Pump cassette and method for use in medical treatment systems using multiple fluid lines

Abstract

A fluid handling cassette is provided that allows fluid to pass through continuously. [Solution] A fluid handling cassette 24 of a type that can be used in conjunction with an APD cycler device or other fluid injection device, the cassette comprising a substantially flat body, the body comprising at least one pump chamber 181 formed as a recess in its first side and a fluid passage including a channel. A patient line port is provided for connection to a patient line and for fluid communication with at least one pump chamber via at least one passage, and an optional membrane 15 can be mounted on the first side of the body, directly above the at least one pump chamber. The membrane may provide a pump chamber portion, which has a stress-free shape substantially matching the pump chamber recess of the body and is movable to move fluid within the usable space of the pump chamber.

Description

[Technical Field]

[0001] The present invention relates to a pump cassette and method for use in a medical treatment system using multiple fluid lines. [Background technology]

[0002] In peritoneal dialysis (PD), a sterile aqueous solution (peritoneal dialysis fluid or dialysate) is periodically infused into the patient's peritoneal cavity. Diffusion and osmotic exchange occur between this solution and the blood flow across the biological membrane. This exchange causes waste products that would normally be excreted by the kidneys to move into the dialysate. Generally, waste products consist of solutes such as sodium ions and chloride ions, and other compounds that are normally excreted by the kidneys, such as urea, creatinine, and water. The method of diffusing water across the peritoneum during dialysis is called ultrafiltration.

[0003] Conventional peritoneal dialysis fluid contains dextrose at a concentration sufficient to produce the osmotic pressure necessary to remove water from the patient by ultrafiltration. Continuous portable peritoneal dialysis (CAPD) is a widely used form of peritoneal dialysis (PD). Patients manually perform CAPD approximately four times a day. During the CAPD drainage / infusion procedure, the patient first drains the used peritoneal dialysis fluid from their peritoneal cavity, and then infuses new, unused peritoneal dialysis fluid into the peritoneal cavity. This drainage and infusion procedure typically takes about one hour.

[0004] Automated peritoneal dialysis (APD) is another form of peritoneal dialysis that is also widely used. APD uses a machine called a cycler to automatically inject peritoneal dialysis fluid into the patient's peritoneal cavity, retain it, and then drain it. APD is particularly attractive to peritoneal dialysis patients because it can be performed at night while they sleep. This frees patients from the need to undergo CAPD during their waking and working hours each day.

[0005] Generally, the entire APD process takes approximately 2-3 hours. In most cases, APD begins with the drainage stage, which removes used dialysate from the peritoneal cavity. The APD process then proceeds sequentially through the infusion, retention, and drainage stages. This series of infusion / retention / drainage is called a cycle.

[0006] During the infusion phase, the cycler moves a predetermined amount of unused, warmed dialysate into the patient's peritoneal cavity. The dialysate remains (or "retains") in the peritoneal cavity for a certain period of time. This is called the retention phase. During the drainage phase, the cycler removes the used dialysate from the peritoneal cavity.

[0007] The number of infusion / retention / drainage cycles required during a given APD session varies depending on the total volume of dialysate prescribed for each patient's APD regimen, and this number is either entered as part of the treatment prescription or calculated by the cycler.

[0008] APD can be implemented in various ways, and is actually being implemented in various ways. Continuous cyclic peritoneal dialysis (CCPD) is one commonly used form of APD. In each infusion / retention / drainage phase of CCPD, the cycler infuses a prescribed amount of dialysate. After the prescribed retention period, the cycler completely drains this fluid from the patient, emptying the peritoneal cavity, or making it "dry." Generally, CCPD involves 4 to 8 infusion / retention / drainage cycles to achieve the prescribed therapeutic dose.

[0009] In CCPD, after the last prescribed infusion / retention / drainage cycle, the cycler infuses a final volume of fluid. This final volume remains in the patient's body for an extended period. This volume is drained at the start of the next CCPD session in the evening or during a daytime fluid change. The final volume may contain dextrose at a different concentration than the volumes of fluid provided by the cycler for the continuous CCPD infusion / retention / drainage cycles.

[0010] Intermittent peritoneal dialysis (IPD) is another form of APD. IPD is generally used in acute situations where a patient suddenly needs dialysis treatment. IPD can also be used when a patient requires peritoneal dialysis but is unable to perform CAPD, or when performing peritoneal dialysis at home.

[0011] Similar to CCPD, IPD involves a series of infusion / retention / drainage cycles. However, unlike CCPD, IPD does not include a final infusion stage. In IPD, the patient's peritoneal cavity remains free of dialysate (i.e., "dry") from the end of one APD treatment session until the start of the next.

[0012] Tydal dialysis (TPD) is a different APD (Advanced Peritoneal Dialysis) method. Like CCPD (Critical Care Dialysis), TPD involves a series of infusion / retention / drainage cycles. Unlike CCPD, TPD does not completely drain the dialysate from the peritoneal cavity at each drainage stage. Instead, a base volume is established in the initial infusion stage, and only a portion of this is drained in the initial drainage stage. In subsequent infusion / retention / drainage cycles, a replenishment volume is injected on top of the base volume and then drained. In the final drainage stage, all dialysate is removed from the peritoneal cavity.

[0013] Some applications of TPD include a cycle in which, after complete drainage, a full volume of base dialysate is newly injected. In TPD, a final infusion cycle can be included, similar to CCPD. Alternatively, the final infusion cycle can be omitted, as in IPD.

[0014] APD offers flexibility and improved quality of life to individuals requiring dialysis. APD frees patients from the fatigue and inconvenience associated with daily CAPD, which can vary from person to person. Furthermore, APD allows patients to reclaim waking and working time during the day, as they do not require dialysis fluid changes. [Overview of the project] [Problems that the invention aims to solve]

[0015] However, the complexity and size of conventional equipment and associated disposable supplies have hindered the widespread acceptance of APD as an alternative manual peritoneal dialysis method by patients. [Means for solving the problem]

[0016] Multiple embodiments of the present invention relate to various components, systems, and methods for use in medical applications, including medical infusion procedures such as peritoneal dialysis. In some examples, multiple embodiments of the present invention are limited to applications in peritoneal dialysis, other embodiments are limited to more general dialysis applications (e.g., hemodialysis) or infusion applications, and yet another set of embodiments are limited to more general methods or processes. Thus, the embodiments of the present invention are not necessarily limited to APD systems and methods, although many of the exemplary embodiments described herein relate to APD.

[0017] In one embodiment of the present invention, a disposable fluid handling cassette, which can be used in conjunction with, for example, an APD cycler device or other intravenous infusion device, includes a substantially planar body having at least one pump chamber formed as a recess on a first surface of the body and a plurality of fluid passages including one channel. A patient line port can be positioned to connect to a patient line and to communicate fluid with at least one pump chamber via at least one passage, and a membrane covering the at least one pump chamber may be attached to the first surface of the body. In one embodiment, the membrane may have a pump chamber portion that is generally stress-free shaped to match the pump chamber recess of the body, and this pump chamber portion is positioned to operate in accordance with the movement of fluid within the usable space of the pump chamber. If the cassette body includes two or more pump chamber recesses, the membrane may also have two or more pre-formed pump portions. In another embodiment, for example, if the control surface of a cycler interacts with the cassette to control pumping and valve functions, the membrane does not necessarily have to be included in the cassette.

[0018] In another embodiment, one or more spacer elements extending from the inner wall of the recess, for example, are provided in the pump chamber so that the membrane does not contact this inner wall, thereby preventing the blockage of the inlet / outlet of the pump chamber, promoting the removal or capture of air in the pump chamber, and / or preventing the membrane from adhering to the inner wall. The spacer elements can be arranged so as to minimize the deformation of the membrane at the edges of the spacer elements when the membrane is pressed against the spacer elements.

[0019] In another embodiment, the patient line port and the drainage line port can be arranged at the first end of the main body and fluidly connected to at least one pump chamber via at least one flow path. On the other hand, a plurality of solution line spikes can be arranged at the second end opposite to the first end of the main body in a state where each solution line spike is fluidly connected to at least one pump chamber via at least one flow path. With this arrangement, it becomes possible to automatically connect the solution line to the cassette and individually block the patient line and the drainage line with respect to the solution line. In one embodiment, the heating bag line port can also be arranged at the first end of the main body and fluidly connected to at least one pump chamber via at least one flow path. Flexible patient lines, drainage lines, and heating bag lines can be connected to the patient line port, the drainage line port, and the heating bag line port, respectively.

[0020] In another embodiment, the main body may include an intake ventilation gap recess formed near at least one pump chamber. This recess promotes the exclusion of the fluid (gas and / or liquid) present between the membrane and the corresponding control surface of the cycler, for example, through the suction port of the control surface. That is, this recess assists in preventing the membrane from being pressed against the suction port and keeps the suction port open, so that the fluid can be drawn into the recovery chamber as needed.

[0021] In one embodiment, one or more ports, such as a drain line port and a heating bag line port, and / or one or more solution line spikes can be made to communicate with a common flow path channel in the cassette base. If desired, each of a plurality of valves can be arranged to control the flow in each flow path between at least one pump chamber, a patient line port, a drain line port, and a plurality of solution line spikes. In one embodiment, each part of the membrane can be positioned over a corresponding valve and made movable so that the valve can be opened and closed. Similarly, the flow entering from an opening into one or more pump chambers can also be controlled by a valve that is opened and closed by the movement of one or more parts of the membrane corresponding thereto.

[0022] In some embodiments, the membrane can close at least several flow paths of the body. That is, an open flow channel closed by the membrane on at least one side may be formed in the body. In one embodiment, flow paths can be formed on opposite flat surfaces of the body, and at least several flow paths on the first surface can be made to communicate with a plurality of flow paths on the second surface.

[0023] In one embodiment, one or more spikes on the cassette (for example, for receiving dialysis fluid) may be covered with a removable spike cap that hermetically seals the spike.

[0024] In another embodiment of the present invention, a disposable fluid handling cassette used in conjunction with a reusable automated peritoneal dialysis cycler device includes a substantially planar body, the body comprising at least one pump chamber formed as a recess on a first surface of the body, a plurality of fluid passages including channels, a patient line port positioned to connect to a patient line and communicating fluid to at least one pump chamber via at least one passage, and a flexible membrane attached to the first surface of the body, located above the at least one pump chamber. The pump chamber portion of the membrane located above the at least one pump chamber has a stress-free shape positioned to operate in accordance with the movement of fluid within the pump chamber, substantially coinciding with the reusable area of ​​the pump chamber recess provided in the body. In one embodiment, the cassette is configured to operably engage with a reusable automated peritoneal dialysis cycler device.

[0025] The cassette may include a drain line port positioned to connect to a drain line, which is in fluid communication with at least one pump chamber via at least one flow path and / or via a plurality of solution line spikes that are in fluid communication with at least one pump chamber via at least one flow path. The pump chamber portion of the membrane may be substantially dome-shaped and may include two pump chamber portions whose shape substantially coincides with the usable area of ​​the corresponding pump chamber recess. In one embodiment, the volume of the pump chamber portion may be 85-110% of the usable volume of the pump chamber recess. In another embodiment, the pump chamber portion may be configured to be 85-110% of the depth of the usable area of ​​the pump chamber recess. In yet another embodiment, the pump chamber portion may be configured to be 85-100% of the circumference of the usable area of ​​the pump chamber recess. The usable area of ​​the pump chamber may be defined at least partially by one or more spacer elements extending from the inner wall of the recess. In one embodiment, the spacer elements may have stepped lengths or variable heights that define a substantially dome-shaped region or other shape. The spacer elements may be arranged in a concentric elliptical pattern or other shape in a plane. One or more divisions can be provided in this pattern to connect, for example, air gaps. In one embodiment, the spacer elements can be arranged such that deformation of the membrane at the edges of the spacer elements is minimized when the membrane is pressed against the spacer elements. In another embodiment, one or more spacers can be configured so that the fluid inlet and / or outlet of the pump chamber are not covered by the membrane.

[0026] In another aspect of the present invention, a fluid handling cassette used in conjunction with a fluid handling system for a medical infusion device comprises a substantially planar body having at least one pump chamber formed as a recess on a first surface of the body, and a plurality of fluid passages including one channel, the at least one pump chamber including one or more spacer elements extending from the inner wall of the recess, the fluid handling cassette further comprises a patient line port arranged to connect to a patient line, the patient line port being in fluid communication with at least one pump chamber via at least one passage, the fluid handling cassette further comprises a drain line port arranged to connect to a drain line, the drain line being in fluid communication with at least one pump chamber via at least one passage, and the fluid handling cassette further comprises a plurality of solution line spikes being in fluid communication with at least one pump chamber via at least one passage.

[0027] In one aspect of the present invention, a disposable component system used in conjunction with a fluid line connection system for a peritoneal dialysis system includes a substantially planar body having at least one pump chamber formed as a recess on its first surface, a fluid handling cassette having a plurality of fluid channels, and a solution line spike positioned at the first end of the body, the solution line spike being in fluid communication with at least one pump chamber via at least one channel, and the disposable component system further includes a spike cap configured to removably cover the solution line spike, wherein the cap includes at least one raised mechanism (e.g., an asymmetric or symmetric flange) to assist in removing the cap for connection to the solution line before initiating peritoneal dialysis treatment.

[0028] In one embodiment, the cassette includes a skirt portion provided around the spike to receive the end of the spike cap, and a recess may be provided between the skirt and the spike to facilitate the formation of a sealing portion between the spike cap and the skirt.

[0029] In another embodiment, the solution line cap can be detachably connected to the solution line, and the solution line cap may include a recessed mechanism (e.g., symmetrical or asymmetrical grooves). At least a portion of the solution line cap may include a flexible material such as silicone rubber. The recessed mechanism facilitates the removal of the spike cap from the cassette.

[0030] In another embodiment, the spike cap includes a second raised mechanism that functions as a stopper for the solution line cap. In another embodiment, the main shafts of one or more spikes are substantially coplanar with the substantially planar body of the fluid handling cassette.

[0031] In another aspect of the present invention, a fluid handling cassette used in conjunction with a peritoneal dialysis system includes a substantially planar body having at least one pump chamber formed as a recess on a first surface of the body and a plurality of fluid passages, and a spike positioned at the first end of the body to engage with a dialysate line. The spike is in fluid communication with at least one pump chamber via at least one passage and includes a tip of an end portion and a lumen arranged such that the tip of the end portion of the spike is positioned substantially close to the longitudinal axis of the spike. In one embodiment, the lumen is positioned substantially off-axis from the longitudinal axis.

[0032] In another aspect of the present invention, a disposable component system used in conjunction with a fluid line connection system for a peritoneal dialysis system includes a spike cap configured to removably cover the spikes of a fluid handling cassette. The cap may include at least one feature to facilitate removal of the cap for connection to a solution line before initiating peritoneal dialysis treatment. This feature may be a raised or recessed mechanism and may be configured to engage with the solution line cap.

[0033] In another aspect of the present invention, a disposable component system used in conjunction with a fluid line connection system for a peritoneal dialysis system includes a solution line cap for detachable attachment to a solution line, the solution line cap including at least one feature that assists in detaching a spike cap to connect the solution line and the spike before initiating peritoneal dialysis treatment. This feature may be a raised or recessed mechanism and may be configured to engage with the spike cap. For example, an indicator may be associated with the solution line to identify the solution associated with the solution line and to affect at least one function of the peritoneal dialysis system.

[0034] In another aspect of the present invention, a medical infusion fluid handling system, such as an APD system, can be configured to remove caps and connect one or more lines (e.g., solution lines) to one or more spikes or other connection ports on a fluid handling cassette. This feature has advantages such as reduced potential contamination because human intervention is not required for cap removal and connection between lines / spikes. For example, an APD system may include a carriage configured to receive a plurality of solution lines, each having connector ends and caps. The carriage may be configured to move along a first direction, thereby allowing the connector ends of the solution lines to move along the first direction, and a cap stripper may be configured to engage with the caps of the solution lines on the carriage. The cap stripper may be configured to move in a second direction across the first direction, or to move along the first direction with the carriage. For example, the carriage may also be configured to move in a first direction toward the cassette within an APD cycler, thereby engaging the caps of the solution lines with the caps of the spikes on the cassette. The cap stripper engages with the cap (for example, by moving in a direction across the carriage's movement), and then moves with the carriage as the carriage is pulled out of the cassette to remove the cap from the spike. Next, as the carriage pulls the connector end of the solution line away from the cap on the cap stripper, the cap stripper retracts, allowing the carriage to engage the now exposed connector end of the solution line with the exposed spike on the cassette.

[0035] In one embodiment, the carriage may include a plurality of grooves, each receiving a corresponding solution line. Positioning the solution lines within their corresponding grooves facilitates further individual identification of each solution line, for example, by reading a barcode or another identifier on the line and controlling the system accordingly. The carriage can be mounted on the door of a cycler housing and moved along a first direction by a carriage drive unit. In one embodiment, the carriage drive unit engages with the carriage when the door is moved to the closed position and disengages from the carriage when the door is moved to the open position.

[0036] In one embodiment, the cap stripper may include a plurality of fork-like elements, which are arranged to engage with the corresponding caps of solution lines housed in a carriage. The fork-like elements can hold the caps removed from the solution lines, and each solution line cap itself can hold a spike cap. In another embodiment, the cap stripper may include a plurality of oscillating arms, each of which is associated with a fork-like element. Each oscillating arm may be arranged to move to engage with a spike cap, for example, to remove a spike cap from its associated spike. Each oscillating arm may be arranged to engage with the corresponding spike cap only when the associated fork-like element engages with the solution line cap. Therefore, the cap stripper cannot engage with a spike cap or remove a spike cap from a cassette where there is no corresponding solution line to connect to a spike.

[0037] In another aspect of the present invention, a method for connecting fluid lines within a medical infusion fluid handling system such as an APD cycler includes locating the solution line and the cassette spike in a closed space that is inaccessible to human contact. By removing the caps of the solution line and / or the spike within the closed space and connecting the solution line to the spike, the connection is provided while minimizing the possibility of contamination at the connection point, for example, by fingers contaminated with pathogens or other potentially harmful substances. For example, one method according to this aspect of the present invention provides a plurality of solution lines, each having a connector end and a cap, and a fluid handling cassette, each having a plurality of spikes, each covered with a spike cap, wherein the connector ends of the plurality of solution lines are surrounded by caps, the plurality of spikes are surrounded by spike caps, and the caps are removed from the connector ends of the plurality of solution lines without removing the caps or connector ends from the space, the spike caps are removed from the spikes without removing the spike caps and spikes from the space, the caps are engaged with each of the spike caps, and the plurality of connector ends are fluidly connected to the corresponding spikes while the connector ends and spikes remain within the space and are protected from human contact.

[0038] In one embodiment, the solution line cap and the spike cap can be engaged with each other before being removed from the line or spike, and then removed from both the line and the spike while remaining engaged. This technique simplifies the cap removal / capping process and also simplifies cap storage.

[0039] In another embodiment, for example, after the treatment is complete, the solution line can be detached from the spike, and the connector end of the line and the spike can be capped again. In another aspect of the present invention, the dialysis apparatus may include a fluid handling cassette comprising a plurality of spikes and a plurality of spike caps covering each of the spikes, a plurality of solution lines each having a cap covering a connector end, and a cap stripper arranged to remove one or more caps from the connector ends of the solution lines and to remove one or more spike caps from the spikes of the cassette with one or more caps fixed to one of the corresponding spike caps. As described above, the apparatus is provided to automatically fluidize the connector ends of the solution lines to their corresponding spikes after the caps have been removed.

[0040] In another aspect of the present invention, a dialysis machine such as an APD system may include a cassette having a plurality of fluid spikes and a plurality of spike caps covering the corresponding fluid spikes; a carriage arranged to receive a plurality of solution lines, each having a cap covering the connector end of each line; and a cap stripper arranged to engage with one or more caps covering the connector ends of the lines. The carriage and the cap stripper may be configured such that one or more caps engage with one or more caps on the connector end of a line while one or more caps are engaged with the corresponding spike caps covering the spikes on the cassette, and to remove the spike caps from the spikes and the caps from the connector ends of the solution lines, and to fluidly connect the spikes and the connector ends of the solution lines after the caps have been removed.

[0041] In another aspect of the present invention, the dialysis machine may further include a cap stripper arranged to remove one or more caps on the connector ends of a solution line and one or more spike caps from spikes on a fluid handling cassette, and to hold and reattach the caps to the solution line and the spike caps to the spikes on the cassette.

[0042] In another aspect of the present invention, a fluid line connection system for a peritoneal dialysis system includes a fluid handling cassette having a substantially planar body having at least one pump chamber formed as a recess in its first surface and a plurality of fluid passages, and a plurality of dialysate line spikes located at the first end of the body, the dialysate line spikes being in fluid communication with at least one pump chamber via at least one passage, and the spikes being positioned substantially coplanar with the substantially planar body of the fluid handling cassette, and including a carriage positioned to receive a plurality of solution lines, each solution line having a connector end. The carriage is positioned to automatically fluidly connect the connector ends of the solution lines to the corresponding spikes.

[0043] In one embodiment, the carriage is configured to move the solution line and each cap along a first direction substantially parallel to the substantially planar body of the fluid handling cassette. A carriage drive that moves the carriage only in the first direction may include a drive element and an air bag or screw drive to move the drive element along the first direction. A cap stripper can be provided that is configured to remove one or more caps from the connector end of a solution line and one or more spike caps from a spike on the cassette, with one or more caps fixed to one of the corresponding spike caps. In one embodiment, the cap stripper is configured to hold and reattach the caps to the solution line and the spike caps to the spikes on the cassette.

[0044] In another aspect of the present invention, a peritoneal dialysis system may include a cycler device equipped with components suitable for controlling the delivery of dialysate into the patient's peritoneal cavity. The cycler device may have a housing that encloses at least some of the components and further has a heating bag housing (wherein "heating bag" refers to any container suitable for heating dialysate, e.g., a flexible or rigid container made of polymer, metal, or any other suitable material). A lid is attached to the housing so as to be movable between an open position in which a heating bag can be placed in the heating bag housing and a closed position in which the heating bag housing is covered by the lid. With such a configuration, the heat is maintained by the lid so that, for example, the dialysate in the heating bag can be heated more quickly and efficiently. Furthermore, the lid prevents a person from touching the heated surface.

[0045] In one embodiment, the dialysis system may include a fluid handling cassette comprising a heated bag port attached to a heated bag line, a patient port line attached to a patient line, and at least one pump chamber for moving fluid within the patient line and the heated bag line. The heated bag is attached to the heated bag line and is provided to be installed within the heated bag housing.

[0046] In another embodiment, the system may include a movable interface (e.g., a visual display with touchscreen components) attached to the housing, which can move between a first position where the interface is received within the heated bag housing and a second position where the interface is removed from the heated bag housing (e.g., a position where a user can interact with the interface). Thus, the interface can be hidden and protected when the system is not in use. Furthermore, by storing the interface within the heated bag housing, the system becomes more compact, at least in the "stored" state.

[0047] In another aspect of the present invention, the dialysis system includes a supply unit for pneumatic and / or vacuum suitable for controlling the system's pneumatically driven components, pneumatically driven components fluidly connected to the supply unit for pneumatic and / or vacuum, and a control system that provides pneumatic or vacuum to the pneumatically driven components and then isolates the pneumatically driven components from the supply unit for a considerable period of time until pneumatic or vacuum is again provided to the pneumatically driven components. Such a configuration is useful for components that are not activated very frequently, such as the occluder devices described herein. Small movements of some components can generate noise, which may cause discomfort to the patient. By isolating a component from pneumatic / vacuum, it can be protected from micro-movements caused by changes in the supply pressure / vacuum, for example, by pressure / vacuum draw-in by other system components. In one embodiment, the above considerable period of time may be five minutes or more, one hour or more, or 50% or more of the time required to deliver or remove a certain amount of dialysate suitable for dialysis treatment into the patient's peritoneal cavity, or any other suitable time.

[0048] In another aspect of the present invention, the dialysis system includes a supply unit for pneumatic and / or vacuum suitable for controlling the system's pneumatically driven components, pneumatically driven components fluidly connected to the supply unit for pneumatic and / or vacuum, and a control system that provides pneumatic or vacuum to the pneumatically driven components and controls the pneumatic or vacuum to reduce noise generated by the pneumatically driven components. For example, the pneumatically driven components may include at least one moving part (e.g., a pump diaphragm), and the control system can reduce the pneumatic or vacuum supplied to the pneumatically driven components to slow down the movement of the moving part when it stops and / or changes direction (e.g., by controlling the pressure / vacuum to slow down the movement of the diaphragm before it changes direction). In another embodiment, noise generated by the moving part of a valve can be reduced by using, for example, pulse width modulation control of a pressure / vacuum supply valve.

[0049] In another embodiment of the present invention, the dialysis system includes a supply of pneumatic and vacuum suitable for controlling the system's pneumatically driven components. A first pneumatically driven component may be fluidly connected to the supply of pneumatic and / or vacuum and also has a first output line for releasing pneumatic pressure. A second pneumatically driven component is fluidly connected to the supply of pneumatic and / or vacuum and also has a second output line for releasing vacuum. A space defined by an accumulator, manifold, or soundproof chamber may be fluidly connected to both the first and second output lines. The control system can supply pneumatic or vacuum to the pneumatically driven components so that when the first and second components release pressure / vacuum during operation, the released pressure / vacuum is received in a common space (e.g., a manifold). In some situations, the positive pressure gas released by a component can be harmonized with the negative pressure released by another component, reducing the generated noise.

[0050] In another aspect of the present invention, a peritoneal dialysis system may include a fluid handling cassette that is fluidly connected to the patient's peritoneal cavity, provides a patient line extending from the peritoneal cavity, and further has at least one pump chamber for moving dialysate within the patient line. A cycler device is provided to receive and interact with the fluid handling cassette, thereby enabling the movement of dialysate within the patient line to at least one pump chamber. The cycler includes a control system provided to operate at least one pump chamber in initial operation and to control the forced flow of dialysate into the patient line to completely remove air from the patient line, and can be adapted to interact with two different types of fluid handling cassettes in relation to the volume of the patient line connected to the cassette body. A first type cassette may provide a relatively low-volume patient line (e.g., for pediatrics), and a second type cassette may provide a relatively high-volume patient line (e.g., for adults), and the control system may sense whether the cassette received by the cycler is of the first or second type and adjust the cycler operation accordingly.

[0051] In one embodiment, the control system detects whether the cassette received by the cycler is of type 1 or type 2 by determining the volume of the patient line during initial operation, and adjusts the volume of fluid flowing through the cassette during system operation. In another embodiment, the cycler detects a barcode-like marking on the cassette and adjusts the pumping operation based on the cassette type.

[0052] In another aspect of the present invention, the dialysis machine includes a fluid handling cassette having a plurality of spikes and at least one pump chamber for moving fluid within the spikes; a plurality of solution lines engaged with each spike on the cassette, and a control system for reading an indicator on each solution line to determine the type of each solution line. The control system can adjust the pumping operation or other cycler operation based on the uniqueness of one or more solution lines. For example, if a solution line is identified as a waste sampling line, the pumping operation is adjusted during the drainage cycle to send used dialysis fluid from the patient to the waste sampling line.

[0053] In another aspect of the present invention, a method for automatically recovering from an inclined state within a dialysis system includes (A) detecting the inclination angle of at least a portion of the dialysis system, the portion of which includes a machine for performing dialysis treatment; (B) determining that an inclined state exists in which the inclination angle exceeds a predetermined threshold; (C) interrupting dialysis treatment in response to (B); (D) monitoring the inclination angle during the interruption of dialysis treatment; (E) determining that the inclined state no longer exists; and (F) automatically resuming dialysis treatment in response to (E).

[0054] In another aspect of the present invention, the patient data interface of a dialysis system includes an apparatus port comprising a recess formed in at least a portion of the chassis of the dialysis system and a first connector disposed within the recess. The patient data storage device may include a housing and a second connector coupled to the housing, the second connector being configured to selectively couple to the first connector. The recess has a first shape, and the housing has a second shape corresponding to the first shape, so that when the first and second connectors are connected, the housing of the patient data storage device is at least partially received within the recess. The first and second shapes may be atypical, and the patient data storage device may have a verification code readable by the dialysis system to confirm that the patient data storage device is of the expected type and / or origin.

[0055] In another aspect of the present invention, a method for providing peritoneal dialysis includes delivering or withdrawing dialysate into or from the patient's peritoneal cavity at a first pressure, and adjusting the pressure of delivering or withdrawing the dialysate to minimize discomfort experienced by the patient due to the movement of the dialysate. In one embodiment, the pressure can be adjusted during the same infusion or emptying cycle of peritoneal dialysis treatment, and / or in different infusion or emptying cycles of peritoneal dialysis treatment. For example, when withdrawing dialysate from the patient, the pressure for withdrawing dialysate can be reduced when the amount of dialysate remaining in the peritoneal cavity falls below a threshold amount. By reducing the pressure (negative pressure or vacuum) near the end of the draining cycle, discomfort experienced by the patient due to the withdrawal of dialysate can be alleviated.

[0056] In another aspect of the present invention, a method for providing peritoneal dialysis includes providing a first solution to the patient's peritoneal cavity using a reusable cycler device during a first peritoneal dialysis treatment, and providing a second solution to the patient's peritoneal cavity using a reusable cycler device during a second peritoneal dialysis treatment immediately following the first treatment, wherein the second solution has a different chemical structure from the first solution. Different solutions can be created by mixing liquid materials from two or more solution containers connected to the cycler (for example, via a cassette attached to the cycler). These solution containers are automatically identified by the cycler reading barcodes, RFID tags, or other markings.

[0057] In another aspect of the present invention, a medical infusion system includes a housing enclosing at least some of the system's components, and a control surface configured and positioned to control the operation of a fluid handling cassette that may be mounted on and detachably attached to the housing. The control surface may have a plurality of movable parts arranged to control fluid delivery and the valve operation of the cassette, and at least one movable part arranged to draw fluid from an area near the movable parts may have associated vacuum ports.

[0058] In one embodiment, the control surface includes a sheet made of an elastic polymer material, and each movable part may have an associated vacuum port. In another embodiment, the cassette includes a membrane that can be positioned adjacent to the control surface, and the vacuum ports are provided to remove fluid from the space between the membrane and the control surface. A liquid sensor may be provided so that, for example, if the membrane ruptures, the liquid sensor detects the liquid drawn into the vacuum port and allows the liquid to leak out of the cassette.

[0059] In another aspect of the present invention, the amount of fluid moved by a pump, such as in an APD system, can be determined based on pressure measurements and the volumes of a specific conventional chamber and / or line, without directly measuring the fluid using, for example, a flow meter or weighing scale. In one embodiment, the volume of a pump chamber with a movable element that changes the volume of the pump chamber is determined by measuring the pressure in the pump chamber and a reference chamber while the pressures in the pump chamber and reference chamber are isolated from each other, and after the two chambers are fluid-connected so that the pressures in both chambers can be equalized. In one embodiment, the pressure equalization is assumed to occur in an adiabatic manner, and the pump chamber volume can be determined using, for example, a mathematical model of the system based on an adiabatic pressure equalization process. In another embodiment, the pressure measured after the chambers are fluid-connected can be measured before complete equalization occurs, and the pressures in the pump chamber and reference chamber measured after the chambers are fluid-connected will be unequal, but can still be used to determine the pump chamber volume. This method reduces the time between the initial and final pressure measurements, thereby reducing the time over which heat transfer may occur, and also reduces the errors that may be introduced when using an adiabatic model to determine the pump chamber volume.

[0060] In one aspect of the present invention, a method for determining the volume of fluid moved by a pump includes measuring a first pressure in the pump control chamber when the pump control chamber is isolated from a reference chamber. The volume of the pump control chamber may change at least partially based on the movement of a part of the pump, such as the pump membrane or diaphragm. A second pressure in the reference chamber is measured when the reference chamber is isolated from the pump control chamber. The reference chamber may have a known volume. A third pressure associated with the pump control chamber can be measured after the reference chamber and the pump control chamber are fluidly connected, but this measurement is performed before a significant amount of pressure equalization occurs between the pump control chamber and the reference chamber. Similarly, a fourth pressure associated with the reference chamber can be measured after the reference chamber and the pump control chamber are fluidly connected, but this measurement is performed before a significant amount of pressure equalization occurs between the pump control chamber and the reference chamber. The volume of the pump control chamber can be determined based on the first, second, third, and fourth measured pressures.

[0061] In one embodiment, the third and fourth pressures are measured almost simultaneously but substantially unequally to each other. For example, the equalization of pressures in the pump control chamber and the reference chamber occurs after the equalization period has elapsed since the pump control chamber and the reference chamber were fluidly connected, while the third and fourth pressures are measured after the pump control chamber and the reference chamber were fluidly connected, i.e., at about 10-50% of the equalization period. Therefore, the third and fourth pressures can be measured considerably (in time) before the pressures in both chambers are completely equalized. In another embodiment, the third and fourth pressures are measured when the pressures in both chambers have reached about 50-70% equalization, for example, when the pressures in both chambers have changed from their initial values ​​to about 50-70% of the equalized pressure values. This minimizes the time between the measurement of the first and second pressures and the measurement of the third and fourth pressures.

[0062] In another embodiment, the model for determining the volume of the pump control chamber assumes that an adiabatic system exists from the time when the first and second pressures of the isolated pump control chamber and reference chamber are measured until the time when the third and fourth pressures are measured.

[0063] To determine the volume of fluid moved by the pump, the steps of measuring the first, second, third, and fourth pressures and determining the fluid volume are performed at two different locations on the pump membrane, thereby determining two different volumes of the pump control chamber. The difference between the two different volumes represents the volume of fluid delivered by the pump.

[0064] As described above, this aspect of the present invention can be used in any suitable system, such as a system in which the pump is part of a disposable cassette and the pump control chamber is part of a dialyzer used for dialysis treatment.

[0065] In one embodiment, the first and / or second pressures can be selected from a set of pressure measurements that coincide with the point in time when the pressure in the pump control chamber or reference chamber first begins to change from a previously stable value. For example, this point in time can be identified based on a determination of when the best-fit line first deviates from the stable slope in a sequence of pressure measurements. This technique helps identify the initial pressures in the pump control chamber and reference chamber as late as possible in time, while reducing errors in determining the pump volume.

[0066] In another embodiment, a technique can be used to identify the best time to measure third and fourth pressures. For example, after fluid connection between the pump control chamber and the reference chamber, multiple pressure values ​​in the pump control chamber can be measured, and based on these multiple pressure values, multiple volume change values ​​can be determined for the pump control chamber. Each of the multiple volume change values ​​corresponds to a specific time and measured pressure value in the pump chamber. In this case, the volume change values ​​are caused by the movement of an imaginary piston in a valve or other component, which initially isolates the pump control chamber from the reference chamber but moves when the valve or other component opens. Therefore, the size or volume of the pump chamber does not actually change; the volume change is a fictional situation caused by the pressures in the pump chamber and reference chamber, which are initially different from each other. Similarly, after fluid connection between the pump control chamber and the reference chamber, multiple pressure values ​​in the reference chamber can be measured, and multiple volume change values ​​in the reference chamber can be determined based on these multiple pressure values. Each of the multiple volume change values ​​can correspond to a specific time and measured pressure value in the reference chamber, and, like the volume change values ​​in the pump chamber, is caused by the movement of an imaginary piston. By determining each difference value for the volume change in the corresponding pump control chamber and the volume change in the corresponding reference chamber, multiple difference values ​​between the volume change values ​​of the pump control chamber and the reference chamber can be determined. That is, multiple pairs of volume change values ​​for which difference values ​​are determined correspond to the same or approximately the same point in time. When the difference values ​​are analyzed, the smallest difference value (or a difference value lower than the desired threshold) indicates the point in time when the third and fourth pressures should be measured. Therefore, the third and fourth pressure values ​​can be identified as being equal to the pump control chamber pressure value and the reference chamber pressure value, respectively, corresponding to the smallest or below-threshold difference value.

[0067] In another embodiment, the measured pressure is the gas pressure in the pump control chamber and the reference chamber, and it is assumed that the equalization of pressures in the pump control chamber and the reference chamber occurs adiabatically, and that the equalization of pressures in the pump control chamber and the reference chamber includes equal but opposite changes in gas volume in the pump control chamber and the reference chamber, and the gas volume in the reference chamber at the fourth pressure measurement is calculated from the known volume of the reference chamber, the second and fourth pressures. The change in gas volume in the reference chamber can be assumed to be the difference between the known volume of the reference chamber and the gas volume value in the reference chamber calculated at the fourth pressure measurement. Furthermore, the change in gas volume in the pump control chamber can be assumed to be the difference between the initial volume of the pump control chamber and the gas volume in the pump control chamber at the third pressure measurement, where the change in gas volume in the pump control chamber is equal to, but opposite to, the change in gas volume in the reference chamber.

[0068] In another aspect of the present invention, a method for determining the volume of a fluid moved by a pump includes providing a fluid pump device comprising a pump chamber separated from a pump control chamber by a movable membrane, a reference chamber fluidly connectable to the pump control chamber, moving the fluid in the pump chamber by adjusting a first pressure in the pump control chamber to move the membrane, isolating the reference chamber from the pump control chamber to establish a second pressure in the reference chamber that is different from the pressure in the pump control chamber, fluidly connecting the reference chamber and the pump control chamber to initiate the equalization of the pressures in the pump control chamber and the reference chamber, and determining the volume of the pump control chamber based on the first and second pressures and the assumption that the pressures in the pump control chamber and the reference chamber begin to equalize adiabatically.

[0069] In one embodiment, after fluid connection between the reference chamber and the pump control chamber, the third and fourth pressures for the pump control chamber and the reference chamber can be measured, and the volume of the pump control chamber can be determined using these third and fourth pressures. The third and fourth pressures are substantially not equal to each other. As described above, the adjustment, isolation, fluid connection, and determination steps can be repeated to determine the difference between the two volumes obtained for the pump control chamber, where this difference represents the volume of fluid pumped by the pump.

[0070] In another embodiment, the pump is part of a disposable cassette, and the pump control chamber is part of a dialyzer used for dialysis. In another aspect of the present invention, the medical infusion system includes a pump control chamber, a control surface associated with the pump control chamber such that at least a portion of the control surface is movable in response to changes in pressure within the pump control chamber, a fluid handling cassette positioned adjacent to the control surface and having at least one pump chamber configured such that the fluid in at least one pump chamber moves in response to the movement of a portion of the control surface, a reference chamber fluidically connectable to the pump control chamber, and a control system configured to adjust the pressure within the pump control chamber and to control the movement of the fluid in the pump chambers of the fluid handling cassette. This control system can be configured to measure a first pressure in the pump control chamber when the pump control chamber is isolated from the reference chamber, measure a second pressure in the reference chamber when the reference chamber is isolated from the pump control chamber, fluidly connect the pump control chamber and the reference chamber, measure a third pressure associated with the pump control chamber and the reference chamber after the fluid connection is established, and further determine the volume of the pump control chamber based on the first, second, third, and fourth measured pressures and a mathematical model that defines the adiabatic equalization of pressures in the pump control chamber and the reference chamber when the pump control chamber and the reference chamber are fluidly connected.

[0071] In one embodiment, the third and fourth pressures are substantially unequal to each other, and the third and fourth pressures can be measured before, for example, the equivalent amounts of pressure in the pump control chamber and the reference chamber are equalized.

[0072] In another aspect of the present invention, a method for determining the volume of a fluid moved by a pump includes measuring a first pressure in a pump control chamber when the pump control chamber, which has a volume that changes at least in part based on the movement of a portion of the pump, is isolated from a reference chamber; measuring a second pressure in a reference chamber when the reference chamber is isolated from the pump control chamber; measuring a third pressure in relation to both the pump control chamber and the reference chamber after the reference chamber and the pump control chamber are fluidly connected; and determining the volume of the pump control chamber based on the first, second, and third measured pressures.

[0073] In one embodiment, a third pressure can be measured after the pressures in the pump control chamber and the reference chamber have been completely equalized. In one embodiment, the model used to determine the pump chamber volume may assume an adiabatic system to equalize the pressures between the pump chamber and the reference chamber.

[0074] In one aspect of the present invention, a method for determining the presence of air in a pump chamber includes measuring the pressure in a pump control chamber when the pump control chamber is isolated from a reference chamber, the pump control chamber having a known volume and separated by a membrane from a pump chamber that is at least partially filled with liquid, and the method further includes measuring the pressure in a reference chamber having a known volume when the reference chamber is isolated from the pump control chamber, measuring the pressure after the reference chamber and the pump control chamber are fluidly connected and before the time for the pressures in both chambers to equalize, and determining the presence or absence of air bubbles in the pump chamber based on the measured pressure and the known volume.

[0075] In one embodiment, the model used to determine the presence or absence of bubbles assumes an adiabatic system from the time the pressures in the isolated pump control chamber and the reference chamber are measured until the two chambers are fluidly connected. In another embodiment, the pressure in the pump control chamber is measured with the membrane pulled towards the wall of the pump control chamber.

[0076] In another aspect of the present invention, an automated peritoneal dialysis system includes a reusable cycler configured and positioned to be coupled to a disposable fluid handling cassette having at least one pump chamber. The disposable fluid handling cassette may be configured to be fluidly connected to the patient's peritoneum via a first collapsible tube and to a second source and / or destination (e.g., a solution container line) via a second collapsible tube. An occluder is positioned within the cycler and configured to selectively block the first collapsible tube when the second collapsible tube is not blocked. In one embodiment, the occluder can block multiple collapsible tubes, such as a patient line, a drainage line and / or a heating bag line. The cassette has a substantially planar body, which includes at least one pump chamber formed as a recess on its first surface, a plurality of fluid passages, a patient line port located at the first end of the body for connection to a first collapsible tube, and a solution line port located at the second end opposite the first end of the body and configured to connect to a second collapsible tube. The occluder is positioned within the cycler and configured to selectively block the first tube and a third collapsible tube (e.g., for waste fluid) without blocking the second collapsible tube.

[0077] In another embodiment, the occluder includes opposing first and second shut-off members that pivotally connect to each other, a pipe contact member connected to or comprising at least one of the first and second shut-off members, and a force actuator configured and positioned to apply force to at least one of the first and second shut-off members. When force is applied by the force actuator, the pipe contact member moves between a pipe shut-off position and an open position. The occluder may include a release member configured and positioned to allow an operator to manually move the pipe contact member from the pipe shut-off position to an open position even when no force is applied to the shut-off member by the force actuator. Since the force actuator can apply force sufficient to bend both the first and second shut-off members, when the force actuator applies force to the first and second shut-off members to bend them, the pipe contact member moves between the pipe shut-off position and an open position. The blocking member may be a spring plate pivotally connected at its opposing first and second ends, and the pipe contact member may be a pinch head connected to the spring plate at its first end, while the second end of the spring plate is fixed directly or indirectly to the housing to which the occluder is connected. In one embodiment, a force actuator comprises an inflatable bag positioned between the first and second blocking members. The force actuator can extend the distance between the first and second blocking members in the region where the first and second blocking members face each other so that the pipe contact member can be moved between a pipe-blocked position and an open position. In one embodiment, the force actuator can bend one or both of the blocking members to move the pipe contact member from the pipe-blocked position to the open position.

[0078] Having described various embodiments up to this point, the following description will refer to exemplary embodiments. It will be understood that various embodiments of the present invention can be used alone and / or in any suitable combination with other embodiments of the present invention. For example, the pump volume determination function described herein can be used in combination with a liquid handling cassette having the specific features described above, or with any other suitable pump configuration.

[0079] Aspects of the present invention will be described below with reference to at least some of the exemplary embodiments shown in the following drawings. In the drawings, similar elements are given the same reference numerals. [Brief explanation of the drawing]

[0080] [Figure 1] A schematic diagram of an automated peritoneal dialysis (APD) system incorporating one or more aspects of the present invention is shown. [Figure 2] Figure 1 is a schematic diagram of an example set used in conjunction with the APD system. [Figure 3] This is an exploded perspective view of the cassette in the first embodiment. [Figure 4] This is a cross-sectional view of the cassette along line 4-4 in Figure 3. [Figure 5] This is a perspective view of a vacuum mold that can be used to form a film having a pre-formed pump chamber portion in an exemplary embodiment. [Figure 6] Figure 3 shows a front view of the cassette unit. [Figure 7] This is a front view of a cassette body including two different spacer arrangements in an exemplary embodiment. [Figure 8] Figure 3 is a rear perspective view of the cassette unit. [Figure 9] Figure 3 is a rear view of the cassette unit. [Figure 10] Figure 1 is a perspective view of the APD system with the cycler door in the open position. [Figure 11] Figure 10 shows a perspective view of the inside of the cycler's door. [Figure 12] This is a right front perspective view of the carriage drive assembly and cap stripper in the first embodiment. [Figure 13] Figure 12 is a left front perspective view of the carriage drive assembly and cap stripper. [Figure 14] Figure 12 is a partial rear view of the carriage drive assembly. [Figure 15]This is a rear perspective view of the carriage drive assembly in a second exemplary embodiment. [Figure 16] Figure 15 is a left rear perspective view of the carriage drive assembly and cap stripper. [Figure 17] This is a left front perspective view of the cap stripper element in an exemplary embodiment. [Figure 18] Figure 17 is a right front perspective view of the cap stripper element. [Figure 19] Figure 17 is a front view of the cap stripper element. [Figure 20] This is a cross-sectional view along line 20-20 in Figure 19. [Figure 21] This is a cross-sectional view along line 21-21 in Figure 19. [Figure 22] This is a cross-sectional view along line 22-22 in Figure 19. [Figure 23] This is a close-up exploded view of the connector end of a solution line in an exemplary embodiment. [Figure 24] Figure 10 is a schematic diagram of the cassette and solution lines installed inside the cycler. [Figure 25] Figure 10 is a schematic diagram showing the cassettes and solution lines positioned at each location on the cycler door. [Figure 26] This is a schematic diagram of the cassette and solution lines with the cycler door closed. [Figure 27] This is a schematic diagram showing the solution line engaged with the spike cap. [Figure 28] This is a schematic diagram of a cap stripper engaged with a spike cap and a solution line cap. [Figure 29] This is a schematic diagram of the solution line with the cap and spike cap attached, separated from the cassette. [Figure 30] This is a schematic diagram of the solution line spaced apart from the solution line cap and spike cap. [Figure 31] This is a schematic diagram of a cap stripper in the retracted position along with the solution line cap and spike cap. [Figure 32] This is a schematic diagram of the solution line engaged with the cassette spike. [Figure 33] This is a cross-sectional view of a cassette with a five-stage solution line connection operation shown in relation to the corresponding cassette spike. [Figure 34] A rear view of a cassette in another exemplary embodiment, including a different arrangement on the rear side of the cassette adjacent to the pump chamber, is shown. [Figure 35] An end view of the cassette spike in an exemplary embodiment is shown. [Figure 36] Figure 10 shows a front view of the control surface of the cycler that interacts with the cassette in the embodiment shown. [Figure 37] Figure 36 shows an exploded view of the assembly for the interface. [Figure 38] An exploded perspective view of the occluder in an exemplary embodiment is shown. [Figure 39] Figure 38 shows a partially unfolded perspective view of the occluder. [Figure 40] Figure 38 shows a top view of the occluder with the air removed from the bag. [Figure 41] Figure 38 shows a top view of the occluder in its inflated state. [Figure 42] This is a schematic diagram of the cassette's pump chamber, associated control components, and inlet / outlet passages in an exemplary embodiment. [Figure 43] Figure 42 shows a graph of exemplary pressure valves for the control chamber and reference chamber, tracking the progress from the moment valve X2 is opened until some time has passed after valve X2 has opened, in the embodiment shown. [Figure 44] Figure 10 is a perspective view of the inside of the cycler with the upper part of the housing removed. [Figure 45] This is a simplified block diagram illustrating an exemplary implementation of a control system for an APD system. [Figure 46] Figure 45 is a schematic block diagram showing exemplary software subsystems of a user interface computer and an automated computer for a control system. [Figure 47] This shows the information between various subsystems and the processing flow of the APD system. [Figure 48] Figure 46 shows the operation of the treatment system. [Figure 49] A sequence diagram illustrating the exemplary interaction of the treatment module process in the initial replacement and dialysis sections of the treatment is shown. [Figure 50] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 51] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 52] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 53] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 54] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 55] This shows an exemplary screen view related to warnings and alerts that can be displayed on the APD system's touchscreen interface. [Figure 56] This illustrates the state and operation of components for detecting and recovering from an error condition in an exemplary embodiment. [Figure 57] This shows an exemplary module of the UI view subsystem of the APD system. [Figure 58] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 59]In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 60] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 61] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 62] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 63] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 64] In an exemplary embodiment, an exemplary user interface screen is shown that provides the user with information regarding system settings, treatment status, display settings, remote assistance, and parameter settings, and receives input from the user. [Figure 65] An exemplary patient data key and, in relation to it, a port for transferring patient data to and from the APD system are shown. [Modes for carrying out the invention]

[0081] While aspects of the present invention will be described in relation to peritoneal dialysis systems, certain aspects of the present invention can also be used for other medical applications, including infusion systems such as intravenous infusion systems or extracorporeal blood flow systems, and irrigation and / or fluid exchange systems for cavities in the stomach, intestines, bladder, pleural cavity, or other parts of the body or organs. Thus, aspects of the present invention are not particularly limited to use in peritoneal dialysis or to use in general dialysis.

[0082] APD system Figure 1 shows an automated peritoneal dialysis (APD) system 10 that can incorporate one or more embodiments of the present invention. As shown in Figure 1, for example, the system 10 of the illustrated embodiment includes a dialysate delivery set 12 (which may be a disposable set in a particular embodiment), a cycler 14 that interacts with the delivery set 12 to deliver the liquid provided by a solution container 20 (e.g., a bag), and a control system 16 that governs the process of performing the APD procedure (e.g., including a programmed computer or other data processor, computer memory, an interface that provides information to and receives input from a user or other device, one or more sensors, actuators, relays, a barometric pump, a tank, a power supply, and / or other suitable components. Only a few buttons for receiving user control input are shown in Figure 1. Further details regarding the components of the control system are described below). In the illustrated embodiment, the cycler 14 and the control system 16 are associated with a common housing 82, but they may be associated with two or more housings and may be independent of each other. The cycler 14 has a compact footprint adapted to operate on a tabletop or other relatively small surface commonly found in a home. The Cycler 14 is lightweight and portable, and can be carried by hand, for example, via a handle located on the opposite side of the housing 82.

[0083] Although set 12 in this embodiment is intended to be a single-use disposable item, it may include one or more reusable components, or the entire set may be reusable. Before initiating each APD treatment session, the user associates set 12 with the cycler 14 by, for example, loading the cassette 24 into the front door 141 of the cycler 14, which interacts with the cassette 24 to deliver and control the fluid flow in the various lines of set 12. For example, dialysate can be delivered to and from the patient to perform APD. After treatment, the user can remove all or some of the components of set 12 from the cycler 14.

[0084] As is well known in the art, prior to use, the user can connect the patient line 34 of set 12 to an indwelling peritoneal catheter (not shown) at a connector 36. In one embodiment, the cycler 14 can be configured to work with one or more different types of cassettes 24, for example, cassettes having patient lines 34 of different sizes. For example, the cycler 14 can be configured to work with a first type of cassette having patient lines 34 sized for adult patients and a second type of cassette having patient lines 34 sized for infants or children. The pediatric patient line 34 has a shorter and smaller inner diameter than the adult line to minimize the volume of the line, which allows for greater control over the delivery of dialysate and helps to avoid a relatively large amount of used dialysate being returned to pediatric patients when set 12 is used in a continuous drainage and infusion cycle. The heating bag 22 connected to the cassette 24 by the line 26 can be placed on the heater container receiving section (in this case, tray) 142 of the cycler 14. The cycler 14 can deliver new dialysate (via cassette 24) to the heating bag 22 so that the dialysate is heated to a temperature of approximately 37°C by a heating tray 142, for example, by an electrical resistance heating element associated with the tray 142. The heated dialysate can be supplied to the patient from the heating bag 22 via cassette 24 and patient line 34. In another embodiment, the dialysate can be heated upon entering cassette 24 or after leaving cassette 24 and on its way to the patient by passing the dialysate through a tube that contacts the heating tray 142, or through an in-line fluid heater (which may be provided in cassette 24). Used dialysate can be discharged from the patient to cassette 24 via patient line 34 and into drain line 28, the drain line may include one or more clamps to control the flow through one or more branches of drain line 28. In the illustrated embodiment, the drain line 28 may include a connector 39 that connects the drain line 28 to a dedicated drain container and a discharge sample port 282 for collecting a sample of used dialysate for testing or other analysis.The user may also install lines 30 of one or more containers 20 inside the door 141. Lines 30 may also be connected to a continuous or real-time dialysate preparation system (lines 26, 28, 30, and 34 may include flexible tubes and / or appropriate connectors and other components (such as pinch valves) as desired). Containers 20 may contain sterile peritoneal dialysate for infusion or other substances (e.g., substances used by the cycler 14 to formulate dialysate by mixing with water or with various types of dialysate). Lines 30 may be connected to spikes 160 of a cassette 24 shown in Figure 1, which are covered by removable caps. According to one aspect of the present invention, which will be described in more detail later, the cycler 14 may automatically remove the caps from one or more spikes 160 of the cassette 24 and connect lines 30 of the solution containers 20 to the corresponding spikes 160. This feature helps reduce the possibility of infection or contamination by reducing the opportunity for contact between the spikes 160 and non-sterile items.

[0085] With various connections made, the control system 16 can pace the cycler 14 through a typical series of infusion, retention, and / or drainage cycles of the APD procedure. For example, during the infusion phase, the cycler 14 can deliver dialysate from one or more containers 20 (or other dialysate sources) to the heating bag 22 (via the cassette 24) for heating. The cycler 14 can then inject the heated dialysate from the heating bag 22 through the cassette 24 into the patient's peritoneal cavity via the patient line 34. After the retention phase, the cycler 14 can initiate the drainage phase, in which the cycler 14 pumps the used dialysate from the patient via the line 34 (again via the cassette 24) and discharges the used dialysate through the drainage line 28 to a nearby drain port (not shown).

[0086] The cycler 14 does not necessarily require the solution container 20 and / or heating bag 22 to be positioned at a predetermined head height above the cycler 14, because the cycler 14 is not necessarily a gravity flow system. Instead, the cycler 14 can mimic gravity flow or otherwise appropriately control the flow of dialysate even when the source solution container 20 is above, below, or at the same height as the cycler 14, and the patient is above or below the cycler. For example, the cycler 14 can mimic being at a constant head height during a given procedure, or the cycler 14 can change its effective head height to increase or decrease the pressure applied to the dialysate during the procedure. The cycler 14 can also adjust the flow rate of the dialysate. In one aspect of the present invention, the cycler 14 can adjust the pressure and / or flow rate of the dialysate when supplying or withdrawing it from the patient to reduce the patient's sensation associated with the infusion or draining operation. Such adjustments can be made during a single infusion and / or drainage cycle, or across different infusion and / or drainage cycles. In one embodiment, the cycler 14 can gradually reduce the pressure used to extract used dialysate from the patient near the end of the drainage operation. Because the cycler 14 can determine an artificial head height, it can interact with and adapt to specific physiological changes or changes in the patient's relative height.

[0087] cassette In one aspect of the present invention, the cassette 24 may include patient lines and drain lines that can be individually shut off from the solution supply lines. That is, safety-critical flows to and from the patient lines can be controlled by pinching the lines to stop the flow, for example, without having to shut off the flow through one or more solution supply lines. This feature enables a simple occluder device because shutoff can be performed with respect to only two lines, in contrast to shutting off other lines that have little or no impact on patient safety. For example, the patient and drain lines can be shut off in a situation where the patient or drain connection is disconnected. However, the solution supply lines and / or heating bag lines remain open for flow so that the cycler 14 can prepare for the next dialysis cycle. For example, individual shutoff of the patient lines and drain lines helps ensure patient safety while allowing the cycler 14 to continue pumping dialysate from one or more containers 20 to the heating bag 22 or other solution containers 20.

[0088] In another aspect of the present invention, the cassette may have patient lines, drainage lines, and heating bag lines on one side or portion of the cassette, and one or more solution supply lines on the other side or portion of the cassette, for example, on the opposite side of the cassette. Such a configuration allows for the individual isolation of patient, drainage, or heating bag lines from the solution lines as described above. By physically separating the lines attached to the cassette by type or function, interaction with lines of a particular type or function can be controlled more efficiently. For example, such a configuration simplifies the design of the occluder because the force required to isolate one, two, or three of these lines is smaller than the force required to isolate all lines going to or out of the cassette. Alternatively, this configuration allows for more effective automatic connection between the solution supply lines and the cassette, as will be described in more detail later. In other words, the solution supply lines and their corresponding connections are located away from the patient lines, drainage lines, and / or heating bag lines, and the automatic cap removal and connection device can remove the caps from the spikes on the cassette and the caps on the solution supply lines, and connect the lines to each spike without interfering with the patient lines, drainage lines, or heating bag lines.

[0089] Figure 2 shows an exemplary embodiment of a cassette 24 incorporating the aspects of the present invention described above. In this embodiment, the cassette 24 has a substantially planar body and a heating bag line 26, the drainage line 28 and patient line 34 are connected to corresponding ports at the left end of the cassette body, and the right end of the cassette body may include five spikes 160 to which a solution supply line 30 can be connected. In the configuration shown in Figure 2, each spike 160 is covered by a spike cap 63, and when the spike cap is removed, the corresponding spike is exposed and can be connected to the corresponding line 30. As described above, the line 30 can be attached to one or more solution containers or other sources of material for use in dialysis and / or for the formulation of dialysate, or it can be connected to one or more recovery bags for sampling or peritoneal equivalence testing (PET testing).

[0090] Figures 3 and 4 are unfolded views (perspective and top views, respectively) of the illustrated cassette 24 of this embodiment. The cassette 24 is formed of substantially planar, relatively thin, and flat members and may include components formed, for example, from suitable plastics by molding, extrusion, or other means. In this embodiment, the cassette 24 includes a base member 18 that functions as the frame or structural member of the cassette 24 and at least partially forms various flow channels, ports, valve sections, etc. The base member 18 can be molded from suitable plastics or other materials such as polymethyl methacrylate (PMMA) acrylic or cyclic olefin copolymer / ultra-low density polyethylene (COC / ULDPE), or formed by other means, and may be relatively rigid. In one embodiment, the ratio of COC to ULDPE can be about 85% / 15%. Figure 3 also shows ports formed within the base member 18 for a heating bag (port 150), drainage (port 152), and patient (port 154). Each of these ports can be positioned in any suitable manner, for example, as a central tube 156 extending from the outer ring or skirt 158, or as a central tube only. The flexible tubes for the heating bag line, drainage line, and patient lines 26, 28, and 34 are connected to the central tube 156 and can engage with the outer ring 158, if any.

[0091] Both sides of the base member 18 can be at least partially covered with films 15 and 16, for example, flexible polymer films made of polyvinyl chloride (PVC) formed by casting, extrusion, or other methods. Alternatively, the sheet can be formed as a laminate of two or more layers of polycyclohexylenecyclohexanedicarboxylic acid dimethylene (PCCE) and / or ULDPE, held together by a co-extrudeable adhesive (CXA), for example. In some embodiments, the film thickness can range from about 0.002 to 0.020 inches (about 0.005 cm to 0.05 cm). In preferred embodiments, the thickness of the PVC-based film can range from about 0.012 to 0.016 inches (about 0.03 cm to 0.04 cm), more preferably about 0.014 inches (about 0.035 cm). In another preferred embodiment, for example, in the case of a laminated sheet, the thickness of the laminate can be in the range of about 0.006 to 0.010 inches (about 0.015 cm to 0.025 cm), more preferably about 0.008 inches (about 0.02 cm).

[0092] Both membranes 15 and 16 can not only serve to close or partition a portion of the flow path of the cassette 24, but can also function as part of a pump partition, diaphragm, or wall that is moved or operated to open and close valve ports or move fluid within the cassette 24. For example, membranes 15 and 16 can be positioned on the base member 18 and (for example, by heat, adhesive, ultrasonic welding, or other means) seal the periphery of the base member 18 to prevent fluid leakage from the cassette 24. Furthermore, membrane 15 can be bonded to other inner walls of the base member 18 that form various channels, for example, or it can be pressed to make sealing contact with the walls and other functions of the base member 18 when the cassette 24 is properly mounted in the cycler 14. Thus, both membranes 15 and 16 can be configured to be positioned on other parts of the base member 18, for example, while sealing the periphery of the base member 18 to prevent fluid leakage from the cassette 24 when it is removed from the cycler 14 after use. Once placed inside the cycler 14, the cassette 24 can be compressed between opposing gaskets or other members so that the membranes 15 and 16 are pressed in the inner region of the outer circumference and make sealing contact with the base member 18, thereby properly sealing channels, valve ports, etc. to each other.

[0093] Other configurations of membranes 15 and 16 are also possible. For example, membrane 16 can be formed from a rigid material sheet that is bonded to or otherwise integrated with the body 18. Thus, membrane 16 does not necessarily have to be a flexible member, nor does it have to contain a flexible member. Similarly, membrane 15 does not have to be flexible throughout, and instead may include one or more flexible parts to enable pump and / or valve operation, and one or more rigid parts to close the flow path of the cassette 24, for example. For example, if the cycler 14 includes appropriate members to seal the flow path of the cassette and control valve and pump functions, etc., the cassette 24 may not include membrane 16 or membrane 15.

[0094] According to another aspect of the present invention, the membrane 15 may include a pump chamber portion 151 ("pump membrane") formed to have a shape that precisely matches the recessed shape of the corresponding pump chamber 181 in the base 18. For example, the membrane 15 can generally be formed as a flat member 151 having a thermoformed (or otherwise formed) dome shape that fits into the pump chamber recess of the base member 18. The dome shape of the pre-formed pump chamber portion 151 can be made, for example, by heating and forming the membrane on a vacuum forming die of the type shown in Figure 5. As shown in Figure 5, vacuum can be applied through a plurality of holes along the wall of the die. Alternatively, the wall of the die can be made of a porous gas-permeable material, resulting in the formed membrane having a more uniformly smooth surface. Thus, when the membrane 15 moves to its maximum extent into the pump chamber 181 and (possibly) into contact with the spacer element 50 (for example, as shown by the solid line in Figure 4 while pumping fluid out of the pump chamber 181), and when the membrane 15 is withdrawn to its maximum extent from the pump chamber 181 (for example, as shown by the dotted line in Figure 4 while drawing fluid into the pump chamber 181), the membrane 15 can be moved relative to the pump chamber 181 so as to perform the pumping operation without requiring stretching of the membrane 15 (or at least minimal stretching of the membrane 15). Preventing stretching of the membrane 15 helps to simplify pump control when trying to avoid pressure spikes or other changes in fluid delivery pressure due to sheet stretching and / or minimize pressure fluctuations during pumping operations. There are also other advantages, such as a reduced possibility of membrane 15 failure (for example, due to rupture of the membrane 15 resulting from stress on the membrane 15 during stretching), and / or improved accuracy of pump delivery volume measurement, as will be discussed in more detail later. In one embodiment, the pump chamber portion 151 can be formed to have a size (e.g., define volume) of approximately 85-110% of the pump chamber 181. For example, if the pump chamber portion 151 defines a volume of approximately 100% of the pump chamber volume, the pump chamber portion 151 can be positioned within the pump chamber 181 in contact with the spacer 50 without any stress being applied while remaining stationary.

[0095] By incorporating a feature that allows for better control of the pressure used to generate the infusion and delivery strokes in which the fluid enters and leaves the pump chamber, several advantages can be gained. For example, when the pump chamber extracts fluid from the patient's peritoneal cavity during the drainage cycle, it would be desirable to apply the smallest possible negative pressure. Patients may experience discomfort during the drainage cycle of treatment, partly due to the negative pressure applied to the pump during the infusion stroke. The ability of a pre-formed membrane to further control the negative pressure applied during the infusion stroke can help reduce patient discomfort.

[0096] Using a pre-formed pump membrane that conforms to the external shape of the cassette pump chamber offers numerous advantages. For example, a constant pressure or vacuum can be applied throughout the entire pumping stroke, resulting in a more consistent fluid velocity through the pump chamber, thereby simplifying the fluid heating control process. Furthermore, temperature changes within the cassette pump can reduce their impact on the dynamics of membrane movement and the accuracy of pressure measurements within the pump chamber. Pressure surges in the fluid line can also be minimized. Correlation between the pressure measured by a pressure transducer on the membrane control (e.g., pneumatic) side and the actual fluid pressure on the pump chamber side of the membrane becomes easier. Consequently, head height measurements of the patient and fluid source bag can be more accurate before treatment, sensitivity to detecting air within the pump chamber can be increased, and accuracy of volume measurements can be improved. Additionally, since there is no need to stretch the membrane, larger volume pump chambers can be configured and used.

[0097] In this embodiment, the cassette 24 includes a pair of pump chambers 181 formed within the base member 18, but one pump chamber or three or more pump chambers are also possible. According to one aspect of the present invention, the inner walls of the pump chambers 181 include spacer elements 50 that are spaced apart from each other and extend from the inner walls of the pump chambers 18 to avoid contact between portions of the membrane 15 and the inner walls of the pump chambers 18 (as shown in the right-hand pump chamber 18 in Figure 4, the inner wall is defined by a side portion 181a and a bottom portion 181b. In this embodiment, the spacer 50 extends upward from the bottom portion 181b, but it may extend from the side portion 181a or be formed in another manner). By avoiding contact between the membrane 15 and the inner walls of the pump chambers, the spacer elements 50 can provide dead space (or capture volume) that can be used to trap air or other gases within the pump chambers 181 and, under certain circumstances, prevent the gas from being pushed out of the pump chambers 181. In other cases, the spacer 50 can help move gas toward the outlet of the pump chamber 181, for example, to remove gas from the pump chamber 181 during startup. The spacer 50 can also help prevent the membrane 15 from sticking to the inner wall of the pump chamber, or help allow the flow to continue passing through the pump chamber 181 even if the membrane 15 is pressed to come into contact with the spacer element 50. The spacer 50 also prevents the outlet ports (openings 187 and / or 191) of the pump chamber from closing prematurely if the sheet accidentally comes into uneven contact with the inner wall of the pump chamber. Further details of the configuration and / or function of the spacer 50 are described in U.S. Patents 6,302,653 and 6,382,923, both of which are incorporated herein by reference.

[0098] In this embodiment, the spacer elements 50 are arranged in a kind of “stadium seating” configuration, in which the spacer elements 50 are arranged in a concentric elliptical pattern, with the ends of the spacer elements 50 rising gradually from the bottom 181b of the inner wall, away from the center of the pump chamber 181, to form a semi-elliptical dome-shaped region (shown by the dotted line in Figure 4). By arranging the spacer elements 50 so that the ends of the spacer elements 50 form a semi-elliptical region defining a dome region intended to be swept by the pump chamber portion 151 of the membrane 15, a desired amount of dead space is allowed, minimizing the reduction to the intended stroke volume of the pump chamber 181. As seen in Figure 3 (and Figure 6), the “stadium seating” configuration in which the spacer elements 50 are arranged may include “passages” or dividers 50a in an elliptical pattern. The dividers (or passages) 50a help maintain a uniform gas level throughout the rows (gaps or dead spaces) 50b between the spacer elements 50 while the fluid is being discharged from the pump chamber 181. For example, if the spacer elements 50 are arranged in a stadium seating configuration as shown in Figure 6 without a divider (or passage) 50a or other means for allowing liquid and air to flow between the spacer elements 50, the membrane 15 will be lowest on the spacer elements 50 located on the outermost periphery of the pump chamber 181, and will capture any gas or liquid present in the gap between this outermost spacer element 50 and the side 181a of the pump chamber wall. Similarly, if the membrane 15 is lowest on any two adjacent spacer elements 50, gas and liquid in the gap between the elements 50 can be captured. In such a configuration, at the end of the pumping stroke, the air or other gas in the center of the pump chamber 181 may be discharged, while liquid may remain in the outer rows. Providing a divider (or passage) 50a or other means for fluid communication in the gap between the spacer elements 50 can help maintain a uniform gas level throughout the gap during the pumping stroke, thus preventing air or other gases from leaving the pump chamber 181 unless a certain volume of liquid is actually discharged.

[0099] In certain embodiments, the spacer elements 50 and / or the membrane 15 can be positioned such that when the membrane 15 contacts the spacers 50 or otherwise expands significantly into the gaps between the spacers 50, it generally does not wrap around or otherwise deform the individual spacers 50. Such a configuration can reduce stretching or damage to the membrane 15 that would result from wrapping around or otherwise deforming one or more individual spacer elements 50. For example, in this embodiment, it has been found beneficial to make the size of the gaps between the spacers 50 substantially uniform in the width direction of the spacers 50. This feature helps prevent deformation of the membrane 15, for example, slackening of the membrane into the gaps between the spacers 50 when the membrane 15 is biased to contact the spacers 50 during a pumping operation.

[0100] According to another aspect of the present invention, the inner wall of the pump chamber 181 can define a recess larger than the space intended to be swept by the pump chamber portion 151 of the membrane 15, such as a semi-elliptical or dome-shaped space. In such an example, one or more spacer elements 50 can be positioned below the dome region intended to be swept by the membrane portion 151 without extending into the dome region. In one example, the ends of the spacer elements 50 can define the outer periphery of the dome region intended to be swept by the membrane 15. Positioning the spacer elements 50 outside or adjacent to the outer periphery of the dome region intended to be swept by the membrane portion 151 offers several advantages. For example, by positioning one or more spacer elements 50 outside or adjacent to the dome region intended to be swept by the flexible membrane, a dead space is created between the spacer and the membrane while minimizing the reduction to the target stroke volume of the pump chamber 181, as described above.

[0101] It should be understood that the spacer elements 50, when located within a pump chamber, can be arranged in any other suitable shape, for example, as shown in Figure 7. The left pump chamber 181 in Figure 7 includes spacers 50 arranged similarly to Figure 6, but with only one divider or passage 50a running vertically through the approximate center of the pump chamber 181. The spacers 50 can be arranged to define a concave shape similar to Figure 6 (i.e., the tops of the spacers 50 can form a semi-ellipse as shown in Figures 3 and 4), or they can be arranged in other suitable shapes, such as forming a spherical or box-shaped shape. The right pump chamber 181 in Figure 7 shows an embodiment in which the spacers 50 are arranged longitudinally, and the gaps 50b between the spacers 50 are also arranged longitudinally. Similar to the left pump chamber, the spacers 50 in the right pump chamber 181 can also define a concave shape that is semi-elliptical, spherical, box-shaped, or other suitable shape. However, it should be understood that the spacer elements 50 can have a fixed height, a different spatial pattern than shown, etc.

[0102] Furthermore, the membrane 15 may have spacer elements itself, or other features such as ribs, bumps, tabs, grooves, or channels, in addition to or instead of the spacer elements 50. Such features on the membrane 15 may help prevent adhesion of the membrane 15 and / or provide other features, such as helping to control how the sheet bends or otherwise deforms as it moves during the pumping operation. For example, bumps or other features on the membrane 15 may help the sheet deform consistently during iterative cycles and prevent it from bending in the same area. Since iterative cycles cause the membrane 15 to degrade prematurely in the bent area, features on the membrane 15 help to control how and where it bends.

[0103] In this illustrated embodiment, the base member 18 of the cassette 24 defines a plurality of controllable valve functions, flow paths, and other structures that guide the movement of fluid within the cassette 24. Figure 6 is a plan view of the base member 18 on the pump chamber side, which is also seen in the perspective view of Figure 3. Figure 8 is a perspective view of the rear side of the base member 18, and Figure 9 is a plan view of the rear side of the base member 18. The tubes 156 for each port 150, 152, and 154 are in fluid communication with corresponding valve wells 183 formed in the base member 18. The valve wells 183 are fluidly isolated from each other by the walls surrounding each valve well 183 and by the sealing engagement of the membrane 15 with the walls around the wells 183. As described above, the membrane 15 can seal engagement with the walls of each valve well 183 (and another wall of the base member 18) by being pressed to contact the walls, for example when loaded into the cycler 14. If the membrane 15 is not pressed to engage with the valve port 184, the fluid in the valve well 183 can flow into the corresponding valve port 184. Thus, each valve port 184 defines a valve (e.g., a "volcano valve") that can be opened and closed by selectively moving the portion of the membrane 15 associated with the valve port 184. As will be described in more detail later, the cycler 14 can selectively control the position of the portion of the membrane 15 so that the valve port (e.g., port 184) can be opened and closed to control the flow through various fluid channels or other paths in the cassette 24. The flow through the valve port 184 leads to the back side of the base member 18. In the case of valve ports 184 associated with the heating bag and drainage (ports 150 and 152), the valve port 184 leads to a common channel 200 formed on the back side of the base member 18. Similar to the valve well 183, the channel 200 is isolated from other channels and paths in the cassette 24 by a sheet 16 that is in sealing contact with the wall of the base member 18 forming the channel 200. In the case of a valve port 184 associated with a patient line port 154, the flow through port 184 connects to a common channel 202 on the back side of the base member 18.

[0104] Returning to Figure 6, each of the spikes 160 (shown with the cap removed in Figure 6) is in fluid communication with a corresponding valve well 185, the valve wells 185 being isolated from each other by walls, and the membrane 15 is in sealing engagement with the walls forming the wells 185. If the membrane 15 is not in sealing engagement with a port 186, the fluid in the valve well 185 can flow into the corresponding valve port 186 (again, the position of the portion of the membrane 15 over each valve port 186 can be controlled by the cycler 14 to open and close the valve port 186). The flow through the valve port 186 leads to the back of the base member 18 and to the common channel 202. Thus, according to one aspect of the present invention, the cassette may have a plurality of solution supply lines (or other lines supplying substances for supplying dialysate) connected to a common manifold or channel of the cassette, and each line may have a corresponding valve for controlling the flow back and forth in the line with respect to the common manifold or channel. The fluid in channel 202 can flow into the lower opening 187 of the pump chamber 181 through an opening 188 leading to the lower pump valve well 189 (see Figure 6). If the relevant portion of the membrane 15 is not pressed to seal-engage with port 190, the flow from the lower pump valve well 189 can pass through the lower pump valve port 190. As seen in Figure 9, the lower pump valve port 190 leads to a channel communicating with the lower opening 187 of the pump chamber 181. The flow leaving the pump chamber 181 can pass through the upper opening 191 and enter a channel communicating with the upper valve port 192. The flow from the upper valve port 192 (if the membrane 15 is not seal-engaged with port 192) can pass through each upper valve well 194 and an opening 193 on the back side of the base member 18 that communicates with the common channel 200.

[0105] Cassette 24 can recognize that the pump chamber 181 can be controlled to pump fluid from and to any of the ports 150, 152, and 154 and / or spikes 160. For example, new dialysate supplied from one of the containers 20 connected by line 30 to one of the spikes 160 can be drawn into the common channel 202 by opening the valve port 186 suitable for the appropriate spike 160 (and possibly closing the other valve ports 186 for the other spikes). Alternatively, the lower pump valve port 190 can be opened and the upper pump valve port 192 can be closed. Subsequently, the portion of the membrane 15 associated with the pump chamber 181 (i.e., the pump membrane 151) is moved (for example, away from the base member 18 and the inner wall of the pump chamber) to reduce the pressure within the pump chamber 181, thereby drawing fluid into the common channel 202 through the selected spike 160 and the corresponding valve port 186, into the lower pump valve well 189 through the opening 188, and into the pump chamber 181 through the (opened) lower pump valve port 190 and the lower opening 187. Since the valve ports 186 are individually operable, it is possible to draw fluid through the spike 160 and the associated source vessel 20, or any combination thereof, in a desired sequence or simultaneously (of course, only one pump chamber 181 may be operated to draw fluid into itself; the other pump chambers may be left inactive and closed by closing the appropriate lower pump valve port 190).

[0106] When there is fluid in the pump chamber 181, the lower pump valve port 190 is closed and the upper pump valve port 192 can be opened. As the membrane 15 moves toward the base member 18, the pressure in the pump chamber 181 increases, allowing the fluid in the pump chamber 181 to be driven through the upper opening 191 and the (opened) upper pump valve port 192 to the upper pump valve well 194 and through the opening 193 to the common channel 200. The fluid in the channel 200 can be driven toward the heating bag port 150 and / or the drain port 152 (and into the corresponding heating bag line or drain line) by opening the appropriate valve port 184. In this way, for example, fluid in one or more containers 20 can be drawn into the cassette 24 and pumped toward the heating bag 22 and / or the drain port.

[0107] The fluid in the heating bag 22 can be drawn into the cassette 24 by opening the valve port 184 for the heating bag port 150, closing the lower pump valve port 190, and opening the upper pump valve port 192 (for example, after it has been properly heated on the heating tray for introduction to the patient). The pressure in the pump chamber 181 can be reduced and the fluid flow can be sent from the heating bag 22 into the pump chamber 181 by moving the portion of the membrane 15 associated with the pump chamber 181 away from the base member 18. Once the pump chamber 181 is injected with heated fluid from the heating bag 22, the upper pump valve port 192 may be closed and the lower pump valve port 190 may be opened. The heated dialysate can be delivered to the patient by opening the valve port 184 for the patient port 154 and closing the valve port 186 for the spike 160. The movement of the membrane toward the base member 18 within the pump chamber 181 increases the pressure within the pump chamber 181, allowing fluid to flow through the lower pump valve port 190 and opening 188 into the common channel 202 and into the (open) valve port 184 for the patient port 154. This operation can be repeated an appropriate number of times to deliver the desired amount of heated dialysate to the patient.

[0108] When draining fluid from the patient, the valve port 184 for the patient port 154 can be opened, the upper pump valve port 192 can be closed, and the lower pump valve port 190 can be opened (the spike valve port 186 can be closed). The membrane 15 can be moved to draw fluid from the patient port 154 into the pump chamber 181. Then, the lower pump valve port 190 can be closed, the upper valve port 192 can be opened, and the valve port 184 for the drain port 152 can be opened. The fluid from the pump chamber 181 can be pumped to the drain line for disposal or sampling, and to the drain port or recovery container (or the fluid can be sent to one or more spikes 160 / line 30 for sampling or drainage). This operation can be repeated until sufficient dialysate has been removed from the patient and pumped to the drain port.

[0109] The heating bag 22 can also function as a mixing container. Depending on the specific treatment requirements of an individual patient, solutions of dialysate or various other components can be connected to the cassette 24 via the appropriate solution line 30 and spike 160. Each measured amount of solution can be added to the heating bag 22 using the cassette 24 and mixed according to one or more predetermined formulas stored in the memory processor memory accessible to the control system 16. Alternatively, specific treatment parameters can be entered by the user via the user interface 144. The control system 16 is programmed to calculate the appropriate mixing requirements based on the type of dialysate or solution container connected to the spike 160, and then control the mixing and delivery of the prescribed mixture to the patient.

[0110] According to one aspect of the present invention, the pressure applied by the pump to the dialysate being injected into or removed from the patient can be controlled to minimize patient sensations such as "traction" or "pulling" resulting from pressure fluctuations during drainage and infusion operations. For example, during dialysate drainage, the suction pressure (or vacuum / negative pressure) can be reduced towards the end of the drainage process to minimize patient sensations of dialysate removal. A similar technique can be used towards the end of the infusion operation, i.e., the delivery pressure (or positive pressure) can be reduced towards the end of the infusion. If the patient becomes somewhat sensitive to fluid movement during different cycles of treatment, various pressure profiles can be used to suit various infusion and / or drainage cycles. For example, relatively higher (or lower) pressures can be used in the infusion and / or drainage cycles when the patient is asleep compared to when the patient is awake. The cycler 14 can detect the patient's sleep / wake state, for example, by using an infrared motion detector to infer that the patient is asleep when their movement decreases, or by detecting changes in blood pressure, electroencephalogram, or other parameters indicating sleep. Alternatively, the Cycler 14 can simply "ask" the patient "Are you asleep?" and control the system's operation based on the patient's response (or lack thereof).

[0111] Set installation and operation Figure 10 is a perspective view of the APD system 10 of Figure 1, with the door 141 of the cycler 14 lowered to the open position, exposing the mounting section 145 for the cassette 24 and the carriage 146 for the solution line 30 (in this embodiment, the door 141 is attached to the cycler housing 82 by a hinge at the bottom of the door 141). When the set 12 is mounted, the cassette 24 is positioned within the mounting section 145, with the membrane 15 and the pump chamber side of the cassette 24 facing upward, and when the door 14 is closed, the portion of the membrane 15 associated with the pump chamber and the valve port interact with the control surface 148 of the cycler 14. The mounting section 145 is molded to match the shape of the base member 18, ensuring the proper orientation of the cassette 24 within the mounting section 145. In the illustrated embodiment, the cassette 24 and the mounting section 145 are substantially rectangular in shape with a single large rounded corner that requires the user to position the cassette 24 in the mounting section 145 with the appropriate orientation (otherwise the door 141 will not close). It should be understood that other shapes and orientations of the cassette 24 and / or the mounting section 145 are also possible.

[0112] In one aspect of the present invention, when the cassette 24 is placed in the mounting section 145, the patient line, drainage line, and heating bag lines 34, 28, and 26 are directed to the left through a channel 40 in the door 141, as shown in Figure 10. The channel 40 may include a guide 41 or other features that can hold the patient line, drainage line, and heating bag lines 34, 28, and 26 so that an occluder 147 can selectively open and close the lines for flow. When the door 141 is closed, the occluder 147 may compress one or more of the patient line, drainage line, and heating bag lines 34, 28, and 26 toward an occluder stop section 29. In general, the occluder 147 allows flow through lines 34, 28, and 26 when the cycler 14 is operating (and operating properly), but can shut off the lines when the cycler 14 is powered off (and / or not operating properly) (shutting off the lines can be done by pressing the lines or pinching the lines to otherwise close off the flow path within the lines). Preferably, the occluder 147 can selectively shut off at least the patient lines and the drainage lines 34 and 28.

[0113] When the cassette 24 is mounted and the door 141 is closed, the pump chamber side of the cassette 24 and the membrane 15 can be pressed to contact the control surface 148 by, for example, an air bladder, spring, or other suitable configuration in the door 141 behind the mounting section 145, which compresses the cassette 24 between the mounting section 145 and the control surface 148. This containment of the cassette 24 can isolate the channels and other flow paths of the cassette 24 as desired by pressing the membranes 15 and 16 to contact the walls and other features of the base member 18. The control surface 148 may comprise a flexible gasket, for example, a sheet made of silicone rubber or other material associated with the membrane 15, which can selectively move portions of the membrane 15 to produce pumping action of the pump chamber 181 and opening and closing of the valve ports of the cassette 24. The control surface 148 can be arranged in close contact with each other, for example, so that portions of the membrane 15 move in response to the movement of corresponding portions of the control surface 148, associated with various portions of the membrane 15. For example, the membrane 15 and the control surface 148 can be positioned in close proximity, and a suitable vacuum (or a pressure lower than atmospheric pressure) can be introduced and maintained between the membrane 15 and the control surface 148 through an intake port appropriately positioned within the control surface 148, so that they are substantially fixed to each other in the region of the membrane 15 that requires motion to open and close the valve port and / or produce a pumping action. In another embodiment, the membrane 15 and the control surface 148 can be bonded to each other or otherwise appropriately associated.

[0114] Before loading the cassette 24 and closing the door 141, one or more solution lines 30 can be loaded onto the carriage 146. The end of each solution line 30 may include an area 33 for labeling the cap 31 or for attaching an indicator or identifier. The indicator may be, for example, an ID tag that snaps onto the tube in the indicator area 33. According to one aspect of the present invention, as will be described in more detail later, the carriage 146 and other components of the cycler 14 can operate to remove the caps 31 from the lines 30, recognize an indicator for each line 30 (which can provide an indication as the type of solution associated with the line, the amount of solution, etc.), and fluidly engage the line 30 with the spike 160 of the cassette 24. This process can be performed automatically, for example, after the door 141 is closed and the caps 31 and spike 160 are housed in a protected space so as not to be touched by a person, reducing the risk of contamination of both when the lines 30 and / or spikes 160 are connected to each other. For example, after the door 141 is closed, the indicator area 33 can be evaluated (visually, for example, by appropriate imaging devices and software-based image recognition such as RFID technology) to identify which solution is associated with which line 30. Aspects of the present invention relating to the ability of indicators in the indicator area 33 to detect the features of line 30 can provide advantages such as allowing the user to position the line 30 at any position on the carriage 146 without affecting the system operation. That is, because the cycler 14 automatically detects the solution line function, it is not necessary to ensure that a particular line is positioned at a specific location on the carriage 146 for the system to function properly. Instead, the cycler 14 can identify which line 30 controls where appropriately. For example, a container connected to one line 30 may be intended, for example, to contain used dialysate for later inspection. Because the cycler 14 can identify the presence of the sample supply line 30, the cycler 14 can send the used dialysate to the appropriate spike 160 and line 30.As described above, all of the spikes 160 of cassette 24 are sent to a common channel, so input from any particular spike 160 can be sent to cassette 24 in any desired way by controlling the valve and other cassette functions.

[0115] Once line 30 is installed, the carriage 146 is moved to the left (while the door 141 is closed again) as shown in Figure 10, so that the cap 31 can be positioned above each spike cap 63 on the spike 160 of the cassette 24, adjacent to the cap stripper 149. The cap stripper 149 can extend outward (from within the recess of the cycler 14 housing toward the door 141) to engage with the cap 31 (for example, the cap stripper 149 may include five fork-like elements which engage with corresponding grooves in the cap 31 so that the cap stripper 149 can resist the lateral movement of the cap 31 relative to the cap stripper 149). By engaging the cap 31 with the cap stripper 149, the cap 31 can also grip the corresponding spike cap 63. Subsequently, with the cap 31 engaged with the corresponding spike cap 63, the carriage 146 and the cap stripper 149 are moved to the right, allowing the spike cap 63 to be removed from the spike 160 that engages with the corresponding cap 31 (one possible advantage of this configuration is that the spike cap 63 is not removed in a position where the solution line 30 is not mounted, since the engagement of the cap 31 from the solution line 30 is required to remove the spike cap 63. Thus, if the solution line is not connected to the spike 160, the cap on the spike 160 remains in place). Subsequently, while the carriage 146 continues to move to the right, the cap stripper 149 can be stopped from moving to the right (for example, by contacting a stopper). As a result, the carriage 146 can pull the end of the line 30 away from the cap 31 that remains attached to the cap stripper 149. With the cap 31 removed from the line 30 (the spike cap 63 remains attached to the cap 31), the cap stripper 149 retracts again with the cap 31 into the recess in the housing of the cycler 14, clearing a path for the carriage 146 and the uncapped end of the line 30 to move toward the spikes 160. The carriage 146 then moves to the left again, connecting the end of the line 30 to each spike 160p of the cassette 24.This connection can be made by a spike 160 penetrating an alternative closed end of line 30 (for example, the spike can penetrate a closed diaphragm or wall at the end), allowing fluid flow from each container 20 to the cassette 24. In one embodiment, the wall or diaphragm may be made of a flexible and / or self-sealing material such as PVC, polypropylene, or silicone rubber.

[0116] According to one aspect of the present invention, the heating bag 22 can be placed in a heating bag housing (e.g., a tray) 142 which is exposed by lifting a lid 143 (in this embodiment, the cycler 14 includes a user or operator interface 144 which is rotatably mounted on a housing 82 as described later. The interface 144 can be rotatably swung upward outside the tray 142 in order to place the heating bag 22 inside the tray 142). As is known in the art, the heating tray 142 can heat the dialysate in the heating bag 22 to an appropriate temperature, for example, a temperature suitable for introduction to a patient. According to one aspect of the present invention, the lid 143 can be closed after the heating bag 22 has been placed inside the tray 142, for example, to help capture heat and accelerate the heating process, and / or to help avoid touching or otherwise coming into contact with relatively warm parts of the heating tray 142, such as the heating surface. In one embodiment, the lid 143 can be locked in a closed position to avoid contact with the heated portion of the tray 142 when that portion of the tray 142 is heated to a temperature that could cause burns to the skin. The lid 143 can be prevented from opening, for example, by a lock, until the temperature beneath it has cooled to a suitable level.

[0117] According to another aspect of the present invention, the cycler 14 includes a user or operator interface 144 that is rotatably mounted in the housing of the cycler 14 and can be folded into the heating tray 142. With the interface 144 folded, the lid 143 can be closed to conceal the interface 144 and / or prevent contact with the interface 144. The interface 144 can be configured to display information to the user, for example, in a diagram, and to receive input from the user, for example, by the use of a touchscreen and a graphical user interface. The interface 144 may include other input devices such as buttons, dials, knobs, and pointing devices. With the set 12 connected and the container 20 properly positioned, the user can interact with the interface 144 to cause the cycler 14 to start treatment and / or perform other functions.

[0118] However, unless the set 12 is provided in a pre-prepared state (for example, at a manufacturing facility or before use with the cycler 14), at least the cassette 24, patient line 34, and heating bag 22 must be pre-prepared in the cycler 14 before the start of a dialysis treatment cycle. Preparation can be carried out in various ways, such as by drawing liquid from one or more solution containers 20 via line 30 and controlling the cassette 24 (i.e., the pump and valves) to pressurize the liquid through the various paths of the cassette 24 to remove air from the cassette 24. The dialysate can be pressurized into the heating bag 22 for heating before delivery to the patient, for example. Once the cassette 24 and heating bag line 26 are prepared, the cycler 14 can then prepare the patient line 34. In one embodiment, the patient line 34 is prepared by connecting the line 34 to an appropriate port or other connection point on the cycler 14 (for example, by connector 36) and pressurizing the cassette 24 to pressurize the liquid into the patient line 34. A port or connection point on the cycler 14 can be configured to detect when a patient line is ready by detecting (for example, optically, by a conductive sensor, or otherwise) when the liquid has arrived at the end of the patient line. As described above, different types of sets 12 may have patient lines 34 of different sizes, such as adult size or pediatric size. According to one aspect of the present invention, the cycler 14 can detect the type of cassette 24 (or at least the type of patient line 34) and control the cycler 14 and cassette 24 accordingly. For example, the cycler 14 can determine the amount of liquid to be dispensed by the pump in the cassette necessary to prepare the patient line 34 and determine the size of the patient line 34 based on that amount. Other methods may also be used, such as recognition of a barcode or other indicator on the cassette 24, patient line 34, or other component indicating the type of patient line.

[0119] Figure 11 is an inside perspective view of the door 141 separated from the housing 82 of the cycler 14. This figure more clearly shows how the line 30 is housed in the corresponding groove in the door 141 and the carriage 146 so that the indicator area 33 is captured in a specific slot of the carriage 146. With the indicator properly positioned in the indicator area 33 when the tube is attached to the carriage 146, a reader or other device can identify the indicator's display, for example, the type of solution in the container 20 connected to the line 30, the amount of solution, the date of manufacture, the manufacturer's ID, etc. The carriage 146 is mounted on a pair of guides 130 at the upper and lower ends of the carriage 146 (only the lower guide 130 is shown in Figure 11). Thus, the carriage 146 can move left and right on the door 141 along the guides 130. When moving towards the cassette mounting section 145 (to the right in Figure 11), the carriage 146 can move until it contacts the fastener 131.

[0120] Figure 12 is a perspective view of a carriage drive assembly 132 of a first embodiment, which performs the function of removing the cap from the spike 160 on the cassette, removing the cap 31 on the solution line 30, and moving the carriage 146 to connect the line 30 to the spike 160. The drive element 133 is configured to move left and right along the rod 134. In the illustrated embodiment, an air bladder powers the movement of the drive element 133 along the rod 134, but any suitable drive mechanism such as a motor or a hydraulic system can be used. The drive element 133 has a forward-extending tab 135 that engages with a corresponding slot 146a on the carriage 146 (see Figure 11 showing the uppermost slot 146a on the carriage 146). The engagement of the tab 135 with the slot 146a allows the drive element 133 to move the carriage 146 along the guide 130. The drive element 133 also includes a window 136 through which an imaging device, such as a CCD or CMOS imager, can capture image information of an indicator in the indicator area 33 of a line 30 mounted on the carriage 146. Information regarding the indicator in the indicator area 33 is provided from the imaging device to a control system 16, for example, which acquires the display by image analysis. The drive element 133 can selectively move the cap stripper 149 both left and right along the rod 134. The cap stripper 149 can be extended forward and backward using another drive mechanism, such as a pneumatic air bag.

[0121] Figure 13 is a left side perspective view of the carriage drive assembly 132, which more clearly shows how the stripper elements of the cap stripper 149 are configured to move in and out along the groove 149a of the housing of the cap stripper 149 (in a direction substantially perpendicular to the rod 134). Each semicircular notch in the stripper element engages with the corresponding groove in the cap 31 on line 30 by expanding forward when the cap 31 is properly positioned in front of the stripper 149 by the drive element 133 and carriage 146. With the stripper elements engaged with the cap 31, the cap stripper 149 can move with the carriage 146 as the drive element 133 moves. Figure 14 is a partial rear view of the carriage drive assembly 132. In this embodiment, the drive element 133 is moved toward the mounting section 145 of the cassette 24 by a first air bladder 137 which expands to force the drive element 133 to move to the right in Figure 14. The drive element can also be moved to the left by the second air bladder 138. Alternatively, the drive element 133 can be moved forward or backward by one or more motors connected to a linear drive gear assembly such as a ball screw assembly (on which the carriage drive assembly is mounted on a ball nut) or a rack and pinion assembly. The stripper element 1491 of the cap stripper 149 can be moved in and out of the cap stripper housing by a third air bladder or by a motor connected to the linear drive assembly as described above.

[0122] Figures 15-18 show another embodiment of the carriage drive assembly 132 and the cap stripper 149. As seen in the rear view of the carriage drive assembly 132 in Figure 15, in this embodiment the drive element 133 is moved left and right by the screw drive mechanism 1321. As seen in the right rear perspective view of the carriage drive assembly 132 in Figure 16, the stripper element is moved inward and outward by the air bladder 139, although other configurations are possible as described above.

[0123] Figures 17 and 18 are left and right front perspective views of another embodiment of the stripper element 1491 of the cap stripper 149. The stripper element 1491 in the embodiment shown in Figure 13 included only a fork-like element positioned to engage with the cap 31 of the solution line 30. In the embodiments of Figures 17 and 18, the stripper element 1491 includes not only the fork-like element 60 but also a rocker arm 61 that is swivelably attached to the stripper element 1491. As will be described in more detail later, the rocker arm 61 helps to remove the spike cap 63 from the cassette 24. Each rocker arm 61 includes a solution line cap engaging portion 61a and a spike cap engaging portion 61b. The rocker arm 61 is typically biased to move so that the spike cap engaging portion 61b is positioned near the stripper element 1491, as shown in the rocker arm 61 of Figure 18. However, when the cap 31 is housed in the corresponding fork-shaped element 60, the solution line cap engaging portion 61a contacts the cap 31, causing the rocker arm 61 to pivot so that the spike cap engaging portion 61b moves away from the stripper element 1491, as shown in Figure 17. In this position, the spike cap engaging portion 61b can contact the spike cap 63, specifically the flange on the spike cap 63.

[0124] Figure 19 is a front view of the stripper element 1491, and Figures 20-22 show the positions of several cross-sectional views. Figure 20 shows the rocker arm 61 when neither the spike cap 63 nor the solution line cap 31 is positioned near the stripper element 1491. The rocker arm 61 is mounted on the stripper element 1491 so as to be pivotable at approximately midway between the spike cap engagement portion 61b and the solution cap engagement portion 61a. As described above, the rocker arm 61 is typically biased to rotate counterclockwise as shown in Figure 20 so that the spike cap engagement portion 61b is positioned near the stripper element 1491. Figure 21 shows that when there is no solution line cap 31 engaging with the fork-shaped element 60, the rocker arm 61 maintains this position (i.e., the spike cap engagement portion 61b is positioned near the stripper element 1491) even when the stripper element 1491 moves forward toward the spike cap 63. As a result, the rocker arm 61 will not rotate clockwise or engage with the spike cap 63 unless the solution line cap 31 is present. Therefore, the spike cap 63, which does not engage with the solution line cap 31, will not be removed from the cassette 24.

[0125] Figure 22 shows an example in which the solution line cap 31 engages with the fork-shaped element 60 and contacts the solution line cap engaging portion 61a of the rocker arm 61. This causes the rocker arm 61 to rotate clockwise (as shown), and the spike cap engaging portion 61b engages with the spike cap 63. In this embodiment, as the stripper element 1491 moves to the right (as shown in Figure 22), the spike cap engaging portion 61b contacts the second flange 63a, and the engagement of portion 61b includes positioning portion 61b adjacent to the second flange 63a on the spike cap 63 to assist in the pulling of the spike cap 63 from the corresponding spike 160. The solution line cap 31 is made of a flexible material such as silicone rubber so that the spikes 63c of the spike cap 63 extend through the holes 31b in the cap 31 (see Figure 23) and are caught in the surrounding inner grooves or recesses within the cap 31. The first flange 63b on the spike cap 63 serves as a fastener for the end of the solution line cap 31. The wall defining the groove or recess in the hole 31b of the cap 31 may be symmetrical, or preferably asymmetrically arranged to match the shape of the spike 63c (see cross-sectional view 33 of the cap 31 and the groove or recess). The second flange 63a on the spike cap 63 serves as a tooth into which the spike cap engaging portion 61b of the rocker arm 61 engages, to provide additional tensile force to separate the spike cap 63 from the spike 160, if necessary.

[0126] Figure 23 is a close-up exploded view of the connector end 30a of the solution line 30 with the cap 31 removed (Figure 23 shows the cap 31 without the finger pull ring as shown in Figure 24 for clarity. The pull ring is not necessary for the operation of the cap 31 in the cycler 14. However, it would be useful when allowing the operator to manually remove the cap 31 from the end of the solution line 30 as needed). In this illustrated embodiment, the indicator in the indicator area 33 has an annular shape of size and configuration that fits into the corresponding slot of the carriage 146 when mounted as shown in Figures 10 and 11. Naturally, the indicator can take any suitable shape. The cap 31 is positioned to fit over the entire distal end of the connector end 30a, having internal holes, seals, and / or other features that enable leak-proof connection with the spike 160 on the cassette 24. The connector end 30a may include a passable wall or diaphragm (not shown; see member number 30b in Figure 33) to prevent the solution in the line 30 from leaking from the connector end 30a even when the cap 31 is removed. The wall or diaphragm may be passed through by the spike 160 when the connector end 30a is mounted on the cassette 24 to allow flow from the line 30 to the cassette 24. As described above, the cap 31 may include a groove 31a that engages with the fork-shaped element 60 of the cap stripper 149. The cap 31 may also include a hole 31b that is positioned to accommodate the spike cap 63. The hole 31b and the cap 31 are positioned such that the cap 31 properly grips the spike cap 63 when the carriage 146 / cap stripper 149 pulls the cap 31 away from the cassette 24, the spike cap 63 is removed from the spike 160 and carried by the cap 31. This removal can be assisted by the rocker arm 61 engaging with the second flange 63a or other features on the spike cap 63, as described above.Subsequently, the cap 31 and spike cap 63 can be removed from the connector end 30a, and the line 30 can be attached to the spike 160 by the carriage 146.

[0127] Once treatment is complete, or when the line 30 and / or cassette 24 are ready to be removed from the cycler 14, the cap 31 and the attached spike cap 63 can be reattached to the spike 160 and line 30 before the door 141 is opened and the cassette 24 and line 30 are removed from the cycler 14. Alternatively, the cassette 24 and solution container can be removed together from the cycler 14 along with line 30 without reattaching the cap 31 and the attached spike cap 63. The advantages of this method are that the removal process is simplified and that any fluid that might leak into the cycler or surrounding area is prevented from being improperly reattached or improperly sealing the cap.

[0128] Figures 24–32 are perspective views of the carriage 146, cap stripper 149, and cassette 24 during line loading and automatic connection operation. The door 141 and other cycler components are not shown for clarity. In Figure 24, the carriage 146 is in the folded position as if the door 141 were open in the position shown in Figure 8. The line 30 and cassette 24 are positioned to be lowered over the door 141. In Figure 25, the line 30 is loaded into the carriage 146 and the cassette 24 is loaded into the loading section 145. At this point, the door 141 is closed to prepare the cycler for operation. In Figure 26, the door 141 is closed. Identifiers or indicators located in the indicator area 33 on the line 30 can be read to identify various line characteristics so that the cycler 14 can determine which solution to load and in what quantities. In Figure 27, the carriage 146 is moved to the left, engaging the cap 31 on line 30 with the corresponding spike cap 63 on cassette 24. During this movement, the drive element 133 engages with the cap stripper 149, moving the cap stripper 149 to the left. However, the cap stripper 149 remains in the retracted position. In Figure 28, the cap stripper 149 moves forward, engaging the cap 31 with the spike cap 63 by engaging the fork-shaped element 60 with the cap 31. If present, the rocker arm 61 can move to the engagement position with the spike cap 63. Next, as shown in Figure 29, the carriage 146 and cap stripper 149 move to the right away from cassette 24, pulling the cap 31 and spike cap 63 away from the corresponding spike 160 on cassette 24. During this movement, if present, the rocker arm 61 can assist in pulling the spike cap 63 away from cassette 24. In Figure 30, the cap stripper 149 stops moving to the right, while the carriage 146 continues to move away from the cassette 24. This pulls the connector end 30a of line 30 away from the cap 31, leaving the cap 31 and spike cap 63 mounted on the cap stripper 149 by the fork-shaped element 60.In Figure 31, the cap stripper 149 retracts, clearing a path for the carriage 146 to move again toward the cassette 24. In Figure 32, the carriage 146 moves toward the cassette 24, engaging the connector end 30a of the line 30 with the corresponding spike 160 on the cassette 24. The carriage 146 remains in this position while the cycler is in operation. Once treatment is complete, the movement shown in Figures 24-32 can be reversed to recap the spike 160 and the solution line 30, and the cassette 24 and / or line 30 can be removed from the cycler 14.

[0129] To further illustrate the removal of the cap 31 and spike cap 63, Figure 33 shows a cross-sectional view of the cassette 24 with the line 30 in five different connection stages. At the uppermost spike 160, the spike cap 63 is still in place on the spike 160, and the solution line 30 is positioned away from the cassette 24, as in Figure 26. At the second spike 160 below the uppermost spike, the solution line 30 and cap 31 are engaged above the spike cap 63, as in Figures 27 and 28. At this point, the cap stripper 149 can engage with the cap 31 and spike cap 63. At the third spike 160 from the top, the solution line 30, cap 31, and spike cap 63 are moving away from the cassette 24, as in Figure 29. At this point, the cap stripper 149 can stop moving to the right. At the fourth spike 160 from the top, the solution line 30 continues to move to the right, dislodging the cap 31 from the line 30 as in Figure 30. Once the caps 31 and 63 have retracted, the solution line 30 moves to the left, fluidizing the connector end 30a of the line 30 to the spike 160 as in Figure 32.

[0130] Various sensors can be used to help verify that the carriage 146 and cap stripper 149 have moved completely to their predicted positions. In one embodiment, the carriage drive assembly 132 may be equipped with six Hall effect sensors (not shown), four for the carriage 146 and two for the cap stripper 149. A first cap stripper sensor may be positioned to detect when the cap stripper 149 has fully retracted. A second cap stripper sensor may be positioned to detect when the cap stripper 149 has fully extended. A first carriage sensor may be positioned to detect when the carriage 146 is in the "home" position, i.e., the position where the cassette 24 and line 30 can be mounted. A second carriage sensor may be positioned to detect when the carriage 146 is engaged with the spike cap 63. A third carriage sensor may be positioned to detect when the carriage 146 has reached the position where the cap 31 has been removed from line 30. A fourth carriage sensor may be positioned to detect when the carriage 146 moves to a position where it engages the connector end 30a of the line 30 with the corresponding spike 160 of the cassette 24. In other embodiments, a single sensor may detect two or more of the carriage positions described above. The cap stripper sensor and carriage sensor can supply input signals to an electronic control panel ("Automatic Connection Panel") and then communicate specific confirmation or error codes to the user via the user interface 144.

[0131] Depending on the number of lines 30 installed, there may be advantages in adjusting the force with which the carriage 146 engages with the spike caps 63. The force required to complete the connection to the cassette 24 increases with the number of caps 31 that must be connected to the spike caps 63. A sensing device that detects and reads information from line indicators in the indicator area 33 can also be used to supply the data necessary to adjust the force applied to the drive element 133. The force can be generated by several devices, such as a first air bag 137 or a linear actuator such as a motor / ball screw. An electronic control panel (e.g., an automatic connection panel) can receive input from the line sensing sensor and be programmed to send appropriate control signals to either the motor of the linear actuator or the pneumatic valve that controls the inflation of the air bag 137. The controller 16 can control the degree or speed of movement of the drive element 133, for example, by adjusting the voltage applied to the motor of the linear actuator or by adjusting the pneumatic valve that controls the inflation of the air bag 137.

[0132] An aspect of the present invention in which the cap 31 on line 30 is removed together with the cap 63 on the spike 160 of the cassette 24 can also provide advantages other than simplification of operation. For example, since the spike cap 63 is removed by engagement with the cap 31 on line 30, if line 30 is not mounted in a particular slot on carriage 146, the spike cap 63 will not be removed in that position. For example, cassette 24 includes five spikes 160 and corresponding spike caps 63, but cycler 14 can operate with four or fewer (or even zero) lines 30 associated with cycler 14. In the case of a slot on carriage 146 where line 30 is not present, there is no cap 31, and therefore no mechanism to remove the spike cap 63 in that position. Thus, if line 30 is not connected to a particular spike 160, the cap 63 on the spike 160 remains in place during the operation of cassette 24. This can help prevent leakage and / or contamination of the spike 160.

[0133] The cassette 24 in Figure 33 includes several features that differ from the cassettes of embodiments shown, for example, in Figures 3, 4, and 6. In the embodiments of Figures 3, 4, and 6, the heating bag port 150, the drainage line port 152, and the patient line port 154 are arranged to have a central tube 156 and a skirt 158. However, as described above and as shown in Figure 33, it is also possible for the ports 150, 152, and 154 to include only the central tube 156 and not the skirt 158. This is also shown in Figure 34. The embodiment shown in Figure 34 includes raised ribs formed on the outer surface of the left pump chamber 181. Raised ribs may also be provided to the right pump chamber 181, which can provide additional contact points on the outer wall of the pump chamber 181, and the chamber has a mechanism in the cassette mounting section 145 inside the door 141 that presses the cassette against the control surface 148 when the door 141 is closed. Raised ribs are not necessary, and instead, the pump chamber 181 may not have ribs or other features, as seen in the right pump chamber 181 in Figure 34. Similarly, the spike 160 in embodiments of Figures 3, 4, and 6 does not include a skirt or similar feature on the base of the spike 160, whereas the embodiment in Figure 33 includes a skirt 160a, which is also shown in Figure 34. The skirt 160a can be positioned to accommodate the end of the spike cap 63 in a recess between the skirt 160a and the spike 160, thereby helping to form a seal between the spike 160 and the spike cap 63.

[0134] Another feature of the present invention, shown in Figure 33, relates to the configuration of the distal end of the spike 163 and the lumen 159 passing through the spike 160. In this embodiment, the distal end of the spike 160 is positioned on or near the longitudinal axis of the spike 160, running substantially along the geometric center of the spike 160. Positioning the distal end of the spike 160 on or near the longitudinal axis reduces alignment tolerances when engaging the spike 160 with the corresponding solution line 30, and helps the spike 160 penetrate the diaphragm or membrane 30b of the connector end 30a of the line 30. As a result, the lumen 159 of the spike 160 is positioned substantially off the longitudinal axis of the spike 160, for example, as shown in Figure 33 and as shown in the end view of the spike 160 in Figure 35, near the bottom of the spike 160. Furthermore, the distal end of the spike 160 has a slightly smaller diameter than the more proximal portion of the spike 160 (in this embodiment, the diameter of the spike 160 actually changes gradually to about 2 / 3 of the length of the spike 160 from the body 18). The reduction in diameter of the spike 160 at the distal end provides a gap between the spike 160 and the inner wall of the line 30, creating space for the diaphragm 30b to fold back and be positioned between the spike 160 and the line 30 when penetrated by the spike 160. The stepped feature of the spike 160 can also be positioned to enhance the seal formed between the line 30 and the spike 160 by engaging with the line 30 where the diaphragm 30b connects to the inner wall of the line 30.

[0135] Once the cassette 24 and line 30 are loaded into the cycler 14, the cycler 14 must control the operation of the cassette 24 to move fluid from the solution line 30 to the heating bag 22 and the patient. Figure 36 is a plan view of the control surface 148 of the cycler 14 that interacts with the pump chamber side of the cassette 24 (for example, shown in Figure 6) to produce fluid pumping and flow path control within the cassette 24. The control surface 148, which can be described as a type of gasket when stationary, may comprise a silicone rubber sheet and may be substantially flat. The valve control area 1481 may be defined on the control surface 148, for example, by folds, grooves, ribs, or other features on the sheet surface, and may (or may not) be movably positioned substantially longitudinally relative to the sheet surface. By moving inward / outward, the valve control region 1481 can move the relevant portion of the membrane 15 on the cassette 24 to open and close the valve ports 184, 186, 190, and 192 of the cassette 24, thereby controlling the flow in the cassette 24. The two larger regions, the pump control regions 1482, can similarly be made movable to move the relevant molded portion 151 of the membrane 15 that cooperates with the pump chamber 181. Similar to the molded portion 151 of the membrane 15, the pump control regions 1482 can be shaped to match the shape of the pump chamber 181 as the control region 1482 expands into the pump chamber 181. Thus, the portion of the control sheet 148 in the pump control region 1482 does not necessarily need to be stretched or otherwise elastically deformed during pumping.

[0136] Regions 1481 and 1482 may each have associated vacuum or vacuum exhaust ports 1483 that can be used to remove all or nearly all air or other fluid that may be present between the membrane 15 of the cassette 24 and the control surface 148 of the cycler 14, for example, after the cassette 24 has been loaded into the cycler 14 and the door 141 has been closed. This can help ensure close contact between the membrane 15 and the control regions 1481 and 1482 and to control the delivery of the desired amount in the pumping operation and / or the open / closed state of the various valve ports. The intake port 1482 is formed in a location where the control surface 148 is not pressed against the wall or other relatively hard feature of the cassette 24. For example, according to one aspect of the present invention, one or both of the pump chambers of the cassette may include intake ventilation gap regions formed adjacent to the pump chambers. In the embodiment shown in Figures 3 and 6, the base member 18 is adjacent to an elliptical recess forming the pump chamber 181 and may include an intake vent port gap or extension 82 (e.g., a recessed area to which fluid is connected to the pump chamber) outside the base member 181, so that the intake vent port 1483 for the pump control area 1482 can remove air or fluid from between the membrane 15 and the control surface 148 without obstruction (e.g., due to a rupture of the membrane 15). The extension may also be located within the periphery of the pump chamber 181. However, locating the vent port function 182 outside the periphery of the pump chamber 181 allows for a larger volume of the pump chamber for pumping fluid, for example, to be available for the entire installation area of ​​the pump chamber 181 used for pumping dialysate. Preferably, the extension 182 is located longitudinally below the pump chamber 181 so that any fluid leaking between the membrane 15 and the control surface 148 can be drawn out through the intake port 1483 at the earliest opportunity. Similarly, the intake port 1483 associated with the valve 1481 is preferably positioned longitudinally below the valve 1481.

[0137] The control regions 1481 and 1482 can be moved by controlling the air pressure and / or air volume on the side of the control surface 148 facing the cassette 24, for example, on the back side of the rubber sheet forming the control surface 148. For example, as shown in Figure 37, the control surface 148 can be supported by mating blocks 170 that are isolated from each other (or at least individually controllable as desired), each having a control chamber 171 positioned in association with each control region 1481, 1482. When the cassette 24 is pressed to be operably associated with the control surface 148 supported by the mating blocks 170, the surface of the mating blocks 170 forms an interface with the cassette 24. Thus, the control chamber of the mating block 170 is connected to a complementary valve or pump chamber of the cassette 24, sandwiching the control regions 1481 and 1482 of the control surface 148 adjacent to the mating block 170 and the associated region of the membrane 15 adjacent to the cassette 24 (e.g., the molded area 151). Air or other control fluid can move in and out of the control chambers 171 of the mating block 170 for regions 1481 and 1482, thereby moving the control regions 1481 and 1482 as desired to open and close the valve ports of the cassette 24 and / or perform the pumping operation of the pump chamber 181. In one embodiment shown in Figure 37, the control chamber 171 can be configured as a cylindrical region backing the valve control region 1481 and a pair of elliptical voids backing the pump control region 1482. Fluid control ports can be provided in each control chamber 171 so that the cycler 14 can control the amount and / or fluid pressure within each control chamber. For example, the mating block 170 can be mated with a manifold 172 which includes various ports, channels, openings, voids, and / or other features that communicate with the control chambers 171 and apply appropriate pneumatic / vacuum pressure to the control chambers 171. Although not shown in the diagram, pneumatic / vacuum control can be performed in an appropriate manner using, for example, controllable valves, pumps, pressure sensors, accumulators, etc.Naturally, it should be understood that the control regions 1481 and 1482 can also be moved in other ways, for example, by gravity-based systems, hydraulic systems, and / or mechanical systems (such as linear motors), or by a combination of systems such as air pressure, hydraulic pressure, gravity-based, and mechanical systems.

[0138] According to one aspect of the present invention, the intake port 1483 can be used to detect leakage within the membrane 15. For example, a liquid sensor in a conduit or chamber connected to the intake port 1483 can detect liquid if a hole is made in the membrane 15 or if liquid is introduced between the membrane 15 and the control surface 148 in any other way. For example, the intake port 1483 can be aligned, sealed and associated with a complementary intake port 173 in a mating block 170, and then sealed and associated with a fluid passage 1721 leading to a common fluid recovery chamber 1722 in a manifold 172. The fluid recovery chamber 1722 may include an inlet from which a vacuum can be applied and distributed to all intake ports 1483 of the control surface 148. By applying a vacuum to the fluid recovery chamber 1722, fluid can be drawn out from each of the intake ports 173 and 1483, thereby removing fluid from the space between the membrane 15 and the control surface 148 in various control regions. However, if the liquid is present in one or more regions, the associated intake port 1483 can draw the liquid into the intake port 173 and the line 1721 leading to the fluid recovery chamber 1722. The fluid is recovered in the fluid recovery chamber 1722 and can be detected by one or more suitable sensors, for example, a pair of conductivity sensors that detect changes in conductivity within the chamber 1722 indicating the presence of liquid. In this embodiment, the sensors are located at the bottom of the fluid recovery chamber 1722, and the vacuum source can be connected to the chamber 1722 at its upper end. Thus, when liquid is drawn into the fluid recovery chamber 1722, the liquid can be detected before the liquid level reaches the vacuum source. Optionally, a hydrophobic filter, valve, or other component can be placed at the vacuum source connection point to the chamber 1722 to further help resist the entry of liquid into the vacuum source. In this way, liquid leakage can be detected and addressed by the controller 16 before the vacuum source valve is at risk of being contaminated by liquid (e.g., generating a warning, closing the liquid inlet valve, and stopping the pumping operation).

[0139] In one embodiment, the inner wall of the control chamber 171 may include raised elements somewhat similar to the spacer elements 50 of the pump chamber, as shown in Figure 37 with respect to the control chamber 171 associated with the pump control region 1482. These raised elements may take the form of high-flat features, ribs, or other protrusions that retract the control ports away from the fully retracted control region 1482. This configuration allows for a more even distribution of pressure or vacuum within the control chamber 171 and prevents premature closure of the control ports by the control surface 148. The pre-formed control surface 148 (at least in the pump control region) does not experience significant tensile pressure when fully expanded until it strikes either the inner wall of the pump chamber of the cassette 24 during the delivery stroke or the inner wall of the control chamber 171 during the injection stroke. Thus, the control region 1482 can spread asymmetrically into the control chamber 171, causing one or more ports of the control chamber to close prematurely by the control region 1482 before the chamber is completely evacuated. Providing a feature on the inner surface of the control chamber 171 that prevents contact between the control region 1482 and the control port helps ensure that the control region 1482 can make uniform contact with the inner wall of the control chamber during the liquid injection process.

[0140] As described above, the cycler 14 may include a control system 16 configured to control the above components according to a desired operating sequence or protocol, and having a data processor that electrically connects to various valves, pressure sensors, motors, etc. of the system. The control system 16 may include appropriate circuitry, programming, computer memory, electrical connections, and / or other components for performing specific tasks. The system may include pumps, tanks, manifolds, valves, or other components that generate a desired pressure of air or other fluid (either positive pressure - above atmospheric pressure or other standard - or negative pressure or vacuum - below atmospheric pressure or other standard) to control the operation of the control surface 148 and other areas of pneumatic components. Further details regarding the control system 16 (or at least a part thereof) will be described later.

[0141] In one illustrated embodiment, the pressure in the pump control chamber 171 can be controlled by a binary valve that opens to expose the control chamber 171 to a suitable pressure / vacuum and closes to cut off the pressure / vacuum source. The binary valve can be controlled using a sawtooth control signal that is adjustable to control the pressure in the pump control chamber 171. For example, during the pump delivery stroke (i.e., positive pressure is introduced into the pump control chamber 171 to move the membrane 15 / control surface 148 and cause the liquid to flow out of the pump chamber 181), the binary valve can be driven by a sawtooth signal to open and close relatively quickly to establish a suitable pressure in the control chamber 171 (e.g., a pressure of about 70-90 mmHg). If the pressure in the control chamber 171 rises above about 90 mmHg, the sawtooth signal can be adjusted to close the binary valve for a further extended period. If the pressure in the control chamber 171 drops below about 70 mmHg, the sawtooth control signal can be applied to the binary valve again to increase the pressure in the control chamber 171. Therefore, during normal pumping operation, the binary valve is opened and closed multiple times and can be closed for one or more extended periods, so that the pressure at which the liquid is forcibly pushed out of the pump chamber 181 is maintained at a desired level or range (e.g., about 70-90 mmHg).

[0142] According to several embodiments and one aspect of the present invention, it may be useful to detect the “end of the stroke” of the membrane 15 / pump control region 1482, for example, when the membrane 15 comes into contact with the spacer 50 in the pump chamber 181, or when the pump control region 1482 comes into contact with the wall of the pump control chamber 171. For example, during pumping, detecting the “end of the stroke” can indicate that the movement of the membrane 15 / pump control region 1482 should be reversed to start a new pumping cycle (injecting liquid into or displacing liquid from the pump chamber 181). In one illustrated embodiment, where the pressure in the control chamber 171 for the pump is controlled by a binary valve driven by a sawtooth control signal, the pressure in the pump chamber 181 fluctuates at a relatively high frequency, for example, at or near the frequency at which the binary valve is opened and closed. A pressure sensor in the control chamber 171 can detect this fluctuation, which has a higher amplitude than usual when the membrane 15 / pump control region 1482 is not in contact with the inner wall of the pump chamber 181 or the wall of the pump control chamber 171. However, once the membrane 15 / pump control region 1482 comes into contact with the inner wall of the pump chamber 181 or the wall of the pump control chamber 171 (i.e., "end of the stroke"), the pressure fluctuation decreases or otherwise changes in a way detectable by the pressure sensor in the pump control chamber 171. This change in pressure fluctuation can be used to identify the end of the stroke, and the pump and other components of the cassette 24 and / or cycler 14 can be controlled accordingly.

[0143] Occluder In one aspect of the present invention, an occluder for opening and closing one or more flexible lines may include a pair of opposing blocking members that may be configured as elastic elements such as flat plates made of spring steel (e.g., leaf springs), and have a force actuator that applies force to one or both of the blocking members to operate the occluder. In certain embodiments, the force actuator may include an expandable or expandable member located between the elastic elements. When the expandable member is in a contracted size state, the elastic elements are flat or substantially flat, forcing their pinch heads to engage with one or more lines to pinch the closed lines. However, when the expandable member forcibly moves the elastic elements away, the elastic elements bend and retract the pinch heads, releasing the lines and allowing flow to pass through them. In another embodiment, the blocking members may be made essentially immobile with respect to the level of force applied by the force actuator. In certain embodiments, the force actuator may apply force to one or both of the opposing blocking members to increase the distance between them in at least a portion of the area in which the blocking members are facing each other to perform the opening or closing of the flexible pipe.

[0144] Figure 38 is an exploded view of an illustrated embodiment of an occluder 147 that can be used to close or block patient lines and drainage lines 34 and 28, and / or other lines in the cycler 14 or set 12 (e.g., heating bag line 26), and Figure 39 is a partial assembled view thereof. The occluder 147 includes an optional pinch head 161, for example, a substantially flat blade-like element that contacts the pipe to press it against a door 141 and pinch the pipe to be closed. In another embodiment, the function of the pinch head can be replaced by one or both extended edges of a blocking member 165. The pinch head 161 includes a gasket 162, such as an O-ring or other member, which works with the pinch head 161 to help resist the entry of fluid (e.g., air or liquid) into the housing of the cycler 14 if, for example, there is a leak in one of the blocked lines. The bellows gasket 162 is attached to a pinch head guide 163 mounted on the front panel of the cycler housing, i.e., the panel exposed when the door 141 is opened, and the pinch head 161 passes through the pinch head guide. The pinch head guide 163 allows the pinch head 161 to move in and out of the pinch head guide 163 without constraint and / or significant resistance to the sliding motion of the pinch head 161. The pivot shaft 164 attaches to the pinch head 161 a pair of opposing occluder members, each including a hook-shaped pivot bearing in the illustrated embodiment's spring plate 165, for example, as found on a standard door hinge. That is, the opening of the shaft guide on the pinch head 161 and the opening formed by the hook-shaped bearing in the spring plate 165 are aligned with each other, and the pivot shaft 164 is inserted into the opening, so that the pinch head 161 and the spring plate 165 are swivel-connected together. The spring plate 165 can be made of a suitable material such as steel and configured to be substantially flat when not under stress. The opposing ends of the spring plate 165 include similar hook-shaped bearings that are pivotably connected to a linear adjuster 167 by a second pivot shaft 164.In this embodiment, the force actuator comprises an air bladder 166, which is positioned between spring plates 165 and configured to push the spring plates 165 so that when a fluid (e.g., pressurized air) is introduced into the air bladder, the air bladder expands and moves away from each other in the region between the pivot axes 164. A linear adjuster 167 is fixed to the cycler housing 82, while the pinch head 161 is allowed to float, but its movement is guided by a pinch head guide 163. The linear adjuster 167 includes a slotted hole at its lower end, allowing the pinch head to be properly positioned when the occluder 147 is installed in the cycler 14 by adjusting the entire assembly into place. A turnbuckle 168 or other configuration may be used to assist in adjusting the position of the linear adjuster 167 relative to the housing 82. In other words, the pinch head 161 must be positioned appropriately so that, under normal circumstances, the spring plates 165 are positioned close together, the air bag 166 is nearly empty, or under atmospheric pressure, and the pinch head 161 properly presses against the patient line and drainage line to pinch the closed tube so that fluid flows without cutting, twisting, or other damage to the tube. The slot opening of the linear adjuster 167 allows the occluder 147 to be precisely positioned and locked in place. An override release device, such as one provided by the release blade 169, is optionally positioned between the spring plates 165 and, as will be described in more detail later, retracts the pinch head 161 into the pinch head guide 163 by rotating it to push the spring plates 165 away. The release blade 169 can be manually activated, for example, to disable the occluder 147 in the event of a power outage, failure of the air bag 166, or other circumstances.

[0145] Further configurations and descriptions of specific components that may be useful in constructing a particular embodiment of the occluder are described in U.S. Patent No. 6,302,653. The spring plate 165 may be made of a material that is elastically resistant to bending forces and has sufficient longitudinal stiffness (bending resistance) in order to provide sufficient restoring force in response to bending displacements that intercept a desired number of collapsible tubes. In the illustrated embodiment, each spring plate is substantially flat when unstressed and is in the shape of a sheet or plate. In another embodiment utilizing one or more elastic interceptors (spring members), any interceptor that is elastically resistant to bending forces and has sufficient longitudinal stiffness (bending resistance) in order to provide sufficient restoring force in response to bending displacements that intercept a desired number of collapsible tubes can be used. Suitable spring members may take a wide range of shapes that are obvious to those skilled in the art, including but not limited to prism-shaped, trapezoidal, square, or rectangular bars or beams, I-beams, elliptical beams, bowl-shaped surfaces, or others. Those skilled in the art will be able to easily select the appropriate material and dimensions for the spring plate 165 based on this instruction and the requirements of the specific application.

[0146] Figure 40 is a top view of the occluder 147 with the air bladder 166 deflated and the spring plates 165 positioned close together, resulting in a flat or nearly flat state. In this position, the pinch head 161 is fully extended from the pinch head guide, and the front panel of the cycler 14 (i.e., the inner panel of the door 141) can block the patient line and drainage line. On the other hand, Figure 41 shows the air bladder 166 in an inflated state, in which the spring plates 165 are pushed away from each other, causing the pinch head 161 to retract into the pinch head guide 163. (Note that the linear adjuster 167 is fixed in place to the cycler housing 82 and thus also to the front panel of the housing 82. The pinch head 161 is configured to move freely in and out of the pinch head guide 163, so as the spring plates 165 are moved further away, the pinch head 161 moves backward relative to the front panel.) This state prevents the pinch head 161 from blocking the patient and drainage lines, and the occluder 147 remains in place during the normal operation of the cycler 14. That is, as described above, the various components of the cycler 14 can be operated using pneumatic / vacuum. For example, the control surface 148 can be operated under appropriate pneumatic / vacuum conditions to produce fluid pumping and valve operation for the cassette 24. Thus, when the cycler 14 is operating normally, it can generate sufficient air pressure not only for the operation of the control system but also to retract the pinch head 161 and inflate the air bag 166 to prevent blocking the patient and drainage lines. However, in the event of a system shutdown, malfunction, defect, or other situation, the air pressure to the air bag 166 is stopped, causing the air bag 166 to deflate, straighten the spring plate 165, and extend the pinch head 161 to block the lines. One advantage of the illustrated configuration is that the restoring force of the spring plate 165 balances the movement of the pinch head 161 so that it does not normally restrain the pinch head guide 163 when moving relative to the pinch head guide 163. In addition, the opposing force of the spring plate 165 tends to reduce the asymmetric frictional wear of the pivot shaft and the assembly bushing.Furthermore, once the spring plate 165 is in a nearly straight position, it exerts a force several times greater than the force applied to the spring plate 165 by the air bladder 166 in a direction roughly along the length of the pinch head 161, separating the spring plates 165 from each other and retracting the pinch head 161. Moreover, when the spring plate 165 is flat or nearly flat, the force required by the fluid in the extruded tube to overwhelm the pinching force from the pinch head 161 is close to the relatively large force required to buckle the spring plate by destroying the column stability of the flattened spring plate when applied to the spring plate nearly parallel to the flattened surface of the spring plate at the end. As a result, the occluder 147 is very effective at shutting off the line while keeping the force applied to the air bladder 166 to retract the pinch head 161 relatively small, thereby reducing the possibility of failure. The double spring plate configuration of the illustrated embodiment may have the further advantage of significantly increasing the pinching force provided by the pinch head for any given force required to bend the spring plate, and / or for any given size and thickness of the spring plate.

[0147] Depending on the circumstances, the force of the occluder 147 on the line may be made relatively large to make it difficult to open the door 141. That is, when the pinch head 161 is in contact with the line and blocking the line, the door 141 must resist the force of the occluder 147, and in some cases this may result in a latch that keeps the door 141 closed, making it difficult or impossible to operate manually. Naturally, once the cycler 14 is started and generates air pressure to operate, the occluder air bladder 166 can be inflated, allowing the occluder pinch head 161 to retract. However, in some cases, such as in the case of a pump failure in the cycler 14, it may be impossible or difficult to inflate the air bladder 166. The occluder 147 may include a manual release to allow the door to be opened. In the illustrated embodiment, the occluder 147 may include a release blade 169 including a pair of vanes that are swivelably mounted for rotational movement between spring plates 165, as shown in Figures 38 and 39. When stationary, the blades of the release blade are aligned with the spring as shown in Figure 39, allowing the occluder to operate normally. However, if the spring plate 165 is flat and it is necessary to manually retract the pinch head 161, the release blade 169 can be rotated by engaging the release blade 169 with a hexagonal key or other tool so that the blades push the spring plate 165 away. The hexagonal key or other tool can be inserted into an opening in the housing 82 of the cycler 14, for example, an opening near the recess of the left-side handle of the cycler housing 82, to actuate the occluder 147 and release the door 141.

[0148] Pump volume discharge measurement In another aspect of the present invention, the cycler 14 can determine the volume of fluid delivered to various lines of the system 10 without using a flow meter, weighing scale, or other direct measurement of the volume or weight of the fluid. For example, in one embodiment, the volume of fluid moved by a pump, such as a pump in a cassette 24, can be determined based on a pressure measurement of the gas used to drive the pump. In one embodiment, volume determination can be performed by isolating two chambers from each other, measuring the corresponding pressures in the isolated chambers, partially or substantially equalizing the pressures in the chambers (by fluid-connecting the two chambers), and measuring that pressure. Using the measured pressure, the known volume of one chamber, and the assumption that the equalization occurs adiabatically, the volume of the other chamber (e.g., the pump chamber) can be calculated. In one embodiment, the pressures measured after the chambers are fluid-connected may be substantially unequal to each other, i.e., the pressures in the chambers cannot yet be perfectly equalized. However, these substantially unequal pressures can be used to determine the volume of the pump control chamber, as described later.

[0149] For example, Figure 42 is a schematic diagram of the pump chamber 181 of the cassette 24, its associated control components, and inflow / outflow paths. In this illustrated example, a liquid supply source, including a heating bag 22, a heating bag line 26, and a flow path through the cassette 24, is shown with a liquid input at the upper opening 191 of the pump chamber. In this example, the liquid outlet is shown as receiving liquid from the lower opening 187 of the pump chamber 181 and may include, for example, the flow path of the cassette 24 and the patient line 34. The liquid supply source may include, for example, a valve including a valve port 192 that can be opened and closed to allow or deny flow into or out of the pump chamber 181. Similarly, the liquid outlet may include, for example, a valve including a valve port 190 that can be opened and closed to allow or deny flow into or out of the pump chamber 181. Naturally, the liquid supply source can include any suitable configuration such as one or more solution containers, patient lines, cassette 24, or one or more channels of other liquid sources, and the liquid outlet can include any suitable configuration such as a drain line, a heating bag and heating bag line, one or more channels within cassette 24, or other liquid outlets. Generally speaking, the pump chamber 181 (i.e., to the left of membrane 14 in Figure 42) is filled with an incompressible liquid such as water or dialysate during operation. However, in some cases, such as during initial operation, preparation, or under other circumstances as described later, air or other gases may be present in the pump chamber 181. Also, while embodiments of the present invention relating to the detection of pump volume and / or pressure have been described with reference to the pump configuration of cassette 24, it should be understood that embodiments of the present invention are applicable to any suitable pump or fluid transfer system.

[0150] Figure 42 schematically shows the membrane 15 and the control surface 148 of the control chamber 171 (adjacent to each other) on the right, the control chamber can be formed as a gap or other space within a fitting block 170 associated with the pump control area 1482 of the control surface 148 for the pump chamber 181, as described above. Appropriate pneumatic pressure is introduced into the control chamber 171 to move the membrane 15 / control area 1482 and perform pumping of the liquid in the pump chamber 181. The control chamber 171 communicates with line L0, which branches to another line L1, and with a first valve X1 that communicates with a pressure source (e.g., a pneumatic source or a vacuum source). The pressure source may include a piston pump in which a piston is moved within the chamber to control the pressure delivered to the control chamber 171, or it may include different types of pressure pumps and / or tanks that deliver appropriate gas pressure to move the membrane 15 / control area 1482 and perform the pumping operation. Line L0 connects to a second valve X2 that communicates with another line L2 and a reference chamber (for example, a space appropriately configured for performing measurements described later). Furthermore, the reference chamber also communicates with line L3, which has a valve X3 that connects to a vent or other reference pressure (for example, an atmospheric pressure source or other reference pressure source). Valves X1, X2, and X3 can each be controlled individually. Pressure sensors can be placed, for example, one sensor in the control chamber 171 and another in the reference chamber to measure the pressure associated with the control chamber and the reference chamber. These pressure sensors can be positioned and operated to detect pressure in an appropriate manner. The pressure sensors can communicate with the control system 16 with respect to a cycler 14 or other appropriate processor to determine the volume delivered by the pump or other feature.

[0151] As described above, the valves or other components of the pump system shown in Figure 42 can be controlled to measure the pressure in the pump chamber 181, the liquid source and / or the liquid outlet, and / or the volume of fluid delivered from the pump chamber 181 to the liquid source or liquid outlet. With regard to volume measurement, one technique used to determine the volume of fluid delivered from the pump chamber 181 is to compare the relative pressure in the control chamber 171 with the pressure in the reference chamber under two different pump conditions. By comparing the relative pressures, it is possible to determine the volume change in the control chamber 171, which corresponds to the volume change in the pump chamber 181 and reflects the volume delivered to / received from the pump chamber 181. For example, after the pressure in the control chamber 171 is reduced so that the membrane 15 and the pump control region 1482 are drawn in to contact at least a portion of the control chamber wall (or another suitable location for the membrane 15 / region 1482) during the pump chamber injection cycle (for example, by applying negative pressure from a pressure source through an open valve X1), valve X1 can be closed to isolate the control chamber from the pressure source, and valve X2 can be closed to isolate the reference chamber from the control chamber 171. Valve X3 can be opened to vent the reference chamber to atmospheric pressure and then closed to isolate the reference chamber. With valve X1 closed and the pressures in the control chamber and reference chamber measured, valve X2 is opened to begin equalizing the pressures in the control chamber and reference chamber. The initial pressures in the reference chamber and control chamber, along with the known volume of the reference chamber and the pressures measured after equalization has begun (but not necessarily completed), can be used to determine the volume of the control chamber. This process can be repeated at the end of a pump delivery cycle when the sheet 15 / control area 1482 is pressed to contact the spacer element 50 of the pump chamber 181. The volume of liquid delivered from the pump can be determined by comparing the volume of the control chamber at the end of the injection cycle with the volume at the end of the delivery cycle.

[0152] Theoretically, the pressure equalization process (e.g., at the opening of valve X2) is assumed to occur adiabatically, i.e., without heat transfer occurring between the air in the control chamber and the reference chamber and in its environment. In theoretical considerations, an imaginary piston is initially positioned in valve X2 when valve X2 is closed, and this imaginary piston moves within line L0 or L2 as valve X2 is opened to equalize the pressure in the control chamber and the reference chamber. The assumption that pressure equalization occurs adiabatically introduces only a small error in volume measurement because (a) the pressure equalization process occurs relatively quickly, (b) the air in the control chamber and the reference chamber has nearly identical component concentrations, and (c) the temperatures are similar. In one embodiment, the pressure obtained after the start of equalization can be measured before substantial equalization occurs, further reducing the time between the initial pressure measurement and the final pressure measurement used to determine the pump chamber volume. For example, errors can be further reduced by using low-conductivity materials for the membrane 15 / control surface 148, cassette 24, control chamber 171, line, reference chamber, etc., to reduce heat transfer.

[0153] Assuming that an adiabatic system exists between the state in which valve X2 is closed until it is opened and the state in which the pressure is equalized, the following holds true: PV γ =Constant (1) Here, P is the pressure, V is the volume, and γ is a constant (for example, approximately 1.4 if the gas is diatomic like air). Therefore, the following equation can be written relating to the pressure and volume of the control chamber and reference chamber before and after opening valve X2 and pressure equalization.

[0154] PrVr γ +PdVd γ =Constant=PfVf γ (2) However, Pr is the pressure in the reference chamber and lines L2 and L3 before valve X2 is opened, Vr is the volume of the reference chamber and lines L2 and L3 before valve X2 is opened, Pd is the pressure in the control chamber and lines L0 and L1 before valve X2 is opened, Vd is the volume of the control chamber and lines L0 and L1 before valve X2 is opened, Pf is the equalized pressure in the reference chamber and control chamber after valve X2 is opened, and Vf is the volume of the entire system including the control chamber, reference chamber, and lines L0, L1, L2, and L3, i.e., Vf = Vd + Vr

[0155] Pr, Vr, Pd, Pf, and γ are known, and since Vf = Vr + Vd, this equation can be used to solve for Vd. (Although this document, including the claims, mentions the use of "measured pressure" when measuring volume values, etc., it should be understood that the measured pressure value does not need to be in a specific format such as psi. Instead, "measured pressure" or "determinative pressure" can include any value representing pressure, such as voltage level, resistance, or multi-bit digital number. For example, a pressure transducer used to measure the pressure in a pump control chamber may output an analog voltage level, resistance, or other indicator representing the pressure in the pump control chamber. The raw output from the transducer can be used as a modified form of the output, such as the measured pressure, and / or a digital number, psi, or other value generated using the analog output from the transducer. The same applies to other values ​​such as determination volume, which do not necessarily need to be in a specific format such as cubic centimeters. Instead, determination volume can include any value representing the volume that can be used to produce an actual volume, so to speak, cubic centimeters.)

[0156] In an embodiment of the fluid management system ("FMS") technology for determining the volume delivered by the pump, it is assumed that pressure equalization after opening valve X2 occurs in an adiabatic system. Therefore, Equation 3 below shows the relationship between the volume of the reference chamber system before and after pressure equalization.

[0157] Vrf=Vri(Pf / Patm) -(1 / γ) (3) However, Vrf is the final (equalized) volume of the reference chamber system, including the volume of the reference chamber, the volumes of lines L2 and L3, and the pressure regulation resulting from the movement of the “piston” which can move left or right of valve X2 after opening; Vri is the initial (pre-equalized) volume of the reference chamber and lines L2 and L3 together with the “piston” located in valve X2; Pf is the final equalized pressure after valve X2 is opened; and Patm is the initial pressure of the reference chamber before valve X2 is opened (atmospheric pressure in this example). Similarly, Equation 4 shows the relationship between the volumes of the control chamber system before and after pressure equalization.

[0158] Vdf = Vdi(Pf / Pdi) -(1 / γ) (4) However, Vdf is the final volume of the control chamber system, including the volume of the control chamber, the volumes of lines L0 and L1, and the pressure regulation resulting from the movement of the "piston" which can move left or right of valve X2 after opening; Vdi is the initial volume of the control chamber and lines L0 and L1 together with the "piston" located in valve X2; Pf is the final volume after valve X2 is opened; and Pdi is the initial pressure of the control chamber before valve X2 is opened.

[0159] The volumes of the reference chamber system and the control chamber system change by the same absolute amount after valve X2 is opened and the pressure is equalized, but with different signs, as shown in Equation 5 (for example, the change in volume is caused by the left or right movement of the "piston" when valve X2 is opened).

[0160] ΔVr=(-1)ΔVd (5) (Note that the volume changes of the reference chamber and control chamber are due only to the movement of an imaginary piston. The volumes of the reference chamber and control chamber do not actually change during the equalization process under normal circumstances.) Furthermore, using the relationship in Equation 3, the volume change of the reference chamber system can be determined by the following equation.

[0161] ΔVr = Vrf - Vri = Vri(-1 + (Pf / Patm)) -(1 / γ) ) (6) Similarly, using Equation 4, the volume change of the control chamber system can be calculated by the following equation.

[0162] ΔVd = Vdf - Vdi = Vdi(-1 + (Pf / Pdi)) -(1 / γ) ) (7) Since Vri is known, and Pf and Patm are measured or known, ΔVr can be calculated and is estimated to be equal to (-)ΔVd by Equation 5. Thus, Vdi (volume of the control chamber system before pressure equalization with the reference chamber) can be calculated using Equation 7. In this embodiment, Vdi represents the volume of the control chamber and lines L0 and L1, where L0 and L1 are fixed and of known quantity. Subtracting L0 and L1 from Vdi gives the volume of the control chamber only. Using Equation 7 above, for example, the volume change of the control chamber can be determined both before (Vdi1) and after (Vdi2) the pumping operation (for example, at the end of the injection cycle and the end of the draining cycle), and the volume of fluid pumped out (or taken in) can be measured. For example, if Vdi1 is the volume of the control chamber at the end of the injection process and Vdi2 is the volume of the control chamber at the end of the next discharge process, the volume of fluid pumped out can be estimated by subtracting Vdi1 from Vdi2. Since this measurement is pressure-based, the volume can be determined with respect to almost any position in the membrane 15 / pump control area 1482 within the pump chamber 181, regardless of whether it is part of the pumping stroke or not. However, measurements at the end of the injection and discharge strokes can be achieved with little or no effect on the pumping operation and / or flow rate.

[0163] One aspect of the present invention includes a technique for identifying pressure measurements used in determining the volume of a control chamber and / or for other purposes. For example, a pressure sensor can be used to detect the pressure in the control chamber and the pressure in a reference chamber, but the sensed pressure value may fluctuate depending on the opening and closing of valves, the introduction of pressure into the control chamber, the exhaust of the reference chamber to atmospheric pressure or other reference pressure, etc. Also, in one embodiment, since it is assumed that an adiabatic system exists from before pressure equalization between the control chamber and the reference chamber until after equalization, determining an appropriate pressure value measured in close proximity over time can help reduce errors (for example, the shorter the time elapsed between multiple pressure measurements, the less heat is exchanged in the system). Therefore, the measured pressure value will need to be carefully selected to help ensure an appropriate pressure used for determining the volume to be delivered by a pump or the like.

[0164] For illustrative purposes, Figure 43 is a graph showing the pressure values ​​in the control chamber and reference chamber from a point in time before valve X2 is opened to some time after valve X2 has been opened and the pressure in the chamber has been equalized. In this illustrated embodiment, the pressure in the control chamber is higher than the pressure in the reference chamber before equalization, however, depending on the configuration, the control chamber pressure may be lower than the reference chamber pressure even before equalization, such as during the fluid injection process and / or at the end of the fluid injection process. Also, the graph in Figure 43 shows a horizontal line representing the equalization pressure, but this line should be understood to be for clarity only. The equalization pressure is generally unknown before valve X2 is opened. In this embodiment, the pressure sensor senses the pressure at a rate of approximately 2000 Hz in both the control chamber and the reference chamber, but other appropriate sampling rates can be used. Before valve X2 is opened, the pressures in the control chamber and reference chamber are approximately constant, and no air or other fluid is introduced into the chambers. Therefore, valves X1 and X3 are generally closed at the point before valve X2 is opened. Furthermore, valves connected to the pump chamber, such as valve ports 190 and 192, can be closed to prevent the effects of pressure differences in the pump chamber, liquid supply source, and liquid outlet.

[0165] First, the measured pressure data is processed to detect the initial pressures, i.e., Pd and Pr, for the control chamber and the reference chamber. In one illustrated embodiment, the initial pressures are identified based on an analysis of a 10-point sliding window used for the measured pressure data. This analysis includes, for example, generating a best-fit line for the data within each window (or set) using the least squares method, and determining the slope of the best-fit line. For example, whenever a new pressure is measured for the control chamber or the reference chamber, a least-squares best-fit line can be determined for a dataset including the most recent measurement and the past nine pressure measurements. This process can be repeated for several sets of pressure data, and a determination can be made regarding when the slope of the least-squares best-fit line becomes negative (or otherwise non-zero) and continues to increase in negativity (or deviates from zero in any other way) in the next dataset. The point at which the least-squares best-fit line begins to have a suitable and continuously increasing non-zero slope can be used to identify the initial pressure in the chamber, i.e., a point in time before valve X2 is opened.

[0166] In one embodiment, the initial pressure values ​​for the reference chamber and the control chamber can be determined with respect to the last of five consecutive datasets, where the slope of the best-fit line for the dataset increases from the first dataset to the fifth dataset, and the slope of the best-fit line for the first dataset is the first to become non-zero (i.e., the slope of the best-fit line for the datasets preceding the first dataset is zero or otherwise not sufficiently non-zero). For example, the pressure sensor can take a sample every 1 / 2 millisecond (or other sampling rate) starting at one point in time before the valve X2 is opened. Each time a pressure measurement is taken, the cycler 14 can perform the latest measurement along with the previous nine measurements to generate the best-fit line for the 10 data points in the set. After the next pressure measurement (for example, 1 / 2 millisecond later), the cycler 14 can perform the latest measurement along with the previous nine measurements to again generate the best-fit line for the 10 points in the set. This process can be repeated, and the cycler 14 can determine, for example, that the slope of the best-fit line for a set of 10 data points is first non-zero (or otherwise a suitable slope), and that the slope of the best-fit line for 5 consecutive sets of 10 data points increases with each subsequent dataset. To identify the specific pressure measurement to use, one method is to select the third measurement from the fifth dataset (i.e., the fifth dataset where the best-fit line consistently increases its slope and the first measurement is the pressure measurement taken earliest in time) as the measurement to be used as the initial pressure in the control chamber or reference chamber, i.e., Pd or Pr. This selection was made using an empirical method, for example, by graphing the pressure measurements and selecting which point best represents when the pressure equalization process began. Naturally, other methods are also available for selecting a suitable initial pressure.

[0167] In one illustrated embodiment, it can be confirmed that the times when the selected Pd and Pr measurements were taken are within a desired time threshold, for example, 1 to 2 milliseconds from each other. For example, if the method described above is used to analyze the control chamber pressure and reference chamber pressure and to identify the pressure measurement (and thus the time) immediately before pressure equalization begins, the times when the pressure was measured should be relatively close to each other. Otherwise, there may have been an error or other failure condition that invalidated one or both of the pressure measurements. By confirming that the times when Pd and Pr occurred are both sufficiently close, the cycler 14 can confirm that the initial pressure was properly identified.

[0168] To determine when the pressure in the control chamber and reference chamber has been equalized, so that the measured pressure in the chamber can be used to reliably determine the pump chamber volume, the cycler 14 analyzes a dataset containing a series of data points from the pressure measurements in both the control chamber and reference chamber, determines the best fit line for each dataset (e.g., using the least squares method), and can identify when the slopes of the best fit lines for the dataset for the control chamber and the dataset for the reference chamber are sufficiently similar to each other, for example, when both slopes are close to zero or have values ​​within each other's thresholds. When the slopes of the best fit lines are similar or close to zero, it can be determined that the pressure has been equalized. The first pressure measurement for either dataset can be used as the final equalization pressure, i.e., Pf. In one illustrated embodiment, it was found that pressure equalization occurred within approximately 200-400 milliseconds after valve X2 was opened, with the majority of the equalization occurring within approximately 50 milliseconds. Therefore, the pressure in the control chamber and reference chamber allows for sampling approximately 400 to 800 times or more throughout the entire equalization process, from before valve X2 is opened until equalization is achieved.

[0169] In some cases, it may be desirable to use an alternative FMS method to improve the accuracy of control chamber volume measurement. Large temperature differences between the pumped fluid, the control chamber gas, and the reference chamber gas can lead to significant errors in calculations based on the assumption that pressure equalization occurs adiabatically. Waiting to measure the pressure until complete pressure equalization occurs between the control chamber and the reference chamber may result in excessive heat transfer. In one aspect of the present invention, pressure values ​​in the pump chamber and the reference chamber that are substantially unequal to each other, i.e., measured before complete equalization occurs, can be used to determine the pump chamber volume.

[0170] In one embodiment, thermal transfer can be minimized, and adiabatic calculation errors can be reduced by measuring the chamber pressure throughout the entire equalization period from the opening of valve X2 to complete pressure equalization, and selecting sampling points during the equalization period for adiabatic calculations. In one embodiment of the APD system, the measured chamber pressure obtained before complete pressure equalization between the control chamber and the reference chamber can be used to determine the pump chamber volume. In one embodiment, these pressure values ​​can be measured for about 50 ms after the chamber is first fluid-connected and equalization has begun. As described above, in one embodiment, complete equalization can be achieved in about 200-400 ms after the opening of valve X2. Therefore, the measured pressure can be obtained at a point after the opening of valve X2 (or the start of equalization), which is about 10%-50% of the total equalization period. In other words, the measured pressure can be obtained when 50-70% of pressure equalization has occurred (i.e., when the reference chamber pressure and the pump chamber pressure have changed by about 50-70% of the difference between the initial chamber pressure and the final equalized pressure). A computer-enabled controller can be used to perform, store, and analyze a significant number of pressure measurements in the control chamber and reference chamber during the equalization period (e.g., 40–100 individual pressure measurements). Within the points sampled during the first 50 ms of the equalization period, there exists a logically optimal sampling point for performing adiabatic calculations (see Figure 43, for example, where the optimized sampling point occurs approximately 50 ms after valve X2 opens). The optimized sampling point can occur well before valve X2 opens, minimizing heat transfer between the gas volumes of the two chambers while avoiding large errors in pressure measurement due to pressure sensor characteristics and valve starting delays. However, as seen in Figure 43, the pressures in the pump chamber and reference chamber may be approximately unequal at this point, and equalization may not be complete (and in some cases, it may be technically difficult to perform reliable pressure measurements immediately after valve X2 opens due to inherent inaccuracies of valve X2, e.g., pressure sensor inaccuracies, the time required for valve X2 to fully open, and the rapid initial pressure change in the control chamber or reference chamber immediately after valve X2 opens).

[0171] During pressure equalization, when the final pressures of the control chamber and the reference chamber are not the same, Equation 2 becomes PriVri γ +PdiVdi γ =Constant=PrfVrf γ +PdfVdf γ (8) where Pri is the pressure in the reference chamber before the opening of valve X2, Pdi is the pressure in the control chamber before the opening of valve X2, Prf is the final reference chamber pressure, and Pdf is the final control chamber pressure.

[0172] That is,

[0173] An optimization algorithm can be used to select a point in the pressure equalization period where the difference between the absolute values ​​of ΔVd and ΔVr is minimized over the entire equalization period (or falls below a desired threshold). (In an adiabatic process, this difference should ideally be zero, as shown in Equation 5. In Figure 43, the point in time where the difference between the absolute values ​​of ΔVd and ΔVr is minimized occurs at the 50ms line labeled "Point in time when final pressure is determined.") First, pressure data can be collected from the control chamber and reference chamber at multiple points j=1 over n between the opening of valve X2 and final pressure equalization. Since the fixed volume Vri of the reference chamber system before pressure equalization is known, the following values ​​for Vrj (volume of the reference chamber system at sampling point j after valve X2 is opened) can be calculated using Equation 3 at each sampling point Prj along the equalization curve. For each of the above values ​​of Vrj, the value of ΔVd can be calculated using Equations 5 and 7, thereby giving each value of Vrj Vdij, an estimate of Vdi, and the volume of the control chamber system before pressure equalization. Using each value of Vrj and the corresponding value of Vdij, and using equations 3 and 4, the difference in the absolute values ​​of ΔVd and ΔVr can be calculated at each pressure measurement point along the equalization curve. The sum of the squares of these differences is a measure of the error in the calculated value of Vdi during pressure equalization for each value of Vrj and the corresponding Vdij. If Prf is the reference chamber pressure that yields the minimum sum of the squared differences of |ΔVd| and |ΔVr|, and Vrf is the volume of the reference chamber in question, then the data points Prf and Pdf corresponding to Vrf can then be used to calculate the optimal estimate of Vdi, which is the initial volume of the control chamber system.

[0174] One method for determining the location on the equalization curve that captures the optimal values ​​for Pdf and Prf is described below. 1) Obtain a series of pressure datasets from the control chamber and reference chamber, starting just before valve X2 opens and ending when Pr and Pd are nearly equal. If Pri is the captured first reference chamber pressure, the next sampling points in Figure 32 are denoted as Prj = Pr1, Pr2, ..., Prn.

[0175] 2) Using Equation 6, for each Prj after Pri, calculate the corresponding ΔVrj where j is the j-th pressure data point after Pri. ΔVrj=Vrj-Vri=Vri(-1+(Prj / Pri) -(1 / γ) 3) For each of the above ΔVrj, calculate the corresponding Vdij using Equation 7. For example,

[0176]

number

[0177] 4) Using Equation 7, calculate all ΔVdj and k for each of Vdi1 to Vdin using the control chamber pressure measurement Pd between time points k=1 to n. For VDIs compatible with Pr1,

[0178]

number

[0179]

number

[0180] 7) The above procedure can be applied whenever it is desired to estimate the control chamber volume, but preferably at the end of each injection and each delivery stroke. The difference between the optimized Vdi at the end of the injection stroke and the optimized Vdi at the end of the corresponding delivery stroke can be used to estimate the volume of liquid delivered by the pump.

[0181] Air detection Another aspect of the present invention includes determining the presence of air in the pump chamber 181 and, if present, determining the volume of that air. Such determination may be important, for example, to ensure proper execution of the preparation sequence for removing air from the cassette 24 and / or to ensure that air is not delivered to the patient. In certain embodiments, for example, when delivering fluid to the patient through the lower opening 187 at the bottom of the pump chamber 181, air or other gases trapped in the pump chamber tend to remain in the pump chamber 181, and the delivery of such air or other gases to the patient is inhibited unless the volume of the gas is greater than the volume of the effective dead space of the pump chamber 181. As described later, air or other gases contained in the pump chamber 181 can be determined according to aspects of the present invention, and the gas can be cleared from the pump chamber 181 before the volume of the gas exceeds the volume of the effective dead space of the pump chamber 181.

[0182] The determination of the amount of air in the pump chamber 181 can be performed at the end of the injection process, and thus can be carried out without interfering with the delivery process. For example, at the end of the injection process, when the membrane 15 and the pump control area 1482 are pulled away from the cassette 24 so that they come into contact with the wall of the control chamber 171, the reference chamber can be vented to atmospheric pressure by closing valve X2 and opening valve X3, for example. Subsequently, valves X1 and X3 can be closed to fix the imaginary "piston" to valve X2. Then, valve X2 can be opened to equalize the pressure in the control chamber and the reference chamber when performing the pressure measurement to determine the volume of the control chamber, as described above.

[0183] If no bubbles are present in the pump chamber 181, the volume change of the reference chamber due to an imaginary "piston" movement, determined using the known initial volume of the reference chamber system and the initial pressure in the reference chamber, will be equal to the volume change of the control chamber, determined using the known initial volume of the control chamber system and the initial pressure in the control chamber (the initial volume of the control chamber is known when the membrane 15 / control region 1482 is in contact with the wall of the control chamber or with the spacer element 50 of the pump chamber 181). However, if air is present in the pump chamber 181, the volume change of the control chamber will actually be distributed between the control chamber volume and the bubbles in the pump chamber 181. As a result, the volume change of the control chamber calculated using the known initial volume of the control chamber system will not be equal to the calculated volume change of the reference chamber, suggesting the presence of air in the pump chamber.

[0184] If air is present in the pump chamber 181, the initial volume Vdi of the control chamber system is actually equal to the sum of the volumes of the control chamber and lines L0 and L1 (referred to as Vdfix) and the initial volume of the air bubbles in the pump chamber 181 (referred to as Vbi), as shown in Equation 9.

[0185] Vdi = Vbi + Vdfix (9) With the membrane 15 / control region 1482 pressed against the wall of the control chamber at the end of the fluid injection process, the volume of the air space within the control chamber and the volumes of lines L0 and L1—collectively Vdfix—can be determined with considerable accuracy, for example, due to the presence of grooves or other features in the control chamber wall (similarly, with the membrane 15 / control region 1482 pressed against the spacer element 50 of the pump chamber 181, the volume of the control chamber and the volumes of lines L0 and L1 can also be determined with considerable accuracy). After the fluid injection process, the volume of the control chamber system is tested using a positive control chamber precharge. Any discrepancy between this test volume and the test volume at the end of the fluid injection process indicates the presence of a certain volume of air within the pump chamber. Substituting Equation 9 into Equation 7, the volume change of the control chamber ΔVd can be determined by the following equation.

[0186] ΔVd=(Vbi+Vdfix)(-1+(Pdf / Pdi) -(1 / γ) ) (10) ΔVr can be calculated from Equation 6, and since it is known from Equation 5 that ΔVr = (-1)ΔVd, Equation 10 is, (-1)ΔVr=(Vbi+Vdfix)(-1+(Pdf / Pdi) -(1 / γ) ) (11) It can be rewritten as follows: Vbi = (-1)ΔVr / (-1 + (Pdf / Pdi)) -(1 / γ) ) (12) And it can be rewritten again.

[0187] Therefore, the cycler 14 can determine whether or not air is present in the pump chamber 181 and estimate the volume of the bubbles using equation 12. This calculation of the bubble volume can be performed, for example, when it is found that the absolute values ​​of ΔVr (determined from equation 6) and ΔVd (determined from equation 7 using Vdi = Vdfix) are not equal to each other. That is, if there are no bubbles in the pump chamber 181, Vdi should be equal to Vdfix, so the absolute value of ΔVd given by equation 7 using Vdfix instead of Vdi will be equal to ΔVr.

[0188] If air is detected after the injection process is complete using the method described above, it may be difficult to determine whether the air is on the pump chamber side or on the control side of the membrane 15. Bubbles may be present in the pumped liquid, or air may remain on the control (air pressure) side of the pump membrane 15 due to conditions during pumping and incomplete injection of the pump chamber that caused an incomplete pumping stroke (e.g., a shutoff). At this point, an adiabatic FMS measurement can be performed using a negative pump chamber precharge. If this FMS volume matches the FMS volume with a positive precharge, the membrane can move freely in both directions, which suggests that the pump chamber is only partially injected (possibly due to a shutoff). If the value of the negative pump chamber precharge FMS volume is equal to the nominal control chamber air volume when the membrane 15 / region 1482 is in contact with the control chamber wall, it can be concluded that there are bubbles in the liquid on the pump chamber side of the flexible membrane.

[0189] Head height detection In some situations, it may be useful to determine the patient's height relative to the cassette 24 or other parts of the system. For example, in some situations, a dialysis patient may feel a "pull" or other movement caused by the fluid flowing in and out of the patient's peritoneal cavity during infusion or drainage operations. To reduce this sensation, the cycler 14 can reduce the pressure applied to the patient line 34 during infusion and / or drainage operations. However, to properly set the pressure in the patient line 34, the cycler 14 can determine the patient's height relative to the cycler 14, the heating bag 22, the drain port of the system, or other parts. For example, when performing an infusion operation, if the patient's peritoneal cavity is located 5 feet (approximately 1.5 m) above the heating bag 22 or cassette 24, the cycler 14 needs to use a higher pressure in the patient line 34 delivering the dialysate than if the patient's peritoneal cavity were located 5 feet (approximately 1.5 m) below the cycler 14. The pressure can be adjusted by alternately opening and closing a binary pressure source valve at variable time intervals to achieve the desired target pump chamber pressure. The average desired target pressure can be maintained, for example, by adjusting the time interval so that the valve is open when the pump chamber pressure is a specific amount lower than the target pressure, and closed when the pump chamber pressure is a specific amount higher than the target pressure. Adjustments to maintain the delivery of the full stroke volume can be performed by adjusting the number of times the pump chamber is injected and / or delivered. When a variable-opening source valve is used, the target pump chamber pressure can be achieved by varying the opening of the source valve in addition to the timing of the intervals in which the valve is opened and closed. To adjust the patient position, the cycler 14 can momentarily stop pumping fluid to open the patient line 34 to one or more pump chambers 181 in the cassette (for example, by opening the appropriate valve port in the cassette 24). However, other fluid lines, such as the upper valve port 192 for the pump chamber 181, can be closed. In this situation, the pressure in the control chamber of one of the pumps can be measured.As is known in the art, this pressure correlates with the patient's "head" height and can be utilized by the cycler 14 to control the pressure at which the fluid is delivered to the patient. If the head height (usually known) of the heating bag 22 and / or solution container 20 affects the pressure required to properly pump the fluid, a similar method can be used to determine the head height of these components.

[0190] Cycler's noise reduction features In aspects of the present invention, the cycler 14 may include one or more features that reduce the noise generated by the cycler 14 during operation and / or idling. According to one aspect of the present invention, the cycler 14 may include a single pump that generates both pressure and vacuum used to control the various pneumatic systems of the cycler 14. In one embodiment, the pump can generate both pressure and vacuum simultaneously, thereby reducing the overall run time and allowing the pump to operate at a lower speed (and thus more quietly). In another embodiment, the starting and / or stopping of the air pump can be gradient, for example, by gradually increasing the pump speed or power output when starting and / or gradually decreasing the pump speed or power output when cutting off. This configuration can help reduce the "on / off" noise associated with starting and stopping the air pump, so the pump noise is not very noticeable. In another embodiment, as it approaches a target output pressure or volumetric flow velocity, the air pump may be operated on a lower duty cycle so that, as opposed to cutting off, the air pump continues to operate and is eventually turned on after a short time. As a result, the disruption caused by the repeated on-off cycles of the air pump can be avoided.

[0191] Figure 44 is a perspective view of the inner portion of the cycler 14 with the upper part of the housing 82 removed. In the illustrated embodiment, the cycler 14 includes a separate air pump 83, which includes an actual pump and motor drive unit housed in a soundproof enclosure. The soundproof enclosure includes an exterior, such as a metal or plastic frame, and soundproofing material that at least partially surrounds the motor and pump within the exterior. The air pump 83 can simultaneously supply pneumatic and vacuum to, for example, a pair of accumulator tanks 84. One tank 84 stores positively pressurized air, and the other tank stores vacuum. Appropriate manifold and valve structures can be connected to the tanks 84 to supply and control the pneumatic / vacuum supplied to the components of the cycler 14.

[0192] According to another aspect of the present invention, components such as occluders that require a relatively constant supply of pressure or vacuum during cycler operation can be isolated from the air pressure / vacuum source for at least a relatively long period of time. For example, an occluder 147 in a cycler 14 typically requires a constant air pressure within the occluder air bag 166 so that the patient lines and drainage lines remain open for flow. Assuming the cycler 14 continues to operate properly without power outages, the air bag 166 can be inflated once at the start of system operation and maintain its inflation until cut. The inventors have recognized that, under certain circumstances, relatively static pneumatic devices such as the air bag 166 may "creak" or otherwise emit noise in response to slight fluctuations in the supplied air pressure. Such fluctuations may cause the air bag 166 to change size slightly, thereby potentially causing the associated mechanical parts to move and generate noise. In one embodiment, the air bag 166 and other components having similar pneumatic requirements can be isolated from the air pump 83 and / or tank 84, for example by closing a valve, to reduce pressure fluctuations within the air bag or other pneumatic components and to reduce any noise that may result from these pressure fluctuations. Another component that can be isolated from the pneumatic supply source is the air bag of the door 141 of the cassette mounting section 145, which inflates to press the cassette 24 against the control surface 148 when the door 141 is closed. Other suitable components can also be isolated as desired.

[0193] According to another aspect of the present invention, the speed and / or force used to start a pneumatic component can be controlled to reduce noise generated by the operation of the component. For example, moving the valve control area 1481 to open or close a valve port on the cassette 24, thereby moving the corresponding portion of the cassette membrane 15, may produce a "popping" sound as the membrane 15 strikes the cassette 24 and / or is pulled away from the cassette 24. Such noise can be reduced by controlling the operating speed of the valve control area 1481, for example, by limiting the airflow velocity used to move the control area 1481. The airflow can be limited, for example, by providing a suitable small opening in a line or other path leading to the associated control chamber.

[0194] The controller can also be programmed to apply pulse width modulation ("PWM") to the starting of one or more pneumatic source valves in the cycler 14's manifold. The pneumatic pressure delivered to the various valves and pumps in the cassette 24 can be controlled by repeatedly opening and closing the associated manifold source valves during the starting period of the valves or pumps in the cassette 24. The rate at which the pressure rises or falls against the membrane 15 / control surface 148 can then be controlled by adjusting the duration of the "on" portion of a particular manifold valve during the starting period. A further advantage of applying PWM to the manifold source valves is that variable pneumatic pressure can be delivered to the components of the cassette 24 using binary (on-off) source valves instead of using more expensive and less reliable variable-open source valves.

[0195] According to another aspect of the present invention, the movement of one or more valve elements can be adequately suppressed to reduce noise generated by the valve cycle. For example, a fluid (e.g., a ferromagnetic fluid) can be provided with valve elements of a high-frequency solenoid valve to suppress element movement and / or reduce noise generated by the movement of the valve elements between open and closed positions.

[0196] According to another embodiment, pneumatic control line vents can be connected together and / or directed to a common sound-insulating space to reduce noise associated with the release of air pressure or vacuum. For example, if the occluder air bag 166 is vented so as to block one or more lines by moving spring plates 165 toward each other, the released air pressure is released to a sound-insulating enclosure, as opposed to being released into a space where noise associated with the release is more easily heard. In another embodiment, lines arranged to release air pressure can be connected together with lines arranged to release vacuum. In connection with this (which may include vents to the atmosphere, accumulators, or others), noise generated by the release of pressure / vacuum can be further reduced.

[0197] control system The control system 16, described in relation to Figure 1, has various functions such as controlling dialysis treatment and communicating information related to dialysis treatment. These functions are performed by a single computer or processor, but it is sometimes desirable to use different computers for different functions so that the implementation of these functions is physically and conceptually separated. For example, it may be desirable to use one computer for controlling the dialyzer and another computer for controlling the user interface.

[0198] Figure 45 is a block diagram showing a specific example of the control system 16, which comprises a computer that controls the dialyzer ("automatic computer" 300) and another computer that controls the user interface ("user interface computer" 302). As will be described later, since system functions where safety is of utmost importance can only be executed by the automatic computer 300, the user interface computer 302 is isolated from the execution of these functions.

[0199] The automated computer 300 controls the hardware, such as valves, heaters, and pumps, that perform dialysis treatment. The automated computer 300 also sequences the treatment and maintains a "model" of the user interface, as further described in this document. As illustrated, the automated computer 300 comprises a computer processing unit (CPU) / memory 304, a flash disk file system 306, a network interface 308, and a hardware interface 310. The hardware interface 310 is connected to a sensor / actuator 312. This connection allows the automated computer 300 to read sensors and control the hardware actuators of the APD system to monitor and execute treatment operations. The network interface 308 provides an interface to connect the automated computer 300 to the user interface computer 302.

[0200] The user interface computer 302 controls components that enable data exchange with the outside world, including the user and external devices and entities. The user interface computer 302 comprises a computer processing unit (CPU) / memory 314, a flash disk file system 316, and a network interface 318, each of which can be identical or similar to its counterpart in the automated computer 300. The Linux operating system can run on both the automated computer 300 and the user interface computer 302. An exemplary processor suitable for use as the CPU of the automated computer 300 and / or the CPU of the user interface computer 302 is Freescale's PowerPC5200B®.

[0201] The user interface computer 302 can be connected to the automated computer 300 via the network interface 318. Both the automated computer 300 and the user interface computer 302 can be housed within the same chassis of the APD system. Alternatively, one or both computers, or a part of them (e.g., the display 324), can be located outside the chassis. The automated computer 300 and the user interface computer 302 can be connected by a wide area network, a local area network, a bus structure, a wireless connection, and / or other data transfer media.

[0202] The network interface 318 can also be used to connect the user interface computer 302 to the Internet 320 and / or other networks. Such a network connection can be used, for example, to initiate a connection with a hospital or doctor, upload treatment data to a remote database server, obtain new prescriptions from doctors, upgrade application software, obtain service support, request supplies, and / or export maintenance data. For example, a call center technician can remotely access alarm logs and machine configuration information over the Internet 320 via the network interface 318. If desired, the user interface computer 302 can be configured so that the connection can be initiated by the user or by the system locally in other ways, rather than by a remote initiation program.

[0203] The user interface computer 302 also includes a graphics interface 322 connected to a user interface, such as the user interface 144 described in relation to Figure 10. In one specific example, the user interface includes a liquid crystal display (LCD) and a display 324 associated with a touchscreen. For example, the touchscreen is mounted on the LCD so that the user can input into the user interface computer 302 by touching the display with their finger or stylus. The display can be associated with a voice system that can play back voice prompts and recorded speech. The user can adjust the brightness of the display 324 based on the environment and their preferences. Optionally, the APD system includes a light sensor, and the brightness of the display can be automatically adjusted according to the ambient light detected by the light sensor.

[0204] Furthermore, the user interface computer 302 is equipped with a USB interface 326. A data storage device 328, such as a USB flash drive, can be selectively connected to the user interface computer 302 via the USB interface 326. The data storage device 328 may be equipped with a “patient data key” used to store patient-specific data. Data from dialysis treatment and / or survey questions (e.g., weight, blood pressure) are recorded in the patient data key. In this way, patient data can be accessed by the user interface computer 302 when connected to the USB interface 326 and portable when disconnected from the interface. The patient data key can be used to transfer data from one system or cycler to another during cycler changes, to transfer new treatment and cycler configuration data from clinical software to the system, and to transfer treatment history and device history information from the system to the clinical software. An exemplary patient data key 325 is shown in Figure 65.

[0205] As illustrated, the patient data key 325 comprises a connector 327 and a housing 329 connected to the connector. The patient data key 325 can optionally be associated with a dedicated USB port 331. The port 331 comprises a recess 333 (for example, within the chassis of the APD system) and a connector 335 located within this recess. The recess can be at least partially defined by the housing 337 associated with the port 331. The patient data key connector 327 and the port connector 335 can be adapted to be selectively connected to each other electrically and mechanically. As can be seen from Figure 65, the patient data key connector 327 and the port connector 335 are connected, and the housing 329 of the patient data storage device 325 is at least partially housed within the recess 333.

[0206] The housing 329 of the patient data key 325 may have a visible cue indicating the port to which it is associated, and / or be shaped to avoid incorrect insertion. For example, the recess 333 and / or housing 337 of port 331 may have a shape corresponding to the shape of the housing 329 of the patient data key 325. For example, each may have a non-rectangular or other irregular shape, such as an elliptical shape with an upper recess as shown in Figure 65. The recess 333 and / or housing 337 of port 331 and the housing 329 of the patient data key 325 may include further visible cues indicating their association. For example, each may be formed of the same material and / or have the same or similar color and / or pattern.

[0207] Alternatively, the patient data key 325 may include a verification code readable by the APD system to verify that the patient data key is of the expected type and / or origin. Such a verification code can be stored in the memory of the patient data key 325, read from the patient data key, and processed by the processor of the APD system. Alternatively, such a verification code may be included outside the patient data key 325, for example, as a barcode or numeric code. In this case, it can be read by a camera and associated processor, a barcode scanner, or another code reader.

[0208] If a patient data key is not inserted while the system is powered on, a warning prompting the insertion of the key can be generated. However, the system may operate without a patient data key, provided it has been previously configured. Therefore, a patient who has lost their patient data key can continue treatment until they obtain a replacement key. Data can be stored directly in the patient data key, or it can be stored in the user interface computer 302 and then transferred to the patient data key. Data can also be transferred from the patient data key to the user interface computer 302.

[0209] Furthermore, to enable data exchange with nearby Bluetooth-enabled devices, for example, the USB Bluetooth adapter 330 can be connected to the user interface computer 302 via the USB interface 326. For example, a nearby Bluetooth-enabled scale can wirelessly transmit patient weight information to the system via the USB interface 326 using the USB Bluetooth adapter 330. Similarly, a Bluetooth-enabled blood pressure cuff can wirelessly transmit patient blood pressure information to the system using the USB Bluetooth adapter 330. The Bluetooth adapter may be built into the user interface computer 302 or it may be an external device (e.g., a Bluetooth dongle).

[0210] The USB interface 326 can have several ports, which can be located in various physical positions and used for various USB devices. For example, it is desirable to have a USB port for patient data keys accessible from the front of the machine, while having another USB port accessible from the back of the machine. A USB port for Bluetooth connectivity can be included on the outside of the chassis, or instead, it can be located, for example, inside the machine or in the battery door.

[0211] As mentioned above, functions that may have implications that require a high degree of safety can be isolated on the automated computer. Information that requires a high degree of safety is related to the operation of the APD system. For example, information that requires a high degree of safety may include the status of the APD procedure and / or algorithms that perform or monitor treatment. Information that requires a high degree of safety may include information about the visual display of a screen display that is not important to the operation of the APD system.

[0212] By isolating functions that may have safety-critical implications on the automated computer 300, the user interface computer 302 can reduce the burden of handling safety-critical operations. Therefore, problems with or changes to software running on the user interface computer 302 will not affect the delivery of patient treatment. Consider the example of graphics libraries (e.g., Trolltech's Qt® toolkit) that are available to the user interface computer 302 to reduce the time required to develop user interface views. Since these libraries are processed by a separate process and processor from the automated computer 300, the automated computer is protected from defects in the libraries that could affect the rest of the system (including safety-critical functions) if they were processed by the same processor or process.

[0213] Naturally, while the user interface computer 302 is involved in displaying the interface to the user, the user can also input data using the user interface computer 302, for example, via the display 324. To maintain isolation between the functions of the automated computer 300 and the user interface computer 302, data received via the display 324 can be sent to the automated computer for interpretation and then returned to the user interface computer for display.

[0214] Figure 45 shows two separate computers, but the separation of the storage and / or execution of functions where security is paramount from the storage device, and / or the storage and / or execution of functions other than those where security is paramount, can be provided by having a single computer containing separate processors such as CPU / memory components 304 and 314. Therefore, it should be recognized that it is not necessary to have separate processors or “computers.” Furthermore, a single processor can be used to perform the functions described above. In this case, it may be desirable to functionally isolate the execution and / or storage of software components that control the dialyzer from the execution and / or storage of software components that control the user interface, but the present invention is not limited thereto.

[0215] Other aspects of the system architecture can also be designed to address safety concerns. For example, the automatic computer 300 and the user interface computer 302 may include a “safety line” that can enable or disable the CPU on each computer. The safety line can be connected to a voltage source that generates a voltage (e.g., 12V) sufficient to enable at least some of the sensors / actuators 312 of the APD system. When both the CPU of the automatic computer 300 and the CPU of the user interface computer 302 send enable signals to the safety line, the voltage generated by the voltage source is sent to the sensors / actuators, enabling and disabling the components. The voltage can, for example, activate pneumatic valves and pumps, disabling occluders, and activating heaters. If either CPU stops sending enable signals to the safety line, the voltage path can be interrupted (e.g., by a mechanical relay) to deactivate the pneumatic valves and pumps, enable occluders, and deactivate heaters. Thus, if either the automated computer 300 or the user interface computer 302 deems it necessary, the patient can be quickly isolated from the fluid pathway, and other activities such as heating and pumping can also be stopped. Each CPU can disable the safety line at any time if an error requiring the highest level of safety is detected, or when a software watchdog detects an error. The system can be configured so that once disabled, the safety line will not be made operational again until both the automated computer 300 and the user interface computer 302 have completed self-tests.

[0216] Figure 46 is a block diagram of the software subsystems of the user interface computer 302 and the automated computer 300. In this example, a “subsystem” is a collection of software, and possibly hardware, assigned to a specific set of related system functions. A “process” may be an independent executable file that operates in its own virtual address space and sends data to other processes using inter-process communication equipment.

[0217] The executive subsystem 332 includes software and scripts used to stock, authenticate, start, and monitor the execution of software running on the CPUs of the automated computer 300 and the user interface computer 302. Custom executive processes run on each of the aforementioned CPUs. Each executive process runs its own software on its own processor and monitors executives on other processors.

[0218] The user interface (UI) subsystem 334 handles system interactions between the user and the hospital. The UI subsystem 334 is implemented using a "model-view-controller" design pattern, separating data display ("view") from the data itself ("model"). Specifically, system state and data modification functions ("model") and cycler control functions ("controller") are handled by the UI model and cycler controller 336 on the automated computer 300, while the "view" portion of the subsystem is handled by the UI screen view 338 on the UI computer 302. Data display and export functions, such as log viewing and remote access, can be handled entirely by the UI screen view 338. The UI screen view 338 monitors and controls further applications, such as applications providing log viewing and physician interfaces. These applications are created within windows controlled by the UI screen view 338, allowing control to be returned to the UI screen view 338 in case of warnings, alarms, or errors.

[0219] The treatment subsystem 340 directs the delivery of dialysis treatment and specifies the time. The system is responsible for confirming the prescription, calculating the number and duration of treatment cycles based on the prescription, time, and available fluid, controlling the treatment cycles, tracking the fluid in the heating bag, tracking the fluid in the supply bag, tracking the amount of fluid in the patient, tracking the amount removed from the patient by ultrafiltration, and detecting warning or alarm conditions.

[0220] The mechanical control subsystem 342 controls the equipment used to perform dialysis treatment and adjusts high-level pumping and control functions as required by the treatment subsystem 340. Specifically, the mechanical control subsystem 342 can perform the following control functions: air compressor control, heater control, fluid delivery control (pumping), and fluid volume measurement. Furthermore, the mechanical control subsystem 342 sends sensor readings as signals via the I / O subsystem 344, which will be described later.

[0221] The I / O subsystem 344 of the automated computer 300 controls access to sensors and actuators used to control treatment. In this specific example, the I / O subsystem 344 is the only application process that has direct access to the hardware. Therefore, the I / O subsystem 344 issues interfaces that allow other processes to obtain the state of hardware inputs and set the state of hardware outputs.

[0222] The database subsystem 346 stores all data in a database used for implementing and storing machine, patient, prescription, user input, and treatment history information on the user interface computer 302, and retrieves all data from the database. This provides a common access point when the above information is needed by the system. The interface provided by the database subsystem 346 is used by several processes for data storage needs. The database subsystem 346 also manages the preservation and backup of the database files.

[0223] The UI screen view 338 can call a treatment log inquiry application to scan the treatment history database. Alternatively, using this application, which can be implemented as multiple applications, the user can graphically review their treatment history, prescriptions, and / or machine status information. The application sends database queries to the database subsystem 346. The application can run without interfering with the safe operation of the machine while the patient is undergoing dialysis.

[0224] A remote access application, which can run as a single application or multiple applications, provides the ability to export therapeutic and machine diagnostic data for analysis and / or display on a remote system. A therapeutic log query application can be used to retrieve requested information, and the data can be reformatted to a machine-neutral format such as XML for transport. The formatted data can be transported offboard via memory storage, a direct network connection, or other external interface 348. A network connection can be initiated by the APD system upon user request.

[0225] When treatment is not in progress, the service interface 356 can be selected by the user. The service interface 356 may include one or more special applications that record test results and optionally generate test reports that can be uploaded to, for example, a diagnostic center. The media player 358 can play, for example, audio and / or video presented to the user.

[0226] To illustrate with one specific example, the aforementioned database is implemented using SQLite, a software library that realizes an independent language, serverless, zero-configuration transactional DQL database engine.

[0227] The executive subsystem 332 implements two executive modules: the User Interface Computer (UIC) executive 352 on the User Interface Computer 302 and the Automated Computer (AC) executive 354 on the Automated Computer 300. Each executive is started by a startup script that runs after the operating system has started and contains a list of processes to start. As each executive traverses its process list, each process image is checked to ensure file system consistency before the process starts. The executive monitors its associated child processes to ensure they start as expected and continues to monitor the child processes while running, for example using Linux parent-child process notifications. If a child process terminates or fails, the executive either restarts the child process (as in the UI view) or puts the system into double-safe mode to ensure the machine operates safely. The executive process is responsible for ensuring the operating system shuts down when the machine is powered off.

[0228] The executive processes can communicate with each other to coordinate the startup and shutdown of various application components. Status information is regularly shared between the two executives to support a watchdog function between processors. Executive subsystem 332 is responsible for enabling or disabling safety lines. When both UIC executive 352 and AC executive 354 enable a safety line, the pumps, heaters, and valves can operate. Before enabling a line, the executives individually test each line to ensure proper operation. Each executive also monitors the status of other safety lines.

[0229] The UIC Executive 352 and the AC Executive 354 cooperate to synchronize the time between the user interface computer 302 and the automated computer 300. The time base is configured via a battery-powered real-time clock on the user interface computer 302 that is accessed at startup. The user interface computer 302 initializes the CPU of the automated computer 300 with respect to the real-time clock. Thereafter, the operating systems of each computer maintain their internal time. The executives cooperate to ensure sufficient time management by periodically performing a power-on self-test. A warning can be issued if the discrepancy between the automated computer time and the user interface computer time exceeds a given threshold.

[0230] FIG. 47 shows the information flow between the various subsystems and processes of the APD system. As described above, the UI Model 360 and the cycler controller 362 operate on the automated computer. The user interface design separates the screen display controlled by the UI View 338 from the screen-to-screen flow controlled by the cycler controller 362 and the displayable data items controlled by the UI Model 360. This allows the visual display of the screen to be changed without affecting the running therapy software. All therapy values and content are stored in the UI Model 360 to isolate the UI View 338 from the therapy functions that should be safety-critical.

[0231] The UI model 360 aggregates information describing the current state of the system and the patient and holds information that can be stored via the user interface. The UI model 360 can update states that are not currently visible or otherwise recognizable to the operator. When the user moves to a new screen, the UI model 360 provides information about the new screen and its content to the UI view 338. The UI model 36 exposes an interface on the display through which the UI view 338 or other processes can query the current user interface screen and its content. Thus, the UI model 360 provides a common point through which interfaces such as a remote user interface or online assistance can obtain the current operating status of the system.

[0232] The cycler controller 362 processes changes in the state of the system based on operator input, time, and treatment layer state. Permissible changes are reflected in the UI model 360. The cycler controller 362 is implemented as a hierarchical state machine that coordinates treatment layer commands, treatment status, user requests, and time events and provides view screen control through updates to the UI model 360. The cycler controller 362 also examines user input. If the user input is permitted, new values regarding the user input are reflected again in the UI view 338 via the UI model 360. The treatment process 368 serves as a server to the cycler controller 362. Treatment commands from the cycler controller 362 are received by the treatment process 368.

[0233] The UI view 338, operating on the UI computer 302, controls the user interface screen display and responds to user input from the touchscreen. The UI view 338 tracks local screen states but does not maintain machine state information. Machine states and displayed data values ​​are obtained from the UI model 360 unless they are being modified by the user. When the UI view 338 is terminated and restarted, it displays a base screen with current data and information about the current state. The UI view 338 determines which class of screen to display from the UI model 360, which delegates screen display to the UI view. The aspects of user interface AU safety that require the highest priority are handled by the UI model 360 and the cycler controller 362.

[0234] The UI view 338 houses and runs other applications 364 on the user interface computer 302. These applications can perform non-treatment control tasks. Exemplary applications include a log viewer, a service interface, and a remote access application. The UI view 338 places these applications within a window controlled by the UI view, which allows the UI view to display status, error, and warning screens as appropriate. Certain applications can be run during active treatment. For example, the log viewer can be run during active treatment, but the service interface and remote access applications cannot. When an application derived from the UI view 338 is running and the user needs to focus their attention on the ongoing treatment, the UI view 338 can abort the application and regain control of the screen and input functions. The aborted application can be resumed or terminated by the UI view 338.

[0235] Figure 48 illustrates the operation of the therapeutic subsystem 340, as described in relation to Figure 46. The functions of the therapeutic subsystem 340 are divided into three processes: therapeutic control, therapeutic calculation, and solution management. This allows for functional decomposition, simplified testing, and simplified updates.

[0236] The treatment control module 370 utilizes the services of the treatment calculation module 372, the solution management module 374, and the machine control subsystem 342 (Figure 46) to complete its tasks. The responsibilities of the treatment control module 370 include tracking the liquid volume in the heating bag, tracking the liquid volume in the patient, tracking patient drainage volume and ultrafiltration, tracking and recording cycle volume, tracking and recording treatment volume, coordinating and executing dialysis treatment (drainage-infusion-retention), and controlling treatment setup operations. The treatment control module 370 executes each stage of treatment as directed by the treatment calculation module 370.

[0237] The treatment control module 370 tracks and recalculates the drain-infusion-retention cycle of peritoneal dialysis treatment. Using the patient's prescription, the treatment calculation module 372 calculates the number of cycles, retention time, and required volume of solution (total treatment volume). As treatment progresses, a subset of these values ​​is recalculated to reveal the actual elapsed time. The treatment calculation module 372 tracks the treatment sequence and passes treatment stages and parameters to the treatment control module 370 as needed.

[0238] The solution management module 374 maps the placement of solution supply bags, tracks the volume in each supply bag, commands the mixing of solutions based on prescriptions in the solution database, commands the transfer of the requested volume of mixed or unmixed solution to a heated bag, and tracks the available volume of mixed solution using the solution prescription and available bag volume.

[0239] Figure 49 is a sequence diagram illustrating the exemplary interaction between the treatment module process described above and the dialysis unit of the treatment during the initial fluid replacement. During the exemplary initial fluid replacement process 376, the treatment control module 370 retrieves the solution ID and the volume of the initial infusion from the treatment calculation module 372. The solution ID is passed to the solution management module 374 along with a request to inject the solution into the heating bag in preparation for providing the patient line and the initial patient infusion. The solution management module 374 requests the mechanical control subsystem 342 to begin pumping the solution into the heating bag.

[0240] During the illustrated dialysis process 378, the treatment control module 370 executes one cycle at a time (initial drainage, infusion, retention-replenishment, and drainage), and orders these cycles under the control of the treatment calculation module 372. During treatment, the treatment calculation module 372 is updated in accordance with the actual cycle timing so that the remaining treatment can be recalculated as needed.

[0241] In this example, the treatment calculation module 372 identifies the stage as "initial drainage," and the treatment control module requests this from the machine control subsystem 342. The next stage identified by the treatment calculation module 372 is "fluid infusion." This instruction is sent to the machine control subsystem 342. The treatment calculation module 372 is called again by the treatment control module 370, which requests that fluid be replenished in the heating bag during the "storage" stage. The solution management module 374 is called by the treatment control module 370, which then calls the machine control subsystem 342 to replenish the heating bag. To proceed to the next stage, the treatment control module 370 calls the treatment calculation module 372, and the process continues. This is repeated until there are no further stages and the treatment is complete.

[0242] Warning alarm function Situations or events in the APD system can trigger warnings and / or alarms that are recorded, displayed to the user, or both. These warnings and alarms are user interface constructs within the user interface subsystem and can be triggered by situations occurring in any part of the system. These situations can be categorized into three categories: (1) system error situations, (2) treatment situations, and (3) system operation situations.

[0243] "System error conditions" refer to errors detected in the software, memory, or other aspects of the APD system's processor. These errors may raise doubts about the system's reliability and may be considered "irreparable." System error conditions trigger alarms that are displayed to the user or otherwise notified. Alarms may also be recorded. If the integrity of the system cannot be guaranteed in an instance of a system error condition, the system may enter a double safety mode in which the safety lines described in this document are disabled.

[0244] Each subsystem, as described in relation to Figure 46, is responsible for detecting system errors within its own set. System errors between subsystems are monitored by the user interface computer executive 352 and the automated computer executive 354. When a system error occurs in a process running on the user interface computer 302, the process reporting the system error terminates. If the UI screen view subsystem 338 terminates, the user interface computer executive 352 attempts to restart it, for example, up to three times. If restarting the UI screen view 338 fails and remediation is in progress, the user interface computer executive 352 puts the machine into dual safety mode.

[0245] If a system error originates from a process running on the automated computer 300, the process terminates. The automated computer executive 354 detects that the process has terminated and, if treatment is in progress, transitions to a safe state.

[0246] When a system error is reported, an attempt is made to log the error in a database, in addition to providing the user with, for example, visual and / or audible feedback. System error handling is enclosed in the executive subsystem 332 to ensure uniform handling of unrecoverable events. The executive processes of the UIC executive 352 and AC executive 354 monitor each other, ensuring that if one executive process fails during treatment, the other executive transitions the machine to a safe state.

[0247] A "treatment status" arises from a status or variable related to treatment outside acceptable boundaries. For example, a treatment status can be caused by an out-of-bounds sensor reading. These statuses are recorded after being associated with a warning or alarm. Alarms are generally critical events that require immediate action. Alarms can be prioritized based on their severity, for example, low, medium, and high. Warnings are not as critical as alarms and usually do not involve any associated risks other than treatment failure or discomfort. Warnings can be classified into one of three categories: message warnings, escalating warnings, and user warnings.

[0248] The responsibility for detecting treatment conditions that may generate alarms or warnings is shared between the UI model and the treatment subsystem. The UI model subsystem 360 (Figure 47) is responsible for detecting alarms and warnings before and after treatment. The treatment subsystem 340 (Figure 46) is responsible for detecting alarms and warnings during treatment.

[0249] The responsibility for handling warnings or alerts related to the treatment status is also shared between the UI model and the treatment subsystem. Before and after treatment, the UI model subsystem 360 is responsible for handling warnings or alert situations. During the treatment session, the treatment subsystem 340 is responsible for handling warnings or alert situations and notifying the UI model subsystem of the presence of such situations. The UI model subsystem 360 is responsible for incremental warnings and, in coordination with the UI view subsystem 338, for providing visual and / or audible feedback to the user when a warning or alert situation is detected.

[0250] "System operation status" does not have any associated warnings or alerts. These statuses are simply recorded to provide a record of system operation. There is no need to provide audio or visual feedback.

[0251] The countermeasures that can be taken in response to the aforementioned system error, treatment, or system operation status are executed by the subsystem (or layer) that detected the situation, and the subsystem transmits the status to a higher subsystem. The subsystem that detected the situation may record the situation and assume safety considerations related to that situation. These safety considerations may include any one or a combination of the following: stopping the treatment, engaging the occluder, clearing the status and timer as necessary, disabling the heater, terminating the entire treatment, deactivating the safety line and closing the occluder, disconnecting the heater, cutting off power to the valve, and preventing the cycler from performing treatment when the power cycle requests a restart. The UI subsystem 334 may play a role in situations that can be resolved automatically (i.e., non-latched situations) and user-recoverable situations that are latched and can only be resolved through interaction with the user.

[0252] Each situation can be defined to include specific information so that software can act according to the severity of the situation. This information can include a numerical identifier that can be used in combination with a lookup table defining priority, descriptive name of the error (i.e., situation name), subsystem that detected the situation, description of what status or error caused the situation, and a flag indicating whether the situation enables one or more of the above actions.

[0253] When multiple situations occur, the situations can be ranked by priority so that higher-priority situations are addressed first. This priority ranking can be based on whether the situation causes the suspension of treatment administration. If a situation that causes treatment suspension occurs, this situation has a high priority when relaying the status to the next higher-level subsystem. As described above, the subsystem that detects the situation processes the situation and sends status information to the above subsystem. Based on the received status information, the higher-level subsystem can cause different situations with different actions and associated different warnings / alerts. Each subsystem performs any additional actions associated with the new situation and sends status information to the above subsystem. According to one specific example, the UI subsystem only displays one warning / alert at a given time. In this case, the UI model sorts all the ongoing events by priority and displays the warning / alert associated with the highest-priority event.

[0254] Priorities can be assigned to warnings based on the severity of the possible damage and the occurrence of the damage. Table 1 below shows an example of how priorities are assigned in this way.

[0255] [Table 1] In the situations shown in Table 1, the occurrence of possible damage refers to the time when damage is occurring, not the time when damage is manifesting. Possible damage designated as "immediate" refers to damage that may progress within a timeframe that is usually insufficient to take the corrective measures outlined in the manual. Possible damage designated as "prompt" refers to damage that may progress within a timeframe that is usually sufficient to take the corrective measures outlined in the manual. Possible damage designated as "delayed" refers to damage that may progress within a longer, unspecified timeframe than in the case of "prompt" damage.

[0256] Figures 50–55 show examples of screen views related to warnings and alarms displayed on the touchscreen user interface. Figure 50 shows a first alarm screen including Figure 380 and text 382 instructing the user to close the transfer set. The screen includes a visible warning 384 and is also associated with an audible warning. The audible warning can be turned off by selecting the “Audio Off” option 386 on the touchscreen. The user closes the transfer set and selects the “Accept” option 388 on the touchscreen. Figure 51 shows a similar alarm screen instructing the user to close the transfer set. In this case, an indication 390 is provided that drainage has been paused, and an indication 392 is provided that an instruction has been given to select “Treatment Complete.”

[0257] As mentioned above, warnings typically have no associated risks other than treatment failure or discomfort. Therefore, warnings may or may not cause a temporary suspension of treatment. Warnings are either "auto-recoverable," meaning they disappear automatically when the event ceases, or "user-recoverable," requiring user interaction with the user interface to resolve the warning. To draw the user's attention to the warning, an audible warning prompt can be used, which may have a volume that can vary within certain limits. Information or instructions may also be displayed to the user. During a warning, the user interface's auto-dimming feature is disabled so that such information or instructions are visible to the user.

[0258] To reduce user confusion, warnings can be categorized into different types based on how important the warning is and how quickly user response is required. Three example types of warnings are "message warnings," "incremental warnings," and "user warnings." These warnings have different characteristics based on what information is presented to the user visually and how audible prompts are used.

[0259] "Message warnings" can be displayed at the top of the status screen and are used to provide information when user interaction is not required. Since no action is required to dismiss the warning, audible prompts are usually not used to avoid disturbing or potentially waking the patient. However, audible warnings may be provided optionally. Figure 52 shows an example of a message warning. Specifically, Figure 52 shows a low-temperature message warning 394 used to notify the user that the dialysate has fallen below the desired temperature range. In this case, the user does not need to take any action, but is notified that treatment will be delayed while the dialysate is heated. If the patient needs additional information, they can select the "View" option 396 on the touchscreen. As shown in Figure 53, this brings up additional information 398 regarding the warning on the screen. Message warnings can also be used when there is a low-flow event that the user is trying to correct. In this case, the message warning can remain displayed until the low-flow event is resolved and feedback is provided to the user on whether the user has resolved the problem.

[0260] A “gradual warning” is intended to prompt the user to take action in a non-disturbing manner. During a gradual warning, a visible prompt may be displayed on the touchscreen, and an audible prompt may be provided (for example, once). If the event that triggered the warning has not been resolved after a given time has elapsed, a stronger audible prompt may be provided. If the event that triggered the warning is not resolved after further time has elapsed, the warning is upgraded to a “user warning.” In one example of a user warning, the visible prompt is displayed until the warning is resolved and an audible prompt is provided that allows the user to mute it. The UI subsystem does not handle the transition from a gradual warning to a user warning. Rather, the subsystem that triggered the initial event triggers a new event that is associated with the user warning. Figure 54 shows a screen view displaying information about a gradual warning. The warning in this example includes a screen warning message 400 and prompts 402 and an audible prompt instructing the user to check whether the drain line is twisted or blocked and tightened. The audible prompt can be kept on until the user mutes it. Figure 55 shows a screen view that includes a “Sound Off” option 404, which can be selected to mute the audible prompt. This warning can be used directly or as part of an increasing warning scheme.

[0261] Each warning / alarm is identified by a warning / alarm code, which is a unique identifier for the warning / alarm; a warning / alarm name, which is the descriptive name of the warning / alarm; a warning / alarm type, which includes the type of warning or the level of the warning; an indication of whether an audible prompt is associated with the warning / alarm; an indication of whether the warning and associated events can be bypassed (or ignored) by the user; and an event code for the event that triggers the warning / alarm.

[0262] During an alarm, escalating warnings and user warnings, as well as event codes (which may differ from the warning or alarm codes as described above), can be displayed on the screen so that the user can call a service representative to read the codes as needed. Alternatively, if connected to a remote call center, a voice guidance system can be used so that the system can speak relevant information about the system configuration, status, and error codes. The system can connect to a remote call center via a network, telephone connection, or other means.

[0263] Examples of situations detected by the treatment subsystem are described below in relation to Figure 56. Important for air management, this situation occurs when the APD system is not positioned horizontally. More specifically, this situation occurs when the tilt sensor detects that the APD system is tilted beyond a predetermined threshold, such as 35 degrees, relative to the horizontal plane. As mentioned above, if the tilt sensor detects an absolute angle greater than the predetermined threshold, the treatment subsystem can generate a correctable user warning. To avoid unpleasant alarms, the user can be instructed to keep the APD system horizontal before starting treatment. The tilt threshold can be lowered during this pre-treatment period (e.g., 35 degrees). The user can also be given some feedback on whether the problem is being corrected.

[0264] If the tilt sensor detects a tilt angle exceeding a threshold during treatment, the machine subsystem 342 responds by stopping the pump, similar to when it detects air in the pump chamber. The treatment subsystem 340 inquires about the status and determines that the machine subsystem 342 has temporarily stopped pumping due to the tilt. The subsystem also receives status information regarding the machine's angle. At this point, the treatment subsystem 340 generates a tilt condition, pauses treatment, and sends a command to the machine subsystem 342 to pause pumping. This command initiates cleanup, such as measurements by the fluid measurement system (FMS) and closing the patient valve. The treatment subsystem 340 also starts a timer and sends an automatically correctable tilt condition to the UI model 360, which then sends the condition to the UI view 338. The UI view 338 maps the condition to an increasing warning. The treatment subsystem 340 continues to monitor the tilt sensor reading, and when the reading drops below the threshold, it resolves the condition and resumes treatment. If the situation is not resolved by the end of the timer, the treatment subsystem 340 triggers a user-recoverable "tilt timeout" situation, which takes precedence over the automatically recoverable tilt situation. The treatment subsystem 340 sends this situation to the UI model 360, which then sends the situation to the UI view 338. The UI view 338 maps the situation to a user alert. This situation cannot be resolved until the UI subsystem receives a restart treatment command (for example, the user presses the restart button). Treatment resumes when the tilt sensor reading falls below the threshold. If the reading does not fall below the threshold, the treatment layer triggers an automatically recoverable tilt situation and starts the timer.

[0265] Screen display As described above, the UI view subsystem 338 (Figure 47) is responsible for providing the interface to the user. The UI view subsystem is a client and interfaces with the UI model subsystem 360 (Figure 47), which operates on an automated computer. For example, the UI view subsystem communicates with the UI model subsystem to determine which screen should be displayed to the user at a given time. The UI view may include templates for screen views and can handle region-specific settings such as display language, skin, audio language, and culturally significant videos.

[0266] There are basically three types of events that occur in the UI view subsystem: local screen events, which are handled by individual screens; model events, which must propagate screen events to the UI model subsystem; and polling events, which occur on the UI model subsystem's timers and queries regarding status. Local screen events only affect the UI view level. These events can be local screen transitions (for example, multiple screens for a single model state), updating view settings (for example, region and language options), or requesting to play a media clip (for example, an instructional video or audio prompt) from a given screen. Model events occur when the UI view subsystem must consult with the UI model subsystem to decide how to handle the event. Examples in this category include checking treatment parameters or pressing the "Start Treatment" button. These events are initiated by the UI view subsystem but processed by the UI model subsystem. The UI model subsystem processes the event and returns the result to the UI view subsystem. This result drives the internal state of the UI view subsystem. Polling events occur when a timer generates a timing signal and the UI model subsystem is polled. In the event of a polling event, the current state of the UI view subsystem is sent to the UI model subsystem for evaluation. The UI model subsystem evaluates the state information and responds with the desired state of the UI view subsystem. This can consist of (1) a change in state, e.g., when the primary states of the UI model subsystem and the UI view subsystem are different; (2) a screen update, e.g., when a value from the UI model subsystem changes the value displayed on the screen; or (3) no change in state, e.g., when the states of the UI model subsystem and the UI view subsystem are identical. Figure 57 shows an illustrative module of a UI view subsystem 338 that performs the functions described above.

[0267] As shown in Figure 57, the UI model client module 406 is used to communicate events to the UI model. This module 406 is used to poll the UI model regarding its current status. Within the response status message, the UI model subsystem can embed the time used for synchronization with the clocks of the automated computer and the user interface computer.

[0268] The global slot module 408 provides a mechanism that allows multiple callback routines (slots) to join so as to be notified when a given event (signal) occurs. This is a "many-to-many" relationship where one slot is linked to many signals, and similarly one signal is linked to many slots, so as to be called at startup. The global slot module 408 handles application-level timers for UI model polling or non-screen specific slots such as button presses that occur off-screen (e.g., voice prompt buttons).

[0269] The screen list class 410 contains a list of all screens in the form of templates and data tables. A screen consists of a template and an associated data table used to mount the screen. A template is a window with a roughly laid-out widget, but the content is not assigned to the widget. The data table contains a record describing the content used to mount the widget and the state of the widget. The state of a widget can be checked or unchecked (for checkbox-style widgets), such as visible or hidden, or operational or inoperable. The data table can also describe the actions that result from pressing a button. For example, a button on window "A" obtained from template "1" can send an event to the UI model, while the same button on window "B" also obtained from template "1" can simply cause a local screen transition without propagating the event to the UI model. The data table can also include an index in a context-sensitive help system.

[0270] The screen list class 410 sends data from the UI model to the intended screen, selects the appropriate screen-based data from the UI model, and displays the screen. The screen list class 410 selects which screen to display based on two factors: the state reported by the UI model and the internal state of the UI view. In some cases, the UI model can only inform the UI view that displaying a screen within a category is permitted. For example, the UI model may report that the machine is idling (e.g., treatment has not yet started, or the setup phase has not yet occurred). In this case, there is no need to consult with the UI model about when the user will proceed from a menu to a submenu. To track changes, the UI view locally remembers the current screen. This local ordering of screens is handled by the table entries described above. The table entries list the actions to initiate when each button is pressed.

[0271] The language manager class 412 is responsible for running the inventory and managing translations. It can perform a checksum on the installed language list to warn the UI view if any translations are corrupted or missing. Classes that require translated strings request the language manager class 412 to do so. Translations can be handled by a library (e.g., Qt®). Preferably, translations are requested as close to rendering time as possible. For this reason, most screen template component access methods request translation rights before passing them to widgets for rendering.

[0272] A skin comprises stylesheets and images that determine the "look and feel" of the user interface. The stylesheet controls fonts, colors, and images used to display various states of widgets (normally pressed, disabled, etc.). Displayed widgets can have appearances that change with skin changes. The skin manager module 414 is responsible for notifying the screen list, and by extension, the screen widgets that should display stylesheets and skin graphics. The skin manager module 414 also includes any video files that the application may want to display. When a skin change event occurs, the skin manager updates the images and stylesheets in the active set directory with the appropriate set found in the archive.

[0273] The video manager module 416 is responsible for playing locally appropriate video in response to requests to display specific video. In the event of a local change, the video manager updates the video and video files in the currently running set directory with the appropriate set from the archive. The video manager also plays video with accompanying audio from the audio manager module 418. When playing these videos, the video manager module 416 makes an appropriate request to the audio manager module 418 to play the recording belonging to the initially requested video clip.

[0274] Similarly, the audio manager module 418 is responsible for playing the appropriate audio locally in response to requests to play specific audio clips. In the event of a local change, the audio manager updates the audio clips in the active set directory with the appropriate set from the archive. The audio manager module 418 handles all audio initiated by the UI view, including dubbing for video and audio clips for audio prompts.

[0275] The database client module 420 is used to communicate with the database manager process, which handles the interface between the UI view subsystem and the database server 366 (Figure 47). The UI view uses this interface to store and retrieve settings and supplement the treatment log with user answers to questions about variables (e.g., weight and blood pressure).

[0276] The Help Manager module 422 is used to manage a context-sensitive help system. Each page in the screen list that displays the help button can include an index to the context-sensitive help system. This index is used so that the Help Manager can display the help screen associated with the page. Help screens can include text, images, audio, and video.

[0277] The automated ID manager 424 is invoked during pre-treatment setup. This module is responsible for capturing images (e.g., photographic images) of the solution bag code (e.g., data matrix code). The data extracted from the images is then sent to the machine control subsystem used by the treatment subsystem to identify the contents of the solution bag and other information contained in the code (e.g., source).

[0278] Using the modules described above, the UI view subsystem 338 provides a screen view that is displayed to the user via a user interface (for example, the display 324 in Figure 45). Figures 58-64 show exemplary screen views that the UI view subsystem can provide. These screen views show, for example, exemplary input mechanisms, display formats, screen transitions, icons, and layouts. The illustrated screens are typically displayed during or before treatment, but the configuration of the screen view can also be used for input / output functions different from those illustrated.

[0279] The screen shown in Figure 58 is the first screen that provides the user with the option to select either "Start Treatment" 426 to begin a specified treatment 428, or "Settings" 430 to change the settings. Icons 432 and 434 are provided to adjust the brightness level and sound level, respectively, and an information icon 436 is provided so that the user can request further information. These icons can also appear on other screens.

[0280] Figure 59 shows a status screen that provides information about the treatment status. Specifically, the screen shows the type of treatment being performed, the estimated completion time, the current number of infusion cycles, and the total number of infusion cycles. The completion percentage of the current infusion cycle and the overall treatment completion percentage are both displayed numerically and graphically. The user can select the "Pause" option to temporarily suspend the treatment.

[0281] Figure 60 shows a menu screen with various comfort settings. The menu includes brightness arrows 450, volume arrows 452, and temperature arrows 454. By selecting either the up or down arrow for each pair, the user can increase or decrease screen brightness, volume, and fluid temperature. The current brightness percentage, volume percentage, and temperature are also displayed. When the desired settings are achieved, the user can select the "OK" button 456.

[0282] Figure 61 shows a help menu that can be reached, for example, by pressing the help or information button on the previous screen. The help menu may include text 458 and / or figures 460 to assist the user. The text and / or figures may be "context-dependent" or based on the content of the previous screen. If the information to be provided to the user cannot be conveniently presented on a single screen, such as in a multi-step process, arrows 462 may be provided to allow the user to move back and forth between a series of screens. Once the user has obtained the desired information, the user can select the "back" button 464. If further assistance is needed, the user can select the "call service center" option 466 to have the system contact a call service center.

[0283] Figure 62 shows a screen where the user can set a set of parameters. For example, the screen displays the current treatment mode 468 and minimum drainage volume 470, allowing the user to choose to change these parameters. Parameters can be changed in many ways, for example, by selecting the desired option from a round-robin style menu on the current screen. Alternatively, once the user selects a parameter to change, a new screen, as shown in Figure 63, can appear. The screen in Figure 63 allows the user to adjust the minimum drainage volume by entering a numerical value 472 using the keypad 474. Once entered, the user can confirm or clear the value using buttons 476 and 478. Referring again to Figure 62, the user can use the "back" and "next" arrows 480 and 482 to navigate through a series of parameter screens, each containing a different set of parameters.

[0284] Once all desired parameters have been set or changed (for example, after the user has navigated through a series of parameter screens), a screen like the one shown in Figure 64 is presented, allowing the user to review and confirm the settings. The changed parameters can optionally be highlighted in some way to draw the user's attention. When the settings are as desired, the user can select the "Confirm" button 486.

[0285] While aspects of the present invention have been described in conjunction with specific embodiments, it will be apparent that many alternatives, modifications, and variations will be obvious to those skilled in the art. Therefore, the embodiments of the present invention described herein are intended to be descriptive rather than restrictive. Various modifications are possible without departing from the spirit and scope of the invention. [Explanation of symbols]

[0286] 15: Flexible membrane, 18: Main body, 24: Fluid handling cassette, 152, 154: Line port.

Claims

1. A fluid handling cassette for use in a medical infusion system, wherein the fluid handling cassette is A substantially planar body having a first pump chamber and a second pump chamber, wherein each of the first and second pump chambers is formed as a recess on the first side of the body, and each of the pump chambers has a first port and a second port connecting the pump chamber of the first and second pump chambers to the second side of the body, A plurality of valve wells located on the first side of the main body, including a first group of valve wells and a second group of valve wells, wherein each of the plurality of valve wells in the first group includes a valve port and an opening, both of which connect the corresponding valve well of the first group of valve wells to the second side of the main body, and each of the plurality of valve wells in the second group of valve wells includes a valve port that connects the corresponding valve well of the second group of valve wells to the second side of the main body, and each of the plurality of valve wells in the second group of valve wells is connected to the second side of the main body only by a corresponding valve port among the plurality of valve ports of the plurality of valve wells in the second group of valve wells, A plurality of cassette ports, including at least three cassette ports located at the first end of the main body and at least three cassette ports located at the second end of the main body, wherein each of the plurality of cassette ports is directly connected to the corresponding valve well of the second group of valve wells, A first fluid channel and a second fluid channel located on the second side of the main body, each of the first and second fluid channels being connected via the valve wells of the first group of valve wells to the first port or the second port of the corresponding pump chamber among the first and second pump chambers, A fluid handling cassette in which each of the plurality of cassette ports is connected to one of the fluid flow paths, the first fluid flow path and the second fluid flow path, via a corresponding valve well of the second group of valve wells.

2. The fluid handling cassette according to claim 1, wherein the second fluid channel is connected to a patient line cassette port among the plurality of cassette ports, and the patient line cassette port is configured to be connected to a patient line.

3. The fluid handling cassette according to claim 1, wherein the first fluid passage is connected to a drain line cassette port and a heating line cassette port among the plurality of cassette ports, the drain line cassette port is configured to be connected to a drain line, and the heating line cassette port is configured to be connected to a heating bag line.

4. The fluid handling cassette according to claim 1, wherein the plurality of cassette ports include at least one solution line spike located at the second end of the main body.

5. The fluid handling cassette according to claim 4, wherein each of the at least one solution line spikes located at the second end of the main body includes a lumen connected to a corresponding valve well of the second group of valve wells.

6. The fluid handling cassette according to claim 4, wherein the second fluid channel is connected to the at least one solution line spike via a corresponding valve well of the second group of valve wells.

7. The fluid handling cassette according to claim 1, comprising a first flexible membrane attached to the first side of the body over the first pump chamber, the second pump chamber and the plurality of valve wells, wherein the first flexible membrane over the first pump chamber and the second pump chamber is configured to move the fluid in the first pump chamber and the second pump chamber, and the first flexible membrane over the plurality of valve wells is configured to selectively close the valve port of each of the valve wells of the plurality of valve wells.

8. The fluid handling cassette according to claim 1, wherein the first fluid passage and the second fluid passage include a plurality of walls on the second side of the main body, and the fluid handling cassette includes a rigid or flexible sheet attached to the second side of the main body, the rigid or flexible sheet is configured to be in sealing contact with the plurality of walls to form the first fluid passage and the second fluid passage.

9. A fluid handling cassette for use in a medical infusion system, wherein the fluid handling cassette is A substantially planar body having a first pump chamber and a second pump chamber, wherein each of the first and second pump chambers is formed as a recess on the first side of the body, and each of the pump chambers has a first port and a second port connecting the pump chamber of the first and second pump chambers to the second side of the body, A plurality of valve wells located on the first side of the main body, comprising a first group of valve wells and a second group of valve wells, wherein each of the plurality of valve wells of the first group includes a valve port and an opening connecting a corresponding valve well of the first group of valve wells to the second side of the main body, and each of the plurality of valve wells of the second group includes a valve port connecting a corresponding valve well of the second group of valve wells to the second side of the main body, and each of the plurality of valve wells of the second group is connected to the second side of the main body only by a corresponding valve port among the plurality of valve ports of the plurality of valve wells of the second group of valve wells, Multiple cassette ports, including at least four cassette ports located at the first end of the main body, A first fluid channel and a second fluid channel located on the second side of the main body, wherein each fluid channel of the first fluid channel and the second fluid channel is connected to the first port or the second port of the corresponding pump chamber among the first and second pump chambers, via only the corresponding valve well of the first group of valve wells, A fluid handling cassette in which each of the plurality of cassette ports is connected to one of the fluid flow paths, the first fluid flow path and the second fluid flow path, via a corresponding valve well of the second group of valve wells.

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