the blood flow circuit 10. 【0329】 In either case, the amount of dialysate that can pass through the dialysis machine 14 is limited. This limitation is imposed by the dimensions of the compressed air tank 70, the amount of dialysate contained in the dialysis machine 14, and, in the embodiment shown in Figure 7B, the dimensions of the fluid tank 75. Limiting the amount of dialysate injected into the dialysis machine is advantageous because giving the patient excess fluid would interfere with the therapeutic benefit of removing fluid during treatment. 【0330】 In another embodiment, in the event of a power outage, the pneumatic pressure that moves the dialysate from the dialysate circuit to the dialyzer can be derived from a pressurized air tank that normally drives the membrane pump and also serves as a pressure source for fluid management system measurements. As shown in Figure 80, for example, this pneumatic source can be accessed via a fluid management system route 170 used to monitor the dialysate tank 169. In the embodiment, manifold valves that direct pneumatic or vacuum to various pumps and valves in the fluid flow paths of the hemodialysis machine are electrically operated. In some embodiments, the valves themselves in the fluid flow paths of the hemodialysis machine can be electrically driven. They can be selected or preset to have a default open or closed position in the event of power outages. For example, if the default position of a manifold valve is closed, no pneumatic (or vacuum) is transmitted to its object. Similarly, if the default position of a manifold valve is open, the connected pressure or vacuum source can pressurize downstream devices (such as membrane-based pumps, membrane-based valves, or other types of valves). If the valves themselves that directly control the flow in the fluid flow paths are electrically driven, the valves can be selected to have a default position that either closes or opens its respective flow path. In the example shown in Figure 80, the pressure from the pressurized air tank can be transmitted to the dialysate tank 169 by configuring the manifold valve 170a and the fluid management system valve 170b to have, for example, a default open position. By configuring various other manifold valves to appropriate default positions, the corresponding flow valves controlled by the manifold valves can open the path from the dialysate tank 169 through the external dialysate pump circuit 159, the ultrafiltration device 73, and part of the equilibrium circuit 143, ultimately to the dialysis machine 14. In this way, in the event of no power supply and when the blood flow side of the dialysis machine 14 does not exhibit impedance, dialysate from the dialysate tank 169 can be flowed to the dialysis machine 14, enabling blood rinse-back. During normal dialysis, the control software can ensure that there is enough dialysate in the dialysate tank 169 to rinse back all the blood present in the blood tube set. 【0331】 In alternative embodiments, if the valve that directly controls the flow in the dialysate path between the dialysate tank and the dialyzer is electrically driven, it can be selected to have a default open position. Conversely, other valves that control the flow in the path diverting from the dialyzer can be selected to have a default closed position. 【0332】 For example, in Figure 80, the default configuration of the appropriate manifold valves leaves the inlet and outlet valves 171 of the outer dialysate pump circuit 159 and the balance circuit valve 172 in the "open" position, providing a flow path to the dialyzer 14. Conversely, the inlet feed valve 173a and recirculation valve 173b of the dialysate tank 169 and the drain valve 174 of the ultrafiltration unit 73 can be set to the "closed" default position when there is no power, preventing dialysate from being pushed into the drain pipe. In addition, the inlet valve 175 of the inner dialysate pump circuit 15 and the inlet valve 176 of the bypass or ultrafiltration pump circuit 35 can be set to the "closed" default position, preventing dialysate from flowing from the dialyzer 14 into its path when there is no power. 【0333】 To avoid uncontrolled rinse-back, the arterial supply and venous return lines of the blood tubing set can be compressed by an occluder mechanism that maintains a default "occluded" position when there is no power and moves to an "unoccluded" position during normal dialysis. The occluder can be positioned to simultaneously occlude both the arterial line before it reaches the blood pump cassette and the venous line after it leaves the dialysis machine or air bubble trap. In a preferred embodiment, before rinse-back is enabled, the patient, operator, or assistant removes the arterial line from the patient's vascular access site when rinse-back is scheduled or when initiating a power outage-related rinse-back. A suitable connector (such as a needle or needleless spike or Luer lock connector) is placed at the end of the arterial line and further connected to an air trap (such as an air trap 19) on the venous return line. This helps prevent air trapped in the blood flow path at the top of the vascular pump cassette or dialysis machine from inadvertently rinse-back towards the patient's vascular access. Once the arterial line is connected to the air trap, the patient, operator, or assistant may manually move the occluder to the "unoccluded" position, which depressurizes the venous return line and pushes the blood in the hemotube set towards the patient's vascular access into the pressurized dialysate from the dialysate circuit. If the patient observes air in the venous line downstream from the air trap, they simply need to reconnect the occluder to stop the rinse back. 【0334】 The rinse-back procedure described above uses dialysate as the solution that ultimately moves the blood in the blood flow path to the patient's vascular access; however, any electrolyte solution that is physiologically compatible and can be safely mixed with blood may be used in the rinse-back procedure. Furthermore, the rinse-back technique is not limited to dialysis systems. Any system that circulates a patient's blood outside the body may benefit from emergency rinse-back systems and methods. For example, it would be possible to introduce a filter with a semipermeable membrane (dialysis machine or ultrafiltration device) into the blood flow path of an extracorporeal system. The other side of the semipermeable membrane would then be exposed to the electrolyte solution in the flow path, which can be pressurized by a compressed gas source communicating through a valve. 【0335】 Another aspect of the present invention relates to a user interface for a system. The user interface is operated by an individual such as a patient, family member, assistant, professional healthcare provider, or maintenance technician to input options such as treatment options and receive information such as treatment procedures, treatment status, device status / condition, and / or patient status. The user interface is mounted on the treatment device and controlled by one or more processors of the treatment device. In other embodiments, the user interface may be a remote device that receives, transmits, or sends and receives data and commands regarding treatment procedures, treatment status, and / or patient status. The remote device may be connected to the treatment device by any suitable technology, including optical radio and / or electronic radio, Bluetooth®, RF frequency, optical frequency, IR frequency, ultrasonic frequency, magnetic effect, etc., for transmitting and / or receiving data and commands from or to the treatment device. In some embodiments, a display device may be used to indicate when data and / or commands have been received by the treatment device or the remote device. The remote device may include input devices such as a keyboard, touch screen, or capacitive input device for inputting data and / or commands to the treatment device. 【0336】 In some embodiments, one or more processors in the treatment device may include a unique identification code, and the remote device may include a function to read and learn the unique identification code of the treatment device. Alternatively, the user may program with a unique identification code. The treatment device and the remote device may use a unique identification code to substantially avoid interference with other receivers, including other treatment devices. 【0337】 In a series of embodiments, the treatment device may include one or more processors connected to a web-enabled server, and this web-enabled server may drive a user interface device. In one embodiment, the device uses an external CPU (e.g., a GUI graphical user interface) to communicate with a web-enabled server built into or connected to the treatment device via the Internet Protocol. The device may have a web page, and the graphical user interface may also communicate directly via IEEE 802.11b or other similar wired or wireless Ethernet® equivalents. The graphical user interface can be operated by individuals such as patients, family members, assistants, professional healthcare providers, or maintenance technicians to input options such as treatment choices and receive information such as treatment procedures, treatment status, device status / condition, and / or patient status. 【0338】 In other embodiments, an internal web server, either built into or connected to the treatment device, can also communicate with appropriate websites on the internet. These internet sites require a password or other user authentication for access. In other embodiments, users may have access to different information depending on the type of user or access provider. For example, a patient or specialized healthcare provider may have full access to the patient's treatment options and patient information, while family members may be granted access to specific patient information such as the status and duration of prescribed treatments and their frequency. Maintenance technicians, dialysis centers, or treatment device providers may have access to other information such as fault repair, preventive maintenance, and clinical trials. The use of a web-enabled server allows one or more individuals to simultaneously access patient information for various purposes. 【0339】 The use of remote devices (e.g., via wired or wireless communication, Internet Protocol, or internet sites utilizing web-enabled servers) allows dialysis centers to more effectively monitor each patient and / or efficiently monitor a large number of patients simultaneously. In some embodiments, the remote device can function as a night monitor or night alarm, monitoring patients during nighttime dialysis procedures and notifying if the patient's condition does not meet certain parameters. In some embodiments, the remote device can also be used to notify patients, families, assistants, specialized healthcare providers, or maintenance technicians. These alarms may also notify individuals of specific conditions such as fluid leaks, blockages, or temperatures outside of normal parameters. These alarms may be audible, visual, and / or vibration alarms. 【0340】 Figure 60 shows an embodiment of the user interface / treatment device combination. Specifically, Figure 60 shows a perspective view of an exemplary hemodialysis system 6000 comprising a dialysis unit 6001 and a user interface unit 6002. In this embodiment, the dialysis unit 6001 comprises a housing 6004 containing components suitable for performing hemodialysis. For example, the dialysis unit 6001 may include a mixing circuit 25, a blood flow circuit 10, an equilibrium circuit 143, and an external dialysate circuit or external dialysate circuit 142, as described, for example, in relation to Figure 2A. The dialysis unit 6001 may also include all patient access connections and dialysate fluid connections necessary for the operation of the system 6000. 【0341】 The user interface unit 6002 includes a user interface 6003 which may be used by a user, such as a hemodialysis patient, to control the operation of the dialysis unit 6001 via a coupling unit 6006. The coupling unit 6006 may include suitable data connections such as a bus, a wireless connection, a local area network connection (e.g., Ethernet® local area network), and / or a wide area network connection (e.g., the Internet). The user interface unit 6002 further includes a housing 6005 which includes components for enabling the operation of the user interface. In the example in Figure 60, the user interface 6003 includes a display screen with a touch-sensitive overlay that enables touch control and interaction with a graphical user interface displayed on the screen. However, many other types of user interfaces are possible, such as screens with separate input mechanisms such as a keyboard and / or a pointing device. The user interface 6003 may also include other features such as push buttons, a speaker, a microphone for receiving voice commands, etc. 【0342】 The hemodialysis system 6000 in Figure 60 includes a user interface unit 6002 that is physically connected to and separate from the dialysis unit 6001, but many alternative configurations are possible. For example, the user interface unit 6002 may be attached to the dialysis unit 6001 or installed inside the dialysis unit 6001. For convenience, the user interface unit 6002 installed in this manner may be movable from its mounting base for use in a different location or position. 【0343】 Figure 61 shows exemplary hardware configurations for the dialysis unit 6001 and the user interface unit 6002, respectively. These are controlled by separate CPUs, separating time and safety-critical software from the user experience software. Once treatment begins, it can be completed even if the user interface computer fails or disconnects. This can be supported by having several physical control buttons and indicator lights that are duplicated in the user interface unit 6002 and connected to the control processor of the dialysis unit 6001. The dialysis unit 6001 includes an automated computer (AC) 6106 that controls hardware actuators and sensors 6107 that communicate and monitor hemodialysis-related treatments. The automated computer 6106 includes an automated control unit 6108, which includes an automated computer processing unit 6109 and an automated computer readable medium 6110. The automated computer processing unit 6109 includes one or more processors that can execute instructions recorded on the automated computer readable medium 6110 and operate according to the data. The data may relate, for example, to hemodialysis processes performed or that can be performed on a patient. The system architecture provides the automated computer 6106 with the ability to command software-accessible safety sensors 6107 and fail-safe states (safely pausing or interrupting treatment). A parallel, independent semiconductor device-based system can perform checks similar to those controlled by software to provide a redundant safety system. This can be implemented, for example, in a field-programmable gate array ("FPGA"), which can also command a fail-safe state independently of the software system if one or more safety checks fail. The integrity of pneumatic, hydraulic, and electrical systems can be checked both during and between treatment sessions. Instructions may include, for example, an operating system (e.g., Linux®), application programs, program modules, and / or other encoded instructions that perform specific processes. 【0344】 The automated computer-readable medium 6110 may comprise any available medium accessible by the automated computer processing unit (dialysis processing unit) 6109. For example, the automated computer-readable medium 6110 may comprise a computer storage medium and / or a communication medium. The computer storage medium may comprise one or more of volatile memory and / or non-volatile memory and removable media and / or non-removable media, which are implemented in any method or technique for storing information such as computer-readable instructions, data structures, program modules or other data. Examples of the computer storage medium include, but are not limited to, RAM, ROM, solid-state disks, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible by the automated computer processing unit 6109. The communication medium typically comprises any information distribution medium that incorporates computer-readable instructions, data structures, program modules or other data into modulated data signals such as carrier waves or other transport mechanisms. The term "modulated data signal" refers to a signal in which one or more of its properties are set or modified to encode information within the signal. Examples include wired media such as wired networks or direct wired connections, and / or wireless media such as acoustic, RF, infrared, and other wireless media. 【0345】 Various components of the automated computer 6106, such as the automated computer readable medium 6110 and the automated computer processing unit 6109, may be electrically connected via a system bus. The system bus may comprise any of several bus structures, including a memory bus or a memory controller, a peripheral bus, and a local bus utilizing one of various bus architectures. Examples of such architectures include the Industry Standard Architecture (ISA), Microchannel Architecture (MCA), Extended ISA (EISA), VESA (Vehicle Electronics Standards Association), and Peripheral Component Interconnect (PCI). 【0346】 The automated computer 6106 may further include a Dialysis Universal Serial Bus (USB) interface 6113 to enable connection of various input and / or output devices to the automated control unit 6108. Examples of the above input and / or output devices include monitors, speakers, printers, keyboards, pointing devices (e.g., mice), scanners, personal digital assistants, microphones, and other peripheral devices. USB is just one example of the type of interface that can be used to connect peripheral devices. Other interfaces may be used instead. 【0347】 As described above, the dialysis unit 6001 includes components for performing and monitoring the hemodialysis process. These components include sensors and actuators 6107. To connect the automation control unit 6108 to the sensors and actuators 6107, the automation computer may include a hardware interface 6111. The hardware interface 6111 may transmit inputs to the sensors and actuators 6107 and receive outputs from them. 【0348】 The automated computer 6106 may further include an automated network interface 6112 that connects the computer to network-connected devices, such as those within a local area network (LAN) and / or wide area network (WAN). For example, the automated network interface 6112 may include a LAN such as an Ethernet® LAN and / or a WAN such as the Internet, and may allow the dialysis unit 6001 to exchange data with the user interface unit 6002 over a network 6114 that may be wired or wireless. Naturally, the dialysis unit 6001 may, instead or additionally, exchange data with the user interface unit 6002 by bus or other data connection. 【0349】 The user interface unit 6002 includes a user interface computer 6119 that controls user interfaces, such as a graphical user interface 6115, that display information to the user and receive user input. Similar to the automation computer 6106, the user interface computer 6119 includes a UI control unit 6116 having a UIC processing unit 6117 and a UI computer-readable medium 6118, a user USB interface 6121, and a UI network interface 6120, each being the same as or similar to its counterpart in the automation computer 6106. In addition, the user interface computer 6119 may include a graphics interface 6122 that connects the UI control unit 6116 to the graphical user interface 6115. In a preferred implementation example, the software of the user interface computer 6119 is responsible not for interpreting data received from the automation computer 6106, but rather for displaying the data in a user-friendly manner. 【0350】 Figure 62 schematically illustrates various exemplary software processes that can be executed in the automation computer processing unit 6109 and the UIC processing unit 6117, respectively, of the automation computer 6106 and the user interface computer 6119. The processes illustrated may be started and monitored by executive processes. For example, the automation computer processing unit 6109 and the UIC processing unit 6117 may each include an automation computer executive 6201 and a UIC executive 6207 to provide a communication mechanism for starting processes within a given processing unit and determining the execution status of child processes. The executive monitors each child process to ensure that each starts and continues to run as expected. Specifically, the automation computer executive 6201 and the UIC executive 6207 may detect hung processes. If a child process terminates or fails, each executive process may take appropriate action to ensure that the system continues to operate safely. This may include terminating the process and notifying the UIC executive 6207, stopping the system, or restarting non-safety-critical processes. In the case of a UIC processor, this involves notifying the operator and completing the action using a hard key. The automation computer executive 6201 and UIC executive 6207 may use Linux parent-child process relationships to receive notifications from the operating system regarding the termination of child processes. This allows for handling abnormal process terminations and expected terminations during power-off sequences. The automation computer 6106, automation computer executive 6201, and UIC executive 6207 may have a message interface between them to share information about their respective running processes. By periodically sharing state information, the state of all system processes can be consistently viewed in both the automation computer processing unit (processor unit) 6109 and the UIC processing unit 6117.The automated computer executive 6201 controls watchdog signals to electronic devices, allowing the machine to enter a fail-safe state if any child process becomes unresponsive or requests a fail-safe state. Preferably, this control can be performed directly via hardware registers without requiring an I / O server. 【0351】 As shown in the example in Figure 62, the automated computer processing unit 6109 includes an I / O server process 6205. The I / O server process 6205 provides an interface that allows other processes to request read operations by directly accessing hardware such as sensors and actuators of the dialysis unit. For example, the I / O server process 6205 may isolate the machine controller from the hardware details by providing an interface for the machine controller 6202 to read from the sensors and actuators. In the embodiment described, only the machine controller 6202 can communicate with the I / O server process 6205. The interface may be synchronized with a message queue. 【0352】 The machine controller 6202 described above functions as an interface for controlling the operation of the machine and reporting the machine's operating status. Specifically, the machine controller 6202 implements a controller that reads sensors via the I / O server process 6205 and sets actuators. These controllers are designed to allow programming of functions (e.g., dispensing and heating) using various parameters (e.g., flow rate, phase, pressure, and temperature) to support various hemodialysis treatments. The controller configuration may be established by a state machine that implements higher-order machine functions such as priming and disinfection. The state machine configures the flow paths and controller setpoints based on the machine's capabilities and higher-order commands received from the treatment application 6203 described later. The machine controller 6202 may also perform safety cross-checks with various sensors to maintain safe and effective treatment. Machine status and health information may be recorded in a database by the machine controller 6202. 【0353】 The treatment application 6203 advances patient treatment by instructing the machine controller 6202 to perform individual operations related to the hemodialysis process. Specifically, the treatment application 6203 may run a state machine that performs treatment and controls the system mode. The state machine controls, for example, priming the system with dialysate, connecting the patient to the machine, dialysis of the patient, rinsing back the patient's blood into the body, cleaning the machine, disinfecting the machine, performing tests on machine components, replacing old or worn parts, and waiting for the patient to return for the next procedure. The treatment application 6203 issues commands to the machine controller 6202 and requests status information from the machine controller 6202 in order to perform treatment operations. To obtain patient, treatment, and machine information, the treatment application 6203 may interface with a database for accessing information and storing treatment status information. The treatment application 6203 may also be used as an interface by the user interface model 6206 process described later to transfer user selections to the user interface and return the treatment status as a report. Therapeutic application 6203 implements a state machine that includes procedure preparation, patient linking, dialysis, solvent injection, patient unlinking, recycling preparation, disinfection, cleaning, and replacement of disposable items. The processes of therapeutic application 6203 may also include a main control module responsible for sequencing the activities of all other therapeutic applications that prepare and deliver routine procedures. 【0354】 Similar to the therapeutic application 6203, the user interface (UI) model 6206 runs on the automated computer processing unit 6109. The UI model 6206 aggregates information describing the current state of the system and the patient, and supports changes to the system state via operator input. The UI model 6206 separates the content of the user interface display from non-content-related aspects (e.g., presentation) by allowing changes to the user interface content without affecting the underlying software that controls the user interface display. Thus, changes to the UI model 6206 can be made without affecting the visual experience provided by the user interface. Rather than directly associating the display with it, the UI model 6206 instructs the graphical user interface (GUI) 6115 (Figure 61) of the user interface unit 6002 to display the screen and return information. For example, when the user moves to a new screen, the UI model 6206 sends information to the user interface unit 6002 to be used when generating the new screen. The UI model 6206 can also verify user data received from the user interface unit 6002, and once verified, it forwards the user data or commands based on it to the treatment application 6203. 【0355】 To create an interactive display for the graphical user interface 6115 (Figure 61) of the user interface unit 6002, a UI view process 6208 runs on the UIC processing unit (UI processor) 6117 of the user interface computer. The UI view process 6208 does not need to keep track of the screen flow or treatment status. Instead, the UI view process 6208 receives information from the UI model 6206, which runs on the automated computer processing unit 6109, specifying what to display to the user about the current state of the treatment and what they can input. As a result, the graphical user interface 6115 can be terminated and resumed without affecting the operation of the system. In addition, the graphical user interface 6115 does not need to be responsible for verifying user input. All inputs and commands received by the UI view 6208 are sent to the UI model 6206 for verification. In this way, all safety-critical aspects of the user interface can ...

Claims

[Claim 1] A disinfection method for disinfecting the blood pathway and dialysate pathway of a dialysis system, wherein the dialysis system has at least one door that closes a portion of the blood pathway and the dialysate pathway, and the disinfection method is A step of storing disinfection parameters, including disinfection temperature and disinfection time, in at least one storage medium; A configuration step of configuring the blood pathway and the dialysate pathway to provide a recirculation channel including the blood pathway, the dialysate pathway and a heater; The process of circulating a single fluid through the aforementioned recirculation channel; A step of monitoring the temperature of the single fluid with at least one temperature sensor in the recirculation channel; The step of monitoring the state of at least one of the doors; If at least one of the doors is open, the disinfection method includes the step of stopping the flow of the single fluid; The process of receiving user input indicating that at least one of the doors has been closed; A disinfection method characterized by comprising the step of determining that disinfection of the blood pathway and the dialysate pathway is complete when the temperature of the single fluid in the temperature sensor remains above the disinfection temperature for at least the disinfection time. [Claim 2] The above configuration step includes connecting the two conduits of the blood pathway to the dialysate orientation circuit of the dialysate pathway. The disinfection method according to claim 1. [Claim 3] The aforementioned disinfection method further, A step of determining that at least one of the monitored temperatures of the single fluid is below the disinfection temperature; The process includes the step of heating the single fluid to at least the disinfection temperature in response to the determination that at least one of the monitored temperatures is below the disinfection temperature, The disinfection method according to claim 1. [Claim 4] The disinfection method further comprises the step of heating the single fluid to a temperature equal to or greater than the disinfection temperature. The disinfection method according to claim 1. [Claim 5] A step of monitoring the temperature of a single fluid using multiple temperature sensors; The method further includes the step of determining that disinfection of the blood pathway and the dialysate pathway is complete when the temperature of the single fluid in each of the plurality of temperature sensors remains above the disinfection temperature for at least the disinfection time, The disinfection method according to claim 4. [Claim 6] The above configuration step includes connecting the dialysate drainage line to the water intake line. The disinfection method according to claim 1. [Claim 7] The process further includes periodically selecting the dialysate path through the filtration device so that air is removed from the filtration device. The disinfection method according to claim 1. [Claim 8] The process further includes a step of flowing a portion of the aforementioned single fluid into a drain pipe. The disinfection method according to claim 1. [Claim 9] The aforementioned recirculation channel includes a dialysis machine. The disinfection method according to claim 1. [Claim 10] The at least one temperature sensor is located in the dialysate pathway. The disinfection method according to claim 1. [Claim 11] The single fluid is water. The disinfection method according to claim 1. [Claim 12] The process further comprises heating the single fluid in accordance with the fact that the temperature of the single fluid exceeds a threshold period but is below a threshold. The disinfection method according to claim 1. [Claim 13] A disinfection method for disinfecting the blood pathway and dialysate pathway of a dialysis system, wherein the dialysis system has at least one door that closes a portion of the blood pathway and the dialysate pathway, and the disinfection method is A process of electronically receiving disinfection parameters, including disinfection temperature and disinfection time; A configuration step of configuring the blood pathway and the dialysate pathway to provide a recirculation channel including the dialysate pathway and the blood pathway, which include a heater; The process of controlling multiple actuators to circulate fluid through the aforementioned recirculation channel; A step of monitoring the temperature of the fluid with at least one temperature sensor; The step of monitoring the state of at least one of the doors; If at least one of the doors is open, the disinfection method includes the step of stopping the flow of the fluid; The process of receiving user input indicating that at least one of the doors has been closed; A disinfection method characterized by comprising the step of determining whether the temperature of the fluid monitored by at least one temperature sensor remains at or above the disinfection temperature for at least the disinfection time. [Claim 14] A step of monitoring the temperature of the fluid using multiple temperature sensors; The method further includes a step of determining whether the temperature of the fluid, monitored by each of the plurality of temperature sensors, remains above the disinfection temperature for at least the disinfection time, The disinfection method according to claim 13.

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