Medical systems and methods using multiple fluid lines

Abstract

To provide medical treatment systems and methods using a plurality of fluid lines.SOLUTION: A medical treatment system, such as a peritoneal dialysis system, may include control and other features to enhance patient comfort and ease of use. For example, a peritoneal dialysis system may include a patient line state detector for detecting whether a patient line is primed before it is to be connected to the patient. The patient line state detector can also detect whether a patient line has been properly mounted for priming. Both patient line presence / absence and fill state can be determined using an optical system, e.g., one that employs a single optical sensor.SELECTED DRAWING: Figure 9- 2

Description

[Technical Field]

[0001] The present invention relates to a medical system and method using multiple fluid lines. [Background technology]

[0002] Peritoneal dialysis (PD) involves the periodic infusion of sterile water dialysate (referred to as peritoneal dialysate or dialysate) into the patient's peritoneal cavity. Diffusion and osmotic exchange occur between the dialysate and the bloodstream through the body's natural membranes. These exchanges transfer waste products to the dialysate, which the kidneys would normally excrete. These waste products typically consist of solutes such as sodium and chloride ions, and other compounds normally excreted through the kidneys, such as urea, creatinine, and water. The diffusion of water across the peritoneum during dialysis is called ultrafiltration.

[0003] Conventional peritoneal dialysis fluid contains glucose at a concentration sufficient to generate the osmotic pressure necessary to remove water from the patient through ultrafiltration. Continuous ambulance peritoneal dialysis (CAPD) is a common form of peritoneal dialysis (PD). Patients perform CAPD manually about four times a day. During the desorption / induction procedure for CAPD, the patient first desorbs the used peritoneal dialysis fluid from their peritoneal cavity, and then injects new peritoneal dialysis fluid into their peritoneal cavity. This desorption and induction procedure usually takes about one hour.

[0004] Automated peritoneal dialysis (APD) is another common form of peritoneal dialysis (PD). APD uses a dialysis machine called a cyclometer to automatically introduce, retain, and drain peritoneal dialysis fluid into and out of the patient's peritoneal cavity. APD is particularly appealing to PD patients because it can be performed at night while the patient is asleep. This frees patients from the daily demands of CAPD during their waking hours and working hours.

[0005] An APD sequence typically lasts several hours. It often begins with the initial desorption phase, during which the used dialysate is emptied from the peritoneal cavity. The APD sequence then proceeds through a series of induction, retention, and desorption phases, which are repeated. Each induction / retention / desorption sequence is referred to as a cycle.

[0006] During the induction phase, the cyclometer transfers a predetermined volume of warmed, fresh 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 desorption phase, the cyclometer removes the used dialysate from the peritoneal cavity.

[0007] The number of induction / retention / extraction cycles required during a given APD session depends on the total volume of dialysate prescribed for the patient's APD therapy and is entered as part of the treatment prescription or calculated by the cyclometer.

[0008] APD can be implemented in various ways, and is implemented in various ways. Continuous periodic peritoneal dialysis (CCPD) is one commonly used form of APD. During each induction / retention / extraction phase of CCPD, the cyclist introduces a predetermined volume of dialysate. After the predetermined retention period, the cyclist completely extracts this fluid volume from the patient, emptying or "drying out" the peritoneal cavity. Typically, CCPD employs 4 to 8 induction / retention / extraction cycles to achieve a predetermined therapeutic volume.

[0009] After the last prescribed induction / retention / extraction cycle during CCPD, the cyclops administers a final induction volume. This final induction volume remains in the patient for an extended period. It is extracted at the beginning of the next CCPD session at night or during a midday exchange. The final induction volume may contain different glucose concentrations than the induction volumes provided in subsequent CCPD induction / retention / extraction induction cycles.

[0010] Intermittent peritoneal dialysis (IPD) is another APD method. IPD is typically used in emergencies when a patient suddenly needs dialysis treatment. IPD can be used when a patient needs PD but cannot perform the role of CAPD or cannot be performed at home.

[0011] Like CCPD, IPD involves a series of induction / retention / extraction cycles. Unlike CCPD, IPD does not have a final induction stage. In IPD, the patient's peritoneal cavity is free of dialysate (or "dry") between APD treatment sessions.

[0012] Tidal Peritoneal Dialysis (TPD) is another APD method. Like CCPD, TPD involves a series of induction / retention / exit cycles. Unlike CCPD, TPD does not completely exit the dialysate from the peritoneal cavity during each exit stage. Instead, TPD establishes a baseline volume during the initial induction stage and exits only a portion of this volume during the initial exit stage. Subsequent induction / retention / exit cycles introduce and then exit an exchange volume on top of the baseline volume. The final exit stage removes all of the dialysate from the peritoneal cavity.

[0013] TPD, which involves a cycle in which the patient is fully emanated and a new, complete baseline volume of dialysis is introduced, is subject to variation. TPD, like CCPD, can have a final implementation cycle. Alternatively, TPD, like IPD, can avoid a final implementation cycle.

[0014] APD offers flexibility and improved quality of life for those who require dialysis. APD can relieve patients of the fatigue and inconvenience that daily CAPD implementation presents to some individuals. APD can return working time to patients when dialysis changes are not required.

[0015] However, the complexity and size of past dialysis machines and associated consumables for various APD means have dulled the acceptance of APD by a wide range of patients as an alternative to manual peritoneal dialysis methods. SUMMARY OF THE INVENTION

[0016] Aspects of the present invention relate to various components, systems, and methods used in medical applications, including medical infusion procedures such as peritoneal dialysis. In some cases, aspects of the present invention are limited to the use of peritoneal dialysis, while other aspects are limited to more general dialysis applications (e.g., hemodialysis) or introduction applications, and other aspects are limited to more general methods or processes. Thus, many of the exemplary embodiments described relate to APD, but aspects of the present invention are not necessarily limited to APD systems and methods.

[0017] In one aspect of the present invention, a dialysis system can include a tube state detector that detects the presence or absence of a tube compartment, such as a portion of a patient line connected to a patient access portion for supplying dialysate to the peritoneal cavity. The tube state detector can include a first light emitter having a first optical axis directed toward a space in which the tube compartment is disposed, and a second light emitter adjacent to the first light emitter and having a second optical axis directed toward the space. The optical sensor is disposed on the opposite space side of the first and second light emitters and is arranged to receive light emitted by the first and second light emitters to determine the presence or absence of the tube compartment in the space.

[0018] In one embodiment, the first optical axis is substantially collinear with the sensor optical axis of the optical sensor and can pass through the approximate center of the tube compartment when the tube compartment is disposed in the space. In contrast, the second optical axis can be substantially parallel to the first optical axis, and thus, the second optical axis can be offset from the centers of the tube compartment and the sensor optical axis.

[0019] The optical sensor can be positioned to detect a range of light source levels when a tube compartment is present in the space (e.g., light source levels higher and / or lower than those detected when no tube compartment is present). However, the optical sensor can also detect a lower light source level from the second light source when a tube compartment is present than that detected when no tube compartment is present. For example, when a tube compartment is present in the space, the light source levels detected for both the first and second light sources can be within a range of approximately 15-20% of the calibration light source level for the first and second light sources, where the calibration light source level is the level detected when it is known that no tube compartment is present in the space. However, when no tube compartment is present in the space, the light source level detected for the second light source can be less than approximately 15-20% of the calibration light source level for the second light source. This low light source level detection can be used to determine that a tube compartment is present in the space.

[0020] In another embodiment, the tube condition detector can be configured to detect whether or not there is liquid in the tube compartment, for example, whether or not the patient line is properly ready for use. For example, the detector can include a third light-emitting element having a third optical axis positioned at an oblique angle with respect to the sensor optical axis. The angle can be 90 to 180° (e.g., about 110 to 120°). The optical sensor and the third light-emitting element can be configured such that, when the tube compartment is in space and does not contain liquid, the light source level detected by the optical sensor is at least 150% of the calibration light source level detected when the tube compartment is not in space. In addition, when the tube compartment is in space and contains liquid, the optical sensor can detect a light source level from the third light-emitting element that is at least 125% of the calibration light source level. Thus, the optical sensor and the third light-emitting element can be configured such that, when the tube compartment is in space and does not contain liquid, the light source level detected by the optical sensor is above a threshold, and when the tube compartment is in space and contains liquid, the light source level detected by the optical sensor is below the threshold level. This configuration may allow the detector to determine whether or not liquid is present in the patient line, for example, whether or not the patient line is properly prepared. In one embodiment, the third light emitter and optical sensor can be arranged so that the optical sensor receives light from the third light emitter in both cases: when the tube compartment in the space is filled with liquid and when the tube compartment in the space is empty of liquid. Thus, the presence or absence of liquid in the tube compartment can be determined based on the intensity of the detected light rather than the presence or absence of light. This can help the system avoid false state detections that may occur if the detector uses the absence of detected light to indicate a state such as the presence of liquid in the tube compartment. In other words, since the optical sensor detects light from the third light emitter regardless of the presence of liquid, the optical sensor can determine whether or not the third light emitter is functioning properly (or not functioning at all).The space in which the tube section is held can be arranged to receive and hold a tube section that may have a cylindrical outer surface without substantially deforming the tube section. Thus, the detector can operate without deforming the tube section, thereby avoiding potential problems such as compression and reduced flow in the tube section.

[0021] In another aspect of the present invention, a tube state detector for detecting whether a liquid is contained in a tube section can include a filling state illuminator having an optical axis arranged to pass through the space in which the tube section is arranged. The space can be arranged to receive a tube section having a cylindrical outer surface and hold the tube section without substantially deforming the tube section. Thus, the detector may be usable with a common tube frequently used in a dialysis system without requiring special-purpose connectors or other components. The optical sensor can be arranged on the side of the space opposite the filling state illuminator, arranged to receive light emitted by the filling state illuminator, and determine the presence or absence of liquid in the tube section. In one embodiment, the optical sensor can have a sensor optical axis arranged at an oblique angle with respect to the optical axis of the filling state illuminator and arranged to detect whether liquid is in the tube section. The oblique angle can be 90 to 180° (e.g., about 110 to 120°), and the optical sensor can also be arranged to receive light from the filling state illuminator whether or not liquid is present in the tube section.

[0022] The optical sensor and the filled state light emitter can be positioned such that, when the tube compartment is in space and does not contain liquid, the light source level detected by the optical sensor is above the threshold level, and when the tube compartment is in space and contains liquid, the light source level detected by the optical sensor is below the threshold level. In this way, when the optical sensor detects a light source level below the threshold (for example, approximately 125-150% or less of the light source level detected when the tube compartment is not in space), it can be determined that the tube compartment is filled with liquid. The filled state light emitter (which may have other light emitters) can be a light-emitting diode, or other electromagnetic wave emitting components such as devices that emit infrared, ultraviolet, visible light, or other light in the visible and / or invisible spectrum.

[0023] In one embodiment, the tube state detector may comprise a first light-emitting element having a first optical axis directed into space, and a second light-emitting element having a second optical axis directed into space. The second light-emitting element may be adjacent to the first light-emitting element, and the second optical axis may be parallel to the first optical axis. An optical sensor is positioned on the opposite side of space from the first and second light-emitting elements, and is positioned to receive the light emitted by the first and second light-emitting elements, and is capable of determining the presence or absence of a tube compartment in space. For example, the first and second light-emitting elements may be positioned relative to each other and to the optical sensor as described above (for example, the first optical axis may pass through the center of the tube compartment in space, and the second optical axis may be offset from the center of the tube compartment, etc.).

[0024] In another aspect of the present invention, a peritoneal dialysis system may comprise at least one pump arranged to pump dialysate into the patient's peritoneal cavity, and a patient line fluid-coupled to at least one pump so that the dialysate pumped from the pump is led into the patient line. The patient line may have a tip positioned for connection to the patient (for example, for connection to a patient access section that supplies dialysate into the patient's peritoneal cavity). A patient line status detector may be associated with the patient line and positioned to detect both the presence of the patient line and the ready state of the patient line. For example, the patient line status detector may be positioned to receive the tip of the patient line and detect the presence of the tip and whether the tip of the patient line is filled with fluid. This configuration may be useful to allow the system and the patient to confirm that the patient line is sufficiently filled with dialysate before connecting the patient line to the patient access connection section.

[0025] A patient line condition detector may comprise a cavity that receives the tip of a patient line, one or more light-emitting elements arranged to guide light into the cavity and associated with the cavity, and one or more photodetectors arranged to detect the light emitted by the one or more light-emitting elements. In one embodiment, a single photodetector may be used to determine whether or not there is liquid in the patient line, and both the presence or absence of the patient line. The patient line condition detector may be arranged in any manner in which the tube condition detector described above may be arranged. For example, the first and second light-emitting elements may be arranged adjacent to each other and on the side of the cavity receiving the patient line that is opposite the optical sensor. The third light-emitting element may be arranged such that its optical axis is positioned at an angle to the sensor axis of the optical sensor, thereby enabling the detection of liquid in the patient line. Other features of the tube condition detector described above may be incorporated into the patient line condition detector, including the detection and use of relative light source levels to indicate the presence of a patient line and / or the presence of liquid in the patient line, etc.

[0026] In another aspect of the present invention, a method for detecting the presence of a tube compartment includes emitting a first light along a first optical axis toward a space in which a tube compartment is optionally positioned, and emitting a second light along a second optical axis toward the space, wherein the first and second lights are emitted from the first side of the space. At least portions of the first and second lights can be detected on the second side of the space, which is opposite the first side, and the presence or absence of a tube compartment in the space can be determined based on the detected portions of the first and second lights. The second optical axis can be substantially parallel to the first optical axis, and the first optical axis can pass through the center of the tube compartment. In one embodiment, a first calibration level of the first light can be detected when there is no tube compartment in the space, and when there is a tube compartment in the space, a first light source level can be detected in the first light. The first light source level may be higher or lower than the first calibration level. However, the second calibration level of the second light can be detected when there is no tube compartment in the space, and when there is a tube compartment in the space, the second light source level can be detected for the second light, and the second light source level is lower than the second calibration level. Thus, the detection of a second light source level lower than the second calibration level can indicate the presence of a tube compartment in the space. In one embodiment, the second light source level detected for the second light can be about 15-20% or less of the second calibration level when there is a tube compartment in the space.

[0027] In another aspect of the present invention, a method for detecting the presence of liquid in a tube compartment may include emitting light along an optical axis toward the space in which the tube compartment is located, wherein the tube compartment has a cylindrical outer surface, and detecting light along a sensor optical axis extending into the space, wherein the sensor optical axis is positioned at an oblique angle (e.g., about 110-120°) with respect to the optical axis. The presence or absence of liquid in the tube compartment in the space may be determined based on the detected light source level detected along the sensor optical axis. For example, if the light source level detected along the sensor optical axis is above a threshold, it may be determined that there is no fluid in the tube compartment, and if the light source level detected along the sensor optical axis is below the threshold level, it may be determined that there is fluid in the tube compartment. The threshold level may be approximately equal to about 125-150% of the light source level detected along the sensor optical axis if there is no tube compartment in the space.

[0028] In one aspect of the present invention, a disposable fluid transport cassette usable with an APD cyclizer or other infusion device comprises a generally planar body having at least one pump chamber formed as a recess on its first side and a plurality of fluid passages with channels. A patient line port is provided for connection to a patient line and is capable of fluid communication with at least one pump chamber via at least one fluid path, and a membrane can be attached to the first side of the body across at least one pump chamber. In one embodiment, the membrane may have a pump chamber portion having an unloaded shape that generally follows the pump chamber recess in the body and is operably positioned for the movement of fluid within the usable space of the pump chamber. If the cassette body has two or more pump chamber recesses, the membrane may similarly have two or more pre-formed pump portions. In other embodiments, the membrane does not need to have a cassette, and for example, a control surface of the cyclizer interacts with the cassette to control pumping and / or valve functions.

[0029] In another embodiment, the pump chamber may be provided with one or more spacer elements extending from the inner wall of the recess, for example, to help prevent the membrane from coming into contact with the inner wall, thereby preventing blocking of the inlet / outlet of the pump chamber, to help remove or trap air within the pump chamber, and / or to prevent the membrane from adhering to the inner wall. The spacer elements may be positioned to minimize deformation of the membrane at the edges of the spacer elements when the membrane is pressed against the spacer elements.

[0030] In another embodiment, patient line ports and outlet line ports are located at the first end of the main body and can be fluidly connected to at least one pump chamber via at least one fluid path. Meanwhile, multiple dialysate line spikes can be located at the second end of the main body opposite the first end, and each dialysate line spike can be fluidly connected to at least one pump chamber via at least one fluid path. This configuration may allow for automatic connection of dialysate lines to a cassette, and / or individual occlusion of patient lines and / or outlet lines to the dialysate lines. In one embodiment, a heater bag line port is also located at the first end of the main body and can be fluidly connected to at least one pump chamber via at least one fluid path. Flexible patient, outlet, and heater bag lines can be connected to the patient line ports, outlet line ports, and heater bag line ports, respectively.

[0031] In another embodiment, the body may include a vacuum venting gap recess formed adjacent to at least one pump chamber. This recess can assist in the removal of fluid (gas and / or liquid) between the membrane and the corresponding control surface of the cyclorama, for example, by a vacuum port on the control surface. That is, the recess helps ensure that the membrane is not pressed against the vacuum port, and allows the port to remain open to draw fluid into the collection chamber when needed.

[0032] In one embodiment, one or more ports, such as outlet line ports and heater bag line ports, and / or one or more dialysate line spikes, can communicate with a common fluid path channel on the cassette base. If necessary, multiple valves can each be arranged to control the flow in their respective fluid paths between at least one pump chamber, the patient line port, the outlet line port, and the multiple dialysate line spikes. In one embodiment, portions of the membrane can be arranged across each valve and operable to open and close each valve. Similarly, the flow through the opening to the pump chamber can be controlled by corresponding valves that are opened and closed by the operation of one or more portions of the membrane.

[0033] In some embodiments, the membrane can close off at least some of the fluid pathways in the body. That is, the body can have open flow channels that are closed off on at least one side by the membrane. In one embodiment, the body can have fluid pathways formed on the opposite planar side, and at least some of the fluid pathways on the first side can communicate with the fluid pathways on the second side.

[0034] In one embodiment, one or more spikes on a cassette (e.g., one that receives dialysate) can be covered by a removable spike cap that seals the spike.

[0035] In another aspect of the present invention, a disposable fluid transport cassette for use with a reusable automated peritoneal dialysis cyclizer comprises a generally planar body having at least one pump chamber formed as a recess on the first side of the body, a plurality of fluid channels comprising a patient line port arranged for connection to a patient line, the patient line port communicating fluidly with at least one pump chamber via at least one fluid path, and a flexible membrane attached to the first side of the body across at least one pump chamber. The pump chamber portion of the membrane across at least one pump chamber may have an unloaded shape that generally conforms to the usable area of ​​the pump chamber recess in the body and may be operably positioned for the movement of fluid within the pump chamber. In one embodiment, the cassette is configured to operably engage with a reusable automated peritoneal dialysis cyclizer.

[0036] The cassette may include a discharge line port that fluid-communicates with at least one pump chamber via at least one fluid path, and / or a plurality of dialysate line spikes that fluid-communicate with at least one pump chamber via at least one fluid path. The pump chamber portion of the membrane may generally be formed in a dome shape and may comprise two pump chamber portions having a shape that generally conforms to the usable area of ​​the corresponding pump chamber recess. In one embodiment, the volume of the pump chamber portion may be in the range of 85–110% of the usable volume of the pump chamber recess. In another embodiment, the pump chamber portion may be positioned 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 positioned to have a size in the range of 85–100% of the outer circumference of the usable area of ​​the pump chamber recess. The usable area of ​​the pump chamber may be at least partially defined by one or more spacer elements extending from the inner wall of the recess. In one embodiment, the multiple spacer elements may have a progressive length or a variable height that defines a generally dome-shaped area or other shape. The spacer elements can be arranged in a concentric elliptical pattern or other shape when viewed in plane. One or more breaks in the pattern can be provided, for example, to allow communication of air gaps. In one embodiment, the spacer elements can be arranged to minimize deformation of the membrane at the edges of the spacer elements when the membrane is pressed against the spacer elements. In another embodiment, one or more spacers can be configured to prevent the membrane from covering the fluid inlet and / or outlet of the pump chamber.

[0037] In another aspect of the present invention, a fluid transport cassette for use with a fluid transport system for medical infusion devices comprises a generally planar body having a plurality of fluid channels and at least one pump chamber formed as a recess on the first side of the body, wherein the at least one pump chamber comprises one or more spacer elements extending from the inner wall of the recess; a patient line port arranged for connection to a patient line, the patient line port being in fluid communication with at least one pump chamber via at least one fluid path; an outlet line port arranged for connection to an outlet line, the outlet line port being in fluid communication with at least one pump chamber via at least one fluid path; and a plurality of dialysate line spikes being in fluid communication with at least one pump chamber via at least one fluid path.

[0038] In one aspect of the present invention, a disposable component system for use with a fluid line connection system for a peritoneal dialysis system comprises a fluid transport cassette having a generally planar body comprising at least one pump chamber formed as a recess on the first side of the body and a plurality of fluid channels; a dialysate line spike positioned at the first end of the body and in fluid communication with at least one pump chamber via at least one fluid path; and a spike cap configured to removably cover the dialysate line spike, the cap comprising at least one raised feature (e.g., an asymmetric or symmetric flange) to assist in the removal of the cap for connection to the dialysate line prior to the commencement of peritoneal dialysis treatment.

[0039] In one embodiment, the cassette comprises a skirt positioned around the spike to receive the end of the spike cap, and a recess may be located between the skirt and the spike, positioned to assist in forming a seal between the spike cap and the skirt.

[0040] In another embodiment, the dialysate line cap can be detachably connected to the dialysate line, and the dialysate line cap can be provided with concave features (such as symmetrical or asymmetrical grooves). At least a portion of the dialysate line cap can be made of a flexible material such as silicone rubber. The concave features can assist in removing the spike cap from the cassette.

[0041] In another embodiment, the spike cap includes a second raised feature which may function as a stopper for a dialysate line cap. In another embodiment, the main shafts of one or more spikes are in substantially the same plane as the generally planar body of the fluid transport cassette.

[0042] In another aspect of the present invention, a fluid transport cassette for use with a peritoneal dialysis system comprises a generally planar body having at least one pump chamber formed as a recess on the first side of the body and a plurality of fluid passages, and a spike positioned at the first end of the body for engagement with a dialysate line. The spike may be in fluid communication with at least one pump chamber via at least one fluid path and may comprise a distal tip and a lumen positioned such that the distal tip of the spike is positioned substantially near the longitudinal axis of the spike. In one embodiment, the lumen may be positioned substantially off the longitudinal axis.

[0043] In another aspect of the present invention, a disposable component system for use with a fluid line connection system for a peritoneal dialysis system comprises a spike cap configured to removably cover the spikes of a fluid transport cassette. The cap may be provided with at least one feature portion to assist in the removal of the cap for connection to the dialysate line prior to the commencement of peritoneal dialysis treatment. The feature portion may be a raised or concave feature portion and may be configured for engagement with the dialysate line cap.

[0044] In another aspect of the present invention, a disposable component system for use with a fluid line connection system for a peritoneal dialysis system comprises a dialysate line cap for removable attachment to a dialysate line, the dialysate line cap comprising at least one feature portion for assisting the removal of a spike cap to enable connection between the dialysate line and the spike prior to the commencement of peritoneal dialysis treatment. The feature portion may be a raised or recessed feature portion and may be configured for engagement with the spike cap. The mark is associated with the dialysate line, and as a result, for example, the dialysate associated with the line may be identified and affect at least one function of the peritoneal dialysis system.

[0045] In another aspect of the present invention, a medical intravenous fluid delivery system, such as an APD system, can be configured to remove the caps of one or more lines (such as dialysate lines) having one or more spikes or other connection ports on a fluid delivery cassette and to connect these lines. This feature can offer advantages such as reduced potential contamination, as human interaction is not required for removing the caps and connecting the lines to the spikes. For example, an APD system can comprise a carriage configured to receive a plurality of dialysate lines, each having a connector end and a cap. The carriage can be configured to move along a first direction to move the connector ends of the dialysate lines along the first direction, and a cap stripper can be configured to engage with the caps on the dialysate lines of the carriage. In addition to moving with the carriage along the first direction, the cap stripper can be configured to move in a second direction intersecting the first direction. For example, the carriage can move toward the cassette of the APD cycler in the first direction to engage the caps on the dialysate lines with the caps on the spikes of the cassette. The cap stripper engages with the cap (for example, by moving in a direction intersecting the carriage's movement), and is then able to move with the carriage as the carriage moves away from the cassette to remove the cap from the spike. The carriage is then able to pull the connector end of the dialysate line away from the cap on the cap stripper, and it is possible to retract the carriage so that the connector end of the dialysate line, which is now exposed, engages with the exposed spike on the cassette.

[0046] In one embodiment, the carriage may be provided with a plurality of grooves, each receiving a corresponding dialysate line. By positioning the dialysate lines in the corresponding grooves, each line can be more easily identified individually, for example, by reading a barcode or other identifier on the line and controlling the system accordingly. The carriage may be mounted on the door of the cyclora housing, and a carriage drive unit may move the carriage along a first direction. In one embodiment, the carriage drive unit may engage with the carriage when the door is moved to the closed position and disengage from the carriage when the door is moved to the open position.

[0047] In one embodiment, the cap stripper may comprise a plurality of fork-shaped elements arranged to engage with corresponding caps on dialysate lines supported by a carriage. The fork-shaped elements hold the cap when removed from the dialysate line, and each dialysate line cap is capable of holding the spike cap itself. In another embodiment, the cap stripper may comprise a plurality of rocker arms, each associated with a fork-shaped element. Each rocker arm may be arranged to move to engage with a spike cap, for example, to assist in removing the spike cap from a corresponding spike. Each rocker arm may be arranged to engage with a corresponding spike cap only when the associated fork-shaped element engages with a cap on the dialysate line. Thus, the cap stripper may not engage the spike cap with the cassette or remove the spike cap from the cassette in locations where there is no corresponding dialysate line to connect to the spike.

[0048] In another aspect of the present invention, a method for connecting fluid lines in a medical intravenous fluid delivery system such as an APD cyclorama may include locating the dialysate lines and the cassette spikes in a sealed space away from human contact. The dialysate lines and / or spikes may have a removed cap and a line connected to the spike while in the sealed space, thus providing a connection while minimizing potential contamination of the connection point, for example, by fingers carrying pathogens or other potentially harmful substances. For example, one method according to this aspect of the present invention includes providing a plurality of dialysate lines, each having a connector end and a cap; providing a fluid transport cassette, each having a plurality of spikes, each covered by a spike cap; surrounding the connector ends of the plurality of dialysate lines with caps covering the connector ends; surrounding the plurality of spikes with spike caps covering the spikes in a space that prevents human contact with the caps or the spike caps; removing the caps from the connector ends of the plurality of dialysate lines without removing the caps or connector ends from the space; removing the spike caps from the spikes without removing the spike caps or spikes from the space; engaging the caps with one of each of the spike caps; and fluidly connecting the plurality of connector ends to the corresponding spikes while keeping the connector ends and spikes in the space to protect them from human contact.

[0049] In one embodiment, the dialysate line cap and spike cap can be engaged with each other before their removal from the line or spike, and then, while remaining engaged with each other, can be removed from both the line and the spike. This technique can simplify cap removal / attachment and allow for easier storage of the caps.

[0050] In another embodiment, the dialysate line can be disconnected from the spike, and the connector end of the line and the spike can be reattached to the cap, for example, after the procedure is completed.

[0051] In another aspect of the present invention, the dialyzer may comprise a fluid transport cassette having a plurality of spikes and a plurality of spike caps covering each spike; a plurality of dialysate lines, each having a cap covering the connector end of each line; and a cap stripper arranged to remove one or more caps from the connector ends of the dialysate lines and remove one or more spike caps from the spikes on the cassette, with one or more caps being secured to one of the corresponding spike caps. As discussed above, the dialyzer may be arranged to automatically fluidize the connector ends of the dialysate lines to the corresponding spikes after the caps have been removed.

[0052] In another aspect of the present invention, a dialysis machine such as an APD system may comprise a cassette having a plurality of fluid spikes and a plurality of spike caps covering each spike, a carriage arranged to receive a plurality of dialysate 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 to engage with one or more caps on the connector ends of the lines, while one or more caps engage with corresponding spike caps covering spikes on the cassette, to remove the spike caps from the spikes, to remove the caps from the connector ends of the dialysate lines, and after the caps have been removed, to fluidly connect the spikes and the connector ends of the dialysate lines.

[0053] In another aspect of the present invention, the dialyzer may be equipped with a cap stripper positioned to remove one or more caps on the connector ends of the dialysate lines, remove one or more spike caps from the spikes on the fluid transport cassette, and hold and reattach the caps to the dialysate lines and the spike caps to the spikes on the cassette.

[0054] In another aspect of the present invention, a fluid line connection system for a peritoneal dialysis system comprises a fluid transport cassette having a generally planar body having at least one pump chamber formed as a recess on the first side of the body and a plurality of fluid passages; a plurality of dialysate line spikes disposed 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 fluid path, and the spikes being arranged to be generally coplanar with the generally planar body of the fluid transport cassette; and a carriage disposed to receive the plurality of dialysate lines, each dialysate line having a connector end. The carriage can be arranged to automatically fluid-connect the connector ends of the dialysate lines to the corresponding spikes.

[0055] In one embodiment, the carriage is positioned to move the dialysate lines and their respective caps along a first direction substantially parallel to the generally planar body of the fluid transport cassette. A carriage drive that moves the carriage only in the first direction may comprise a drive element and a pneumatic air bag or screw drive that moves the drive element along the first direction. A cap stripper may be positioned to remove one or more caps from the connector ends of the dialysate lines and remove one or more spike caps from the spikes on the cassette, with one or more caps secured to one of the corresponding spike caps. In one embodiment, the cap stripper may be positioned to hold and reattach the caps to the dialysate lines and the spike caps to the spikes on the cassette.

[0056] In another aspect of the present invention, a peritoneal dialysis system may comprise a cyclizer having components suitable for controlling the supply of dialysate to the patient's peritoneal cavity. The cyclizer may have a housing enclosing at least some of the components and having a heater bag receptacle (here, the term “heater bag” is used to refer to any suitable container for heating dialysate, such as a flexible or rigid container made of polymer, metal, or other suitable material). A cap may be attached to the housing and movable between an open position in which the heater bag can be positioned in the heater bag receptacle and a closed position in which the cap covers the heater bag receptacle. Such a configuration may allow for faster or more efficient heating of the dialysate in the heater bag, for example, because heat can be retained by the cap. Furthermore, the cap may help prevent human contact with potentially hot surfaces.

[0057] In one embodiment, the dialysis system may include a fluid transport cassette having a heater bag port attached to a heater bag line, a patient port attached to a patient line, and at least one pump chamber for moving fluid in the patient line and the heater bag line. The heater bag may be attached to the heater bag line and configured for placement in the heater bag receiving section.

[0058] In another embodiment, the system may include a movable interface (such as a visual display unit with a touchscreen component) mounted on the housing, the interface being movable between a first position in which the interface is received within the heater bag receptacle and a second position in which the interface is located outside the heater bag receptacle (for example, a position in which a user may interact with the interface). In this way, the interface can be hidden from view when the system is idle, thus allowing for protection of the interface. Also, housing the interface within the heater bag receptacle makes the system more compact, at least in a "stored" state.

[0059] In another aspect of the present invention, a dialysis system comprises a pneumatic and / or vacuum source suitable for controlling the pneumatic operating components of the system; a pneumatic operating component fluidly connected to the pneumatic and / or vacuum source; and a control system that provides pneumatic or vacuum to the pneumatic operating component and then isolates the pneumatic operating component from the pneumatic or vacuum source for a substantial amount of time before supplying pneumatic or vacuum to the pneumatic operating component again. Such a configuration can be useful for components that operate relatively infrequently, such as the occlusion components described herein. Small movements of some components may generate noise in that component that can be perceived as bothersome by the patient. By isolating a component from pneumatic / vacuum, it is possible for that component to avoid slight movements caused by fluctuations in the pressure / vacuum source, for example, pressure / vacuum draw-in by other system components. In one embodiment, the substantial time can be five minutes or more, one hour or more, 50% or more of the time required to supply or remove a volume of dialysate suitable for artificial dialysis into the patient's peritoneal cavity, or other suitable time.

[0060] In another aspect of the present invention, a dialysis system comprises a pneumatic and / or vacuum source suitable for controlling the system's pneumatic operating components, pneumatic operating components fluidly connected to the pneumatic and / or vacuum source, and a control system that supplies pneumatic or vacuum to the pneumatic operating components and controls the pneumatic or vacuum to reduce noise generated by the pneumatic operating components. For example, the pneumatic operating component may comprise at least one moving part (such as a pump diaphragm), and the control system reduces the pneumatic or vacuum supplied to the pneumatic operating component to slow down the movement of the moving part when the moving part stops or changes direction (for example, the pressure / vacuum may be controlled to slow down the movement of the diaphragm before the diaphragm changes direction). In another embodiment, pulse width modulation control of a pressure / vacuum supply valve may be used, for example, to reduce noise generated by the moving part of the valve.

[0061] In another aspect of the present invention, a dialysis system is provided with a supply of pneumatic and vacuum suitable for controlling the pneumatic operating components of the system. A first pneumatic operating component may be fluidly connected to the supply of pneumatic and / or vacuum and have a first output line for releasing pneumatic pressure. A second pneumatic operating component may be fluidly connected to the supply of pneumatic and / or vacuum and have a second output line for releasing pneumatic vacuum. A space, such as one defined by an accumulator, manifold, or soundproof chamber, may be fluidly connected to both the first and second output lines. The control system may supply pneumatic or vacuum to the pneumatic operating components, and as a result, when the first and second components release pressure / vacuum during operation, the released pressure / vacuum may be received in a common space (e.g., a manifold). In some situations, a gas under positive pressure released by a component may be balanced by a negative pressure released by another component, thus reducing the resulting noise.

[0062] In another aspect of the present invention, a peritoneal dialysis system comprises a fluid transport cassette having a patient line fluidly connected to the patient's peritoneal cavity and leading from the peritoneal cavity, the cassette may comprise at least one pump chamber for moving dialysate in the patient line. A cyclizer may be configured to receive the fluid transport cassette, interact with the cassette, and move dialysate in the patient line to at least one pump chamber. The cyclizer may comprise a control system configured to control at least one pump chamber to operate in a preparatory operation to push dialysate into the patient line to remove any air in the patient line, and may be configured to interact with two different fluid transport cassettes with respect to the volume of the patient line connected to the cassette body. A first type of cassette can have a relatively small volume patient line (for example, for pediatric use), and a second type of cassette can have a relatively large volume patient line (for example, for adult use). The control system can detect whether the cassette received by the cyclorama is of the first or second type, and thus adjust the cyclorama's operation.

[0063] In one embodiment, the control system can detect whether a cassette received by the cyclorama is of type 1 or type 2 by determining the volume of the patient line during preparation, and adjust the volume of fluid moving through the cassette during system operation. In another embodiment, a mark such as a barcode on the cassette can be detected by the cyclorama, causing the cyclorama to adjust the pump operation based on the type of cassette.

[0064] In another aspect of the present invention, the dialyzer comprises a fluid transport cassette having a plurality of spikes and at least one pump chamber for moving fluid in the spikes; a plurality of dialysate lines, each engaging with each spike on the cassette; and a control system that reads the markings on each dialysate line and determines the type of each dialysate line. The control system can adjust the pump operation or other cyclization operation based on the identity of one or more of the dialysate lines. For example, a dialysate line may be identified as an outlet sampling line, and the pump operation can be adjusted to guide used dialysate from the patient to the outlet sampling line during the outlet cycle.

[0065] In another aspect of the present invention, a method for automatically recovering from a tilted state of a dialysis system may include: (A) detecting the tilt angle of at least a portion of the dialysis system and providing a mechanism for the portion of the dialysis system to perform dialysis treatment; (B) determining that there is a tilted state in which the tilt angle exceeds a predetermined threshold; (C) pausing the dialysis treatment in response to (B); (D) monitoring the tilt angle while the dialysis treatment is paused; (E) determining that the tilted state no longer exists; and (F) automatically resuming the dialysis treatment in response to (E).

[0066] In another aspect of the present invention, a patient data interface for a dialysis system comprises an apparatus port having a recess in at least a portion of the chassis of the dialysis system and a first connector disposed within the recess. A patient data storage device may comprise a housing and a second connector coupled to the housing, the second connector configured to selectively couple to the first connector. The recess may have a first shape, and the housing may have a second shape corresponding to the first shape, so that when the first and second connectors are coupled, the housing of the patient data storage device is at least partially received within the recess. The first and second shapes may be irregular, 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 manufacturer.

[0067] In another aspect of the present invention, a method for providing peritoneal dialysis includes supplying or withdrawing dialysate to or from the patient's peritoneal cavity at a first pressure, and adjusting the pressure at which the dialysate is supplied or withdrawn in order to minimize the patient's sensation of dialysate movement. In one embodiment, the pressure can be adjusted during the same initiation or empty cycle of peritoneal dialysis treatment, and / or within different initiation or empty cycles of peritoneal dialysis treatment. For example, when withdrawing dialysate from the patient, the pressure at which the dialysate is withdrawn can be reduced when the volume of dialysate remaining in the peritoneal cavity falls below a threshold volume. Reducing the pressure (negative pressure or vacuum) near the end of the detoxification cycle can reduce the sensation that the patient may have when dialysate is withdrawn.

[0068] In another aspect of the present invention, a method for providing peritoneal dialysis includes supplying a first dialysate to the patient's peritoneal cavity using a reusable cyclizer during a first treatment of peritoneal dialysis, and supplying a second dialysate to the patient's peritoneal cavity using a reusable cyclizer during a second treatment of peritoneal dialysis immediately following the first treatment, wherein the second dialysate has a different chemical composition from the first dialysate. Different dialysates can be produced by mixing liquid materials from two or more dialysate containers connected to the cyclizer (e.g., via cassettes attached to the cyclizer). The dialysate containers can be automatically identified by the cyclizer, for example, by reading barcodes, RFID tags, or other markings.

[0069] In another aspect of the present invention, a medical intravenous drip system comprises a housing enclosing at least some of the components of the system, and a control surface constructed and arranged to control the operation of a fluid delivery cassette attached to and removable from the housing. The control surface may have a plurality of movable parts arranged to control the pumping of fluid and the valve operation of the cassette, at least one of the movable parts may have an accompanying vacuum port arranged to withdraw fluid from an area near the movable part.

[0070] In one embodiment, the control surface comprises a single elastic polymer material, and each of its movable parts may have an associated vacuum port. In another embodiment, the cassette comprises a membrane that can be positioned adjacent to the control surface, and the vacuum port is arranged to remove fluid from the space between the membrane and the control surface. A liquid sensor may be arranged to detect, for example, liquid being drawn into the vacuum port if the membrane ruptures, allowing fluid to leak from the cassette.

[0071] In another aspect of the present invention, the volume of fluid moved by a pump, such as a pump in an APD system, can be determined based on pressure measurements and some known chamber volume and / or in-line volume, but not on direct measurements of the fluid by a flow meter, weight, etc. In one embodiment, the volume of a pump chamber having a movable element that changes the volume of the pump chamber can be determined by measuring the pressure in the pump chamber and the pressure in the reference chamber while both the pump chamber and the reference chamber are separated from each other, and after the two chambers are fluid-connected, their chamber pressures can become equal. In one embodiment, pressure equalization may be assumed to occur adiabatically, and for example, a mathematical model of the system based on an adiabatic pressure equalization process can be used to determine the pump chamber volume. In another embodiment, the pressures measured after the two chambers are fluid-connected can be measured at once before complete equalization occurs, and therefore the pressures in the pump chamber and reference chamber measured after the two chambers are fluid-connected may not be equal, but can still be used to determine the pump chamber volume. This approach can reduce the time between the initial and final pressure measurements, thereby reducing the time during which heat conduction occurs and decreasing the errors that may be introduced when given an adiabatic model used to determine the pump chamber volume.

[0072] 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 separated from the reference chamber. The pump control chamber may have a volume that changes at least partially based on the operation of a part of the pump, such as a pump membrane or diaphragm. A second pressure may be measured relative to the reference chamber when the reference chamber is separated from the pump control chamber. The reference chamber may have a known volume. A third pressure associated with the pump control chamber after the reference chamber and the pump control chamber are fluid-connected may be measured, but this measurement may occur before substantial pressure equalization occurs between the pump control chamber and the reference chamber. Similarly, a fourth pressure associated with the reference chamber after the reference chamber and the pump control chamber are fluid-connected may be measured, but this is before substantial pressure equalization occurs between the pump control chamber and the reference chamber. The volume of the pump control chamber may be determined based on the first, second, third, and fourth measured pressures.

[0073] In one embodiment, the third and fourth pressures are measured at approximately the same time, and the third and fourth pressures are not substantially equal to each other. For example, once the pump control chamber and reference chamber are fluid-connected, pressure equalization within the pump control chamber and reference chamber may occur after a equalization period, but the third and fourth pressures can be measured at once after the pump control chamber and reference chamber are fluid-connected, which is about 10% to 50% of the equalization period. Thus, the third and fourth pressures can be measured (in time) long before the pressures in the two chambers are completely equal. In another embodiment, the third and fourth pressures can be measured at once when the pressures in the two chambers have reached about 50-70% equalization, for example, when the pressures in the two chambers have changed from an initial value that is within about 50-70% of the equalization pressure value. In this way, it is possible to minimize the time between the measurements of the first and second pressures and the measurements of the third and fourth pressures.

[0074] In another embodiment, the model for determining the volume of the pump control chamber can incorporate the assumption that an adiabatic system exists from the time the first and second pressures are measured relative to the separate pump control chamber and reference chamber until the third and fourth pressures are measured.

[0075] Determining the volume of fluid moved by the pump can be done by measuring the first, second, third, and fourth pressures, and by determining the volume at two different locations on the pump membrane to determine two different volumes for the pump control chamber. The difference between the two different volumes can represent the volume of fluid supplied by the pump.

[0076] 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 room is part of a dialysis machine used in dialysis treatment.

[0077] In one embodiment, the first and / or second pressures can be selected from a plurality of pressure measurements to 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 (as appropriate). For example, this point in time can be determined based on a determination of when the nearest line first deviates from a constant slope for a plurality of consecutive sets of measured pressures. This approach can help identify the initial pressures in the pump control chamber and reference chamber at the latest possible point in time while reducing errors in pump volume determination.

[0078] In another embodiment, a certain technique can be used to determine the optimal time for measuring the third and fourth pressures. For example, multiple pressure values ​​in the pump control chamber can be measured after the pump control chamber and the reference chamber are fluid-connected, and multiple changes in volume can be determined relative to the pump control chamber based on multiple pressure values ​​in the pump control chamber. Each of the multiple changes in volume can correspond to a specific time and a pressure value measured relative to the pump chamber. In this case, the change in volume is due to the movement of a virtual piston present in the valve or other component that initially separated the pump control chamber and the reference chamber, but by moving the opening of the valve or other component. Thus, the pump chamber does not actually change in size or volume, but rather the change in volume is a virtual condition due to the pressures in the pump chamber and the reference chamber that were initially different from each other. Similarly, multiple pressure values ​​in the reference chamber can be measured after the pump control chamber and the reference chamber are fluid-connected, and multiple changes in volume relative to the reference chamber can be determined based on multiple pressure values ​​relative to the reference chamber. Each of the multiple changes in volume can correspond to a specific point in time and a pressure value measured relative to the reference chamber, and is a result of the movement of a virtual piston, as is the change in volume of the pump chamber. Multiple difference values ​​can be determined between the changes in volume of the pump control chamber and the reference chamber, and each difference value is determined in relation to the change in volume of the pump control chamber and the change in volume of the reference chamber. That is, pairs of volume changes for which a difference value is determined correspond to the same or substantially the same point in time. The difference values ​​can be analyzed, and the smallest difference value (or a difference value below a desired threshold) can indicate the point in time when the third and fourth pressures should be measured. Thus, the third and fourth pressure values ​​can be identified as equal to the pump control chamber pressure value and the reference chamber pressure value, respectively, and they correspond to the smallest or below-threshold difference value.

[0079] In another embodiment, the measured pressure is the pressure of the gas in the pump control chamber and the reference chamber, the equalization of pressure in the pump control chamber and the reference chamber is assumed to occur adiabatically, the equalization of pressure between the pump control chamber and the reference chamber is assumed to include equal but opposite changes in the volume of the gas in the pump control chamber and the reference chamber, and the volume of the gas in the reference chamber at the fourth pressure measurement is calculated from the known volume of the reference chamber and the second and fourth pressures. The change in the volume of the gas in the reference chamber can be assumed to be the difference between the known volume of the reference chamber and the calculated value of the volume of the gas in the reference chamber at the fourth pressure measurement. Alternatively, the change in the volume of the gas in the pump control chamber can be assumed to be the difference between the initial volume of the pump control chamber and the volume of the gas in the pump control chamber at the third pressure measurement, and the change in the volume of the gas in the pump control chamber is equal to but opposite to the change in the volume of the gas in the reference chamber.

[0080] In another aspect of the present invention, a method for determining the volume of fluid to be moved by a pump includes providing a fluid pump device having a pump chamber separated from a pump control chamber by a movable membrane and a reference chamber to which the fluid can be connected to the pump control chamber; adjusting a first pressure in the pump control chamber to operate the membrane and thereby move the fluid in the pump chamber; separating 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; fluid connecting the reference chamber and the pump control chamber to initiate pressure equalization 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.

[0081] In one embodiment, the third and fourth pressures in the pump control chamber and the reference chamber, respectively, can be measured after the reference chamber and the pump control chamber are fluid-connected, and the third and fourth pressures can be used to determine the volume of the pump control chamber. The third and fourth pressures may not be substantially equal to each other. As described above, the adjustment step, the separation step, the fluid-connection step, and the determination step can be repeated, and the difference between the two determined volumes for the pump control chamber can be determined, the difference representing the volume of fluid supplied by the pump.

[0082] In another embodiment, the pump is part of a disposable cassette, and the pump control room is part of a dialysis machine used in dialysis procedures. In another aspect of the present invention, a medical intravenous drip system comprises a pump control chamber, a control surface associated with the pump control chamber, wherein at least a portion of the control surface is movable in response to pressure changes in the pump control chamber, a fluid transport cassette having at least one pump chamber located adjacent to the control surface, wherein the fluid in at least one pump chamber is arranged to move in response to the movement of a portion of the control surface, a reference chamber to which the fluid can be connected to the pump control chamber, and a control system arranged to adjust the pressure in the pump control chamber and thus control the movement of the fluid in the pump chamber of the fluid transport cassette. The control system can be configured to measure a first pressure in the pump control chamber when the pump control chamber is separated from the reference chamber, measure a second pressure in the reference chamber when the reference chamber is separated from the pump control chamber, fluidly connect the pump control chamber and the reference chamber, and after the reference chamber and the pump control chamber are fluidly connected, measure third and fourth pressures associated with the pump control chamber and the reference chamber, respectively, and 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 pressure equalization within the pump control chamber and the reference chamber that occurs adiabatically when the pump control chamber and the reference chamber are fluidly connected.

[0083] In one embodiment, the third and fourth pressures are not substantially equal to each other. For example, the third and fourth pressures can be measured prior to the substantial pressure equalization of the pump control chamber and the reference chamber.

[0084] In another 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 separated from the reference chamber, wherein the pump control chamber has a volume that changes at least partially based on the operation of part of the pump; measuring a second pressure in the reference chamber when the reference chamber is separated from the pump control chamber; measuring a third pressure associated with 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.

[0085] In one embodiment, the third pressure can be measured after complete pressure equalization of the pump control chamber and the reference chamber is complete. In one embodiment, the model used to determine the pump chamber volume can assume an adiabatic system in the pressure equalization between the pump chamber and the reference chamber.

[0086] In one aspect of the present invention, a method for determining the presence of air in a pump chamber includes measuring the pressure in the pump control chamber when the pump control chamber is separated from the reference chamber, wherein the pump control chamber is separated by a membrane from the pump chamber which has a known volume and is at least partially filled with liquid; measuring the pressure in the reference chamber when the reference chamber is separated from the pump control chamber, wherein the reference chamber has a known volume; measuring the pressure after the reference chamber and the pump control chamber are fluidly connected, prior to the point in time when the pressures in the two chambers are equalized; and determining the presence or absence of air bubbles in the pump chamber based on the measured pressure and known volume.

[0087] In one embodiment, the model used to determine the presence or absence of bubbles assumes an adiabatic system from the point in time when pressure is measured for the separated pump control chamber and reference chamber until after the two chambers are fluidly connected. In another embodiment, the pressure inside the pump control chamber is measured by a membrane stretched toward the wall of the pump control chamber.

[0088] In another aspect of the present invention, an automated peritoneal dialysis system comprises a reusable cyclorama constructed and positioned to be coupled to a disposable fluid transport cassette having at least one pump chamber. The disposable fluid transport cassette can be configured to be fluidly connected to the patient's peritoneum via a first extrusion tube and to a second source and / or destination (such as a dialysate container line) via a second extrusion tube. A occlusion can be configured and positioned within the cyclorama to selectively occlude the first extrusion tube without occluding the second extrusion tube. In one embodiment, the occlusion can occlude multiple extrusion tubes, such as patient lines, discharge lines, and / or heater bag lines. The cassette can have a generally planar body having at least one pump chamber formed as a recess on the first side of the body and multiple fluid paths for fluid, a patient line port located at a first end of the body arranged for connection to the first extrusion tube, and a dialysate line port located at a second end of the body opposite the first end and arranged for connection to the second extrusion tube. The occlusion section can be configured and positioned within the cyclorama to selectively occlude the first tube and the third extrusion tube (e.g., for discharge) without occluding the second extrusion tube.

[0089] In another embodiment, the closure comprises first and second opposing closure members pivotably connected to each other, a tube contact member connected to at least one of the first and second closure members or comprising at least a portion of at least one of the first and second closure members, and a force actuator constructed and positioned to apply force to at least one of the first and second closure members. The force applied by the force actuator allows the tube contact member to move between closed and open positions of the tube. The closure may also include a release member configured and positioned to allow an operator to manually move the tube contact member from the closed position to the open position, even when no force is applied to the closure members by the force actuator. The force actuator is capable of applying sufficient force to bend both the first and second closure members, and as a result, the tube contact member can move between the closed and open positions of the tube when force is applied by the force actuator to bend the first and second closure members. The occlusion member can be a leaf spring pivotably connected to both opposing first and second ends, and the tube contact member can be a pinch head connected to the leaf spring at the first end, while the second end of the leaf spring can be directly or indirectly attached to the housing to which the occlusion is connected. In one embodiment, a force actuator comprises an inflatable air bladder positioned between the first and second occlusion members. The force actuator can increase the distance between the first and second occlusion members in the region where the first and second occlusion members face each other, thereby moving the tube contact member between a tube occlusion and an open position. In one embodiment, the force actuator can bend one or both of the occlusion members to move the tube contact member from the tube occlusion position to the open position.

[0090] Various aspects of the present invention have been described above and are described below with reference to exemplary embodiments. It should be understood that various aspects of the present invention can be used alone and / or in any suitable combination with other aspects of the present invention. For example, the pump volume determination feature described herein can be used in a liquid transport cassette with the specific feature described or any other suitable pump configuration. [Brief explanation of the drawing]

[0091] Aspects of the present invention are described below with reference to exemplary embodiments shown at least partially in the following figures, where similar reference numerals refer to similar elements. [Figure 1] A schematic diagram of an automated peritoneal dialysis (APD) system incorporating one or more embodiments of the present invention. [Figure 1A] This shows an alternative configuration to the dialysate supply set shown in Figure 1. [Figure 2] Schematic diagram of an example set for use with the APD system in Figure 1. [Figure 3] An exploded perspective view of the cassette in the first embodiment. [Figure 4] Cross-sectional view of the cassette along line 4-4 in Figure 3. [Figure 5] A perspective view of a vacuum type, which may be used to form a membrane, 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] Front view of the 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 shows the rear view of the cassette unit. [Figure 9-1A] A forward perspective view of a typical configuration of a patient line status detector or liquid level detector. [Figure 9-1B] A rearward perspective view of a patient line status detector or liquid level detector. [Figure 9-2]A perspective view of the layout of three surface-mounted LEDs and an optical detector on a printed circuit board. [Figure 9-3] Plan view of the three LEDs and optical detector mounted on the detector circuit board. [Figure 9-4] Figure 9-1 is an exploded perspective view of the detector showing the printed circuit board and a transparent or translucent plastic insert. [Figure 9-5] Perspective view of an alternative configuration for the liquid level detector. [Figure 9-6] A forward perspective view of an organizer without any installed components (no dialysate lines present). [Figure 9-7] Rear view of the organizer in Figure 9-6. [Figure 9-8] A perspective view of an organizer equipped with multiple dialysis fluid lines, a patient line, and an outlet line. [Figure 9-9] An oblique view of an organizer clip. [Figure 9-10] Perspective view of the organizer clip receiver. [Figure 9-11] Perspective view of the door latch sensor assembly associated with the Cycra. [Figure 9-11a] Cross-sectional view of the door latch sensor assembly shown in Figure 9-11. [Figure 9-12] A graph showing the capabilities of the liquid level detector in Figure 9-1 for identifying prepared and unprepared patient lines. [Figure 9-13] A graph showing measurements collected by an optical sensor comparing liquid detection using angled LEDs with that using orthogonally arranged LEDs. [Figure 9-14] A graph showing the liquid level detector's ability to identify the presence or absence of tube compartments within the detector, as shown in Figure 9-1. [Figure 10] Figure 1 shows a perspective view of the APD system (with the Cycra door in the open position). [Figure 11] Figure 10 shows a perspective view of the inside of the Cycra door. [Figure 11-1] A perspective view of the carriage in the first embodiment. [Figure 11-2]An enlarged perspective view of the dialysate line mounted on the carriage shown in Figure 11-1. [Figure 11-3] An oblique view of an open-type specific tag. [Figure 11-4] A perspective view of a carriage drive assembly equipped with an automatic ID camera mounted on an automatic ID camera circuit board. [Figure 11-5] A perspective view of an embodiment of a cap stripper with respect to the stripper element. [Figure 11-6] Figure 11-4 is a front perspective view of the carriage drive assembly, showing the location of the stripper element in Figure 11-5 within the carriage drive assembly. [Figure 11-7a] Figure 11-5 shows a perspective view of part of the stripper element (where the spike cap is located). [Figure 11-7b] Figure 11-5 shows a perspective view of a part of the stripper element (the dialysate line cap is positioned on the spike cap). [Figure 11-7c] Figure 11-5 is a perspective view of a portion of the stripper element (showing the sensor element and rocker arm without the spike cap). [Figure 12] A right front perspective view of the carriage drive assembly and cap stripper in the first embodiment. [Figure 13] Figure 12 shows a left front perspective view of the carriage drive assembly and cap stripper. [Figure 14] A partial rear view of the carriage drive assembly in Figure 12. [Figure 15] A rear perspective view of the carriage drive assembly in a second exemplary embodiment. [Figure 16] Figure 15 shows a left rearward perspective view of the carriage drive assembly and cap stripper. [Figure 17] A left front perspective view of the cap stripper element in an exemplary embodiment. [Figure 18] Figure 17 shows a right-front perspective view of the cap stripper element. [Figure 19] Front view of the cap stripper element in Figure 17. [Figure 20] Cross-sectional view along line 20-20 in Figure 19. [Figure 21] Cross-sectional view along line 21-21 in Figure 19. [Figure 22] Cross-sectional view along line 22-22 in Figure 19. [Figure 23] An enlarged exploded view of the connector end of the dialysate line in an exemplary embodiment. [Figure 24] Figure 10 shows a schematic diagram of the cassette and dialysate lines installed in the cyclometer. [Figure 25] Schematic diagram of the cassette and dialysate lines after placement at each position of the cyclorama door in Figure 10. [Figure 26] Schematic diagram of the cassette and dialysate lines after the cyclometer door is closed. [Figure 27] Schematic diagram of the dialysate line engaged with the spike cap. [Figure 28] Schematic diagram of a cap stripper that engages with spike caps and dialysate line caps. [Figure 29] A schematic diagram of the dialysate line with caps and spike caps attached after movement away from the cassette. [Figure 30] Schematic diagram of the dialysate line after movement away from the dialysate line cap and spike cap. [Figure 31] Schematic diagram of a cap stripper retracting together with the dialysate line cap and spike cap. [Figure 32] A schematic diagram of the dialysate line engaging with the cassette spike. [Figure 33] A cross-sectional view of a cassette with a five-stage dialysate line connection operation, shown relative to the corresponding spike on the cassette. [Figure 34] A rear view of a cassette in another exemplary embodiment, including a different arrangement for the rear of the cassette adjacent to the pump chamber. [Figure 35] End view of the cassette spike in an exemplary embodiment. [Figure 35A]Perspective view of another embodiment of the cassette spike. [Figure 35B] Figure 35A shows an embodiment of a spike cap configured to fit onto the spike shown. [Figure 35C] Cross-sectional view of the spike cap shown in Figure 35B. [Figure 36] Front view of the control surface of the cyclorama for interaction with the cassette in the embodiment shown in Figure 10. [Figure 36A] Front view and selected cross-sectional view of an embodiment of the control surface of the Cycra. [Figure 37] Figure 36 shows an exploded view of the interface assembly. [Figure 38] An exploded perspective view of the occlusion section in the exemplary embodiment. [Figure 39] A partially exploded perspective view of the occluded area in Figure 38. [Figure 40] A plan view of the occlusion section of Figure 38, which is equipped with an air bag in a deflated state. [Figure 41] A plan view of the closure section of Figure 38, which is equipped with an inflated air bladder. [Figure 42] A schematic diagram of the cassette's pump chamber, associated control components, and inflow / outflow paths in an exemplary embodiment. [Figure 43] A plot of exemplary pressure values ​​for the control chamber and reference chamber from before valve X2 is opened to some time after valve X2 is opened, for the embodiment shown in Figure 42. [Figure 44] Figure 10 shows a perspective view of the internal compartment of the Cycra (with the upper part of the housing removed). [Figure 45] A schematic block diagram illustrating a typical implementation of a control system for an APD system. [Figure 46] Schematic block diagram of an example software subsystem for a user interface computer and automation computer for a control system in Figure 45. [Figure 47] Information flow between various subsystems and processes of the APD system in an exemplary embodiment. [Figure 48]Figure 46 illustrates the operation of the therapeutic subsystem. [Figure 49] A sequence diagram illustrating typical interactions between the initial induction of treatment and the processing of treatment modules during the dialysis portion. [Figure 50] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 51] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 52] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 53] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 54] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 55] A typical screen view of warnings and alerts that can be displayed on the touchscreen user interface for an APD system. [Figure 56] The diagram illustrates the state and operation of the components for error state detection and recovery in an exemplary embodiment. [Figure 57] This shows a typical module of the UI view subsystem for APD systems. [Figure 58] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 59]An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 60] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 61] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 62] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 63] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 64] An exemplary user interface screen that provides user information and accepts user input in an exemplary embodiment, relating to system setup, treatment status, display settings, remote assistance, and parameter settings. [Figure 65] This shows a typical patient data key and associated ports for transferring patient data to and from an APD system. [Figure 65A] This shows a patient data key with an alternative housing configuration. [Modes for carrying out the invention]

[0092] While aspects of the present invention are described in relation to peritoneal dialysis systems, certain aspects of the present invention can be used in other medical applications, including introduction systems such as intravenous infusion systems or extracorporeal blood flow systems, and lavage and / or fluid exchange systems for the stomach, intestines, bladder, pleural cavity, or other body or organ cavities. Thus, aspects of the present invention are not limited in particular to peritoneal dialysis or dialysis in general. [APD System] Figure 1 shows an automated peritoneal dialysis (APD) system 10 that can incorporate one or more aspects of the present invention. As shown in Figure 1, for example, the system 10 in this exemplary embodiment comprises a dialysate supply set 12 (which may be disposable in some embodiments), a cyclorama 14 that interacts with the supply set 12 to pump the liquid supplied by a dialysate container 20 (e.g., a bag), and a control system 16 that manages the process for performing the APD procedure (e.g., a programmed computer or other data processor, computer memory, an interface that provides information to and receives input from the user or other device, one or more sensors, actuators, relays, pneumatic pumps, tanks, power supplies, and / or other suitable components, only a few buttons for receiving user control input are shown in Figure 1, but further details regarding the components of the control system are provided below). In this exemplary embodiment, the cyclorama 14 and the control system 16 are associated with a common housing 82, but they can be associated with two or more housings and / or can be separated from each other. The Cycra 14 can have a compact footprint, making it suitable for operation on a table surface or other relatively small surfaces commonly found in homes. The Cycra 14 can be lightweight and portable, for example, carried by hand via a handle on the opposite side of the housing 82.

[0093] In this embodiment, set 12 is intended to be a single-use, disposable item, but instead, it may have 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 cyclorama 14, which interacts with the cassette 24 to pump and control the fluid flow in the various lines of set 12, for example, by installing the cassette 24 inside the front door 141 of the cyclorama 14. For example, dialysate can be pumped between the patient and the cyclorama to achieve APD. After treatment, the user can remove all or some of the components of set 12 from the cyclorama 14.

[0094] As is known in the art, prior to use, the user can connect the patient line 34 of set 12 to their indwelling peritoneal catheter (not shown) at the connector 36. In one embodiment, the cyclorama 14 can be configured to work with one or more different types of cassettes 24, such as those having patient lines 34 of various sizes. For example, the cyclorama 14 can be arranged to work with a first type of cassette having patient lines 34 sized for use in adult patients and a second type of cassette having patient lines 34 sized for use in infants or children. The pediatric patient line 34 can be shorter and have a smaller inner diameter than the adult line to minimize the volume of the line, allowing for a more controlled supply of dialysate and helping to prevent a relatively large volume of spent dialysate from being returned to pediatric patients when set 12 is used in a continuous draw-out and draw-in cycle. The heater bag 22 connected to the cassette 24 by the line 26 can be placed on the heater container receiving portion (in this case, a tray) 142 of the cyclorama 14. The cyclorama 14 is capable of pumping new dialysate into the heater bag 22 (via the cassette 24), and as a result, the dialysate is heated by the heater tray 142, for example, by an electrically resistive heating element associated with the tray 142 to a temperature of about 37°C. The heated dialysate can be supplied to the patient from the heater bag 22 via the cassette 24 and the patient line 34. In an alternative embodiment, the dialysate can be heated in the patient pathway by passing through a tube or a series fluid heater (which can be provided inside the cassette 24) that comes into contact with the heater tray 142 as it enters and leaves the cassette 24. Used dialysate can be pumped from the patient to the cassette 24 and then to the outlet line 28 via the patient line 34, which may be equipped with one or more clamps to regulate the flow through one or more branching points of the outlet line 28.In this exemplary embodiment, the lead line 28 may comprise a connector 39 for connecting the lead line 28 to a dedicated lead receptacle and a lead sample port 282 for taking a sample of used dialysate for testing or other analysis. The user may further install lines 30 to 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, 34 may comprise flexible tubing and / or appropriate connectors and other components as desired (such as pinch valves)). Containers 20 may contain sterile peritoneal dialysate or other materials for introduction (e.g., materials used by the cyclorama 14 to produce dialysate by mixing with water or by mixing various types of dialysate). Line 30 may be connected to a spike 160 of a cassette 24, which is covered by a removable cap as shown in Figure 1. In one aspect of the present invention, described in more detail below, the cyclorama 14 is capable of automatically removing caps from one or more spikes 160 of the cassette 24 and connecting lines 30 of the dialysate container 20 to each spike 160. This feature can help reduce the possibility of infection or contamination by reducing the opportunity for non-sterile items to come into contact with the spikes 160.

[0095] In another embodiment, the dialysate supply set 12a may not have a cassette spike 160. Instead, as shown in Figure 1A, one or more dialysate lines 30 can be permanently attached to the inlet port of the cassette 24. In this case, each dialysate line 30 may have a (capped) spike connector 35 for manual connection to a dialysate container or dialysate bag 20.

[0096] With various connections in place, the control system 16 can regulate the cyclorama 14 through a series of introduction, retention, and / or detoxification cycles typical of an APD procedure. For example, during the introduction phase, the cyclorama 14 can pump dialysate from one or more containers 20 (or other dialysate sources) to a heater bag 22 (by cassette 24) for heating. The cyclorama 14 can then introduce heated dialysate from the heater bag 22 through cassette 24 into the patient's peritoneal cavity via patient line 34. Following the retention phase, the cyclorama 14 can initiate a detoxification phase in which the cyclorama 14 pumps used dialysate from the patient through line 34 (again by cassette 24) and discharges the used dialysate to a nearby drain (not shown) via detoxification line 28.

[0097] The Cycla 14 does not necessarily require the dialysate container 20 and / or heater bag 22 to be positioned at a defined head height above the Cycla 14, for example, because the Cycla 14 is not necessarily a gravity flow system. Instead, the Cycla 14 can mimic or appropriately control gravity flow of dialysate even if the dialysate source container 20 is above, below, or at the same height as the Cycla 14, when the patient is above or below the Cycla 14. For example, the Cycla 14 can mimic a fixed head height during a given procedure, or the Cycla 14 can change its effective head height to increase or decrease the pressure applied to the dialysate during the procedure. The Cycla 14 can also adjust the flow rate of dialysate. In one aspect of the present invention, the Cycla 14 can adjust the pressure and / or flow rate of dialysate to reduce the patient's sensation of the inlet or outlet action when it is supplied to or withdrawn from the patient. Such adjustments may occur during a single inlet and / or outlet cycle, or they may be adjusted over different inlet and / or outlet cycles. In one embodiment, the cyclorama 14 is capable of gradually reducing the pressure used to draw used dialysate from the patient near the end of the outlet operation. Since the cyclorama 14 is capable of establishing an artificial head height, it may interact with and have the flexibility to fit into that physiology, or it may be capable of changing the relative height of the patient. [cassette] In one aspect of the present invention, the cassette 24 may be equipped with patient and outlet lines that can be separately occluded with respect to the dialysate supply lines. That is, a safe critical flow between the patient line and the outlet line can be controlled, for example, by clamping the line to stop the flow, without the need to occlude the flow through one or more dialysate supply lines. This feature may enable a simplified occlusion device, as occlusion can be performed on only two lines, as opposed to occluding other lines that have little or no effect on patient safety. For example, the patient and outlet lines can be occluded if the connection of the patient or outlet line is disconnected. However, the dialysate supply source and / or heater bag line can remain open to the flow, thereby allowing the cyclorama 14 to prepare for the next dialysis cycle. For example, separate occlusion of the patient and outlet lines can help ensure patient safety while allowing the cyclorama 14 to continue pumping dialysate from one or more containers 20 to the heater bag 22 or other dialysate containers 20.

[0098] In another aspect of the present invention, the cassette may have patient, discharge, and heater bag lines on one side or part of the cassette, and one or more dialysate supply lines on the other side or part of the cassette (e.g., on the opposite side of the cassette). Such a configuration may allow for individual occlusion of patient, discharge, or heater bag lines to the dialysate lines as discussed above. Physically separating the lines attached to the cassette by type or function allows for more efficient control of interaction with lines of a certain type or function. For example, such a configuration may allow for a simplified occlusion design, as less force is required to occlude one, two, or three of these lines than all the lines preceding or moving away from the cassette. Alternatively, this configuration may allow for more effective automatic connection of dialysate supply lines to the cassette, as discussed in more detail below. In other words, when the dialysate supply line and its respective connections are located away from the patient, discharge, or heater bag line, an automated cap removal and connection device can remove caps from the spikes on the cassette, remove caps from the dialysate supply line, and connect the line to each spike without interference from the patient, discharge, or heater bag line.

[0099] 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 generally planar body, and the heater bag line 26, the outlet line 28, and the patient line 34 are connected to their respective ports at the left end of the cassette body, while the right end of the cassette body may have five spikes 160 to which the dialysate supply line 30 may be connected. In the configuration shown in Figure 2, each of the spikes 160 is covered by a spike cap 63 which can be removed to expose the respective spike and allow connection to the respective line 30. As described above, the line 30 may be attached to one or more dialysate containers or other material sources for use in dialysis and / or for the formulation of dialysate, or it may be connected to one or more collection bags for sampling purposes or for peritoneal equilibrium testing (PET testing).

[0100] Figures 3 and 4 show exploded views (perspective and plan views, respectively) of the cassette 24 in this exemplary embodiment. The cassette 24 is formed as a relatively thin, flat member having a generally planar shape and can be, for example, molded from a suitable plastic, extruded, or comprised of formed components. In this embodiment, the cassette 24 includes a base member 18 that functions as a frame or structural member for the cassette 24 and at least partially forms various flow channels, ports, valve portions, etc. The base member 18 can be molded or constructed from a suitable plastic or other material such as polymethyl methacrylate resin (PMMA) acrylic or cyclic olefin copolymer / ultra-low density polyethylene (COC / ULDPE) and can be relatively rigid. In one embodiment, the COC / ULDPE ratio can be about 85% / 15%. Furthermore, Figure 3 shows ports formed on the base member 18 for the heater bag (port 150), outlet (port 152), and patient (port 154). Each of these ports can be positioned in any suitable manner, for example, on a central tube 156 extending from an outer ring or skirt 158, or on a standalone central tube. Flexible tubes for the heater bag, derivation, and patient lines 26, 28, and 34, respectively, can be connected to the central tube 156 and engaged by the outer ring 158 (if present).

[0101] Both sides of the base member 18 can be covered at least partially by molding, extrusion, or a formed film 15,16 (for example, a flexible polymer film made from polyvinyl chloride (PVC)). Alternatively, the sheet can be formed as a laminate of two or more layers of polycyclohexylenedimethylenecyclohexanedicarboxylate (PCCE) and / or low-density polyethylene (ULDPE), held together by, for example, a co-extrusion adhesive resin (CXA). In some embodiments, the film thickness can be in the range of about 0.002 to 0.020 inches. In preferred embodiments, the thickness of the PVC-based film can be in the range of about 0.012 to 0.016 inches, more preferably about 0.014 inches. In another preferred embodiment, for example, for a laminated sheet, the thickness of the laminate can be in the range of about 0.006 to 0.010 inches, more preferably about 0.008 inches.

[0102] Both membranes 15 and 16 can function not only to close or form a portion of the fluid path of the cassette 24, but can also be actuated or operated to open / close valve ports and / or function as part of a pump diaphragm, partition, or wall that moves fluid within the cassette 24. For example, membranes 15 and 16 can be positioned on the base member 18 and seal the rim around the base member 18 to prevent fluid from leaking out of the cassette 24 (e.g., by heat, adhesive, ultrasonic welding, or other means). Membrane 15 can be bonded to the other, the inner wall of the base member 18, for example, to form various channels, or can be pressed to adhere tightly to the wall and other features of the base member 18 when the cassette 24 is properly installed in the cyclorama 14. Thus, both membranes 15 and 16 can seal the peripheral rim of the base member 18, for example, to help prevent fluid leakage from the cassette 24 when it is removed from the cyclorama 14 after use, but can be positioned so as not to contact other parts of the base member 18. Once placed in the cyclorama 14, the cassette 24 can be squeezed between opposing gaskets or other members, and as a result, membranes 15 and 16 are pressed tightly against the base member 18 in their surrounding inner regions, thereby properly sealing channels, valve ports, etc., from each other.

[0103] Other configurations for membranes 15 and 16 are also possible. For example, membrane 16 can be formed from a rigid sheet made of a material bonded to or integrally manufactured with the body 18. Thus, membrane 16 does not necessarily have to be a flexible member, or does not necessarily have to include a flexible member. Similarly, membrane 15 does not have to be flexible over its entire surface, but instead may have one or more flexible portions to allow pumping and / or valve operation, and one or more rigid portions to close, for example, the fluid path of cassette 24. Cassette 24 may not have membranes 16 or 15, and for example, cyclora 14 may have appropriate members to seal the paths of cassette, control valves, and pump functions, etc.

[0104] According to another aspect of the present invention, the membrane 15 may comprise a pump chamber portion 151 (pump membrane) formed to have a shape that closely conforms to the shape of the corresponding recess of the pump chamber 181 in the base 18. For example, the membrane 15 may generally be formed as a flat member having a thermoformed (or formed) dome shape 151 that conforms to the pump chamber recess of the base member 18. The dome shape of the pre-formed pump chamber portion 151 can be constructed, for example, by heating and forming the membrane over a vacuum forming die of the type shown in Figure 5. As shown in Figure 5, vacuum can be applied through a number of holes along the wall of the die. Alternatively, the wall of the die can be constructed from a porous gas-permeable material, which can result in a more uniformly smooth surface of the formed membrane. Thus, when the membrane 15 is moved to its maximum extent into the pump chamber 181 and moved to (potentially) contact the spacer element 50 (for example, as shown by the solid line in Figure 4 when pumping fluid from the pump chamber 181), and when the membrane 15 is pulled back to its maximum extent from the pump chamber 181 (for example, as shown by the dashed line in Figure 4 when drawing fluid into the pump chamber 181), the membrane 15 can move relative to the pump chamber 181 to achieve the pumping action without requiring stretching of the membrane 15 (or with at least minimal stretching of the membrane 15). Avoiding stretching of the membrane 15 can help prevent pressure surges or other changes in the fluid supply pressure due to sheet stretching, and / or help simplify the control of the pump when attempting to minimize pressure fluctuations during pumping. As described in more detail below, other advantages can also be observed, including a reduced likelihood of membrane 15 failure (e.g., due to tearing of the membrane 15 caused by stress applied to the membrane 15 during stretching), and / or improved accuracy of pump supply measurement. In one embodiment, the pump chamber portion 151 can be formed to have a size (e.g., define a volume) that is about 85-110% of the pump chamber 181, for example, if the pump chamber portion 151 defines a volume that is about 100% of the pump chamber volume, the pump chamber portion 151 can be located within the pump chamber 181 and remain stationary and stress-free while in contact with the spacer 50.

[0105] Providing better control over the pressure used to generate the fluid filling and supply strokes with the pump chamber can have several advantages. For example, when the pump chamber draws fluid from the patient's peritoneal cavity during the decompression cycle, it may be desirable to apply the smallest possible negative pressure. Patients may experience discomfort during the treatment decompression cycle, partly due to the negative pressure applied by the pump during the filling stroke. Additional control that a pre-formed membrane can provide to the negative pressure applied during the filling stroke can help reduce patient discomfort.

[0106] Numerous other advantages can be realized by using a pump membrane pre-formed to the contour of the cassette pump chamber. For example, the flow rate of the liquid through the pump chamber can be more uniform because a constant pressure or vacuum can be applied throughout the pumping stroke, which in turn simplifies the process of limiting the heating of the liquid. Furthermore, temperature changes within the cassette pump may have a smaller impact on the dynamics of membrane displacement and the accuracy of the measured pressure in the pump chamber. In addition, pressure spikes in the fluid line can be minimized, and it may be simpler to correlate the pressure measured by the pressure transducer on the membrane control side (e.g., pneumatic) with the actual liquid pressure on the pump chamber side of the membrane. This in turn allows for more accurate head height measurements of the patient and fluid source bag prior to treatment, improves the sensitivity of detecting air in the pump chamber, and improves the accuracy of volume measurements. Furthermore, eliminating the need to stretch the membrane may allow for the construction and use of pump chambers with larger volumes.

[0107] In this embodiment, the cassette 24 comprises a pair of pump chambers 181 formed in the base member 18 (one or more pump chambers are also possible). According to an aspect of the present invention, the inner walls of the pump chambers 181 are spaced apart from each other and comprise spacer elements 50 extending from the inner walls of the pump chambers 18 to help prevent portions of the membrane 15 from contacting the inner walls of the pump chambers 181 (as shown in the right-hand pump chamber 181 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 can extend from the side portion 181a or be formed in other ways). By preventing contact of the membrane 15 with the inner walls of the pump chambers, the spacer elements 50 can provide dead space (or trap volume), which can help trap air or other gases in the pump chambers 181 to prevent gas from being pumped out of the pump chambers 181 in certain circumstances. In other cases, the spacer 50 can assist in the movement of gas to the outlet of the pump chamber 181, thereby removing the gas from the pump chamber 181, for example, during preparation. The spacer 50 may also help prevent the membrane 15 from adhering to the inner wall of the pump chamber even when pressed against the spacer element 50, and / or allow the flow to continue through the pump chamber 181. In addition, if the sheet makes non-uniform contact with the inner wall of the pump chamber, the spacer 50 helps prevent premature shielding of the outlet ports (openings 187 and / or 191) of the pump chamber. Further details regarding the configuration and / or function of the spacer 50 are provided in U.S. Patent Nos. 6,302,653 and 6,382,923, both of which are incorporated herein by reference.

[0108] In this embodiment, the spacer elements 50 are arranged in a kind of "stadium seating" configuration, resulting in the spacer elements 50 being arranged in a concentric elliptical pattern, with the ends of the spacer elements 50 increasing in height from the bottom 181b of the inner wall as they move away from the center of the pump chamber 181, thereby forming a semi-elliptical dome-shaped region (shown by dashed lines in Figure 4). Arranging the spacer elements 50 such that the ends of the spacer elements 50 form a semi-elliptical region defining a dome-shaped region intended to be swept by the pump chamber portion 151 of the membrane 15 may allow for a desired volume of dead space that minimizes any reduction in the intended stroke volume of the pump chamber 181. As can be seen in Figure 3 (and Figure 6), the "stadium seating" configuration in which the spacer elements 50 are arranged may include elliptical "passages" or breaks 50a. The rupture (or passage) 50a helps maintain an equal gas level throughout the rows (gaps or dead spaces) 50b between the spacer elements 50 as the fluid is delivered from the pump chamber 181. For example, if the spacer elements 50 are arranged in the stadium seating configuration shown in Figure 6 without the rupture (or passage) 50a or other means allowing liquid and air to flow between the spacer elements 50, the membrane 15 can reach the bottom on the spacer elements 50 located around the outermost perimeter of the pump chamber 181, trapping all gas or liquid present in the gaps between these outermost spacer elements 50 and the sides 181a of the pump chamber wall. Similarly, if the membrane 15 reaches the bottom on any two adjacent spacer elements 50, it is possible that any gas and liquid in the gaps between the elements 50 will be trapped. In such a configuration, at the end of the pumping stroke, air or other gases in the center of the pump chamber 181 can be delivered, while liquids remain in the outer rows. Providing fluid-communicating ruptures (or passages) 50a or other means between the spacer elements 50 helps maintain an equal gas level throughout the space during the pumping stroke, and as a result, air or other gases can be prevented from leaving the pump chamber 181 unless a substantial volume of liquid is being transmitted.

[0109] In some embodiments, the spacer elements 50 and / or the membrane 15 can be arranged such that, when the membrane 15 is pressed to contact the spacers 50, it does not generally wrap around or deform around the individual spacers 50, or it stretches significantly into the gaps between the spacers 50. Such a configuration can reduce any stretching or damage to the membrane 15 that would result from wrapping around or deforming around one or more individual spacer elements 50. For example, in this embodiment, it has also been found to be advantageous to make the size of the gaps between the spacers 50 such that its width is approximately equal to the width of the spacers 50. This feature is shown to help prevent deformation of the membrane 15 (e.g., sagging of the membrane into the gaps between the spacers 50) when the membrane 15 is pressed to contact the spacers 50 during pump operation.

[0110] According to another aspect of the present invention, the inner wall of the pump chamber 181 can define a recess larger than the space (e.g., a semi-elliptical or dome-shaped space) intended to be swept by the pump chamber portion 151 of the membrane 15. In such examples, one or more spacer elements 50 can be positioned below the dome-shaped region intended to be swept by the membrane portion 151, rather than extending into the dome-shaped region. In some examples, the ends of the spacer elements 50 can define the periphery of the dome-shaped region intended to be swept by the membrane 15. Positioning the spacer elements 50 outside or adjacent to the periphery of the dome-shaped region intended to be swept by the membrane portion 151 can have numerous advantages. For example, positioning one or more spacer elements 50 outside or adjacent to the dome-shaped region intended to be swept by the flexible membrane minimizes any reduction in the intended stroke volume of the pump chamber 181 while providing dead space between the spacer and the membrane, as described above.

[0111] It should be understood that the spacer elements 50 (if any) within the pump chamber can be arranged in any other suitable manner, for example, as shown in Figure 7. The left pump chamber 181 in Figure 7 has spacers 50 arranged similarly to those in Figure 6, except that there is only one break or passage 50a running perpendicularly through the approximate center of the pump chamber 181. The spacers 50 can be arranged to define a concave shape similar to that in Figure 6 (i.e., the top of the spacers 50 may form a semi-ellipse as shown in Figures 3 and 4), or they can be arranged in any other suitable manner to form a spherical, box-shaped, etc. The right pump chamber 181 in Figure 7 shows an embodiment in which the spacers 50 are arranged perpendicularly with gaps 50b, and the gaps are arranged perpendicularly between the spacers 50. In the left pump chamber, the spacers 50 in the right pump chamber 181 can define a semi-ellipse, spherical, box-shaped, or any other suitablely formed recess. However, it should be understood that the spacer elements 50 can have a fixed height, a different spatial pattern than those shown, etc.

[0112] Furthermore, the membrane 15 may itself have spacer elements, or other features such as ribs, protrusions, tabs, grooves, channels, etc., in place of or in addition to spacer elements 50. Such features on the membrane 15 may help provide other features, such as preventing adhesion of the membrane 15 and / or helping to control how the sheet folds or deforms as it moves during pumping action. For example, protrusions or other features on the membrane 15 may help the sheet deform consistently so that it does not fold over the same area during repeated cycles. Folding over the same area of ​​the membrane 15 during repeated cycles may lead to premature failure of the membrane 15 in its fold area, and therefore features on the membrane 15 may help to regulate how and where folds occur.

[0113] In this exemplary embodiment, the base member 18 of the cassette 24 defines a plurality of controllable valve features, fluid paths, and other structures that guide the movement of fluid within the cassette 24. Figure 6 shows a plan view of the base member 18 from the pump chamber side, which is also seen in the perspective view in Figure 3. Figure 8 shows a rear perspective view of the base member 18, and Figure 9 shows a rear plan view of the base member 18. Tubes 156 for ports 150, 152, and 154, respectively, are in fluid communication with the respective valve wells 183 formed in the base member 18. The valve wells 183 are fluidically separated from each other by walls surrounding each valve well 183 and by the sealed engagement of a membrane 15 with the walls surrounding the wells 183. As described above, the membrane 15 can be sealed engaged with the walls surrounding each valve well 183 (and other walls of the base member 18) by being pressed to contact the walls, for example, when mounted on the cyclorama 14. If the membrane 15 is not pressed to engage tightly with the valve port 184, the fluid in the valve well 183 can flow into the respective valve port 184. Thus, each valve port 184 defines a valve (e.g., a "volcano valve") that can be opened and closed by selectively operating the portion of the membrane 15 associated with the valve port 184. As described in more detail below, the cyclorama 14 is capable of selectively controlling the position of the portion of the membrane 15, and as a result, the valve ports (such as port 184) can be opened and closed to control the flow through various fluid channels and other paths in the cassette 24. The flow through the valve port 184 is led to the rear side of the base member 18. For the valve ports 184 associated with the heater bag and outlets (ports 150 and 152), the valve port 184 is led to a common channel 200 formed on the rear side of the base member 18. As in the valve well 183, the channel 200 is separated from the paths of other channels and cassette 24 by the sheet 16 and is in close contact with the wall of the base member 18 that forms the channel 200.For the valve port 184 associated with the patient line port 154, the flow through port 184 is directed to a common channel 202 at the rear of the base member 18.

[0114] Returning to Figure 6, each of the spikes 160 (shown with the caps removed in Figure 6) is in fluid communication with its respective valve well 185, and they are separated from each other by the walls and the sealed engagement of the membrane 15 with the walls forming the wells 185. When the membrane 15 is not in sealed engagement with the port 186, the fluid in the valve well 185 can flow into the respective valve port 186 (again, the position of the portion of the membrane 15 over each valve port 186 can be controlled by the cyclorama 14 that opens and closes the valve port 186). The flow through the valve port 186 is led to the rear of the base member 18 and into the common channel 202. Thus, according to one aspect of the present invention, the cassette may have a plurality of dialysate supply lines (or other lines supplying materials for providing dialysate) connected to a common manifold or channel of the cassette, and each line may have a corresponding valve for controlling the flow between the line and 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 that leads to the lower pump valve well 189 (see Figure 6). If each portion of the membrane 15 is not pressed to tightly engage with the port 190, the flow from the lower pump valve well 189 can pass through the respective lower pump valve port 190. As can be seen in Figure 9, the lower pump valve port 190 leads to a channel that communicates 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 that communicates with the upper valve port 192. The flow from the upper valve port 192 (if the membrane 15 is not tightly engaged with the port 192) enters the respective upper valve well 194 and then into an opening 193 that communicates with the common channel 200 at the rear of the base member 18.

[0115] Naturally, the cassette 24 can be controlled so that the pump chamber 181 can pump fluid between any of the ports 150, 152, and 154 and / or between any of the spikes 160. For example, new dialysate supplied by 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 appropriate valve port 186 for the appropriate spike 160 (and optionally closing the other valve ports 186 for the other spikes). It is also possible to open the lower pump valve port 190 and close the upper pump valve port 192. Next, a portion of the membrane 15 associated with the pump chamber 181 (i.e., the pump membrane 151) can be moved (for example, away from the base member 18 and the pump chamber wall), thereby reducing the pressure in the pump chamber 181, and thereby drawing the fluid through the selected spike 160 into the common channel 202 through the corresponding valve port 186, through the opening 188 into the lower pump valve well 189, and through the (open) lower pump valve port 190 into the pump chamber 181 through the lower opening 187. The valve port 186 is independently operable and can optionally draw fluid through the spike 160 and any one or a combination thereof of the associated dialysate source containers 20 in any desired sequence or simultaneously (of course, only one pump chamber 181 needs to be operable to draw fluid into itself; other pump chambers can be made inoperable and kept shielded from the flow by closing the appropriate lower pump valve port 190).

[0116] In the fluid in the pump chamber 181, the lower pump valve port 190 can be 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 may increase, thereby sending the fluid in the pump chamber 181 through the upper opening 191, through the (open) upper pump valve port 192 to the upper pump valve well 194, and through opening 193 to the common channel 200. The fluid in the channel 200 can be sent to the heater bag port 150 and / or outlet port 152 (and corresponding heater bag line or outlet line) by opening the appropriate valve port 184. Thus, for example, the fluid in one or more of the vessels 20 can be drawn into the cassette 24 and discharged to the heater bag 22 and / or drain.

[0117] The fluid in the heater bag 22 (after being properly heated, for example, on the heater tray for introduction to the patient) can be drawn into the cassette 24 by opening the valve port 184 for the heater bag port 150, closing the lower pump valve port 190, and opening the upper pump valve port 192. By moving the portion of the membrane 15 associated with the pump chamber 181 away from the base member 18, the pressure in the pump chamber 181 is reduced, thereby allowing the fluid to flow from the heater bag 22 into the pump chamber 181. With the pump chamber 181 filled with heated fluid from the heater bag 22, the upper pump valve port 192 can be closed and the lower pump valve port 190 can be opened. To deliver the heated dialysate to the patient, the valve port 184 for the patient port 154 can be opened and the valve port 186 for the spike 160 can be closed. The movement of the membrane 15 in the pump chamber 181 toward the base member 18 can increase the pressure in the pump chamber 181, causing the fluid to flow through the lower pump valve port 190, through the opening 188 to 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 a desired volume of heated dialysate to the patient.

[0118] When drawing fluid from the patient, the valve port 184 for the patient port 154 is opened, the upper pump valve port 192 is closed, and the lower pump valve port 190 can be opened (the spike valve port 186 is closed). The membrane 15 can operate to draw fluid from the patient port 154 into the pump chamber 181. Next, the lower pump valve port 190 is closed, the upper valve port 192 is opened, and the valve port 184 for the discharge port 152 can be opened. The fluid from the pump chamber 181 can then be pumped into the discharge line for disposal or sampling into a discharge or recovery container (alternatively, the fluid may also be sent to one or more spikes 160 / line 30 for sampling or discharge purposes). This operation can be repeated until sufficient dialysate has been removed from the patient and pumped into the drain.

[0119] The heater bag 22 can also function as a mixing container. Depending on the specific treatment requirements for individual patients, dialysate or other solutions with different compositions can be connected to the cassette 24 via the appropriate dialysate line 30 and spike 160. Each measured amount of dialysate is added to the heater bag 22 using the cassette 24 and mixed according to one or more predetermined compositions stored in the microprocessor memory and accessible by the control system 16. Alternatively, specific treatment parameters can be entered by the user via the user interface 144. The control system 16 can be programmed to calculate the appropriate mixing requirements based on the type of dialysate or dialysate container connected to the spike 160, and can then control the mixing and supply of the prescribed mixture to the patient.

[0120] According to aspects of the present invention, the pressure applied by the pump to the dialysate being introduced to or removed from the patient is controlled such that the patient's sensation of "pulling" or "being pulled" due to pressure fluctuations during the infusion and defusion operations is minimized. For example, when defusioning dialysate, the suction pressure (or vacuum / negative pressure) can be reduced near the end of the defusion process, thereby minimizing the patient's sensation of dialysate removal. A similar approach can be used when approaching the end of the infusion operation, i.e., the supply pressure (or positive pressure) can be reduced near the end of the infusion. If it is found that the patient is more or less sensitive to fluid movement during various cycles of treatment, various pressure profiles can be used for various infusion and / or defusion cycles. For example, relatively higher (or lower) pressures can be used during the infusion and / or defusion cycles when the patient is asleep compared to when the patient is awake. Cycra 14 can, for example, use an infrared motion detector to detect a patient's sleep / wake state and infer that the patient is asleep if their activity decreases, or it can use detected changes such as blood pressure, electroencephalogram (EEG), or other parameters indicating sleep. Alternatively, Cycra 14 can simply "ask" the patient, "Are you sleeping?", and control system operation based on the patient's response (or lack thereof). [Patient Line Status Detection Device] In one embodiment, the patient line condition detector detects when the fluid line to the patient (such as patient line 34) was properly prepared before being connected to the patient (although the patient line condition detector is described in relation to patient lines, embodiments of the invention should be understood to include the detection of the presence of any suitable tubular compartment or other conduit, and / or the filling state of the tubular compartment or other conduit. Thus, embodiments of the invention are not limited to use with patient lines, as the tubular condition detector can be used with any suitable conduit). In some embodiments, the patient line condition detector can be used to detect the proper preparation of the tubular compartment at the patient connection end of the fluid line. Patient line 34 can be connected to an indwelling catheter in the patient's blood vessels, body cavities, subcutaneous tissue, or another organ. In one embodiment, patient line 34 can be a component of a peritoneal dialysis system 10, which delivers dialysate to the patient's peritoneal cavity and receives fluid from the peritoneal cavity. The tubular compartment near the tip of the line can be positioned upright on a basin where the sensor element of the detector is located. Figure 9-1A is a front perspective view of a typical configuration of the patient line status detector 1000, which can be mounted or exposed on the left external side of the housing 82 (e.g., to the left of the front door 141). The patient line 34 should preferably be prepared before being connected to the patient, because otherwise air will be delivered to the patient, increasing the risk of complications. Under some setting conditions, it is acceptable for up to 1 mL of air to be present in the patient line 34 before it is connected to the patient's peritoneal dialysis catheter. Typical configurations of the patient line status detector 1000 described below generally meet or exceed this criterion, because their detectors can detect the fluid level in a properly positioned tubular compartment of the line 34, and as a result, at most about 0.2 mL of air can remain at the end of the line 34 after preparation.

[0121] In one embodiment, the first configuration of the patient line status detector 1000 may include a base member 1002. There may also be a patient line status detector housing 1006 attached to (or integrally molded with) the base member 1002, so that the detector housing 1006 may extend outward from the base member 1002. The detector housing 1006 defines a tube or connector holding channel 1012 in which a tube section 34a or an associated connector 36 near the tip of the patient line 34 can be located. The portion of the detector housing 1006 facing the base member 1002 is substantially hollow, so that an open cavity 1008 (shown in Figure 9-3) can be created behind the detector housing 1006. The open cavity 1008 can provide placement and positioning of sensor elements (1026, 1028, 1030, and 1032 shown in Figure 9-3) adjacent to the channel 1012 in which the tube section 34a can be located. In other embodiments, a stabilizing tab 1010 extending outward from the base member 1002 may optionally be present. The stabilizing tab 1010 may have a concave outer shape, which may substantially match the curvature of the patient line connector 36 when the patient line 34 is placed in the patient line state detector housing 1006. The stabilizing tab 1010 may help prevent the connector 36 from moving during the preparation of the patient line 34, thereby improving the accuracy and efficiency of the preparation process. The detector housing 1006 may have a shape that generally helps define a tube or connector retaining channel 1012, which may also have dimensions that change to allow a transition from the tube compartment 34a to the tube connector 36.

[0122] In this exemplary embodiment, the channel 1012 can substantially mimic the shape of the patient line connector 36. As a result, the channel 1012 can be "U-shaped" so as to encompass a portion of the connector 36 when it is positioned within the channel 1012. The channel 1012 can consist of two separate feature parts (a tube portion 1014 and a base 1016). In another embodiment, the tube portion 1014 can be positioned below the base 1016. In addition, the base 1016 can be formed by a pair of side walls 1018 and a rear wall 1020. Both side walls 1018 can be slightly convex in shape, while the rear wall 1020 can be generally horizontal or have a contour that generally matches the shape of the adjacent portion of the connector 36. The generally convex shape of the side walls 1018 helps to lock the patient line connector 36 into place when it is positioned in the base 1016.

[0123] In an exemplary embodiment for a first configuration of the patient line status detector 1000, a region 36a of the patient line connector 36 can have a generally planar surface that can be fixedly positioned against the opposing rear wall 1020 of the channel 1012. In addition, this region 36a of the connector 36 can have an opposite recess 37, which can be positioned adjacent to the opposing side wall 1018 of the channel 1012 when the connector 36 is placed in the detector housing 1006. The recess 37 can be defined by a raised element 37a located on the side of the connector 36. One of these recesses 37 is partially visible in Figure 9-1. The two side walls 1018 can have a generally interlocking shape (e.g., a convex shape) that engages with the recess 37, assisting in locking the connector 36 in place within the base 1016. This helps prevent the connector 36 and tube compartment 34a from being inadvertently removed from the detector housing 1006 during preparation of the patient line 34. If the raised element 37a of the connector 36 is made of a sufficiently flexible material (e.g., polypropylene, polyethylene, or other similar polymer-based material), the tensile force threshold on the connector 36 will be sufficient to disengage the connector 36 and the tube section 34a from the detector housing 1006.

[0124] In another embodiment, the tubular portion 1014 of the cavity 1012 can enclose most of the tubular compartment 34a immediately before the tubular compartment 34a is attached to the connector 36. The tubular portion 1014 can accommodate most of the tubular compartment 34a using three structures (two side walls 1018 and a rear wall 1020). In one embodiment, the two side walls 1018 and the rear wall 1020 can be transparent or sufficiently translucent (e.g., constructed from plexiglass) so as to allow light from multiple LEDs (e.g., LEDs 1028, 1030, and 1032 in Figure 9-3) to be guided through the walls without being significantly obstructed or diffused. An optical sensor 1026 (shown in Figure 9-2) can also be positioned along one of the walls 1018 to detect the light emitted by the LEDs. In the exemplary embodiment, the transparent or translucent plastic insert 1019 can be constructed to snap into place within the main detector housing 1006 in the area where the LED is located within the housing.

[0125] Figure 9-2 shows a layout perspective view of the patient line status detector printed circuit board 1022 with surface-mounted LEDs 1028, 1030, and 1032, as well as an optical sensor 1026. Figure 9-3 shows a plan view of the LEDs 1028, 1030, and 1032, as well as the optical sensor 1026, mounted on the detector circuit board 1022, where the detector circuit board 1022 can be positioned adjacent to the rear wall 1020 and side wall 1018 of the detector housing 1006. Figure 9-4 is an exploded perspective view of the detection assembly 1000, showing the relative positions of the printed circuit board 1022 and the translucent or transparent plastic insert 1019 with respect to the housing 1006.

[0126] Furthermore, referring to the exemplary embodiment in Figure 9-1B, the detector circuit board 1022 can be positioned in the support structure 1004 and the inner open cavity 1008, which is formed from a detector housing 1006 extending outward from the base member 1002. The base member 1002 and the support structure 1004 can be attached to each other or integrally molded, so that the base member 1002 is generally perpendicular to the support structure 1004. This orientation generally allows the plane of the detector circuit board 1022 to be generally perpendicular to the long axis of the tube section 34a when fixed in the channel 1012. The detector circuit board 1022 can generally conform to the cross-sectional shape of the open cavity 1008, and it can also include a cutout 1024 (Figures 9-2 and 9-3) that generally matches the cross-sectional shape of the channel 1012 formed by the rear wall 1020 and the side walls 1018 (Figure 9-1A). Next, the detector circuit board 1022 can be placed in the open cavity 1008, and the cutout portion 1024 is substantially adjacent to the rear wall 1020 and side wall 1018 of the detector housing 1006 to ensure proper positioning of the detector circuit board 1022 with respect to the tube section 34a or connector 36.

[0127] The detector circuit board 1022 may comprise a plurality of LEDs and at least one optical sensor that can be mounted on the circuit board 1022, and in one embodiment, the LEDs and optical sensor may be surface-mounted on the circuit board 1022. In one embodiment, the detector circuit board 1022 may comprise a first LED 1028, a second LED 1030, a third LED 1032, and an optical sensor 1026. The first LED 1028 and the second LED 1030 may be arranged to guide light through the same side wall 1018a of the channel 1012. The light emitted by the first LED 1028 and the second LED 1030 may be guided in generally parallel directions, and their light may be guided generally perpendicular to the nearest side wall 1018a. The optical sensor 1026 may be arranged along the opposite side wall 1018b of the channel 1012. Furthermore, the third LED 1032 may be arranged along the rear wall 1020 of the channel 1012. In this exemplary embodiment, such a configuration of the LED and optical sensor 1026 allows the patient line status detector 1000 to detect three different states during the preparation of the patient line 34 (the tube compartment 34a or connector 36 is substantially completely filled with fluid (ready state), the tube compartment 34a or connector 36 is incompletely filled (unprepared state), or the tube compartment 34a and / or connector 36 is absent from the channel 1012 (line absent state)).

[0128] For example, when used in a peritoneal dialysis system such as the peritoneal dialysis system 10, configuring the detector circuit board 1022 in this manner allows appropriate control signals to be sent to the PD cycle controller system 16. The controller system 16 can then, via the user interface 144, notify the user to position the tip of line 34 in the patient line status detector 1000 before connecting it to the peritoneal dialysis catheter. The controller can then monitor the position of the tubing compartment 34a in the patient line status detector 1000. The controller can then instruct the preparation of line 34, and once line 34 is prepared, instruct the completion of preparation, and then proceed to instruct the user to disengage the tip of line 34 from the patient line status detector 1000 and connect it to the user's peritoneal dialysis catheter.

[0129] Surface mounting the LEDs 1028, 1030, and 1032 and the optical sensor 1026 onto the circuit board 1022 simplifies the manufacturing process of the device, allows the patient line status detector 1000 and the circuit board 1022 to occupy relatively little space, and helps eliminate errors that may arise from the movement of the LEDs or optical sensors relative to each other or to the channel 1012. Without surface mounting of the sensor components, misalignment of the components may occur during the assembly or use of the device.

[0130] In one embodiment, the optical axis (or central optical axis) of LED 1032 can form an oblique angle with respect to the optical axis of optical sensor 1026. In the exemplary embodiment, the optical axes of the first LED 1028, the second LED 1030, and optical sensor 1026 are generally parallel to each other and to the rear wall 1020 of channel 1012, respectively. Thus, the amount of light guided from the LED toward optical sensor 1026 may vary depending on (a) the presence or absence of a translucent or transparent conduit in channel 1012, and / or (b) the presence of liquid in the conduit (which can be, for example, a tube compartment 34a). Preferably, LED 1032 can be positioned near the side wall furthest from optical sensor 1026 (e.g., 1018a) for some of the light emitted by LED 1032 that is refracted by the presence of a translucent or transparent tube compartment 34a in channel 1012. The degree of refraction away from or towards the optical sensor 1026 may depend on the presence or absence of fluid in the tube compartment 34a.

[0131] In various embodiments, the angle of the LED 1032 relative to the optical sensor 1026 generates a more robust system for determining the presence or absence of liquid, with a translucent or transparent conduit in the channel 1012. The LED 1032 can be positioned so that its optical axis can form any angle in the range of 91° to 179° relative to the optical axis of the optical sensor 1026. Preferably, the angle can be set in the range of about 95° to about 135° relative to the optical axis of the optical sensor. More preferably, the LED 1032 can be set to have an optical axis of about 115° ± 5° relative to the optical axis of the optical sensor 1026. In the exemplary embodiment shown in Figure 9-3, the angle θ of the optical axis of the LED 1032 relative to the optical axis of the optical sensor 1026 is set to about 115° ± 5° (in this particular embodiment, the optical axis of the optical sensor 1026 is roughly parallel to the rear wall 1020 and roughly perpendicular to the side wall 1018b). The advantages of angling the LED 1032 with respect to the optical axis of the optical sensor 1026 were confirmed in a series of tests comparing the performance of the optical sensor 1026 in distinguishing fluid-filled tube compartments (wet tubes) from air-filled tube compartments (dry tubes) using an LED 1032 oriented at an angle of approximately 115° with an LED whose optical axis is oriented perpendicular or parallel to the optical axis of the optical sensor 1026. The results showed that the angled LED-based system was more robust in determining the presence or absence of liquid in the tube compartment 34a. It is possible to select an optical sensor signal intensity threshold using the angled LED 1032, above which empty tube compartments 34a can be reliably detected. It is also possible to select an optical sensor signal intensity threshold below which liquid-filled tube compartments 34a can be reliably detected.

[0132] Figures 9 to 12 show graphs of test results demonstrating the ability of the patient line status detector 1000 to identify tube compartments 34a filled with liquid (ready state) and empty tube compartments 34a (unready state). The results were recorded for LED 1032 (third LED) oriented at an angle of approximately 115° with respect to the optical axis of optical sensor 1026 and LED 1030 (second LED) oriented roughly parallel to the optical axis of optical sensor 1026. The results plotted in Figures 9 to 12 demonstrate that the patient line status detector 1000 can reliably distinguish between the ready state and the unready state. When the relative signal intensity associated with the light received from LED 1030 is approximately 0.4 or higher, it is possible to determine the upper signal detection threshold 1027 and the lower signal detection threshold 1029 for the ready state versus the unready state using only the light signal received from LED 1032. An upper threshold 1027 can be used to identify an unprepared state, and a lower threshold 1029 can be used to identify a prepared state. Data points located above the upper threshold 1027 are associated with an empty tube compartment 34a (unprepared state), and data points located below the lower threshold 1029 are associated with a tube compartment 34a filled with liquid (prepared state). A relatively narrow region 1031 between these two thresholds defines a range of relative signal intensity associated with light received from the LED 1032 where the assessment of the prepared state of the tube compartment 34a may be uncertain. A controller (e.g., control system 16) can be programmed to send an appropriate message to the user whenever the signal intensity associated with light received from the LED 1032 falls within this uncertain range. For example, the user can be instructed to assess whether the tube compartment 34a and / or connector 36 are properly attached to the patient line status detector 1000. In relation to a peritoneal dialysis system, if the optical sensor 1026 generates a signal corresponding to an empty tubing compartment 34a, the controller can instruct the cyclorama to continue preparing the patient line 34 with dialysate.A signal corresponding to the fluid-filled tubular compartment 34a can be used by the controller to stop further preparations and inform the user that the fluid line 34 is ready to be connected to the dialysis catheter.

[0133] Figure 9-13 shows a graph of test results demonstrating the superiority of the angled LED 1032 (LEDc) compared to an LED (LEDd) whose optical axis is approximately perpendicular to the optical axis of the optical sensor 1026. In this case, the relative signal intensity generated by the optical sensor 1026 in response to the light from LEDc was plotted against the signal intensity associated with the light from LEDd. A certain separation between liquid-filled (prepared) and empty (unprepared) tube compartments 34a was evident at a relative signal intensity of approximately 0.015 for LEDd, but a substantial number of "unprepared" data points 1035 remained that could not be identified from the "prepared" data points based on this threshold. On the other hand, relative signal intensities 1033 associated with the light from LEDc, ranging from 0.028 to 0.03, could effectively distinguish between "prepared" tube compartments 34a (prepared state) and "unprepared" tube compartments 34a (unprepared state). Thus, angled LEDs (1032) can generate more reliable data than LEDs oriented at right angles.

[0134] In another embodiment, the patient line status detector 1000 can further determine whether a tubing compartment 34a is in channel 1012. In one embodiment, a first LED 1028 and a second LED 1030 can be positioned next to each other. One LED (e.g., LED 1028) can be positioned so that its optical axis passes approximately through the center of a well-located translucent or transparent conduit or tubing compartment 34a in channel 1012. A second LED (e.g., LED 1030) can be positioned so that its optical axis is slightly off-center relative to the conduit or tubing compartment 34a in channel 1012. Such a pair of LEDs, centered / off-centered on one side of channel 1012, has been shown to increase the reliability of determining whether a liquid conduit or tubing compartment 34a is present or absent in channel 1012 when the optical sensor 1026 is on the opposite side of channel 1012. In a series of tests in which tube compartments 34a alternately were absent, present but improperly positioned, or present and properly positioned within channel 1012, signal measurements were obtained from the first and second LEDs 1030 by the optical sensor 1026. The signals received from each LED were plotted against each other, and the results are shown in Figure 9-14.

[0135] As shown in Figure 9-14, in most cases where tube compartment 34a was absent from channel 1012 (region 1039), the signal intensity received by the optical sensor 1026 due to LEDa (LEDa received intensity) was found not to differ significantly from the signal intensity received from LEDa during a calibration step when any tube in channel 1012 was known to be absent. Similarly, the signal intensity associated with LEDb (LEDb received intensity) was found not to differ significantly from that of LEDb during a calibration step when any tube in channel 1012 was known to be absent. The patient line status detector 1000 can reliably determine that no tube is present in channel 1012 when the ratio of LEDa to its calibration value and the ratio of LEDb to its calibration value are approximately 1 ± 20%. In a preferred embodiment, the threshold ratio can be set to 1 ± 15%. In embodiments where the patient line status detector 1000 is used with a peritoneal dialysis cycla, the values ​​of LEDa and LEDb in region 1039 of Figure 9-14 can be used, for example, to indicate the absence of tubing compartment 34a from channel 1012. The cycla controller can be programmed to notify the user via the user interface 144 of the need to pause further pumping and properly position the end of the patient line 34 in the patient line status detector 1000.

[0136] The configuration and positioning of the three LEDs and optical sensor 1026 described above can generate the necessary data using translucent or transparent fluid conduits (e.g., tube compartment 34a) with a wide range of translucency. In supplementary tests, it was found that the patient line status detector 1000 can provide reliable data for distinguishing liquid from air in the fluid conduit and for distinguishing the presence or absence of the fluid conduit, using samples of tubes with significantly different degrees of translucency. It was also possible to provide reliable data regardless of whether the PVC tubes used were unsterilized or sterilized (e.g., sterilized with EtOx (ethylene oxide)).

[0137] The measurements obtained from the LED by the optical sensor 1026 can be used as input to the patient line status detector algorithm to detect the state of the tube compartment 34a. Aside from detecting a filled, empty, or absent tube compartment 34a, the algorithm's results are indeterminate and may indicate movement or improper positioning of the tube compartment 34a within the patient line status detector 1000, or possibly the presence of foreign matter in the channel 1012 of the patient line status detector 1000. The manufacture of such foreign matter can vary the output from the LED and the sensitivity of the optical sensor 1026 in different assemblies. Therefore, it may be advantageous to perform an initial calibration of the patient line status detector 1000. For example, the following procedure can be used to obtain calibration values ​​for the LED and sensor.

[0138] (1) Confirm that the tube compartment 34a is not loaded into the patient line status detector 1000. (2) Inquire about the four different states of the optical sensor 1026.

[0139] (a) No LEDs are lit (b) The first LED 1028 (LEDa) is lit. (c) The second LED1030 (LEDb) is lit. (d) The third LED 1032 (LEDc) is lit. (3) The signal value for "no lit LEDs" is subtracted from each of the other signal values ​​to determine their environmental correction values, and these three measured values ​​are stored as the "no tube" calibration value.

[0140] Once calibration values ​​for the LED and sensor are obtained, it is possible to detect the state of the tube compartment 34a. In this exemplary embodiment, the patient line state detector algorithm performs state detection during testing as follows.

[0141] (1) Inquire about the four different states of the optical sensor 1026. (a) No LEDs are lit (b) The first LED 1028 (LEDa) is lit. (c) The second LED1030 (LEDb) is lit. (d) The third LED 1032 (LEDc) is lit. (2) Subtract the value for "no lit LEDs" from each of the other values ​​to determine the corresponding environmental correction values.

[0142] (3) The relative LED value is calculated by dividing the test value associated with each LED by its corresponding calibration (without tube) value. [result] If the environmental correction LEDa value is less than 0.10, the user may be informed that there may be foreign matter in the detector or that the result is inconclusive.

[0143] If the environmentally corrected LEDa and LEDb values ​​are within ±15% of their respective stored calibration (without tube) values, the system will report to the user that there is no tube compartment within the detector.

[0144] If the environmentally corrected LEDb value is approximately 40% or more of its stored calibration (without tube) value, (a) Check the signal associated with LEDc, (i) If the environmental correction signal associated with LEDc is approximately 150% or more of its calibration (without tube) value, the user is informed that the tube compartment is empty.

[0145] (ii) If the environmental correction signal associated with LEDc is less than or equal to approximately 125% of its calibration (without tube) value, the user is informed that the tube compartment is filled with liquid. (iii) Otherwise, the user should be informed that the result is uncertain and that the measurement (e.g., the tube compartment may be moving, uneven, or unclear) should be repeated or checked to ensure that the tube compartment is properly inserted into the detector.

[0146] If the environmentally corrected LEDb value is less than or equal to approximately 40% of its stored calibration (no tube) value, the LEDc threshold for determining the presence of a dry tube may be larger. In one embodiment, for example, the empty tube threshold for LEDc has been empirically found to follow the following relationship: ([empty tube threshold for LEDc] = -3.75 × [LEDb value] + 3).

[0147] Once it is determined that tube compartment 34a has been placed on the patient line status detector 1000, the patient line status detector algorithm can perform the following actions: a) Inquire whether the optical sensor 1026 has any lit LEDs, and store this as an LED-less value.

[0148] b) Turn on LEDc. c) Inquire about the optical sensor 1026, subtract the value of no LED from the LEDc value, and store this as the initial value.

[0149] d) Start pumping. e) Inquire about optical sensor 1026 and subtract the value without LED from the following LEDc value.

[0150] f) If this value is less than 75% of the initial value, it is determined that tube compartment 34a is filled with liquid, pumping is stopped, the detector status is checked using the procedure described above, and the user is informed that it is ready when indicated. Otherwise, the query, calculation, and comparison are repeated. In one embodiment, the system controller can be programmed to perform the query protocol at any desired frequency, such as every 0.005 to 0.01 seconds. In one embodiment, the entire query cycle can be conveniently performed every 0.5 seconds.

[0151] Figure 9-5 shows a perspective view of a second configuration of the patient line status detector 1000. Two or more different patient line status detector configurations may be necessary to provide various types of patient line connectors. In this exemplary embodiment, the second configuration of the patient line status detector 1000 can have almost the same components as the first configuration of the patient line status detector 1000. However, in order to provide different types of connectors, the second configuration can have a raised element 1036 above the housing 1006 instead of the stabilizing tab 1010 found in the first configuration of the patient line status detector 1000. The raised element 1036 can generally mimic the shape of a standard patient line connector cap or connector flange.

[0152] According to aspects of this disclosure, the detector housing 1006 may not include the tubular portion 1014. Therefore, the open cavity 1008 can be positioned to allow for the placement of the detector circuit board 1022 such that the LED and optical sensor are located next to the translucent or transparent patient line connector 36 rather than in the tubular compartment. Thus, the channel 1012 can be shaped differently to provide transmission of LED light through the connector 36. [Dialysis fluid line organizer] Figures 9-6, 9-7, and 9-8 show a front perspective view of the organizer 1038 without mounting, a rear perspective view of the organizer 1038 without mounting, and a perspective view of the organizer 1038 with mounting, respectively. In this embodiment, the organizer 1038 can be substantially formed from a moderately flexible material (e.g., PAXON AL55-003 HDPE resin). Forming the organizer 1038 from this material or another relatively flexible polymer material improves the durability of the organizer 1038 when attaching and detaching dialysate lines or dialysate line connectors.

[0153] The organizer 1038 can be conveniently installed or mounted on the exterior wall of the Cycra housing 82. The organizer 1038 can comprise a tube holder compartment 1040, a base 1042, and tabs 1044. The tube holder compartment 1040, base 1042, and tabs 1044 can all be flexibly connected and can be substantially formed from the same HDPE-based material. The tube holder compartment 1040 can generally have a rectangular shape and can comprise a generally horizontal upper edge and a lower edge that may be slightly curved outward. The tube holder compartment 1040 can comprise a series of recessed compartments 1046 extending horizontally along the lower edge of the tube holder compartment 1040. Each of the recessed compartments 1046 can be separated by a series of support columns 1048, which may also define the shape and size of the compartment 1046. The tube holder compartment 1040 may further comprise a raised region extending horizontally along its upper edge. The raised region may comprise a plurality of slots 1050. The slots 1050 may be defined as vertically oriented and may extend from the upper edge of the tube holder compartment 1040 to the top of the concave compartment 1046. The slots 1050 may generally have a cylindrical shape, conforming to the shape of the outlet line 28, dialysate line 30, or patient line 34. The depth of the slots 1050 is such that the opening of the slot 1050 is narrower than the internal region of the slot 1050. Thus, once a line is inserted into a slot 1050, it locks or snaps into place. The line may then require a predetermined minimum force to be removed from the slot 1050. This ensures that the line is not accidentally removed from the organizer 1050.

[0154] In one embodiment, the tab 1044 can be flexibly connected to the upper edge of the tube holder compartment 1040. The tab 1044 can generally have a rectangular shape. In another embodiment, the tab 1044 can further comprise two corner sections with slightly larger radii. The tab 1044 can further comprise two vertically extending support columns 1048. The support columns 1048 can be connected to the upper edge of the tube holder compartment 1040 and can extend upward within the tab 1044. In an alternative embodiment, the length and number of the support columns 1048 may vary depending on the desired degree of flexibility of the tab 1044. In another embodiment, the tab 1044 can comprise a ribbed region 1052. The purpose of the tab 1044 and the ribbed region 1052 is to allow the user to easily understand the organizer 1038, and as a result, the user can easily install, transport, or remove the dialysate line 30 from the organizer 1038. Additionally, the tab 1044 provides an additional support area when removing the line and loading it into the organizer 1038.

[0155] In another embodiment, the base 1042 can be flexibly connected to the lower edge of the tube holder section 1040. The base 1042 can generally have a rectangular shape. In another embodiment, the base 1042 can further comprise two slightly larger radius corner sections. The base 1042 can comprise an elongated concave section 1046, which can be defined by a support ring 1054 surrounding the concave section 1046. The support column 1050, the support ring 1054, and the raised region can all generate a series of gaps 1056 along the rear of the organizer 1038 (as shown, for example, in Figure 9-7).

[0156] Figures 9-9 and 9-10 show perspective views of the organizer clip 1058 and the organizer clip receiver 1060, respectively. In these exemplary embodiments, the clip 1058 can be made from a relatively high durometer polyurethane elastomer, such as 80 Shore A durometer urethane. In alternative embodiments, the clip 1058 can be made from any kind of flexible and durable material that allows the organizer 1038 to bend and rotate along the base 1042 when placed inside the clip 1058. The clip 1058 can be "U-shaped" and may have a rear portion that extends slightly higher than the front portion. In addition, a lip portion 1062 may be present that extends along the upper edge of the front portion of the clip 1058. The lip portion 1062 extends slightly into the cavity of the clip 1058. The rear portion of the clip 1058 may further comprise several elastomer pegs 1064 connected to (or formed from) the rear portion of the clip 1058 and extending away from the rear portion. The pegs 1064 may comprise both a cylindrical portion 1066 and a conical portion 1068. The cylindrical portion 1066 may connect to the rear portion of the clip 1058, and the conical portion 1068 may be attached to the open end of the cylindrical portion 1066. The pegs 1064 enable the clip 1058 to be permanently connected to the organizer clip receiver 1060 by engaging the pegs 1064 with several holes 1070 in the organizer clip receiver 1060.

[0157] The organizer clip receiver 1060 may be provided with a plurality of chamfered tabs 1072. The chamfered tabs 1072 can engage with corresponding slots in the rear portion of the clip 1058 when the peg 1064 engages with the organizer clip receiver 1060. Once the chamfered tabs 1072 engage with the slots, they extend through the rear portion of the clip 1058 and can act as a locking mechanism to hold the organizer 1038 in place when it is placed on the clip 1058. When the organizer 1038 is placed on the clip 1058, the chamfered portions 1072 fit into the gap 1056 at the rear of the base 1042, which is created by the raised support ring 1054. Referring again to Figure 9-7, and according to another aspect of the present disclosure, a plurality of ramps 1074 may extend outward from the rear of the organizer 1038. The ramp 1074 can generally be formed as an inclined surface. This allows the organizer 1038 to be angled away from the cyclorama 14 when inserted into the clip 1058, which offers numerous advantages over previous designs. For example, in this exemplary embodiment, the angle of the organizer 1038 ensures that neither the tab 1044 nor any of the lines (or line caps) connected to the organizer 1038 interfere with the heater cover 143 when the cover 143 is opened and closed. In addition, coupled with the flexibility of the organizer 1038, the angle of the organizer 1038 relative to the cyclorama 14 both allow the user to remove the dialysate line 30 from its bottom rather than from the connector end 30a of the dialysate line. Preferably, the user should not remove the dialysate line 30 by grasping the connector end 30a, because in doing so the user may inadvertently remove one or more caps 31, causing contamination and spillage. Another advantage of the organizer 1038 is that it helps the user connect the color-coded dialysate lines 30 to the correct containers 20 by assisting in the separation of the color-coded lines 30. [Door latch sensor] Figure 9-11 shows a perspective view of the door latch sensor assembly 1076. In this exemplary embodiment, the door latch sensor assembly 1076 may include a magnet 1078 attached to or connected to the door latch 1080, which can pivot with the door latch 1080 as it pivots to and from a latch position with a base unit catch 1082 with which it engages. A sensor (not shown in Figure 9-11) may be located near the base unit catch 1082, behind the front panel 1084 of the cyclorama 14, thereby detecting the presence of the magnet 1078 when the door latch 1080 engages with the base unit catch 1082. In one embodiment, the sensor may be an analog Hall effect sensor. The purpose of the door latch sensor assembly 1076 is to confirm both that the door 141 is closed and that the door latch 1080 is fully engaged with the catch 1082 to ensure a structurally sound connection. Figure 9-11a shows a cross-sectional view of the door latch sensor assembly 1076. The sensor 1079 is located on the circuit board 1077 behind the front panel 1084. The sensor 1079 is preferably oriented with its axis offset from the path of the magnet 1078. This orientation allows the sensor 1079 to better determine the various positions of the magnet 1078 as the door 141 approaches the front panel 1084 when it is closed.

[0158] In one example, door 141 can be considered fully engaged if door latch 1080 is engaged with catch 1082 by at least 50%. In one embodiment, door latch 1080 can nominally engage by about 0.120 inches. In addition, sensor 1079 can detect the closure of door 141 only when door latch 1080 is fully engaged with catch 1082. Thus, sensor 1082 can detect the closure of door 141 only when door latch 1080 is engaged by about 0.060 inches. These engagement thresholds for door latch 1080 can be set to a substantially intermediate range relative to acceptable engagement between door latch 1080 and catch 1082. This can help ensure a robust design by taking into account sensor drift due to time, temperature, and other variations. Testing was conducted to determine the robustness of sensor 1082 by collecting numerous measurements at both room temperature (approximately 24°C) and abnormally cold temperatures (approximately -2°C to 9°C). Room temperature measurements were consistently higher than low-temperature measurements, but the difference was only a few percent in the range of 0 to 0.060 inches.

[0159] In one embodiment, the output of sensor 1079 may have an output characteristic proportional to the supplied voltage. Therefore, it is possible to measure both the supplied voltage and the output of sensor 1079 (see the following equations where the supplied voltage and the output of sensor 1079 are represented by Door_Latch and Monitor_5V0, respectively). Next, both the output of sensor 1079 and the supplied voltage can pass through a quarter resistor divider circuit. Dividing the output of sensor 1079 and the supplied voltage may enable the generation of a stable output. This procedure makes it possible to ensure that the output remains stable even if the supplied voltage fluctuates.

[0160] In another embodiment, the sensor 1079 can respond to positive and negative magnetic fields. Therefore, in the absence of a magnetic field, the sensor 1079 can output half of the supply voltage. In addition, a positive magnetic field may increase the output of the sensor 1079, while a negative magnetic field may decrease it. To obtain accurate measurements of the output from the sensor 1079, the polarity of the magnet can be ignored, and the supply voltage can be compensated for at the same time. The following equation can be used to calculate the latch-sensor ratio.

[0161] Latch-sensor ratio = absolute value (VDoor_Latch / VMonitor_5V0) - noFieldRatio) …(1) noFieldRatio (shim-free ratio) is calculated by (VDoor_Latch / VMonitor_5V0) with door 141 fully open.

[0162] Using this formula, A ratio of 0.0 indicates the absence of a magnetic field. A ratio > 0.0 indicates some magnetic field, but does not specify its direction.

[0163] To calibrate the magnetic field strength detected by the sensor 1079 along with various engagement positions of the door latch assembly 1076, shims of varying thicknesses can be used between the inside of the door 141 and the front panel 1084, thereby changing the degree of engagement between the latch 1080 and the catch 1082. In one embodiment, this data can be used to determine the magnetic field strength ratio with and without shims, and in other embodiments, it can be used with several shims of varying thicknesses. In one example, the door latch sensor assembly 1076 can complete a procedure to determine whether the door latch 1080 is fully engaged with the catch 1082 by doing the following:

[0164] Calculate nearRatio and farRatio. nearRatio=noShimRatio-(0.025 / 0.060)×(noShimRatio-withShimRatio) …(2) farRatio=noShimRatio-(0.035 / 0.060)×(noShimRatio-withShimRatio) …(3) In this embodiment, the door latch sensor assembly 1076 is capable of saving noFieldRatio, nearRatio, and farRatio to a calibration file. The door latch sensor assembly 1076 is then capable of loading noFieldRatio, nearRatio, and farRatio from the calibration file, and the sensor assembly 1076 is then capable of using nearRatio and farRatio as hysteresis ranges for the sensor 1079. The door latch sensor assembly 1076 is then capable of iteratively calculating the latch-sensor ratio, starting from the initial condition that the door 141 is open. If the latch-sensor ratio is greater than or equal to nearRatio, the door latch sensor assembly 1076 changes the latch state to closed, and if the latch-sensor ratio is less than or equal to farRatio, the door latch sensor assembly 1076 changes the latch state to open. In another embodiment for the door latch sensor assembly 1076, the middleRatio can be calculated from calibration data by taking the average of noShimRatio and withShimRatio. In this case, a measurement greater than or equal to the middleRatio indicates that the door latch 1080 is engaged, and a measurement less than or equal to the middleRatio indicates that the door latch 1080 is not engaged. [Settings loading and operation] Figure 10 shows a perspective view of the APD system 10 of Figure 1, with the door 141 of the cyclorama 14 lowered to the open position, exposing the mounting position 145 for the cassette 24 and the carriage 146 for the dialysate line 30 (in this embodiment, the door 141 is attached to the cyclorama housing 82 by a hinge at the bottom of the door 141). When loading the set 12, the cassette 24 is positioned at the mounting position 145 with the membrane 15 and the pump chamber side of the cassette 24 facing upward, and the portion of the membrane 15 associated with the pump chamber and valve port interacts with the control surface 148 of the cyclorama 14 when the door 141 is closed. The mounting position 145 can be formed to match the shape of the base member 18, thereby ensuring proper orientation of the cassette 24 at the mounting position 145. In this exemplary embodiment, the cassette 24 and mounting position 145 require the user to position the cassette 24 in an appropriate orientation at the mounting position 145, or they have a generally rectangular shape with a single corner of a large radius so that the door 141 does not close. However, it should be understood that other shapes or orientations of the cassette 24 and / or mounting position 145 are also possible.

[0165] According to an aspect of the present invention, when the cassette 24 is positioned at the mounting position 145, the patient, outlet, and heater bag lines 34, 28, and 26 are routed to the left through a channel 40 of the door 141, as shown in Figure 10. The channel 40, which may be equipped with a guide 41 or other features, is capable of holding the patient, outlet, and heater bag lines 34, 28, and 26, and as a result, the occlusion 147 selectively opens and closes the lines for flow. When the door 141 is closed, the occlusion 147 can press one or more of the patient, outlet, and heater bag lines 34, 28, and 26 against an occlusion stopper 29. Generally, when the cyclorama 14 is operating (and operating properly), the occlusion unit 147 is capable of allowing flow through lines 34, 28, and 26, but when the cyclorama 14 is powered off (and / or not operating properly), it occludes the lines (this can be done by compressing the lines or by pinching the lines to close off the fluid path within them). Preferably, the occlusion unit 147 may selectively occlude at least patient and outlet lines 34 and 28.

[0166] When the cassette 24 is installed and the door 141 is closed, the pump chamber side of the cassette 24 and the membrane 15 can be pressed against the control surface 148, for example, by an air bladder, a spring, or other suitable configuration of the door 141 behind the mounting position 145 that compresses the cassette 24 between the mounting position 145 and the control surface 148. This containment of the cassette 24 can press the membranes 15 and 16 against the wall and other feature parts of the base member 18, thereby separating the channel and other fluid paths of the cassette 24 as desired. The control surface 148 can be equipped with a flexible gasket (e.g., a single piece of silicone rubber or other material) which is associated with the membrane 15 and can selectively move portions of the membrane 15 to result in the pumping action of the pump chamber 181 and the opening and closing of the valve ports of the cassette 24. The control surface 148 can be associated with various parts of the membrane 15, for example, and can be in close contact with each other, so that parts of the membrane 15 move in accordance with the operation of the corresponding parts of the control surface 148. For example, the membrane 15 and the control surface 148 can be positioned close to each other, and a suitable vacuum (or pressure lower than the ambient pressure) can be introduced through a vacuum port appropriately positioned on the control surface 148 and maintained between the membrane 15 and the control surface 148, so that the membrane 15 and the control surface 148 essentially stick to each other in at least the area of ​​the membrane 15 where an operation is required to open and close a valve port and / or produce a pumping action. In another embodiment, the membrane 15 and the control surface 148 can adhere to each other or be appropriately associated with each other.

[0167] Before closing the door 141 with the cassette 24 installed, one or more dialysate lines 30 may be installed on the carriage 146. The end of each dialysate line 30 may be provided with a cap 31 and an area 33 for labeling or for attaching an indicator or identifier. For example, the indicator may be a specific tag that snaps onto the tube in the indicator area 33. According to aspects of the present invention, and also as will be discussed in more detail below, the carriage 146 and other components of the cyclorama 14 may be operated to remove the caps 31 from the lines 30, recognize an indicator for each line 30 (which may provide an indication of the type of dialysate associated with the line, the amount of dialysate, etc.), and fluidly engage the lines 30 with the respective spikes 160 of the cassette 24. This process can be performed automatically (for example, after door 141 is closed, the cap 31 and spike 160 are enclosed in a space protected from human contact, thereby potentially reducing the risk of contamination of line 30 and / or spike 160 when connecting them to each other. For example, upon closing door 141, the indicator area 33 may be evaluated (for example, visually by appropriate imaging devices and software-based image recognition, or by RFID technology) to identify which dialysate is associated with which line 30. The ability of the indicator area 33 to detect the characteristics of line 30 by its indicators. Aspects of the present invention relating to this can offer the advantage of allowing the user to position the line 30 at any position on the carriage 146 without affecting the system operation. That is, since the cyclorama 14 can automatically detect the characteristics of the dialysate line, there is no need to ensure that a specific line is positioned at a specific location on the carriage 146 for the system to function properly. Instead, the cyclorama 14 identifies which line 30 is where and appropriately controls the cassette 24 and other system features. For example, a certain line 30 and connected container may be intended to receive used dialysate, for example, for later testing.Since the cyclorama 14 can identify the presence of the sample supply line 30, the cyclorama 14 can deliver the used dialysate to the appropriate spike 160 and line 30. As discussed above, since all the spikes 160 of the cassette 24 supply to a common channel, input from any particular spike 160 can be delivered to the cassette 24 in any desired manner by controlling valves and other cassette features.

[0168] With line 30 installed, carriage 146 can be moved to the left as shown in Figure 10 (again, with door 141 closed), positioning cap 31 on each spike cap 63 on the spike 160 of cassette 24, and adjacent to cap stripper 149. Cap stripper 149 can extend outward (from inside the recess in the housing of cycra 14 toward door 141) to engage with cap 31 (for example, cap stripper 149 can have five fork-shaped elements that engage with corresponding grooves in cap 31, thereby allowing cap stripper 149 to resist lateral movement of cap 31 relative to cap stripper 149). By engaging cap 31 with cap stripper 149, cap 31 can also grip the corresponding spike cap 63. Subsequently, with cap 31 engaged with the corresponding spike cap 63, the carriage 146 and cap stripper 149 are able to move to the right, thereby removing the spike cap 63 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 positions where the dialysate line 30 is not loaded, because the engagement of cap 31 from the dialysate line 30 requires the removal of spike cap 63. Thus, when the dialysate line is not connected to spike 160, the cap on spike 160 remains in place). Next, the cap stripper 149 is able to stop moving to the right while the carriage 146 continues to move to the right (for example, by contacting a stopper). As a result, the carriage 146 is able to pull the terminal end of line 30, which remains attached to the cap stripper 149, away from cap 31.With the cap 31 removed from the line 30 (and the spike cap 63 still attached to the cap 31), the cap stripper 149 can retract together with the cap 31 into the recess of the housing of the cyclorama 14, thereby clearing the path of the carriage 146 and the uncapped end of the line 30 toward the spikes 160. The carriage 146 then moves to the left again, attaching the terminal end of the line 30 to each spike 160 of the cassette 24. This connection can be made by the spikes 160 through the end of the line 30 (otherwise the end is closed), allowing fluid flow from each container 20 to the cassette 24 (for example, the spike may penetrate a closed partition or wall of the terminal end). In one embodiment, the wall or partition can be constructed from a flexible and / or self-sealing material such as PVC, polypropylene, or silicone rubber.

[0169] According to aspects of the present invention, the heater bag 22 can be placed in a heater bag receiving section (e.g., a tray) 142, which is exposed by lifting a lid 143 (in this embodiment, as discussed below, the cyclorama 14 includes a user or operator interface 144 pivotably mounted to a housing 82. To allow the heater bag 22 to be placed in the tray 142, the interface 144 can be pivoted upward and out of the tray 142). As is known in the art, the heater tray 142 is capable of heating the dialysate in the heater bag 22 to a suitable temperature (e.g., a temperature suitable for introduction to a patient). According to aspects of the present invention, the lid 143 can be closed, for example, after the heater bag 22 has been placed in the tray 142, thereby helping to trap heat and facilitate the heating process, and / or helping to prevent touching or other contact with relatively warm parts of the heater tray 142, such as its heating surface. In one embodiment, the lid 143 can be locked in a closed position, thereby preventing contact with the heated portion of the tray 142 in situations where, for example, a portion of the tray 142 is heated to a temperature that could cause skin burns. The opening of the lid 143 can be prevented, for example by locking, until the temperature on the underside of the lid 143 has cooled to a sufficiently low temperature.

[0170] According to another aspect of the present invention, the cycra 14 includes a user or operator interface 144 that is pivotably mounted in the housing of the cycra 14 and can be folded downward into the heater tray 142. With the interface 144 folded downward, 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 graphical form, and to accept input from the user, for example, by using a touchscreen and GUI. The interface 144 can include other input devices such as buttons, dials, knobs, and pointing device devices. With the set 12 connected, the container 20 is appropriately positioned, and the user can interact with the interface 144 to cause the cycra 14 to start treatment and / or perform other functions.

[0171] However, before starting a dialysis cycle, unless set 12 is provided in a pre-prepared state (e.g., in the manufacturing facility or before use in cyclo14), cyclo14 must have at least the cassette 24, patient line 34, heater bag 22, etc. prepared. Preparation can be done in various ways, such as by controlling cassette 24 (i.e., pump and valve), thereby drawing fluid from one or more dialysate containers 20 via line 30 and pressurizing the fluid through various paths in cassette 24, thereby removing air from cassette 24. Dialysis fluid can be pressurized into heater bag 22 (e.g., to be heated prior to supply to the patient). Once cassette 24 and heater bag line 26 are prepared, cyclo14 can then prepare patient line 34. In one embodiment, the patient line 34 can be prepared by connecting the line 34 to an appropriate port or other connection point on the cyclor 14 (e.g., by a connector 36) and causing the cassette 24 to pump liquid into the patient line 34. The port or connection point on the cyclor 14 is configured to detect when the liquid reaches the end of the patient line (e.g., optically, by a conductive sensor, or otherwise) and thereby it is possible to detect that the patient line has been prepared. As discussed above, various types of sets 12 can have patient lines 34 of different sizes (e.g., adult or pediatric size). According to aspects of the present invention, the cyclor 14 can detect the type of cassette 24 (or at least the type of patient line 34) and thereby control the cyclor 14 and the cassette 24. For example, the cyclor 14 can determine the volume of liquid supplied by the pump in the cassette required to prepare the patient line 34 and determine the size of the patient line 34 based on this volume. It is also possible to use other techniques, such as recognizing barcodes or other indicators on cassette 24, patient line 34, or other components that indicate the type of patient line.

[0172] Figure 11 shows an inside perspective view of the door 141 after it has been disconnected from the housing 82 of the cyclorama 14. This figure more clearly shows how the line 30 is received in the corresponding grooves of the door 141 and carriage 146, so that the indicator area 33 is captured in a specific slot of the carriage 146. With the indicator of the indicator area 33 properly positioned when the tube is attached to the carriage 146, a reader or other device can identify the markings on the indicator (e.g., representing the type of dialysate in the container 20 connected to the line 30, the amount of dialysate, the date of manufacture, the manufacturer's specificity, etc.). The carriage 146 is attached to a pair of guides 130 at its upper and lower ends (only the lower guide 130 is shown in Figure 11). In this way, the carriage 146 can move along the guides 130 on the door 141 from left to right. When moving toward the cassette mounting position 145 (to the right in Figure 11), the carriage 146 can move until it comes into contact with the stopper 131.

[0173] Figures 11-1 and 11-2 show a perspective view of the carriage 146 and a magnified perspective view of the dialysate lines 30 mounted on the carriage 146. In these exemplary embodiments, the carriage 146 may have the ability to move along the guide 130 on the door 141. The carriage 146 may have five slots 1086 and thus be able to support up to five dialysate lines 30. Each slot 1086 may have three different parts (dialysate line section 1088, ID section 1090, and clip section 1092). The dialysate line section 1088 may have a generally cylindrical cavity that allows the dialysate lines 30 to remain organized and tangle-free when mounted on the carriage 146. The clip section 1092 may be located at the opposite end of each slot 1086 relative to the dialysate line section 1088. The purpose of the clip portion 1092 is to provide a secure housing for the membrane port 1094 located on the connector end 30a of the dialysate line 30, thereby preventing the dialysate line 30 from moving during treatment.

[0174] In one embodiment of the present disclosure, the clip portion 1092 may have a semicircular shape and may include an intermediate region that extends slightly deeper than the two peripheral edge regions. The purpose of the deeper intermediate region is to accommodate the membrane port flange 1096, which may have a substantially larger radius than the rest of the membrane port. Thus, the deeper intermediate region is designed to fit the wider flange 1096, and the two edge regions provide support to prevent movement of the membrane port 1094. In addition, the deeper intermediate region may have two cutouts 1098 located on the opposite side of the semicircle. The cutouts 1098 may generally have a rectangular shape, which may allow smaller portions of the flange 1096 to extend into each of the cutouts 1098 when positioned in the clip portion 1092. The cutouts 1098 may be formed such that the distance between the upper edges of each cutout 1098 is slightly smaller than the radius of the flange 1096. Therefore, a sufficiently large force is required to snap the flange 1096 into the clip portion 1092. Furthermore, allowing the distance between the upper edges of the two cutouts 1098 to be smaller than the radius of the flange 1096 helps prevent the dialysate line 30 from being accidentally removed during processing.

[0175] In this exemplary embodiment, the carriage 146 can offer superior performance compared to previous designs due to its ability to withstand any deformation of the membrane port 1094. The carriage 146 is designed to extend the membrane port 1094 between the front of the flange 1096 and the rear of the sleeve. If the membrane port 1094 is further extended to any location during treatment, the walls of the carriage 146 can support the flange 1096.

[0176] According to another aspect of this disclosure, the ID section 1090 can be positioned between the dialysate line section 1088 and the clip section 1092. The ID section 1090 can generally have a rectangular shape and thus have the capacity to accommodate a specific tag 1100 which can be snapped onto the dialysate line 30 in an indicator area 33. The indicator area 33 can have an annular shape that is sized and configured to fit within the ID section 1090 when attached to the carriage 146. The specific tag 1100 can provide indications of the type of dialysate associated with each line 30, the amount of dialysate, the date of manufacture, and the manufacturer's specificity. As shown in Figure 11-1, the ID section 1090 can include a two-dimensional (2-D) barcode 1102 which can be printed on the bottom of the ID section 1090. The barcode 1102 can be a data matrix symbol with 10 blocks per side and may include an "empty" data matrix code. The barcode 1102 can be placed on the carriage 146 directly below the specific tag 1100 when the dialysis fluid line 30 is mounted on the carriage 146. However, in an alternative embodiment, the barcode 1102 can be applied to the ID section 1090 of the carriage 146 by sticker or laser engraving. In yet another embodiment, the barcode 1102 can include a data matrix in which the length and width dimensions vary and the number of blocks per side varies.

[0177] However, in this exemplary embodiment, a specific number of blocks per side and specific lengths and widths of each barcode 1102 were specifically chosen to provide the most robust design under various conditions. Using only 10 blocks per side may result in barcodes 1102 with larger blocks, thus ensuring that the barcodes 1102 are easily readable even under the dark conditions present inside the cyclo housing 82.

[0178] Figures 11-3 and 11-4 show perspective views of a folded identification tag 1100 and a carriage drive assembly 132 equipped with an automatic ID camera 1104 mounted on an automatic ID camera substrate 1106, respectively. According to aspects of this disclosure, the identification tag 1100 can be formed from an injection mold and then folded for snapping in the vicinity of the indicator area 33. The identification tag 1100 can be equipped with rounded edges, which can prevent damage to the dialysis fluid container 20 during transport. The identification tag 1100 can further be equipped with an 8x8 mm two-dimensional (2-D) data matrix symbol 1103 having 18 blocks and a quiescent zone (which can be provided by a sticker) per side. The information contained in these data matrix symbols 1103 can be provided from the camera 1104 to the control system 16, which can then acquire a mark through various processing such as image analysis. Therefore, the automatic ID camera 1104 will have the ability to detect slots 1086, including accurately installed dialysate lines 30, incorrectly installed lines 30, or absent lines 30. An accurately installed dialysate line 30 allows the camera 1104 to detect a data matrix symbol 1103 placed on a specific tag 1100; the absence of a dialysate line 30 allows the camera 1104 to detect an empty data matrix barcode 1102 placed on the carriage 146 directly below the membrane port 1094; and an incorrectly installed dialysate line 30 will block the empty data matrix barcode 1102, resulting in no data matrix for that slot to be encoded by the camera 1104. Thus, the camera 1104 should always encode data matrices in all slots 1086 on the carriage 146, exposing incorrectly installed dialysate lines 30.

[0179] In this exemplary embodiment, the ability to detect the characteristics of the dialysate line 30 by a specific tag 1100 located in the indicator area 33 can provide the advantage of allowing the user to position the line 30 at any location on the carriage 146 without affecting the system operation. In addition, since the cyclorama 14 can automatically detect the characteristics of the dialysate line, it is not necessary to ensure that a specific line 30 is positioned at a specific location on the carriage 146 for the system to function properly. Instead, the cyclorama 14 can identify which line 30 is where and appropriately control the characteristics of the cassette 24 and other systems.

[0180] According to another aspect of this disclosure, the specific tag 1100 must face the carriage drive assembly 132 for encoding by the camera 1104. To ensure this, the carriage 146 and the specific tag 1100 may have supplemental positioning features. Furthermore, the dialysate line 30 with the specific tag 1100 should also be compatible with a clean flush dialyzer, and therefore the dialysate line 30 with the specific tag 1100 can be constructed to fit into a cylinder with a diameter of 0.53 inches. In one embodiment, the positioning features may be a simply flat bottom bill on the specific tag 1100 and a matching rib on the carriage 146. In one embodiment of this disclosure, the bill and rib may slightly interfere to push the rear of the specific tag 1100 upward. This arrangement may result in a small amount of misalignment but reduces misalignment on another axis. Finally, to ensure that the specific tag 1100 is properly mounted, the front of the carriage drive assembly 132 can be designed with a clearance of only about 0.02 inches relative to the current positioning of the carriage 146 and the specific tag 1100.

[0181] According to another aspect of this disclosure, the automatic ID camera board 1106 can be mounted to the rear of the carriage drive assembly 132. In addition, the automatic ID camera 1104 can be mounted to the camera board 1106. The camera board 1106 can be positioned approximately 4.19 inches from the specific tag 1100. However, in other embodiments, the camera board 1106 may be moved to the rear without any significant consequences. The plastic window 1108 can also be mounted to the front of the carriage drive assembly 132, which allows the specific tag 1100 to be imaged while also preventing the entry of fluids and fingers. The automatic ID camera 1104 can be equipped with a camera lens of any type, such as those used for security applications, or a lens intended for a camera phone with the IR filter removed. According to aspects of this disclosure, the camera lens can be small, lightweight, low-cost, and have high image quality.

[0182] In addition, a single SMD infrared LED 1110 can be mounted on the camera board 1106. The LED 1110 can then illuminate a specific tag 1100 so that the camera 1104 can easily encode the data matrix. Illumination of the specific tag 1100 is important because the internal environment of the Cycla housing 82 is almost entirely devoid of light. Therefore, without the LED 1110 illuminating the specific tag 1100, the camera 1104 would be unable to encode the data matrix. Furthermore, to avoid generating a flash in front of the specific tag 1100, the LED 1110 may be mounted 0.75 inches away from the camera 1104. An FPGA can also be mounted on the camera board 1106 and act as a relay between the OV3640 image sensor and the Voyager UI processor. In addition to simplifying the processor's work, this architecture may allow the use of different image sensors without any other Voyager hardware or software modifications. Finally, image encoding is handled by the open-source package libdmtx, which is addressable from numerous programming languages ​​and can be executed from an instruction line for testing purposes.

[0183] Figure 12 shows a perspective view of the carriage drive assembly 132 in the first embodiment, which functions to move the carriage 146 to remove the cap from the spike 160 on the cassette, remove the cap 31 on the dialysate line 30, and connect the line 30 to the spike 160. The drive element 133 is configured to move from left to right along the rod 134. In this exemplary embodiment, the air bag powers the movement of the drive element 133 along the rod 134, but any suitable drive mechanism, including a motor, hydraulic system, etc., 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 upper 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 further includes a window 136 through which an imaging device, such as a CCD or CMOS imager, can capture image information of the indicators in the indicator area 33 on the line 30 mounted on the carriage 146. The image information of the indicators in the indicator area 33 can be provided from the imaging device to a control system 16, which can acquire the marks, for example, 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 extends forward and backward using a separate drive mechanism, such as a pneumatic air bladder.

[0184] Figure 13 shows 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 positioned to move in and out along the groove 149a within the housing of the cap stripper 149 (generally perpendicular to the rod 134). Each of the semicircular cutouts of the stripper element extends forward, allowing it to engage with the corresponding groove of the cap 31 on line 30 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 is able to move with the carriage 146 as the drive element 133 moves. Figure 14 shows a partial rear view of the carriage drive assembly 132. In this embodiment, the drive element 133 is moved toward the mounting position 145 of the cassette 24 by the first air bag 137, which expands to move the drive element 133 to the right in Figure 14. The drive element can be moved to the left by the second air bag 138. Alternatively, the drive element 133 can be moved forward or backward by one or more motors coupled to a gear assembly of a linear drive mechanism, such as a ball screw assembly (where the carriage drive assembly is attached to a ball nut) or a rack and pinion assembly. The stripper element 1491 of the cap stripper 149 can move in and out of the cap stripper housing by the third air bag, or alternatively, by a motor coupled to the linear drive mechanism assembly as described above.

[0185] Figures 15 to 18 show another embodiment of the carriage drive assembly 132 and the cap stripper 149. As can be 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 can be seen in the right rear perspective view of the carriage drive assembly 132 in Figure 16 the stripper element is moved outward and inward by the air bladder 139, although other configurations are possible as described above.

[0186] Figures 17 and 18 show left and right front perspective views of another embodiment of the cap stripper 149 relative to the stripper element 1491. In the embodiment shown in Figure 13, the stripper element 1491 comprised only a fork-shaped element configured to engage with the cap 31 of the dialysate line 30. In the embodiments of Figures 17 and 18, the stripper element 1491 comprises not only the fork-shaped element 60 but also rocker arms 61 pivotably mounted to the stripper element 1491. As will be described in more detail below, the rocker arms 61 support the removal of the spike cap 63 from the cassette 24. Each of the rocker arms 61 comprises a dialysate line cap engaging portion 61a and a spike cap engaging portion 61b. The rocker arm 61 is normally biased to operate, and as a result, the spike cap engaging portion 61b is positioned near the stripper element 1491, as shown in the rocker arm 61 in Figure 18. However, when the cap 31 is received by the corresponding fork-shaped element 60, the dialysate line cap engaging portion 61a comes into contact with the cap 31, which causes the rocker arm 61 to pivot, and as a result, the spike cap engaging portion 61b moves away from the stripper element 1491, as shown in Figure 17. This position allows the spike cap engaging portion 61b to come into contact with the spike cap 63 (in particular, the flange on the spike cap 63).

[0187] Figure 19 shows a front view of the stripper element 1491 and its position in several cross-sectional views shown in Figures 20-22. Figure 20 shows the rocker arm 61 without the spike cap 63 or dialysate line cap 31 located near the stripper element 1491. The rocker arm 61 is pivotally attached to the stripper element 1491 at a point approximately midway between the spike cap engagement portion 61b and the dialysate 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 located near the stripper element 1491. Figure 21 shows that even when the stripper element 1491 moves forward toward the spike cap 63 without the dialysate line cap 31 engaging with the fork-shaped element 60, the rocker arm 61 maintains this position (i.e., the spike cap engaging portion 61b is in the vicinity of the stripper element 1491). As a result, the rocker arm 61 does not rotate clockwise or engage with the spike cap 63 unless the dialysate line cap 31 is present. Thus, the spike cap 63, which does not engage with the dialysate line cap 31, is not removed from the cassette 24.

[0188] Figure 22 shows an example in which the dialysate line cap 31 engages with the fork-shaped element 60 and contacts the dialysate line cap engaging portion 61a of the rocker arm 61. This rotates the rocker arm 61 clockwise (as shown in the figure) to engage the spike cap engaging portion 61b with the spike cap 63. In this embodiment, the engagement of portion 61b involves positioning portion 61b adjacent to the second flange 63a on the spike cap 63, so that as the stripper element 1491 is moved to the right (as shown in Figure 22), the spike cap engaging portion 61b contacts the second flange 63a and assists in pulling the spike cap 63 away from the corresponding spike 160. The dialysate line cap 31 is made of a flexible material such as silicone rubber, thereby allowing the return portion 63c of the spike cap 63 to expand the hole 31b of the cap 31 (see Figure 23) and be caught by the surrounding internal groove or recess within the cap 31. The first flange 63b on the spike cap 63 acts as a stopper at the end of the dialysate line cap 31. The wall defining the groove or recess in the hole 31b of the cap 31 can be symmetrical or preferably asymmetrically configured to conform to the shape of the return portion 63c (see Figure 33 for a cross-sectional view of the cap 31 and the groove or recess). The second flange 63a on the spike cap 63 acts as a tooth, engaging with the spike cap engaging portion 61b of the rocker arm 61 to provide additional tensile force to disengage the spike cap 63 from the spike 160 if necessary.

[0189] Figures 11-5 and 11-6 show two different perspective views of another embodiment of the stripper element 1491 of the cap stripper 149. In the embodiment shown in Figure 13, the stripper element 1491 uses a fork-shaped element 60 configured to engage with the cap 31 of the dialysate line 30. In the embodiment shown in Figure 11-5, the stripper element 1491 may further comprise a plurality of detection elements 1112 and a plurality of rocker arms 1114, in addition to comprising the fork-shaped element 60. The detection elements 1112 and rocker arms 1114 may be arranged in two parallel columns running perpendicularly along the stripper element 1491. In one embodiment, each column may comprise five individual detection elements 1112 and rocker arms 1114, each of which is arranged to generally align with the column corresponding to each of the fork-shaped elements 60. Each detection element 1112 may be mechanically connected or linked to one of the corresponding rocker arms 1114. In addition, an assembly comprising each detection element 1112 and rocker arm 1114 may include a biasing spring (not shown) that continues to bias each rocker arm 1114 toward a disengaged position, and detection elements 1112 in a position that is in contact with and moved by the presence of the dialysate line cap 31 on the fork-shaped element 60. Each detection element 1112 can be displaced and tilted toward the rear of the stripper element 1491 by contact with the corresponding dialysate line cap 31 on the fork-shaped element 60. Through the mechanical connection between the detection element 1112 and the rocker arm 1114, the rocker arm 1114 can pivot or tilt laterally toward the spike cap 63 in contact between the dialysate line cap 31 and the detection element 1112. As the rocker arm 1114 rotates or tilts toward the spike cap 63, it can engage with the second flange 63a on the spike cap 63, allowing the stripper assembly to remove the spike cap 63 from its corresponding spike.

[0190] Figures 11-7a to 11-7c illustrate the relationship between the detection element 1112 and the dialysate line cap 31, and between the rocker arm 1114 and the spike cap 63. Figure 11-7c shows the detection element 1112 and the rocker arm 1114 without the spike cap 63 and the dialysate line cap 31. As shown in Figure 11-7b, the outer flange 31c of the dialysate line cap 31 has a diameter large enough to contact the detection element 1112. As shown in Figure 11-7a, without the dialysate line cap 31, the spike cap 63 does not come into contact with the detection element 1112 sufficiently by the cap 63 alone to displace it and rotate it away from the spike cap 63. As shown in Figure 11-7b, the displacement of the detection element 1112 rotates or tilts the rocker arm 1114 toward the spike cap 63, eventually rotating or tilting it to a position adjacent to the flange 63a of the spike cap 63. As shown in Figure 11-7a, when the rocker arm 1114 is in the non-extended position, it can leave a predetermined amount (e.g., 0.040 inches) of empty space around the outside of the second flange 63a of the spike cap 63. When the rocker arm 1114 moves toward the extended position, its range of motion can be configured to impart a slight compressive force to its corresponding spike cap 63 to ensure secure engagement.

[0191] Once the rocker arm 1114 is positioned adjacent to the flange 63a of the spike cap 63, the movement of the stripper element 1491 to the right engages with the spike cap 63 via the flange 63a, assisting in pulling the spike cap 63 away from its corresponding spike 160. In the absence of dialysate lines and their associated dialysate line caps 31, the stripper element 1491 does not remove the corresponding spike cap 63, leaving its associated spike 160 sealed. In this way, fewer cassette spikes 161 are accessible when fewer than the maximum number of dialysate lines that need to be used are present.

[0192] Figure 23 shows an enlarged exploded view of the connector end 30a of the dialysate line 30 with the cap 31 removed (in Figure 23, the cap 31 is shown 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 with the cyclorama 14. However, it may be useful in allowing the operator to manually remove the cap 31 from the terminal end of the dialysate line 30 if necessary). In this exemplary embodiment, the indicator in the indicator area 33 has an annular shape that is sized and configured to fit into the corresponding slot of the carriage 146 when mounted as shown in Figures 10 and 11. Of course, the indicator can be any suitable form. The cap 31 is configured to fit onto the leading edge of the connector end 30a and has internal holes, seals, or other features that allow for a leak-free connection with the spike 160 on the cassette 24. The connector end 30a may be provided with a passable wall or partition (not shown; see item 30b in Figure 33) to prevent leakage of dialysate from the connector end 30a into the line 30 even when the cap 31 is removed. The wall or partition may be passed through by the spike 160 when the connector end 30a is attached to the cassette 24, allowing flow from the line 30 to the cassette 24. As discussed above, the cap 31 may be provided with a groove 31a that engages with the fork-shaped element 60 of the cap stripper 149. The cap 31 may further be provided with a hole 31b configured to receive the spike cap 63. The hole 31b and the cap 31 can be configured such that the cap 31 can properly grip the spike cap 63 when the cap stripper 149 engages with the groove 31a and the spike cap 63 of the spike 160 is received in the hole 31b, so that 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 supported by the cap 31.This removal can be assisted by a rocker arm 61 that engages with the second flange 63a or with other feature parts on the spike cap 63, as described above. The cap 31 and spike cap 63 can then be removed from the connector end 30a and line 30 attached to the spike 160 by the carriage 146.

[0193] Once the procedure is complete, or when line 30 and / or cassette 24 are ready to be removed from the cyclora 14, the door 141 may be opened, and the cap 31 and attached spike cap 63 can be reattached to the spike 160 and line 30 before cassette 24 and line 30 are removed from the cyclora 14. Alternatively, the dialysate container with cassette 24 and line 30 can be removed together from the cyclora 14 without reattaching the cap 31 and attached spike cap 63. The advantages of this approach include a simplified removal process and avoidance of any potential fluid leakage onto or into the cyclora due to improper reattachment or improper sealing of the cap.

[0194] Figures 24–32 show perspective views of the carriage 146, cap stripper 149, and cassette 24 during line mounting and automatic connection operation. The door 141 and other cyclo components are not shown for clarity. In Figure 24, the carriage 146 is shown in a folded position downward, 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 mounted on the carriage 146 and the cassette 24 is mounted in mounting position 145. At this point, the door 141 can be closed to prepare the cyclo for operation. In Figure 26, the door 141 is closed. Identifiers or indicators in the indicator area 33 on the line 30 can be read to identify various line characteristics, so that the cyclo 14 can determine which dialysate and how much is loaded, etc. In Figure 27, the carriage 146 moves to the left and engages with the cap 31 on line 30 along with the corresponding spike cap 63 on cassette 24. During operation, the drive element 133 engages with the cap stripper 149 and similarly moves 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 and engages the fork-shaped element 60 with the cap 31, thereby engaging with the cap 31 which is coupled to the spike cap 63. If any, the rocker arm 61 can move to an engagement position with respect to 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, as a result pulling the cap 31 and spike cap 63 from the corresponding spike 160 on cassette 24. During this operation, the rocker arm 61 (if any) can assist in pulling the spike cap 63 away from the cassette 24. In Figure 30, the cap stripper 149 stops moving to the right, and the carriage 146 continues to move away from the cassette 24.This causes the connector end 30a of line 30 to be pulled away from the cap 31, leaving the cap 31 and spike cap 63 attached to the cap stripper 149 by the fork-shaped element 60. In Figure 31, the cap stripper 149 retracts, clearing the 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 line 30 with the corresponding spike 160 on the cassette 24. The carriage 146 may remain in this position during the cyclization operation. Once the procedure is complete, the operation shown in Figures 24–32 is reversed, allowing the caps to be reattached to the spike 160 and the dialysate line 30, and the cassette 24 and / or line 30 to be removed from the cyclization 14.

[0195] To further illustrate the removal of the cap 31 and spike cap 63, Figure 33 shows a cross-sectional view of the cassette 24 at five different stages of the connection of the line 30. At the upper spike 160, as shown in Figure 26, the spike cap 63 remains in place on the spike 160, and the dialysate line 30 is located away from the cassette 24. At the second spike 160, from top to bottom, as shown in Figures 27 and 28, the dialysate line 30 and cap 31 engage with the spike cap 63. At this point, the cap stripper 149 can engage with the cap 31 and spike cap 63. At the third spike 160, from top to bottom, the dialysate line 30, cap 31, and spike cap 63 move away from the cassette 24, as shown in Figure 29. At this point, the cap stripper 149 can stop moving to the right. At the fourth spike 160, the dialysate line 30 continues to move to the right from above, as shown in Figure 30, and the cap 31 is removed from the line 30. Once the caps 31 and 63 are retracted, the dialysate line 30 moves to the left, as shown in Figure 32, and the connector end 30a of the line 30 is fluidly connected to the spike 160.

[0196] Various sensors can be used to assist in ensuring that the carriage 146 and cap stripper 149 move completely to their expected positions. In one embodiment, the carriage drive assembly 132 may be equipped with six Hall effect sensors (not shown) (four of which are for the carriage 146 and two are for the cap stripper 149). A first cap stripper sensor may be positioned to detect when the cap stripper 149 is fully retracted. A second cap stripper sensor may be positioned to detect when the cap stripper 149 is fully extended. A first carriage sensor may be positioned to detect when the carriage 146 is in the "home" position, i.e., in the position that allows the cassette 24 and line 30 to be loaded. A second carriage sensor may be positioned to detect when the carriage 146 is in the position to engage with the spike cap 63. A third carriage sensor may be positioned to detect when the carriage 146 has reached the position to remove the cap 31 from line 30. A fourth carriage sensor can be positioned to detect when the carriage 146 moves to a position where the connector end 30a of line 30 engages with the corresponding spike 160 of cassette 24. In other embodiments, a single sensor can be used to detect two or more of the carriage positions described above. The cap stripper and carriage sensors can supply input signals to an electronic control board (automatic connection board), which can then communicate specific confirmation or error codes to the user via the user interface 144.

[0197] Figure 11-6 shows a perspective view of another embodiment of the carriage drive assembly 132. In the embodiment shown in Figure 12, the carriage drive assembly 132 comprised only the drive element 133, rod 134, tab 135, and window 136. In the embodiment of Figure 11-6, the carriage drive assembly 132 may further comprise a tandem automatic ID view box 1116 in addition to the drive element 133, rod 134, tab 135, and window 136. The view box 1116 may be positioned directly adjacent to the window 136. The view box 1116 may also be positioned and formed such that, as the carriage 146 moves either to the right or to the left along the guide 130, the horizontal axis of each of the five slots 1086 positioned on the carriage 146 passes through the center of the corresponding view box 1116. The view box 1116 may allow an automatic ID camera 1104 mounted on the camera board 1106 to detect whether the dialysate line cap 31 is positioned on the line 30 before the dialysate line engages with the spike cap 63. This may allow confirmation that the user has not removed the cap 31 prematurely. Once the presence or absence of the cap 31 is determined, the camera 1104 can provide a corresponding input signal to the electronic control board (referred to herein as the automatic connection board), which can then communicate a specific confirmation or error code regarding the presence of the cap 31 on the line 30 to the user via the user interface 144.

[0198] According to another aspect of the present disclosure, the carriage drive assembly 132 may further comprise an autoconnection board 1118. The autoconnection board 1118 may be mounted on top of the carriage drive assembly 132, thereby extending the overall length of the assembly 132. In this exemplary embodiment, an LED 1120 may be further mounted on the autoconnection board 1118. The LED 1120 may be positioned in a fixed location directly above the fork-shaped element 60. The LED 1120 may also be directed so that the light emitted from the LED 1120 moves downward across the stripper element 1491. According to another aspect of the present disclosure, the carriage drive assembly 132 may further comprise a fluid board 1122. The fluid board 1122 may be mounted on the bottom of the carriage drive assembly 132, thereby extending the length of the assembly 132. In this exemplary embodiment, a receiver 1124 (not shown) can be mounted on the fluid substrate 1122 directly below the LED 1120, which is mounted on the autoconnection substrate 1118. Thus, the LED 1120 can emit light across the fork-shaped element 60, and if the light is detected by the receiver 1124, the dialysis fluid line cap 31 is not left on the stripper element 1491, but if the light is blocked on its way to the receiver 1124, the cap 31 may be left on the stripper element 1491. This combination of LED 1120 and receiver 1124 enables the detection of the cap 31 which may be inadvertently left on the stripper element 1491 by the user or the cyclorama 14. According to aspects of this disclosure, the fluid substrate 1122 may further have the ability to detect humidity, moisture, or other liquids which may be located inside the carriage drive assembly 132 and which may potentially cause the cyclorama 14 to fail.

[0199] There may be advantages in adjusting the force with which the carriage 146 engages with the spike cap 63, depending on how many lines 30 are installed. The force required to complete the connection to the cassette 24 increases with the number of caps 31 that must be coupled to the spike cap 63. A detection device that detects and reads information from line indicators in the indicator area 33 can also be used to provide the data necessary to adjust the force applied to the drive element 133. The force can be generated by a number of devices, including, for example, the first air bag 137, or a linear actuator such as a motor / ball screw. An electronic control board (e.g., an auto-connection board) can receive input from the line detection 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.

[0200] According to aspects of this disclosure, the carriage drive assembly 132 may need to be able to generate a force of at least 550 N (124 lbf) on the carriage 146 to engage the membrane ports with the spikes 160. This force is measured in the carriage direction for spiking the membrane ports onto the cassette 24. The maximum force required to strike a sterile PVC membrane port onto the spikes 160 may be 110 N. In addition, the maximum force required to strike a sterile JPOC membrane port onto the spikes 160 may be 110 N. These force requirements ensure that the carriage drive assembly 132 can strike five JPOC ports. In other embodiments, the force requirements for the PVC ports may be further reduced based on the current insertion force.

[0201] 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 may have other advantages in addition to the simplicity of operation. For example, since the spike cap 63 is removed by their engagement with the cap 31 on line 30, if there is no line 30 mounted on a particular slot on the carriage 146, the spike cap 63 will not be removed in that position. For example, the cassette 24 has five spikes 160 and corresponding spike caps 63, but the cyclorama 14 can operate with four or fewer lines 30 (or even zero) associated with the cyclorama 14. In those slots on the carriage 146 where there are no lines 30, there is no cap 31, and therefore no mechanism from which the spike cap 63 can be removed in that position. Thus, if there is no line 30 connected to a particular spike 160, the cap 63 on that spike 160 may remain in place during use of the cassette 24. This can help prevent leaks and / or contamination at the spike 160.

[0202] The cassette 24 in Figure 33 has a few features that differ from those shown in the embodiments shown in Figures 3, 4, and 6, for example. In the embodiments of Figures 3, 4, and 6, the heater bag port 150, the lead line port 152, and the patient line port 154 are configured to have a central tube 156 and a skirt 158. However, as described above and shown in Figure 33, the ports 150, 152, and 154 can have only the central tube 156 and not the skirt 158. This is also shown in Figure 34. The embodiment shown in Figure 34 has raised ribs formed on the outer surface of the left pump chamber 181. Raised ribs are also provided in the right pump chamber 181, and can provide the mechanism inside the door 141 at the cassette mounting position 145 to an additional contact point on the outer wall of the pump chamber 181, which presses the cassette against the control surface 148 when the door 141 is closed. The raised ribs are not necessary, and instead, the pump chamber 181 may not have ribs or other features, as shown for the right-hand pump chamber 181 in Figure 34. Similarly, the spike 160 in embodiments of Figures 3, 4, and 6 does not have a skirt or similar feature on the base of the spike 160, while the embodiment in Figure 33 has a skirt 160a, also shown in Figure 34. The skirt 160a can be positioned to receive the end of the spike cap 63 in a recess between the skirt 160a and the spike 160, thereby assisting in forming a seal between the spike 160 and the spike cap 63.

[0203] A feature of another invention shown in Figure 33 relates to the arrangement of the distal tip of the spike 163 through the spike 160 and the lumen 159. In this embodiment, the distal tip of the spike 160 is positioned on or near the longitudinal axis of the spike 160, which generally passes along the geometric center of the spike 160. Positioning the distal tip of the spike 160 on or near the longitudinal axis can help to reduce positioning tolerances when the spike 160 is engaged with the corresponding dialysate line 30, and helps the spike 160 pierce the partition or membrane 30b at the connector end 30a of the line 30. As a result, the lumen 159 of the spike 160 is positioned near the bottom of the spike 160, generally offset from the longitudinal axis of the spike 160, as shown, for example, in Figure 33 and in the end view of the spike 160 in Figure 35. Furthermore, the tip of the spike 160 has a somewhat reduced diameter compared to the closer portion of the spike 160 (in this embodiment, the spike 160 actually has a stepped change in diameter for about two-thirds of the length of the spike 160 from the body 18). The reduced diameter of the spike 160 at the tip can provide clearance between the spike 160 and the inner wall of the line 30, and thus, when the spike 160 penetrates the partition wall 30b, it folds back and provides space for the spike 160 to position itself between the spike 160 and the line 30. The stepped feature 160b on the spike 160 (for example, shown in Figure 35A) can also be positioned to engage with the line 30 in a location where the partition wall 30b connects to the inner wall of the line 30, thereby improving the seal formed between the line 30 and the spike 160.

[0204] In another embodiment, as shown in Figure 35A, the length of the base portion 160c of the spike 160 can be shortened, thereby reducing the force required to remove the spike cap 63 from the spike 160 or to strike it against the connector end 30a of the dialysate line 30. Shortening the base portion 160c reduces the area of ​​frictional contact between the spike 160 and its cap 63 or between the spike 160 and the inner surface of the connector end 30a. In addition, the skirt 160a at the base portion of the spike 160 can be replaced with individual posts 160d. The posts 160d allow the spike cap 63 to properly seat on the spike 160 and allow for more complete circulation of the sterile fluid or gas around the spike 160 during sterilization before and after packaging of the dialysate supply set 12.

[0205] To make more full use of the embodiment shown in Figure 35A, a spike cap 64 as shown in Figure 35B can be used. The skirt 65 on the base of the spike cap 64 is constructed to fit snugly over the post 160d of the base of the spike 160 shown in Figure 35A. In addition, the intermittent ribs 66 and 67 around the inside of the base of the spike 160 can provide a slip fit between the spike cap 64 and the base 160c of the spike 160, and allow sterile gas or fluid to penetrate further over the base of the capped spike 160. In the cross-sectional view of the spike cap 64 shown in Figure 35C, a set of three inner ribs 66, 67, 68 can be used to provide a slip fit between the spike cap 64 and the base 160c of the spike 160. In one embodiment, ribs 66 and 67 have interruptions or gaps 66a and 67a along their circumferential surfaces, allowing external gas or fluid to flow across the base portion 160c of the spike 160. A third rib 68 is free of imperfections around it to form a sealed engagement between the spike cap 64 and the base portion 160c of the spike 160, sealing the base portion 160c from the rest of the outer surface of the spike 160. In other embodiments, the ribs within the spike cap 64 can be oriented longitudinally rather than circumferentially, or in other orientations that provide a sliding fit between the spike cap 64 and the spike 160, while allowing external gas or fluid to come into contact with the outside of the base portion 160c of the spike 160. In the shown embodiments, for example, most of the outer surfaces of the cassette, spike cap, and base portion 160c of the spike 160 can be sterilized by exposing the outside of the cassette to ethylene oxide gas. Since the diameter of the stepped feature portion 160b and the tip of the spike 160 are smaller than the inner diameter of the overlapping portion of the spike cap 64, any gas or fluid entering the spike lumen from inside the cassette can reach the sealing rib 68 on the outer surface of the spike 160.Thus, any sterilizing gas, such as ethylene oxide, entering the fluid passage of the cassette can reach the rest of the outer surface of the spike 160. In one embodiment, the gas can enter the cassette, for example, through a vent cap at the end of the patient line 34 or the outlet line 28.

[0206] Once the cassette 24 and line 30 are mounted on the cyclorama 14, the cyclorama 14 must control the operation of the cassette 24 to move the fluid from the dialysate line 30 to the heater bag 22 and the patient. Figure 36 shows a plan view of the control surface 148 of the cyclorama 14 that interacts with the pump chamber side of the cassette 24 (e.g., shown in Figure 6) to control the fluid pumping and fluid path within the cassette 24. The control surface 148, which may consist of a single sheet of silicone rubber and can be described as a kind of gasket when stopped, can generally be flat. The valve control area 1481 may be defined (or not defined) on the control surface 148 by, for example, scoring, grooves, ribs, or other features on or over the sheet surface, and can be positioned to be movable in a direction generally intersecting the plane of the sheet. By moving inward / outward, the valve control region 1481 can move the relevant portion of the membrane 15 on the cassette 24, thereby opening and closing the respective valve ports 184, 186, 190, and 192 of the cassette 24, and thus controlling the flow within the cassette 24. Two larger regions (pump control regions 1482) are similarly movable, thereby moving the relevant shaped portion 151 of the membrane 15 that cooperates with the pump chamber 181. Like the shaped portion 151 of the membrane 15, the pump control region 1482 can be shaped to correspond to the shape of the pump chamber 181 when the control region 1482 is extended into the pump chamber 181. In this way, the portion of the control sheet 148 in the pump control region 1482 does not necessarily need to be stretched or elastically deformed during pump operation.

[0207] Regions 1481 and 1482 can each have associated vacuum or outlet ports 1483 which can be used to remove all or substantially all of any air or other fluid that may be present between the membrane 15 of the cassette 24 and the control surface 148 of the cyclorama 14 after, for example, the cassette 24 has been mounted on the cyclorama 14 and the door 141 has been closed. This can help ensure tight contact of the membrane 15 with the control regions 1481 and 1482 and help control the supply of a desired volume by the pump operation and / or the open / closed state of various valve ports. The vacuum port 1482 is formed in a position where the control surface 148 is not pressed against the wall or other relatively rigid 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 can have a vacuum vent clearance region formed adjacent to the pump chamber. In this exemplary embodiment, as shown in Figures 3 and 6, the base member 18 may be provided with a vacuum vent port clearance or extension feature 182 (e.g., a concave region fluid-connected to the pump chamber) adjacent to and outside the elliptical recess forming the pump chamber 181, thereby allowing the vacuum vent port 1483 for the pump control area 1482 to remove any air or fluid from between the membrane 15 and the control surface 148 (e.g., by rupture of the membrane 15) without interference. The extension feature may also be located within the boundary of the pump chamber 181. However, locating the vent port feature 182 outside the periphery of the pump chamber 181 makes it possible to secure a larger pump chamber volume for pumping fluid, for example, allowing the maximum footprint of the pump chamber 181 to be used for pumping dialysate. Preferably, the extended feature section 182 is positioned lower vertically relative to the pump chamber 181, so that any liquid leaking between the membrane 15 and the control surface 148 is drawn out through the vacuum port 1483 as early as possible. Similarly, the vacuum port 1483 associated with the valve 1481 is preferably positioned lower vertically relative to the valve 1481.

[0208] Figure 36A shows that the control surface 148 may be constructed or molded to have a rounded transition portion between the base element 1480 of the control surface 148 and its valve and pump control regions 1481 and 1482. The joints 1491 and 1492 can be molded to a small radius to transition from the base element 1480 to the valve control region 1481 and the pump control region 1482, respectively. The rounded or smooth transition portion can help prevent premature fatigue and failure of the material including the control surface 148, thereby extending its lifespan. In this embodiment, the channel 1484 leading from the vacuum port 1483 to the pump control region 1482 and the valve control region 1481 may need to be made somewhat longer to accommodate the transition portion feature.

[0209] The control regions 1481 and 1482 may be moved by controlling the air pressure and / or volume on the opposite side of the control surface 148 of the cassette 24 (e.g., the rear side of the rubber sheet forming the control surface 148). For example, as shown in Figure 37, the control surface 148 has control chambers 171 positioned in relation to each of the control regions 1481 and 1482, and fitting blocks 170 spaced apart from each other (or, if desired, can be controlled at least independently of each other) can contact the rear surface. The surfaces of the fitting blocks 170 form an interface with the cassette 24 when the cassette 24 is pressed against it and the fitting blocks 170 operate in relation to the control surface 148 with its rear surface in contact with it. Accordingly, the control chamber of the fitting block 170 is coupled to a supplementary valve or pump chamber of the cassette 24, sandwiching the control regions 1481 and 1482 of the control surface 148 adjacent to the fitting block 170, as well as the relevant regions (such as the shaped portion 151) of the membrane 15 adjacent to the cassette 24. Air or other control fluid can enter and exit the control chamber 171 of the fitting 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 achieve pumping action in the pump chamber 181. In one exemplary embodiment shown in Figure 37, the control chamber 171 can be arranged as a cylindrical shaped region adjacent to the back of each valve control region 1481, and a pair of elliptical voids adjacent to the back of the pump control region 1482. Fluid control ports may be provided in each control chamber 171, thereby allowing the cyclorama 14 to control the fluid volume and / or fluid pressure in each control chamber. For example, the fitting block 170 can be fitted into a manifold 172 which includes various ports, channels, openings, gaps, and / or other features that communicate with the control chambers 171 and allow appropriate pneumatic / vacuum pressure to be supplied to the control chambers 171. Although not shown, pneumatic / vacuum control can be achieved in any suitable manner through the use of controllable valves, pumps, pressure sensors, accumulators, etc.Of course, it should be understood that the control regions 1481 and 1482 may be moved in other ways by gravity systems, fluid pressure systems, and / or mechanical systems (such as linear motors), or by combinations of systems including pneumatic systems, fluid pressure systems, gravity systems, and mechanical systems.

[0210] According to aspects of the present invention, vacuum port 1483 can be used to detect leaks in membrane 15. For example, a liquid sensor in a conduit or chamber connected to vacuum port 1483 can detect liquid if a hole opens in membrane 15 or if liquid is introduced between membrane 15 and control surface 148. For example, vacuum port 1483 is positioned and hermetically associated with a supplemental vacuum port 173 of fitting block 170, which in turn can be hermetically associated with a fluid passage 1721 leading to a common fluid collection chamber 1722 of manifold 172. Fluid collection chamber 1722 can have an inlet through which vacuum can be applied and distributed to all vacuum ports 1483 of control surface 148. By applying vacuum to fluid collection chamber 1722, fluid can be drawn out of each of vacuum ports 173 and 1483, thus removing fluid from any space between membrane 15 and control surface 148 in various control regions. However, if liquid is present in one or more regions, the associated vacuum port 1483 can draw the liquid into vacuum port 173 and line 1721 leading to fluid collection chamber 1722. Any such liquid can be collected in fluid collection chamber 1722 and detected by one or more suitable sensors (e.g., a pair of conductivity sensors that detect a change in conductivity within chamber 1722 indicating the presence of liquid). In this embodiment, the sensors can be disposed on the bottom side of fluid collection chamber 1722 and the vacuum source is connected to chamber 1722 at the upper end of the chamber. Thus, if liquid is drawn into fluid collection 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 disposed at the vacuum source connection to chamber 1722 to further assist in resisting the entry of fluid into the vacuum source. Thus, liquid leaks can be detected and acted upon (e.g., issue a warning, close a liquid inlet valve, and stop pump operation) by controller 16 before the vacuum source valve is exposed to the risk of contamination by the liquid.

[0211] In one embodiment, the inner wall of the control chamber 171 may have raised elements somewhat similar to the spacer elements 50 of the pump chamber, as shown in Figure 37, relative to the control chamber 171 associated with the pump control area 1482. These raised elements may take the form of plateau-shaped features, ribs, or other protrusions that recess the control ports away from the fully recessed control area 1482. This configuration allows for a more uniform distribution of pressure or vacuum in the control chamber 171 and prevents premature closure of any control ports by the control surface 148. The pre-formed control surface 148 (at least in the pump control area) may not be subjected to significant tensile forces even when fully extended relative to either the inner wall of the pump chamber of the cassette 24 during the feeding stroke or the inner wall of the control chamber 171 during the filling stroke. Therefore, the control region 1482 extends asymmetrically into the control chamber 171, allowing the control region 1482 to prematurely close one or more ports in the control chamber before the chamber is completely emptied. Having a feature on the inner surface of the control chamber 171 that prevents contact between the control region 1482 and the control ports helps ensure that the control region 1482 can make uniform contact with the inner wall of the control chamber during the filling process.

[0212] As suggested above, the cycler 14 can include a control system 16 having a data processor that is in electrical communication with various valves, pressure sensors, motors, etc. of the system, and is preferably configured to control such components according to a desired operating sequence or protocol. The control system 16 can include suitable circuitry, programs, computer memory, electrical connections, and / or other components for performing designated tasks. The system can include pumps, tanks, manifolds, valves, or other components for generating a desired pneumatic or other fluid pressure (a positive pressure higher than atmospheric pressure or some other reference pressure, or a negative pressure or vacuum lower than atmospheric pressure or some other reference pressure), thereby controlling the operation of the area of the control surface 148 and other pneumatic operating components. Further details regarding the control system 16 (or at least portions thereof) are provided below.

[0213] In one exemplary embodiment, the pressure in the pump control chamber 171 can be controlled by a binary valve, for example, by opening it to expose the control chamber 171 to a suitable pressure / vacuum and by closing it to shut off the pressure / vacuum source. The binary valve can be controlled using a sawtooth-shaped control signal, which can be modulated to the control pressure in the pump control chamber 171. For example, during the pump supply stroke (i.e., positive pressure is introduced into the pump control chamber 171, moving the membrane 15 / control surface 148 and pushing the liquid out of the pump chamber 181), the binary valve is driven by the sawtooth signal to open and close at a relatively fast rate 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 keep the binary valve closed for a longer time. If the pressure in control chamber 171 drops below approximately 70 mmHg, the sawtooth control signal can be applied again to the binary valve to increase the pressure in control chamber 171. In this way, during typical pump operation, the binary valve can be opened and closed multiple times and closed for one or more long periods, so that the pressure at which the liquid is pushed out of pump chamber 181 is maintained at a desired level or range (e.g., approximately 70-90 mmHg).

[0214] In some embodiments, and according to aspects of the present invention, it may be useful to detect the “end of stroke” of the membrane 15 / pump control area 1482 when, for example, the membrane 15 comes into contact with the spacer 50 in the pump chamber 181, or when the pump control area 1482 comes into contact with the wall of the pump control chamber 171. For example, during pump operation, detecting the “end of stroke” may indicate that the movement of the membrane 15 / pump control area 1482 should be reversed to start a new pump cycle (filling the pump chamber 181 or driving fluid from the pump chamber 181). In one exemplary 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 (e.g., the frequency 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 generally has a higher amplitude when the membrane 15 / pump control area 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 area 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 stroke"), the pressure fluctuation generally attenuates or changes in a manner detectable by the pressure sensor in the pump control chamber 171. This change in pressure fluctuation can be used to identify the end of stroke, and accordingly, the pump and other components of the cassette 24 and / or cyclor 14 can be controlled. [Occluded part] In one aspect of the present invention, a closure for opening and closing one or more flexible lines may comprise a pair of opposing closure members, which may be formed as flexible elements such as flat plates (e.g., leaf springs) made of spring steel, and have a force actuator configured to apply force to one or both of the closure members to operate the closure. In one embodiment, the force actuator may comprise an expandable or expandable member positioned between the flexible elements. With the expandable member reduced in size, the flexible elements are flat or substantially flat and bias their pinch heads to engage with one or more lines to clamp them in order to close them. However, when the expandable member biases the flexible elements away from each other, the flexible elements bend and pull back the pinch heads, releasing the lines and allowing flow through them. In other embodiments, the closure members may be inherently rigid to the level of force applied by the force actuator. In one embodiment, a force actuator is capable of applying force to one or both of the opposing closure members, thereby increasing the distance between the closure members in at least a portion of the area in which they face each other, and achieving opening and closing of the flexible tube.

[0215] Figure 38 shows an exploded view, and Figure 39 shows a partial assembled view of an exemplary embodiment of a occlusion section 147 that can be used to close or block patient lines 34 and derivation lines 28, and / or other lines of the cyclorama 14 or set 12 (e.g., heater bag line 26). The occlusion section 147 comprises an optional pinch head 161 (e.g., a generally flat blade-like element that contacts the tube so as to press against the door 141 and pinches the tube to close it. In other embodiments, the function of the pinch head can be replaced by one or both extended edges of the occlusion member 165. The pinch head 161 comprises a gasket 162 such as an O-ring or other member which works in cooperation with the pinch head 161 to help resist the entry of fluid (e.g., air or liquid) into the cyclorama 14 housing, for example, if there is a leak in one of the blocked lines. The bellows-type gasket 162 is located in the cyclorama housing. The pinch head 161 is mounted on a pinch head guide 163 attached to the front panel of the door, and passes through the pinch head guide 163 (i.e., the panel is exposed by opening the door 141). 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 substantial resistance to the sliding of the pinch head 161. The pivot shaft 164 attaches to the pinch head 161 a pair of opposing closing members, each having a leaf spring 165 of an exemplary embodiment, each having a hook-shaped pivot shaft bearing (e.g., as found in a standard door hinge). In other words, the opening of the axial guide on the pinch head 161 and the opening formed by the hook bearing on the leaf spring 165 are aligned with each other, and the pivot shaft 164 is inserted into the opening, so that the pinch head 161 and the leaf spring 165 are pivotably connected to each other. The leaf spring 165 can be made from any suitable material such as steel and can be positioned to be generally horizontal when unloaded. The opposite end of the leaf spring 165 is fitted with a similar hook bearing, which is pivotably connected to a linear adjuster 167 by a second pivot shaft 164. In this embodiment, the force actuator includes an air bag 166 positioned between the leaf springs 165 so that when a fluid (e.g., compressed air) is introduced into the air bag, the air bag can expand in the region between the pivot shafts 164 and push the leaf springs 165 apart from each other. The linear adjuster 167 is fixed to the cyclora housing 82, while the pinch head 161 is levitable, but its movement is guided by the pinch head guide 163. The linear adjuster 167 has a slotted opening at its lower end, allowing the entire assembly to be adjusted into place, thus enabling proper positioning of the pinch head when the occlusion 147 is installed in the cyclora 14. 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 generally needs to be properly positioned so that, as a result, with the leaf springs 165 positioned close to each other and the air bladder 166 substantially empty or at atmospheric pressure, the pinch head 161 properly compresses the patient and lead line, pinching to close the flow of the tube without cutting, twisting, or damaging the tube. The slotted opening of the linear adjuster 167 allows for high-precision positioning and fixing of the occlusion 147 into place. An override release device, such as one provided by the release blade 169, is optionally positioned between the leaf springs 165 and can be rotated to push the leaf springs 165 apart, as will be discussed in more detail below, thereby retracting the pinch head 161 into the pinch head guide 163.The release blade 169 can be operated manually to disable the occlusion unit 147, for example, in the event of power loss, failure of the air bag 166, or other circumstances.

[0216] Additional configurations and descriptions of certain components that may be useful in constructing certain embodiments of the closure are provided in U.S. Patent No. 6,302,653. The leaf spring 165 can be constructed from any material having sufficient longitudinal stiffness (resistance to bending) to elastically resist bending forces and provide sufficient restoring force in response to bending displacement to closure a desired number of extruded tubes. In the exemplary embodiment, each leaf spring is essentially flat when unloaded and in the form of a sheet or plate. In alternative embodiments utilizing one or more flexible closure members (spring members), any closure member having sufficient longitudinal stiffness (resistance to bending) to elastically resist bending forces and provide sufficient restoring force in response to bending displacement to closure a desired number of extruded tubes can be used. Potentially suitable spring members can have a wide variety of shapes, as will be apparent to those skilled in the art, such as cylindrical, prism-shaped, trapezoidal, square, or rectangular rods or beams, I-beams, elliptical beams, and bowl-shaped surfaces. Those skilled in the art can easily select the appropriate material and dimensions for the leaf spring 165 based on this instruction and the requirements of their specific application.

[0217] Figure 40 shows a plan view of the occlusion section 147, where air has been removed from the air bag 166, and the leaf springs 165 are positioned close to each other and are flat or nearly flat. In this position, the pinch head 161 is fully extended away from the pinch head guide and the front panel of the cyclorama 14 (i.e., the panel inside the door 141), allowing for occlusion of the patient and the lead-out line. On the other hand, Figure 41 shows the air bag 166 in an inflated state, where the leaf springs 165 are pushed away from each other, thereby retracting the pinch head 161 into the pinch head guide 163. (Note that the linear adjuster 167 is fixed in place relative to the cyclorama housing 82 and therefore fixed relative to the front panel of the housing 82. The leaf springs 165 are moved so as to push away from each other, so that the pinch head 161 is positioned to move freely in and out of the pinch head guide 163, and the pinch head 161 moves backward relative to the front panel.) This condition ensures that the pinch head 161 does not obstruct the patient and the lead line, and that the obstruction section 147 remains in place during the normal operation of the cyclorama 14. In other words, as discussed above, various components of the cyclorama 14 can operate using pneumatic / vacuum, for example, the control surface 148 can operate under appropriate pneumatic / vacuum drive, resulting in fluid pumping and valve operation to the cassette 24. Thus, when the cyclorama 14 is operating normally, it is possible to generate sufficient pneumatic pressure to control the system operation, as well as inflate the air bag 166, retract the pinch head 161, and prevent obstruction of the patient and the lead line. However, in the event of system shutdown, failure, error, or other conditions, it is possible to stop the pneumatic pressure to the air bag 166, thereby deflating the air bag 166, straightening the leaf spring 165, and expanding the pinch head 161 to obstruct the line. One possible advantage of the configuration shown is that the restoring force of the leaf spring 165 is balanced, and as a result, the pinch head 161 is generally not constrained by the pinch head guide 163 when moving relative to it.In addition, the opposing forces of the leaf springs 165 tend to reduce the asymmetrical wear of the assembly's pivot shafts and bushings. Also, once the leaf springs 165 are in a nearly straight position, they can exert a force in a direction generally along the length of the pinch heads 161, a force several times greater than the force exerted by the air bladder 166 on the leaf springs 165, thereby separating the leaf springs 165 from each other and retracting the pinch heads 161. Furthermore, when the leaf springs 165 are flat or nearly flat, the force that needs to be exerted by the fluid in the crushed tubes to overcome the compressive force exerted by the pinch heads 161 is applied to the leaf springs at their ends, reaching a relatively large force required when they are essentially parallel to the plane of the flattened leaf springs, thereby buckling the leaf springs by breaking the column stability of the flattened leaf springs. As a result, the occlusion 147 is highly effective at occluding the line and can reduce the chance of failure, while requiring a relatively small force to be applied by the air bladder 166 to retract the pinch head 161. The double leaf spring arrangement of the exemplary embodiment may have the additional advantage of significantly increasing the compressive force provided by the pinch head for any given force required to bend the leaf springs and / or for any given size and thickness of the leaf springs.

[0218] In some situations, the force of the closure 147 on the line may be relatively large, making it difficult to open the door 141. That is, when the pinch head 161 contacts the line and closes, the door 141 must resist the force of the closure 147, and in some cases this may make it difficult or impossible to manually operate the latch that holds the door 141 closed. Of course, when the cyclorama 14 is started and generating air pressure for operation, the closure air bladder 166 can be inflated, and the closure pinch head 161 will retract. However, in some cases, such as a pump failure in the cyclorama 14, inflation of the air bladder 166 may be impossible or difficult. To allow the door to be opened, the closure 147 may be equipped with a manual release. In this exemplary embodiment, the closure 147 may be equipped with a release blade 169 as shown in Figures 38 and 39, which comprises a pair of blades pivotably mounted for rotational movement between leaf springs 165. When stopped, the release blade can be aligned with the spring as shown in Figure 39, allowing the closing section to operate normally. However, if the leaf spring 165 is flat and the pinch head 161 needs to be manually retracted, the release blade 169 can be rotated by engaging it with, for example, a hex wrench or other tool, and turning the release blade 169, thereby pushing the blade away from the leaf spring 165. The hex wrench or other tool can be inserted into an opening in the housing 82 of the Cycra 14 (for example, an opening near the left-side handle recess of the Cycra housing 82) and operated to disengage the closing section 147, allowing the door 141 to be opened. [Pump supply volume measurement] In another aspect of the present invention, the cyclorama 14 can determine the volume of fluid supplied to various lines of the system 10 without the use of a flow meter, weighing scale, or other direct means of measuring fluid volume or weight. 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, the volume determination can be made by separating two chambers from each other, measuring the pressure in each of the two separated chambers, allowing the pressures in the two chambers to be partially or substantially equal (by fluid-connecting the two chambers), and measuring the pressure. Using the measured pressure, a known volume of one of the two chambers, and the assumption that the homogenization occurs adiabatically, the volume of the other chamber (e.g., the pump chamber) can be calculated. In one embodiment, the pressures measured after fluid-connecting the two chambers may not be substantially equal to each other (i.e., the pressures in the two chambers may not be perfectly equal). However, as described below, these substantially unequal pressures can be used to determine the volume of the pump control chamber.

[0219] For example, Figure 42 shows a schematic diagram of the pump chamber 181 of the cassette 24, its associated control components, and the inflow / outflow paths. In this illustrated example, a liquid supply source, which may comprise a heater bag 22, a heater bag line 26, and a fluid path through the cassette 24, is shown to have a liquid input at the upper opening 191 of the pump chamber. The liquid outlet, in this example, is shown to receive liquid from the lower opening 187 of the pump chamber 181 and may comprise, for example, the fluid path and patient line 34 of the cassette 24. The liquid supply source may comprise a valve (e.g., comprising a valve port 192) which can be opened and closed to allow / block flow to and from the pump chamber 181. Similarly, the liquid outlet may comprise a valve (e.g., comprising a valve port 190) which can be opened and closed to allow / block flow to and from the pump chamber 181. Of course, the liquid supply source can consist of any suitable configuration such as one or more dialysate containers, patient lines, one or more channels within the cassette 24, or other liquid sources, and similarly, the liquid outlet can consist of any suitable configuration such as a discharge line, heater bag and heater bag line, one or more channels within the cassette 24, or other liquid outlet. Generally speaking, the pump chamber 181 (i.e., to the left of the membrane 14 in Figure 42) is filled with an incompressible liquid such as water or dialysate during operation. However, air or other gases may be present in the pump chamber 181 in some situations such as during initial operation, preparation, or other situations as discussed below. Also, while aspects of the invention relating to pump volume and / or pressure detection are described in relation to the pump configuration of the cassette 24, it should be understood that aspects of the invention can be used with any suitable pump or fluid transfer system.

[0220] Furthermore, Figure 42 schematically shows, to the right of the membrane 15 and control surface 148 (they are adjacent to each other), a control chamber 171 which may be formed as a gap or other space in a fitting block 170 associated with the pump control region 1482 of the control surface 148 relative to the pump chamber 181, as discussed above. Appropriate pneumatic pressure is introduced into the control chamber 171, thereby moving the membrane 15 / control region 1482 to achieve pumping of the liquid in the pump chamber 181. The control chamber 171 can communicate with line L0, which branches to another line L1 and a first valve X1 that communicates with a pressure source (e.g., a pneumatic source or a vacuum source). The pressure source may comprise a piston pump, thereby capable of controlling the pressure supplied to the control chamber 171 by the movement of a piston within the chamber, or it may comprise a different type of pressure pump and / or tank, thereby capable of supplying appropriate gas pressure to move the membrane 15 / control region 1482 and perform a pumping action. Furthermore, line L0 leads to a second valve X2 that communicates with another line L2 and a reference chamber (e.g., a space appropriately configured to perform the measurements described below). The reference chamber further communicates with line L3, which has a valve X3 that leads to a vent or other reference pressure (e.g., an atmospheric pressure source or other reference pressure source). Each of the valves X1, X2, and X3 can be controlled independently. Pressure sensors can be positioned to measure the pressure associated with the control chamber and the reference chamber, for example, one sensor in the control chamber 171 and another in the reference chamber. These pressure sensors can be positioned and operated to detect pressure in any suitable manner. The pressure sensors can communicate with a control system 16 for the cyclorama 14, or with other suitable processors that determine the volume supplied by a pump or other feature.

[0221] As described above, the valves and other components of the pump mechanism 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 liquid supplied 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 supplied 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, a change in the volume of the control chamber 171 can be determined, which corresponds to a change in the volume of the pump chamber 181 and is reflected in the volume supplied from and received into the pump chamber 181. For example, the pressure in the control chamber 171 is reduced during the pump chamber introduction cycle (e.g., by applying negative pressure from the pressure source through an open valve X1), resulting in the membrane 15 and pump control region 1482 being retracted so as to contact at least a portion of the control chamber wall (or to another suitable location on the membrane 15 / region 1482). After this, valve X1 is closed to isolate the control chamber from the pressure source, and valve X2 is closed, thereby isolating the reference chamber from the control chamber 171. Valve X3 can be opened to allow the reference chamber to be ventilated 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 then opened to initiate pressure equalization 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 pressure measured after equalization has begun (but does not necessarily need to be completed), may be used to determine the volume of the control chamber. This process can be repeated at the end of the pump supply cycle when the sheet 15 / control area 1482 is pressed into contact with the spacer element 50 of the pump chamber 181. The volume of liquid supplied from the pump can be determined by comparing the volume of the control chamber at the end of the supply cycle with the volume at the end of the introduction cycle.

[0222] Conceptually, the pressure equalization process (e.g., when opening valve X2) is assumed to occur adiabatically, that is, without heat conduction between the air in the control chamber and reference chamber and the surrounding environment. The conceptual idea is that a virtual piston is initially positioned in valve X2 when valve X2 is closed, and when valve X2 is opened, the virtual piston moves in line L0 or L2 to equalize the pressure in the control chamber and reference chamber. The assumption that (a) the pressure equalization process occurs relatively quickly, (b) the air in the control chamber and reference chamber has approximately the same elemental concentration, (c) the temperature is similar, and that the pressure equalization occurs adiabatically may introduce only small errors in volume measurement. In one embodiment, the pressure obtained after equalization has started 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. Furthermore, errors can be reduced by using materials with low thermal conductivity for, for example, the film 15 / control surface 148, cassette 24, control chamber 171, line, reference chamber, etc., thereby reducing heat conduction.

[0223] Assuming that an adiabatic system exists between the state where valve X2 is closed and the state where valve X2 is open and the pressure is equalized, the following holds true. PV γ = constant …(1) Here, P is pressure, V is volume, and γ is equal to a constant (for example, approximately 1.4 if the gas is a diatomic gas such as air). Thus, the following equation can be written to relate the pressure and volume in the control chamber and reference chamber before and after opening valve X2 and pressure equalization occurs.

[0224] PrVr γ +PdVd γ =Constant=PfVf γ …(2) Here, Pr is the pressure in the reference chamber and lines L2 and L3 before opening valve X2, Vr is the volume in the reference chamber and lines L2 and L3 before opening valve X2, Pd is the pressure in the control chamber and lines L0 and L1 before opening valve X2, Vd is the volume in the control chamber and lines L0 and L1 before opening valve X2, Pf is the equalized pressure in the reference chamber and control chamber after opening valve X2, 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). Since Pr, Vr, Pd, Pf, and γ are known and Vf = Vr + Vd, this formula can be used to solve for Vd (here, including in the claims, it is mentioned to be used for "measured pressure" when determining volume values, etc., but it should be understood that such measured pressure values ​​do not necessarily have to be in any particular form such as psi units). Alternatively, "measured pressure" or "determined pressure" can include any value that represents pressure, such as potential, resistance, or a multi-bit digital value. For example, a pressure transducer used to measure pressure in a pump control room can output an analog potential, resistance, or other representation that represents the pressure in the pump control room. The raw output from the transducer can also be used as a modified form of the output, such as measured pressure and / or a digital value generated using the analog output from the transducer, psi, or other values ​​generated based on the transducer output. The same is true for other values, such as determined volume, but they do not necessarily have to be in a specific form such as cubic centimeters. Alternatively, determined volume can include any value that represents volume and can be used, for example, to generate an actual volume in cubic centimeters.

[0225] In an embodiment of fluid management system (FMS) technology for determining the volume supplied by a pump, it is assumed that pressure equalization occurs in an adiabatic system when valve X2 is opened. Thus, equation (3) below gives the relationship between the volume of the reference chamber system before and after pressure equalization.

[0226] Vrf=Vri(Pf / Patm) -(1 / γ) …(3) Here, Vrf is the final (after equalization) volume of the reference chamber system, including the volume of the reference chamber, the volumes of lines L2 and L3, and the volume adjustment resulting from the movement of the "piston," which can move to the left or right of valve X2 after it opens; Vri is the initial (before equalization) volume of lines L2 and L3 with the reference chamber and the "piston" positioned at valve X2; Pf is the final equalization pressure after valve X2 opens; and Patm is the initial pressure of the reference chamber (atmospheric pressure in this example) before valve X2 opens. Similarly, equation (4) gives the relationship between the volumes of the control chamber system before and after pressure equalization.

[0227] Vdf = Vdi(Pf / Pdi) -(1 / γ) …(4) Here, 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 volume adjustment resulting from the movement of the "piston," which can move to the left or right of valve X2 after it has opened; Vdi is the initial volume of the control chamber and lines L0 and L1 with the "piston" positioned at valve X2; Pf is the final pressure after valve X2 has opened; and Pdi is the initial pressure of the control chamber before valve X2 has opened.

[0228] The volumes of the reference chamber system and the control chamber system change by the same absolute amount after valve X2 opens and the pressure is equalized, but with different signs, as shown in equation (5) (for example, because the volume change when valve X2 opens is caused by the movement of the "piston" to the left or right).

[0229] ΔVr = (-l)ΔVd …(5) (Note that the volume changes of this reference chamber and the control chamber are only due to the movement of the virtual piston. The reference chamber and the control chamber do not actually change in volume during the equalization process under normal conditions.) Also, using the relationship from Equation (3), the volume change of the reference chamber system is given by the following equation.

[0230] ΔVr = Vrf - Vri = Vri(-1 + (Pf / Patm) -(1 / γ) ) …(6) Similarly, using Equation (4), the volume change of the control chamber system is given by the following equation.

[0231] 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, which is assumed to be equal to (-)ΔVd according to Equation (5). Therefore, Vdi (the 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 known quantities. Subtracting L0 and L1 from Vdi gives the volume of the control chamber alone. By using Equation (7) above, for example, the volume change of the control chamber can be determined both before (Vdi1) and after (Vdi2) the pump operation (e.g., at the end of the introduction cycle and the end of the extraction cycle), and thus a measured value of the volume of the fluid supplied (or taken in by the pump) can be provided. For example, if Vdi1 is the volume of the control chamber at the end of the filling stroke and Vdi2 is the volume of the control chamber at the end of the subsequent supply stroke, the volume of the fluid supplied by the pump can be estimated by subtracting Vdi1 from Vdi2. Since this measurement is based on pressure, the volume determination can be made for almost any position of the membrane 15 / pump control region 1482 within the pump chamber 181 regardless of whether the pumping stroke is complete or partial. However, the measurements made at the end of the filling and supply strokes can be achieved with little or no influence on the pump operation and / or flow rate.

[0232] One aspect of the present invention relates to a technique for identifying pressure values ​​used for 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 the reference chamber, but the detected pressure values ​​may change depending on the opening and closing of valves, the introduction of pressure into the control chamber, the ventilation of the reference chamber to atmospheric pressure or other reference pressure, etc. Also, in one embodiment, it is assumed that an adiabatic system exists from before pressure equalization between the control chamber and the reference chamber until after equalization, so identifying appropriate pressure values ​​measured at close time intervals can help reduce errors (for example, a short elapsed time between pressure measurements can reduce the amount of heat exchanged in the system). Thus, the measured pressure values ​​may need to be carefully selected so as to help ensure that the appropriate pressure is used to determine the volume supplied by a pump or the like.

[0233] For illustrative purposes, Figure 43 shows a plot of exemplary pressure values ​​for the control chamber and reference chamber from before valve X2 is opened until some time has passed after valve X2 has been opened and the pressures in the two chambers have been equalized. In this exemplary embodiment, it should be understood that the pressure in the control chamber is higher than the pressure in the reference chamber before equalization, but the pressure in the control chamber may be lower than the pressure in the reference chamber before equalization in some configurations, such as during and / or at the end of the filling stroke. Also, the plot in Figure 43 shows a horizontal line marked at the equalization pressure, but it should be understood that this line is shown for clarity only. The equalization pressure is generally unknown before valve X2 is opened. In this embodiment, the pressure sensor detects pressure at a frequency of approximately 2000 Hz for both the control chamber and the reference chamber, but other suitable sampling rates may be used. Before valve X2 is opened, the pressures in the control chamber and reference chamber are substantially constant, and no air or other fluid has been introduced into the two chambers. Thus, valves X1 and X3 are generally closed before valve X2 is opened. Furthermore, valves leading to the pump chamber, such as valve ports 190 and 192, can be closed to prevent the effects of pressure changes in the pump chamber, liquid supply source, or liquid outlet.

[0234] First, the measured pressure data is processed to identify the initial pressures (i.e., Pd and Pr) for the control chamber and reference chamber. In one exemplary embodiment, the initial pressures are identified based on an analysis of a 10-point slide window used for the measured pressure data. This analysis involves generating a nearest-closest approximation for the data (or dataset) within each window, for example using the least squares method, and determining the slope of the nearest-closest approximation. For example, each time a new pressure is measured for the control chamber or reference chamber, a least-squares approximation can be determined for a dataset containing the most recent measurement and nine previous pressure measurements. This process can be repeated for several sets of pressure data, with determinations made when the slope of the least-squares approximation first becomes negative (or non-zero) and continues to grow further negative (or deviate from zero) for subsequent datasets. Points where the least-squares approximation has a suitable increasing non-zero slope can be used to identify the initial pressures of the two chambers (i.e., before valve X2 opens).

[0235] In one embodiment, the initial pressure values ​​for the reference chamber and control chamber can be determined to be at the end of a sequence of five data sets, where the slope of the nearest nearest line for those data sets increases from the first to the fifth data set, with the slope of the nearest nearest line for the first data set being the first to become non-zero (i.e., the slope of the nearest nearest line for the data sets preceding the first data set is zero or not sufficiently non-zero). For example, the pressure sensor can sample every 1 / 2 millisecond (or at other sampling rates), and sampling begins before valve X2 is opened. Each time a pressure measurement is taken, the cyclor 14 can take the latest measurement along with the previous nine measurements and generate a nearest nearest line for the 10 data points in the set. When taking the next pressure measurement (e.g., after 1 / 2 millisecond), the cyclor 14 can take the measurement along with the previous nine measurements and again generate a nearest nearest line for the 10 points in the set. This process can be repeated, and Cycla 14 can determine when the slope of the nearest-closest line for a set of 10 data points first becomes non-zero (or slopes appropriately), for example, when the slope of the nearest-closest line for 5 subsequent sets of 10 data points increases in accordance with each subsequent dataset. To identify the specific pressure measurement to use, one technique is to select the third measurement from the fifth dataset (i.e., the fifth dataset where the nearest-closest line is found to increase with a consistent slope and the first measurement is the pressure measurement obtained earliest in time) as the measurement to be used as the initial pressure (i.e., Pd or Pr) for the control chamber or reference chamber. This selection was made using an empirical method (e.g., plotting the pressure measurements and then selecting the point that best represents when the pressure began the equalization process). Of course, other techniques can also be used to select an appropriate initial pressure.

[0236] In one exemplary embodiment, it is possible to verify that the selected Pd and Pr measurements occurred within a desired time threshold (e.g., within 1-2 milliseconds of each other). For example, if the technique described above is used to analyze the control chamber pressure and reference chamber pressure and to identify a pressure measurement (and thus a time point) immediately before pressure equalization begins, the timing of the pressure measurements should be relatively close to each other. Otherwise, there would be an error or other erroneous condition that invalidates one or both of the pressure measurements. By verifying that the resulting Pd and Pr are appropriately close to each other, the cyclor 14 can verify that the initial pressure has been properly identified.

[0237] To identify the timing at which the pressures in the control chamber and reference chamber are equalized, and as a result the measured chamber pressure can be used to reliably determine the pump chamber volume, the Cycla 14 analyzes a dataset containing a series of data points from pressure measurements for both the control chamber and the reference chamber, determines the nearest line for each of the datasets (e.g., using the least squares method), and can identify the timing at which the slopes of the nearest lines for the datasets for the control chamber and the reference chamber first become sufficiently similar to each other (e.g., the slopes are both near zero or have values ​​within a threshold of each other). When the slopes of the nearest lines are similar or close to zero, the pressure can be determined to be equalized. The first pressure measurement for either dataset can also be used as the final equalized pressure (i.e., Pf). In one exemplary embodiment, it was found that pressure equalization generally occurred within about 200–400 milliseconds after opening valve X2, with the majority of equalization occurring within about 50 milliseconds. Therefore, the pressure in the control chamber and the reference chamber can be sampled approximately 400 to 800 times, or more, throughout the entire homogenization process, from before valve X2 is opened until homogenization is achieved.

[0238] In some cases, it may be desirable to use alternative FMS techniques to improve the accuracy of control chamber volume measurements. Substantial temperature differences between the pumped liquid and the control chamber gas and reference chamber gas can introduce significant errors into calculations based on the assumption that pressure equalization occurs adiabatically. Waiting to take pressure measurements until sufficient pressure equalization occurs between the control chamber and the reference chamber can result in excessive heat conduction. In one aspect of the present invention, pressure values ​​in the pump chamber and 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.

[0239] In one embodiment, heat conduction may be minimized, and adiabatic calculation errors are reduced by measuring the chamber pressure over the entire equalization period from the opening of valve X2 through complete pressure equalization, and selecting sampling points for the equalization period for adiabatic calculations. In one embodiment of the APD system, the measured chamber pressure obtained prior to 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 about 50 milliseconds after the two chambers are first fluid-connected and equalization has begun. As described above, in one embodiment, complete equalization may occur about 200-400 milliseconds after valve X2 is opened. Thus, the measured pressure can be obtained at a point after valve X2 is opened (or equalization has begun), which is about 10-50% or less of the entire equalization period. Alternatively, the measured pressure can be obtained when 50-70% of the pressure equalization has occurred (i.e., the reference chamber and pump chamber pressures have changed by approximately 50-70% of the difference between the initial chamber pressure and the final equalized pressure). Using a computer-enabled controller, a substantial number of pressure measurements in the control chamber and reference chamber can be made, stored, and analyzed during the equalization period (e.g., 40-100 individual pressure measurements). Among the sampled time points in the first 50 milliseconds of the equalization period, there exists a theoretically optimized sampling point for performing adiabatic calculations (e.g., the optimized sampling point is valve X2 This occurs approximately 50 milliseconds after opening the valve (see Figure 43). The optimized sampling point can occur well early after the opening of valve X2, thereby minimizing heat transfer between the two gas volumes, but not so early as to introduce significant errors in pressure measurement due to the characteristics of the pressure sensor and the delay in valve operation. However, as can be seen in Figure 43, the pressures in the pump chamber and the reference chamber may not be substantially equal at this point, and therefore, homogenization may not be complete (and in some cases, it may be technically difficult to obtain reliable pressure measurements immediately after opening valve X2).For example, there are reasons such as the inherent inaccuracy of the pressure sensor, the time required to fully open valve X2, and the sudden initial change in the pressure of either the control chamber or the reference chamber immediately after valve X2 is opened).

[0240] During pressure equalization, when the final pressures in the control chamber and the reference chamber are not the same, Equation (2) becomes as follows. PriVri γ +PdiVdi γ = Constant = PrfVrf γ +PdfVdf γ …(8) Here, Pri = the pressure in the reference chamber before valve X2 is opened, Pdi = the pressure in the control chamber before valve X2 is opened, Prf = the final reference chamber pressure, and Pdf = the final control chamber pressure.

[0241] The 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 (or below a desired threshold) over the equalization period (in adiabatic processing, this difference should ideally be zero, as shown by equation (5). In Figure 43, the point in time when the difference between the absolute values ​​of ΔVd and ΔVr is minimized occurs on the 50-millisecond line and is marked as "the point in time when the final pressure is determined"). First, pressure data can be collected from the control chamber and reference chamber at multiple points j=1~n between the opening of valve X2 and the final pressure equalization. Since Vri, i.e., the fixed volume of the reference chamber system before pressure equalization, is known, the subsequent value of Vrj (the volume of the reference chamber system at sampling point j after opening valve X2) can be calculated using equation (3) at each sampling point Prj along the equalization curve. For each such value of Vrj, the value for ΔVd can be calculated using equations (5) and (7), i.e., each value of Vrj, and thus obtain the estimated value for Vdij, Vdi, and the volume of the control chamber system before pressure equalization. Using each value of Vrj and its corresponding value of Vdij, and also 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 squared differences provides a measure of the error in the calculated value of Vdi during pressure equalization for each value of Vrj and its corresponding Vdij. If we denote the reference chamber pressure as Prf and its associated reference chamber volume as Vrf to obtain the minimum sum of the squared differences of |ΔVd| and |ΔVr|, then the data points Prf and Vdf corresponding to Vrf can be used to calculate the optimized estimate of Vdi, the initial volume of the control chamber system.

[0242] One way to determine where on the homogenization curve to capture the optimized values ​​for Pdf and Prf is as follows: 1) Obtain a series of pressure datasets from the control chamber and reference chamber, starting just before valve X2 is opened and ending when Pr and Pd are approaching each other. If Pri is the first reference chamber pressure captured, the subsequent sampling points in Figure 32 are denoted as Prj = Pr1, Pr2, ..., Prn.

[0243] 2) Using equation (6), calculate the corresponding ΔVrj for each Prj after Pri (where j represents the j-th pressure data point after Pri). ΔVrj=Vrj-Vri=Vri(-1+(Prj / Pri) -(1 / γ) ) 3) For each such ΔVrj, calculate the corresponding Vdij using equation (7). for example, ΔVr1 = Vri*(-1 + (Pr1 / Pri)) -(1 / γ) ) ΔVd1 = -ΔVr1 Therefore, Vdi1 = ΔVd1 / (-1 + (Pd1 / Pdi)) -(1 / γ) ) Vdin = ΔVdn / (-1 + (Pdn / Pdi)) -(1 / γ) ) The initial volumes (Vdi1 to Vdin) of a set of n control chamber systems are calculated based on the reference chamber pressure data points Pr1 to Prn for that set during pressure equalization. Then, a point in time (f) can be selected to obtain an optimized measurement of the initial volume (Vdi) of the control chamber system over the entire pressure equalization period.

[0244] 4) Using equation (7), calculate ΔVdj,k for each of Vdi1 to Vdin using the control room pressure measurement Pd for time points k=1 to n. Regarding VDI compatible with Pr1, ΔVd1,1=Vdi1*(-1+(Pd1 / Pdi) -(1 / γ) ) ΔVd1,2 = Vdi1 * (-1 + (Pd2 / Pdi)) -(1 / γ) ) · · · ΔVd1,n=Vdi1*(-1+(Pdn / Pdi) -(1 / γ) ) · · · Regarding VDIs that correspond to Prn, ΔVdn,l=Vdin*(-1+(Pd1 / Pdi) -(1 / γ) ) ΔVdn,2 = Vdin*(-1 + (Pd2 / Pdi)) -(1 / γ) ) · · · ΔVdn,n=Vdin*(-1+(Pdn / Pdi) -(1 / γ) ) 5) Take the sum of the squared errors between the absolute values ​​of ΔVr and ΔVdj,k.

[0245]

number

[0246]

number

[0247]

number

[0248] 7) The above procedure can be applied whenever an estimate of the control chamber volume is desired, but it is preferably applied at the end of each filling stroke and each supply stroke. The difference between the optimized Vdi at the end of the filling stroke and the optimized Vdi at the end of the corresponding supply stroke can be used to estimate the volume of liquid supplied by the pump. [Air detection] Another aspect of the present invention involves determining the presence of air in the pump chamber 181 and the volume of air present (if any). Such determination may be important, for example, to help ensure that the preparation sequence is performed correctly to remove air from the cassette 24 and / or to ensure that air is not supplied to the patient. In some embodiments, for example, when supplying 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 181 may tend to remain in the pump chamber 181 and are prohibited from being pumped to the patient unless the volume of that gas is greater than the volume of the effective dead space of the pump chamber 181. As discussed below, the volume of 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 removed from the pump chamber 181 before the volume of the gas exceeds the volume of the effective dead space of the pump chamber 181.

[0249] The amount of air in the pump chamber 181 can be determined at the end of the filling stroke, and therefore can be done without interrupting the pumping process. For example, at the end of the filling stroke, when the membrane 15 and the pump control region 1482 are separated from the cassette 24, and as a result the membrane 15 / region 1482 is brought into contact with the wall of the control chamber 171, valve X2 can be closed, and the reference chamber is ventilated to atmospheric pressure, for example, by opening valve X3. Subsequently, valves X1 and X3 can be closed, thereby fixing the virtual "piston" to valve X2. Next, valve X2 can be opened, thereby enabling pressure equalization in the control chamber and reference chamber, as described above when performing pressure measurements to determine the volume of the control chamber.

[0250] If there are no bubbles in the pump chamber 181, the change in the volume of the reference chamber (i.e., due to the movement of the virtual "piston"), determined using the known initial volume of the reference chamber system and the initial pressure of the reference chamber, is equal to the change in the volume of the control chamber, determined using the known initial volume of the control chamber system and the initial pressure of the control chamber (the initial volume of the control chamber may be known under the condition that 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 there is air in the pump chamber 181, the change in the volume of the control chamber is actually dispersed between the control chamber volume and the bubbles in the pump chamber 181. As a result, the change in volume for the control chamber calculated using the known initial volume of the control chamber system is not equal to the calculated change in volume for the reference chamber, and therefore a signal indicating the presence of air in the pump chamber is output.

[0251] If there is air 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 bubbles in the pump chamber 181 (referred to as Vbi), as shown in equation (9).

[0252] Vdi = Vbi + Vdfix …(9) With the membrane 15 / control region 1482 pressed against the control chamber wall at the end of the filling stroke, the volume of any air space within the control chamber (e.g., due to the presence of grooves or other features in the control chamber wall, and the volumes of lines L0 and L1 (collectively Vdfix)) can be determined with considerable accuracy (similarly, with the membrane 15 / control region 1482 pressed against the spacer element 50 of the pump chamber 181, the volumes of the control chamber and lines L0 and L1 can be determined accurately). After the filling stroke, the volume of the control chamber system is tested using a positive-pressure control chamber precharge. Any difference between this tested volume and the volume tested at the end of the filling stroke can indicate the volume of air in the pump chamber. Substituting equation (9) into equation (7), the volume change ΔVd of the control chamber is given by the following equation:

[0253] ΔVd=(Vbi+Vdfix)(-1+(Pdf / Pdi) -(1 / γ) ) …(10) ΔVr can be calculated from equation (6), and from equation (5), we can see that ΔVr = (-1)ΔVd, so equation (10) can be rewritten as follows.

[0254] (-l)ΔVr=(Vbi+Vdfix)(-1+(Pdf / Pdi) -(1 / γ) ) …(11) And then, again, Vbi = (-1)ΔVr / (-l + (Pdf / Pdi)) -(1 / γ) )-Vdfix …(12) Therefore, the Cycla 14 can use equation (12) to determine whether or not there is air in the pump chamber 181 and the approximate volume of the bubble. This calculation of the bubble volume can be done, for example, if it is found that the absolute values ​​of ΔVr (as determined from equation (6)) and ΔVd (as determined from equation (7) using Vdi = Vdfix) are not equal to each other. That is, Vdi should be equal to Vdfix when there is no air present in the pump chamber 181, and therefore the absolute value of ΔVd given from equation (7) using Vdfix instead of Vdi is equal to ΔVr.

[0255] After the filling process is complete, and if air is detected by the method described above, it can be difficult to determine whether air is located on the pump chamber side or the control side of the membrane 15. Due to conditions during pumping that result in an incomplete pumping process and incomplete pump chamber filling (e.g., blockage), there may be air bubbles in the pumped liquid or residual air on the control (air pressure) side of the pump membrane 15. At this point, an adiabatic FMS measurement can be performed using a negative pressure pump chamber precharge. If this FMS volume matches the FMS volume with a positive pressure precharge, the membrane can move freely in both directions, which suggests that the pump chamber is only partially filled (e.g., possibly due to blockage). If the value of the negative pressure pump chamber precharge FMS volume is equal to the nominal control chamber air volume when the membrane 15 / region 1482 contacts the inner wall of the control chamber, it is possible to conclude that there are air bubbles in the fluid on the pump chamber side of the flexible membrane. [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, dialysis patients may feel a "pull" or other movement from the fluid flowing into or out of their peritoneal cavity during induction or evacuation. To reduce this sensation, the cyclorama 14 can reduce the pressure applied to the patient line 34 during induction and / or evacuation. However, to properly set the pressure on the patient line 34, the cyclorama 14 can determine the patient's height relative to the cyclorama 14, the heater bag 22, the drain, or other parts of the system. For example, when performing an induction operation, if the patient's peritoneal cavity is positioned 5 feet above the heater bag 22 or cassette 24, the cyclorama 14 may need to use a higher pressure on the patient line 34 to deliver dialysate than if the patient's peritoneal cavity were positioned 5 feet below the cyclorama 14. This pressure can be adjusted, for example, by alternately opening and closing a binary pneumatic source valve at variable time intervals to achieve a desired target pump chamber pressure. The average desired target pressure can be maintained, for example, by adjusting the time interval so that the valve remains open when the pump chamber pressure falls below the target pressure by a predetermined amount, and remains closed when the pump chamber pressure rises above the target pressure by a predetermined amount. Any adjustments to maintain the supply of the full stroke volume can be made by adjusting the pump chamber filling and / or supply time. When a variable orifice source valve is used, the target pump chamber pressure can be achieved by changing the orifice of the source valve, in addition to adjusting the timing of the intervals in which the valve is opened and closed. For patient position adjustment, the cyclor 14 can momentarily stop pumping the fluid, thereby leaving the patient line 34 in open fluid communication with 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 pump chamber 181, can be closed. Under these conditions, it is possible to measure the pressure inside the control chamber for one of the pumps.As is well known in the art, this pressure correlates with the height of the patient's "head" and can be used by the cyclorama 14 to control the pressure of the fluid supply to the patient. A similar approach can be used to determine the "head" height of the heater bag 22 (commonly known) and / or the head height of the dialysate container 20, because the head heights of these components may affect the pressure required to pump the fluid in the proper manner. [Cycra's noise reduction features] According to aspects of the present invention, the cyclorama 14 may be equipped with one or more features that reduce noise generated by the cyclorama 14 during operation or while idle. In one aspect of the present invention, the cyclorama 14 may be equipped with a single pump that generates both pressure and vacuum used to control the various pneumatic devices of the cyclorama 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 more slowly (and therefore more quietly). In another embodiment, the starting and / or stopping of the air pump is gradually increased or decreased (e.g., increasing the pump speed or output at startup and / or decreasing the pump speed or output). This configuration may help reduce the "on / off" noise associated with starting and stopping the air pump, and therefore the pump noise becomes less noticeable. In another embodiment, the air pump may be operated on a low duty cycle when approaching a target output pressure or volumetric flow rate, so that the air pump can continue to operate rather than being stopped and then restarted a short time later. As a result, it is possible to avoid interruptions caused by repeatedly turning the air pump on and off.

[0256] Figure 44 shows a perspective view of the internal compartment of the cyclorama 14, with the top of the housing 82 removed. In this exemplary embodiment, the cyclorama 14 comprises a single air pump 83, which includes the actual pump and motor drive unit contained within a soundproof enclosure. The soundproof enclosure comprises an outer shield, such as a metal or plastic frame, and soundproofing material within the outer shield, at least partially enclosing the motor and pump. The air pump 83 is capable of simultaneously supplying pneumatic pressure and vacuum to, for example, a pair of accumulator tanks 84. One of the tanks 84 can store positively pressurized air, and the other can store vacuum. A suitable manifold and valve configuration can be coupled to the tanks 84, thereby providing and controlling the pneumatic pressure / vacuum supplied to the components of the cyclorama 14.

[0257] According to another aspect of the present invention, components that require a relatively constant pressure or vacuum supply during cyclo operation, such as occlusions, can be isolated from the air pressure / vacuum source for at least a relatively long time. For example, an occlusion 147 in a cyclo 14 generally requires a constant air pressure within the occlusion air bladder 166, and as a result, the patient and outlet lines remain open to the flow. Assuming the cyclo 14 continues to operate properly without power failures, the air bladder 166 may inflate once at the beginning of system operation and may continue to inflate until it is shut down. The inventors have observed that in some situations, relatively static pneumatic devices such as the air bladder 166 may produce a "creaking" sound or generate noise in response to slight changes in the supplied air pressure. Such changes may slightly alter the size of the air bladder 166, which moves associated mechanical parts and potentially generates noise. According to embodiments of the air bag 166 and other components requiring similar pneumatic power, they can be isolated from the air pump 83 and / or tank 84, for example, by closing a valve, thereby reducing pressure changes within the air bag or other pneumatic components and thus reducing noise that may be generated as a result of pressure changes. Another component that may be isolated from the pneumatic supply source is the air bag in the door 141 of the cassette mounting position 145, which inflates to press the cassette 24 against the control surface 148 when the door 141 is closed. Other suitable components may also be isolated as desired.

[0258] According to another aspect of the present invention, the speed and / or force at which a pneumatic component is actuated can be controlled to reduce noise generated by the operation of the component. For example, the operation of a valve control area 1481 that operates a corresponding portion of a cassette membrane 1...

Claims

1. A peritoneal dialysis system, At least one pump (181) arranged to pump dialysis fluid for delivery to the patient's peritoneal cavity, A patient line (34) is fluid-coupled to at least one pump so that dialysate delivered from the pump is guided through it, wherein the patient line (34) has a distal end having a connector (36) for connection to a patient, The system includes a patient line status detector (1000) positioned to receive the distal end of the patient line and to detect the presence of the distal end and whether or not the distal end of the patient line is filled with fluid, The patient line status detector is configured to house the connector in a peritoneal dialysis system.

2. The system according to claim 1, wherein the patient line status detector includes a base member (1002) and a detector housing (1006) attached to the base member or co-molded with the base member so as to extend outward from the base member, the detector housing defines a tube or connector holding channel (1012) disposed to receive a tubular section near the distal end of the patient line or an associated connector of the patient line.

3. The patient line status detector is configured to house the connector. (a) A connector retaining channel, wherein the detector housing defines the connector retaining channel, (b) A stabilizing tab extending outward from the base member, wherein the stabilizing tab has a concave outer shape that matches the curvature of the connector of the patient line, (c) The system according to claim 2, wherein a raised element located above the detector housing comprises at least one of the raised elements, the raised element conforming to the shape of a standard patient line connector cap or connector flange.

4. The system according to claim 2 or 3, wherein the tube or connector retaining channel substantially conforms to the shape of the connector.

5. The system according to any one of claims 2 to 4, wherein the tube or connector retaining channel has dimensions that change to accommodate the transition from the tube section of the patient line to the connector.

6. The system according to any one of claims 2 to 5, wherein the tube or connector holding channel has a tube portion (1014) and a receiving base (1016) for receiving the tube section and the connector of the patient line, respectively.

7. The system according to claim 6, wherein the support base is formed by a pair of side walls (1018) and a rear wall (1020), both of which are slightly convex in shape, and the rear wall is substantially flat or has a contour substantially matching the shape of the adjacent portion of the connector.

8. The system according to claim 6 or 7, wherein the tube portion surrounds most of the tube section immediately before the tube section is attached to the connector.

9. The system according to any one of claims 2 to 8, wherein the portion of the detector housing facing the base member is hollow such that an open cavity (1008) is created behind the detector housing, and sensor elements (1026, 1028, 1030, 1032) are housed in the cavity adjacent to the tube or connector holding channel.

10. The system according to claim 9, wherein the sensor element is positioned adjacent to a portion of the tube or connector holding channel in which the tubing section of the patient line is located.

11. The system according to claim 9, wherein the sensor element is positioned adjacent to the tube or connector holding channel on which the connector of the patient line is located, and the connector of the patient line is translucent or transparent.

12. The aforementioned patient line status detector is A cavity (1012) for receiving the distal end of the patient line, One or more light-emitting elements (1028, 1030, 1032) related to the cavity are arranged to guide light into the cavity, The system according to any one of claims 1 to 8, further comprising one or more photodetectors (1026) arranged to detect light emitted by the one or more light emitters.

13. The aforementioned patient line status detector is A first light-emitting body (1028) having a first optical axis directed toward the space in which the distal end of the patient line is located, A second light-emitting element (1030) having a second optical axis directed toward the aforementioned space and adjacent to the first light-emitting element, The system according to any one of claims 1 to 9, further comprising: an optical sensor (1026) positioned on the side of the space opposite to the first and second light emitters, and configured to receive light emitted by the first and second light emitters to determine the presence or absence of the patient line in the space.

14. The system according to claim 13, wherein the second optical axis is substantially parallel to the first optical axis.

15. The system according to claim 13, wherein the optical sensor detects a higher or lower light level from the first light-emitting element when the distal end of the patient line is in the space.

16. The system according to claim 15, wherein the optical sensor detects a lower light level from the second light-emitting element when the distal end of the patient line is in the space.

17. The system according to claim 13, wherein the optical sensor has a sensor optical axis, and the patient line status detector further comprises a third light-emitting element (1032) having a third optical axis positioned at an oblique angle with respect to the sensor optical axis.

18. The system according to claim 13, wherein the distal end of the patient line has a cylindrical outer surface, and the patient line state detector is positioned to receive and hold the patient line without substantially deforming the patient line.

19. A peritoneal dialysis system, At least one pump (181) arranged to pump dialysis fluid for delivery to the patient's peritoneal cavity, A peritoneal dialysis system comprising: a patient line (34) which is fluid-coupled to at least one pump (181) to guide dialysate delivered from the pump (181), wherein the patient line (34) has a distal end (34a) positioned for connection to a patient; The peritoneal dialysis system further comprises a patient line status detector (1000) having a base member (1002) and a housing (1006), wherein the housing is attached to the base member so as to extend outward from the base member, or is co-molded with the base member, and the portion of the detector housing facing the base member is hollow such that an open cavity (1008) is created behind the detector housing, and sensor elements (1026, 1028, 1030, 1032) are housed in the cavity, and the detector housing receives the distal end of the patient line (34a) or an associated connector (36) of the patient line. A peritoneal dialysis system characterized in that it defines a tube or connector holding channel (1012) positioned to detect both the presence of the distal end of the patient line (34) on the patient line state detector (1000) and whether the distal end of the patient line (34) is prepared with fluid, wherein the tube or connector holding channel has dimensions that change to accommodate the transition from the patient line (34) to the connector (36), and the tube or connector holding channel has a tube portion (1014) and a base (1016) for receiving the patient line (34) and the connector (36), respectively.

20. The patient line status detector (1000) is A cavity for receiving the distal end of the patient line (34), One or more light-emitting elements related to the cavity, arranged to guide light into the cavity, The system according to claim 19, further comprising one or more photodetectors arranged to detect light emitted by the one or more light emitters.

21. The patient line status detector (1000) is A first light-emitting body having a first optical axis directed toward the space in which the distal end of the patient line (34) is located, A second light-emitting element having a second optical axis directed toward the aforementioned space, and adjacent to the first light-emitting element, The system according to claim 19, further comprising: an optical sensor (1026) positioned on the side of the space opposite to the first and second light emitters, and configured to receive light emitted by the first and second light emitters to determine the presence or absence of the patient line (34) in the space.

22. The system according to claim 21, wherein the second optical axis is substantially parallel to the first optical axis.

23. The system according to claim 21, wherein the optical sensor has an optical axis that is substantially colinear with the first optical axis.

24. The system according to claim 21, wherein the optical sensor (1026) has a sensor optical axis, and the patient line status detector further comprises a third light-emitting body having a third optical axis arranged at an oblique angle with respect to the sensor optical axis.

25. The system according to claim 24, wherein the angle of inclination is approximately 110 to 120 degrees.

26. The system according to claim 21, wherein the first and second light-emitting elements are light-emitting diodes.

27. ​​The system according to claim 2 or 19, wherein a portion of the tube or connector retaining channel (1012) is translucent or transparent.

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