Dialysis machine with intelligent load monitoring

Dialysis systems and methods for operating dialysis machines (e.g., peritoneal dialysis machines) for conducting dialysis treatments are disclosed. The dialysis system may include a dialysis machine for transferring dialysate to a patient from a dialysate source. The dialysate may flow from the dialysate source through a cartridge or cassette (e.g., a disposable cartridge or cassette) positionable within the dialysis machine. The dialysis machine includes a piston or pump for pumping fluid (e.g., dialysate) from the cassette to the patient. In various embodiments, the dialysis machine includes one or more sensors for monitoring a condition. For example, the dialysis machine may include sensor(s) for monitoring proper alignment of the cassette within the cassette compartment, or sensors mounted on the pump head for monitoring a leak during a dialysis operation, or sensors for monitoring improper operation of the pumps (e.g., pistons), or a combination thereof.

FIELD OF THE DISCLOSURE

The disclosure generally relates to dialysis machines, and more particularly to a dialysis machine including one or more sensors to detect (i) proper loading, inserting, positioning, alignment, etc. of a cassette within the dialysis machine, (ii) fluid or leakage on a face of a pump, (iii) proper operation of the pumps, and (iv) a combination thereof.

BACKGROUND

Dialysis machines are known for use in the treatment of renal disease. The two principal dialysis methods are hemodialysis (HD) and peritoneal dialysis (PD). During HD, the patient's blood is passed through a dialyzer of an HD machine while also passing dialysate through the dialyzer. A semi-permeable membrane in the dialyzer separates the blood from the dialysate within the dialyzer and allows diffusion and osmosis exchanges to take place between the dialysate and the blood stream. During PD, the patient's peritoneal cavity is periodically infused with dialysate or dialysis solution. The membranous lining of the patient's peritoneum acts as a natural semi-permeable membrane that allows diffusion and osmosis exchanges to take place between the solution and the blood stream. Automated PD machines, called PD cyclers, are designed to control the entire PD process so that it can be performed at home, usually overnight, without clinical staff in attendance.

A dialysis machine, such as a PD machine, may include one or more containers (e.g., bags) containing a fluid (e.g., a dialysate) for patient infusion. In addition, a PD machine may include a removable and/or replaceable cartridge or cassette (used interchangeably without the intent to limit) attached to one or more fluid lines for pumping fluid to and from a patient. In PD machines, for example, one or more fluid lines are inserted into an abdomen of a patient for flowing fresh dialysate and removing used dialysate, waste, and excess fluid. As the cassette facilitates pumping of the fluid, the dialysis machine may monitor fluid delivery, fluid temperature, flow path, and pressure.

The cassette may be insertable into the PD machine and enclosed within the PD machine during a dialysis operation. At the conclusion of the operation, the cassette may be removed and properly disposed of. The cassette and accompanying fluid flow lines, valves, and/or connectors may be single use items.

In use, the PD machines and cassette include an interface where a pump, a piston, a pump assembly, a piston assembly, etc. (terms used interchangeably herein without the intent to limit) of the PD machine contacts the cassette. That is, the cassette typically includes a membrane such as, for example, a rigid material that forms one or more channels, pump chambers, etc. in the cassette. The rigid material may be bonded to a flexible membrane that can be distorted by the pump of the PD machine. The fluid (e.g., dialysate) may be contained between the rigid material and the flexible membrane. In use, the fluid (e.g., dialysate) may be moved from the PD machine to the patient via the action of a piston or pump head in the PD machine on the membrane of the cassette.

In some cases, a patient or caregiver may insert the cassette into the PD machine in such a way that the interface between the cassette and the pump isn't properly aligned causing misalignment between the pump chambers formed in the cassette and the pistons, pump head, valve actuators, etc. of the PD machine. Misalignment of the cassette within the PD machine may cause leaks in the cassette when the pump heads contact the cassette outside of the intended target area of the cassette.

In addition, and/or alternatively, during manufacturing of the dialysis machines, problems may arise such as, for example, using parts that are bent, etc. that may cause the pump heads to be misaligned in the dialysis machine. As a result, engagement of the pump heads in the dialysis machine with the pump chamber of the cassette positioned within the dialysis machine may be inaccurate, which may cause problems resulting in leaks in the cassette or prevent proper positioning, alignment, etc. of the pump heads with the pump chambers of the cassette.

Cassette leaking may affect the quality of the fluid flow and the exchange of the dialysate with the patient, potentially affecting a patient's treatment procedure (e.g., dialysate may not be delivered to the patient's peritoneal cavity or incorrect amounts of fluid may be delivered or removed from the patient's peritoneal cavity). In addition, when leaks develop and remain undetected in the PD machine, leaking fluid may damage the PD machine, possibly beyond repair, requiring full replacement. This can be problematic when a patient requires frequent dialysis treatment and needs to obtain an immediate replacement, which can be costly.

A leak developed at the interface between the piston or pump head of the pump in the PD machine and the membrane proximate the pump chamber of the cassette can be particularly problematic since the pump chamber contains one of the largest volume of fluid collection in the cassette and, therefore, a leak at this location can lead to large amounts of leaking fluid. As such, it would be advantageous to detect a leak right at, or adjacent to, the interface between the piston or pump head and the membrane of the cassette. In addition, and/or alternatively, it would be advantageous to monitor the pumps (e.g., piston, pump heads, etc.) to confirm proper operation.

It is with respect to these and other considerations that the present improvements may be useful.

SUMMARY

According to an exemplary embodiment of the present disclosure, a dialysis system for conducting a dialysis treatment is disclosed. The dialysis system comprises a dialysis machine for transferring dialysate to a patient from a dialysate source, the dialysis machine including a housing including a cassette compartment, a pump positioned within the housing, and one or more sensors and a cassette positionable within the cassette compartment, the cassette being in fluid communication with the patient and the dialysate source; wherein, when the cassette is positioned within the cassette compartment, movement of the pump causes dialysate to be transferred from the dialysate source to the patient and wherein the one or more sensors are arranged and configured to detect proper alignment of the cassette within the cassette compartment.

In this and other embodiments, the one or more sensors is one or more limit switches, the one or more limit switches arranged and configured so that proper alignment of the cassette within the cassette compartment causes the cassette to trigger the one or more limit switches.

In this and other embodiments, the dialysis machine includes one or more locating pins extending from a surface thereof, the one or more limit switches built into the locating pins.

In this and other embodiments, the one or more sensors includes an optical sensor arranged and configured to detect a location of the cassette within the cassette compartment.

In this and other embodiments, the optical sensor is arranged and configured to detect a location of a perimeter of the cassette relative to the cassette compartment to detect proper alignment of the cassette within the cassette compartment.

In this and other embodiments, the cassette includes one or more registration marks printed on an outer surface thereof, the one or more sensors includes an image sensor arranged and configured to detect alignment of the cassette relative to the cassette compartment based on imaging of the one or more registration marks on the cassette.

In this and other embodiments, the one or more sensors includes one or more capacitive sensors arranged and configured to detect proper alignment of the cassette within the cassette compartment.

In this and other embodiments, the one or more capacitive sensors are arranged and configured to detect if the cassette is properly seated within the cassette compartment via determining if the cassette is positioned adjacent with a surface of the cassette compartment.

In this and other embodiments, the dialysis system further comprises one or more capacitive sensors positioned on a head of the pump, the one or more capacitive sensors arranged and configured to detect a presence of a liquid on the head of the pump or on a surface of the cassette.

In this and other embodiments, the dialysis system further comprises one or more sensors arranged and configured to detect proper axial extension of the pump.

In this and other embodiments, the one or more sensors arranged and configured to detect proper axial extension of the pump includes a plurality of proximity sensors positioned about the pump.

In this and other embodiments, the plurality of proximity sensors are arranged and configured to detect alignment of the pump during extension.

In this and other embodiments, the one or more sensors are configured to send a signal based on a detection of improper alignment of the cassette within the cassette compartment; wherein the signal is sent to a user interface of the dialysis machine, an audible indicator, or a light indicator, or a combination thereof.

In this and other embodiments, the dialysis machine is arranged and configured to automatically terminate the transfer of dialysate to the patient from the dialysate source upon receipt of the signal.

According to an exemplary embodiment of the present disclosure, a dialysis system for conducting a dialysis treatment is disclosed. The dialysis system comprises a dialysis machine for transferring dialysate to a patient from a dialysate source, the dialysis machine including a housing including a cassette compartment, a pump positioned within the housing, and one or more sensors, and a cassette positionable within the cassette compartment, the cassette being in fluid communication with the patient and the dialysate source, wherein, when the cassette is positioned within the cassette compartment, movement of the pump causes dialysate to be transferred from the dialysate source to the patient and wherein the one or more sensors are arranged and configured to: (i) detect proper alignment of the cassette within the cassette compartment, (ii) detect a leak within the dialysis machine, (iii) detect proper axial alignment of the pump; or (iv) a combination thereof.

In this and other embodiments, the one or more sensors is one or more limit switches, the one or more limit switches arranged and configured so that proper alignment of the cassette within the cassette compartment causes the cassette to trigger the one or more limit switches.

In this and other embodiments, the dialysis machine includes one or more locating pins extending from a surface thereof, the one or more limit switches built into the locating pins.

In this and other embodiments, the one or more sensors includes an optical sensor arranged and configured to detect a location of the cassette within the cassette compartment.

In this and other embodiments, the optical sensor is arranged and configured to detect a location of a perimeter of the cassette relative to the cassette compartment to detect proper alignment of the cassette within the cassette compartment.

In this and other embodiments, the cassette includes one or more registration marks printed on an outer surface thereof, the one or more sensors includes an image sensor arranged and configured to detect alignment of the cassette relative to the cassette compartment based on imaging of the one or more registration marks on the cassette.

In this and other embodiments, the one or more sensors includes one or more capacitive sensors arranged and configured to detect proper alignment of the cassette within the cassette compartment.

In this and other embodiments, the one or more capacitive sensors are arranged and configured to detect if the cassette is properly seated within the cassette compartment via determining if the cassette is positioned adjacent with a surface of the cassette compartment.

In this and other embodiments, the dialysis system further comprises one or more capacitive sensors positioned on a head of the pump, the one or more capacitive sensors arranged and configured to detect a presence of a liquid on the head of the pump or on a surface of the cassette.

In this and other embodiments, the dialysis system further comprises one or more sensors arranged and configured to detect proper axial extension of the pump.

In this and other embodiments, the one or more sensors arranged and configured to detect proper axial extension of the pump includes a plurality of proximity sensors positioned about the pump.

In this and other embodiments, the plurality of proximity sensors are arranged and configured to detect alignment of the pump during extension.

In this and other embodiments, the one or more sensors are configured to send a signal based on a detection of improper alignment of the cassette within the cassette compartment; wherein the signal is sent to a user interface of the dialysis machine, an audible indicator, or a light indicator, or a combination thereof.

In this and other embodiments, the dialysis machine is arranged and configured to automatically terminate the transfer of dialysate to the patient from the dialysate source upon receipt of the signal.

DETAILED DESCRIPTION

The present embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which several exemplary embodiments are shown. The subject matter of the present disclosure, however, may be embodied in many different forms and types of methods and devices for dialysis machines and other potential medical devices and treatments, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and willfully convey the scope of the subject matter to those skilled in the art. In the drawings, like numbers refer to like elements throughout.

Exemplary embodiments of systems and methods arranged and configured to detect proper loading, inserting, positioning, alignment, etc. (terms used interchangeably herein without the intent to limit) of the cassette into a dialysis machine, and/or fluid or leakage at the interface between the pumps and the cassette, and/or proper operation of the pumps (e.g., piston, pump heads, etc.) of the dialysis machine will now be described. It will be appreciated that dialysis operation is often not able to be monitored manually on a continual basis for leaks or other conditions, or it may not be efficient or practical to do so. This is particularly the case where dialysis is performed while a patient is sleeping, e.g., in the case of PD machines that are often self-administered in the home of a patient. Automatic detection and shutdown is therefore important to prevent any potential machine malfunction or delivery of improper treatment.

In accordance with one or more aspects of the present disclosure, a dialysis machine such as, for example, a PD machine, may be able to quickly detect misalignment of the cassette within the PD machine, any leaks at the interface between the cassette and the pumps, and/or mis-operation of the pumps (e.g., piston, pump heads, etc.) that may develop. For example, it would be beneficial for a dialysis machine to quickly detect misalignment of a cassette within the PD machine. In addition, and/or alternatively, it would be beneficial for a dialysis machine to quickly detect any leaks between the PD machine and the cassette positioned within the PD machine, and/or to detect improper operation of the pumps in the PD machine, so that operation of the dialysis machine may be shut down, thereby ensuring patient safety and limiting or eliminating the potential for damage or further damage to components of the machine. In one example of an embodiment, the PD machine may include one or more sensors to detect proper positioning of the cassette within a cassette compartment of the PD machine. In addition, and/or alternatively, in one example of an embodiment, the cassette interface between the dialysis machine and the cassette may include one or more sensors to detect a leak. In addition, and/or alternatively, in one embodiment, a pump (e.g., a piston, a pump head, etc.) positioned in a dialysis machine may include one or more sensors such as, for example, one or more capacitive sensors, disposed on a front surface of the pump (e.g., a piston, a pump head, etc.). The sensors being arranged and configured to detect fluid on the surface of the piston or pump head, or on the surface of the cassette. In addition, and/or alternatively, in one embodiment, one or more sensors can be positioned about the pump to detect proper operation (e.g., extension and retraction) of the pump (e.g., pistons).

Referring toFIG.1, a dialysis system100may include a PD machine150, for flowing fresh dialysate into a patient and draining used dialysate out of the patient. During treatment, a volume of dialysate may enter the patient's abdomen and remain for a period of time, e.g., a dwell time. During the dwell time, the dialysate may flow across the peritoneum and absorb contaminants and/or particulates from a patient's blood and exchange substances and fluids (e.g., electrolytes, urea, glucose, albumin, osmotically active particles, and other small molecules). At the end of the dwell time, the used dialysate may be flowed out of the patient's abdomen and purged to a drain connected to the tubing, e.g., the drain line. This exchange of fresh dialysate and used dialysate after a dwell time may occur for several cycles depending on the patient's treatment regimen.

One or more dialysate sources may be connected to the dialysis machine150. In some embodiments, as illustrated, the dialysate source(s) may be dialysate bags122that are hung near the PD machine150which may improve air content management as any air content is disposed by gravity to a top portion of the dialysate bag122. Valves may be attached to a bottom portion of the dialysate bags122so fluid is drawn out and air content delivery is minimized. In one embodiment, as shown, dialysate from the dialysate bags122may be transferred directly to the patient through a warmer pouch, a heating chamber, or the like152(used interchangeably without the intent to limit) formed in the dialysis machine150. When the dialysate has reached a predetermined temperature (e.g., approximately 98°-100° F., 37° C.) in the heating chamber152, the dialysate may be flowed into the patient. As will be described and illustrated in greater detail below, the dialysate bags122may be connected to a cartridge or cassette (used interchangeably without the intent to limit), which may be insertable into the dialysis machine150. In use, the cassette may be connected to dialysate bag lines, which may be used to pass dialysate from dialysate bags122to the cassette. In use, the cassette may be disposable. Alternatively, the cassette may be reusable. In addition, a patient line and a drain line may be connected to the cassette. The patient line may be connected to a patient's abdomen via a catheter and may be used to pass dialysate back and forth between the cassette and the patient's peritoneal cavity during use. The drain line may be connected to a drain or drain receptacle and may be used to pass dialysate from the cassette to the drain or drain receptacle during use. Although the system described herein is discussed principally in connection with the use of dialysate bags as the dialysate source, it is noted that, in other embodiments, different dialysate sources may be used. For example, in other embodiments, the dialysate source may include one or more containers in which dialysate is mixed and/or otherwise prepared at the PD machine from a dialysate concentrate, see, e.g., U.S. Pat. No. 10,076,599 to Eyrard et al., entitled “Dry Peritoneal Dialysis Concentrate System,” which is incorporated by reference herein in its entirety.

Referring toFIG.2, a schematic of an exemplary embodiment of a dialysis machine such as, for example, dialysis machine150is shown. The dialysis machine150may be a home dialysis machine, e.g., a PD machine, for performing a dialysis treatment on a patient, and may be included in the system100described above with respect toFIG.1. In use, the dialysis machine150may include a controller155disposed in the dialysis machine150. Alternatively, the dialysis machine150may be coupled to the controller155, or other external systems, via a communication port or wireless communication links. The controller155may automatically control execution of a treatment function during a course of dialysis treatment.

The controller155may be operatively connected to the sensors160and deliver a signal to execute a treatment function (e.g., transferring dialysate from the dialysate bag122through the heating chamber152and then to the patient), or a course of treatment associated with various treatment systems. In some embodiments, a timer165may be included for timing the triggering of the sensors160. The controller155may communicate control signals or triggering voltages to the components of the dialysis machine150, and may include wireless communication interfaces. The controller155may detect remote devices to determine if any remote sensors are available to augment any sensor data being used to evaluate the patient. For example, remote devices may include smart phone microphones, video cameras, cameras, thermal imaging cameras, in bed sensors, sleep manager applications and sensors, web cameras, fitness sensors, stand-alone sensors, and the like.

In some embodiments, the machine150may also include a processor170, a memory175, and/or the controller155, or combinations thereof and/or the machine150may receive signals from the sensor(s)160indicating various parameters. Each fluid bag (e.g., the dialysate bags122) may contain an approximate amount of dialysate, such that “approximate amount” may be defined as a 3 L fluid bag containing 3000 to 3150 mL, a 5 L fluid bag containing 5000 to 5250 mL, and a 6 L fluid bag containing 6000 to 6300 mL. The controller155may also detect connection of all fluid bags122connected.

Communication between the controller155and the treatment system may be bi-directional, whereby the treatment system acknowledges control signals, and/or may provide state information associated with the treatment system and/or requested operations. For example, system state information may include a state associated with specific operations to be executed by the treatment system (e.g., trigger pump to deliver dialysate, trigger pumps and/or compressors to deliver filtered blood, and the like) and a status associated with specific operations (e.g., ready to execute, executing, completed, successfully completed, queued for execution, waiting for control signal, and the like).

In some embodiments, as will be described in greater detail below, the dialysis machine150may include at least one pump180operatively connected to the controller155. During a treatment operation, the controller155may control the pump180for pumping fluid, e.g., fresh and spent dialysate, to and from a patient. The pump180may also pump dialysate from the dialysate bag122through, for example, the heating chamber152.

The dialysis machine150may also include a user input interface190, which may include a combination of hardware and software components that allow the controller155to communicate with an external entity, such as a patient or other user. These components may be configured to receive information from actions such as physical movement or gestures and verbal intonation. In some embodiments, the components of the user input interface190may provide information to external entities. Examples of the components that may be employed within the user input interface190include keypads, buttons, microphones, touch screens, gesture recognition devices, display screens, and speakers. The dialysis machine150may also include a display195and a power source197.

In some embodiment, the user interface190and display195may be, for example, a touch screen and a control panel operable by a user (e.g., a caregiver or a patient) to allow, for example, set up, initiation, and/or termination of a dialysis treatment. The touch screen and the control panel may allow an operator to input various treatment parameters to the dialysis machine and to otherwise control the dialysis machine. In addition, the touch screen may serve as the display. The touch screen may function to provide information to the patient and/or the operator of the dialysis system. For example, the touch screen may display information related to a dialysis treatment to be applied to the patient, including information related to a prescription. The touch screen and/or display may include one or more buttons for selecting and/or entering user information.

The dialysis machine150may also be connectable for remote communication. For example, the dialysis machine150may be configured to connect to a network. The connection to network may be via a wired and/or wireless connection. In one embodiment, the dialysis machine150includes, for example, an antenna or other connection component192to facilitate connection to a network. The antenna192may be, for example, a transceiver for wireless connections and/or other signal processor for processing signals transmitted and received. Other medical devices (e.g., other dialysis machines) or components may be configured to connect to the network and communicate with the dialysis machine150.

The dialysis machine150may also include a speaker185and a microphone187. The controller155being operatively connected to the speaker185and the microphone187.

As shown inFIG.2, the sensors160may be included for monitoring parameters and may be operatively connected to at least the controller155, the processor170, and/or the memory175, or combinations thereof. The processor170may be configured to execute an operating system, which may provide platform services to application software, e.g., for operating the dialysis machine150. These platform services may include inter-process and network communication, file system management and standard database manipulation. One or more of many operating systems may be used, and examples are not limited to any particular operating system or operating system characteristic. In some examples, the processor170may be configured to execute a real-time operating system (RTOS), such as RTLinux, or a non-real time operating system, such as BSD or GNU/Linux.

In one embodiment, the processor170is arranged and configured to communicate with the user interface (e.g., touch screen and control panel). The processor170may be configured to receive data from the user interface190(e.g., touch screen, control panel), sensors such as, for example, weight, air content, flow, temperature, and/or pressure sensors, and control the dialysis machine150based on the received data. For example, the processor170may adjust the operating parameters of the dialysis machine150. According to a variety of examples, the processor170may be a commercially available processor such as a processor manufactured by INTEL, AMD, MOTOROLA, and FREESCALE. However, the processor170may be any type of processor, multiprocessor or controller, whether commercially available or specially manufactured. For instance, according to one example, the processor170may include an MPC823 microprocessor manufactured by MOTOROLA.

The memory175may include a computer readable and writeable nonvolatile data storage medium configured to store non-transitory instructions and data. In addition, the memory175may include a processor memory that stores data during operation of the processor170. In some examples, the processor memory includes a relatively high performance, volatile, random access memory such as dynamic random-access memory (DRAM), static memory (SRAM), or synchronous DRAM. However, the processor memory may include any device for storing data, such as a non-volatile memory, with sufficient throughput and storage capacity to support the functions described herein. Further, examples are not limited to a particular memory, memory system, or data storage system.

The instructions stored on the memory175may include executable programs or other code that may be executed by the processor170. The instructions may be persistently stored as encoded signals, and the instructions may cause the processor170to perform the functions described herein. The memory175may include information that is recorded, on or in, the medium, and this information may be processed by the processor170during execution of instructions. The memory175may also include, for example, specification of data records for user timing requirements, timing for treatment and/or operations, historic sensor information, and the like. The medium may, for example, be optical disk, magnetic disk or flash memory, among others, and may be permanently affixed to, or removable from, the controller155.

The sensor(s)160may include a pressure sensor for monitoring fluid pressure of the machine150, although the sensors160may also include any of a heart rate sensor, a respiration sensor, a temperature sensor, a weight sensor, an air sensor, a video sensor, a thermal imaging sensor, an electroencephalogram sensor, a motion sensor, an audio sensor, an accelerometer, a capacitance sensor, or any other suitable sensor. It is appreciated that the sensors160may include sensors with varying sampling rates, including wireless sensors.

The controller155may be disposed in the dialysis machine150or may be coupled to the dialysis machine150via a communication port or wireless communication links, shown schematically as communication element158. According to various examples, the communication element158may support a variety of one or more standards and protocols, examples of which include USB, Wi-Fi, TCP/IP, Ethernet, Bluetooth, Zigbee, CAN-bus, IP, IPV6, UDP, UTN, HTTP, HTTPS, FTP, SNMP, CDMA, NMEA and/or GSM. As a component disposed within the machine150, the controller155may be operatively connected to any of the sensors160, the pump180, and the like. The controller155may communicate control signals or triggering voltages to the components of the machine150. As discussed, exemplary embodiments of the controller155may include wireless communication interfaces. The controller155may detect remote devices to determine if any remote sensors are available to augment any sensor data being used to evaluate the patient.

Referring now toFIGS.3A and3B, an example of an embodiment of a dialysis machine200in accordance with the present disclosure is shown. The dialysis machine200may include the components described above with respect to the schematic of the system100and the machine150illustrated inFIGS.1and2. The machine200may be configured to provide home dialysis treatment, for example, PD. In some implementations, the dialysis system and machine may be a home PD system, e.g., a PD system configured for use at a patient's home.

The dialysis machine200may include a housing242, a door226, and a cassette interface including pumps for contacting a cartridge or cassette202(used interchangeably without the intent to limit), where the cassette202is located within a cassette compartment214formed between the cassette interface and the closed door226. Fluid lines (e.g., tubing) may be coupled to the cassette202in a known manner, such as via a connector, and may further include valves for controlling fluid flow to and from fluid bags including fresh dialysate and warming pouch. In some embodiments, when a cassette202is incorporated, at least a portion of the fluid lines (e.g., tubing) may be integral to the cassette202. Prior to operation, a user may open the door226to insert a fresh cassette202and to remove the used cassette202after operation.

The cassette202may be placed in the cassette compartment214of the dialysis machine200for operation. The dialysis machine200may manage flowing dialysate into a patient's abdomen, and removal of the used dialysate and waste after a predetermined amount of time. During operation, dialysate fluid may be flowed into a patient's abdomen via the cassette202, and spent dialysate, waste, and/or excess fluid may be removed from the patient's abdomen via the cassette202.

While the dialysate is present in a peritoneal cavity of the patient, the dialysate may absorb contaminants and/or particulates from the patient's blood. PD uses the patient's peritoneum in the abdomen as a membrane across which fluids and dissolved substances (e.g., electrolytes, urea, glucose, albumin, osmotically active particles, and other small molecules) are exchanged from the blood. PD for a patient may include a total treatment of approximately 10 to 30 liters of fluid, where approximately 2 liters of dialysate fluid are pumped into a patient's abdomen, held for a period of time, e.g., about an hour, and then pumped out of the patient. This is repeated until the full treatment volume is achieved, and usually occurs overnight while a patient sleeps.

The dialysis machine200may operate the pumps (as will be described in greater detail below) to move the fluid. In use, the pumps apply force to the cassette202, that connect a fluid reservoir, e.g., dialysate bags to a catheter at the patient's peritoneum. By operation of the pumps, fresh dialysate may be introduced into the patient's peritoneum. Likewise, the pumps may draw fluid from the patient's peritoneum into a fluid reservoir or drain to waste. Multiple dialysate bags may be used including a clean fluid reservoir and a waste fluid reservoir. Operation of the pumps in conjunction with valves controls delivery or retrieval of fluid.

In connection with PD machine200, the heating element152may be in the form of a heater tray240including a heating element235positioned, for example, on top of the housing242of the dialysis machine200. The heater tray240may be any size and shape to accommodate a bag of dialysate (e.g., a 5 L bag of dialysate) for batch heating. In use, for example as illustrated in the example embodiment ofFIG.3A, dialysate bags234may be suspended from hooks on the sides of a cart244, and a heater bag237may be positioned in the heater tray240. Connectors and tubing ports may connect the dialysate bags234and lines for transferring dialysate. Dialysate from the dialysate bags234may be transferred to the heater bag237in batches. For example, a batch of dialysate may be transferred from one or more dialysate bags234to the heater bag237, where the dialysate is heated by the heating element235. When the batch of dialysate has reached a predetermined temperature (e.g., approximately 98°−100° F., 37° C.), the batch of dialysate may be flowed into the patient. The dialysate bags234and the heater bag237may be connected to the cassette202via dialysate bag lines or tubing238and a heater bag line or tubing238, respectively. The dialysate bag lines238may be used to pass dialysate from dialysate bags234to the cassette202during use, and a heater bag line246may be used to pass dialysate back and forth between the cassette202and the heater bag237during use. In addition, a patient line248and a drain line250may be connected to the cassette202. The patient line248may be connected to a patient's abdomen via a catheter and may be used to pass dialysate back and forth between the cassette202and the patient's peritoneal cavity by the pumps during use. The drain line250may be connected to a drain or drain receptacle and may be used to pass dialysate from the cassette202to the drain or drain receptacle during use.

As previously mentioned, fluid may leak from the cassette202. Specifically, fluid may leak at the interface between the cassette202and the pumps (e.g., pump heads) formed in the PD machine200(e.g., a leak can develop, for example, at the interface between a piston or pump head of a pump mechanism in the dialysis machine and a membrane proximate a fluid chamber formed in the cassette). In addition, and/or alternatively, the cassette202may be improperly positioned within the cassette compartment214of the PD machine200.

Referring toFIG.3B, a more detailed view of the cassette interface210of the dialysis machine200is shown. As shown, in one embodiment, the PD machine200includes pumps or pumping mechanisms, which include pistons233A,233B with pump heads241A,241B attached to piston shafts that can be axially moved within piston access ports236A,236B formed in the cassette interface210. In one embodiment, the piston shafts are connected to stepper motors that can be operated to move the pistons233A,233B axially inward and outward such that the pump heads241A,241B move axially inward and outward within the piston access ports236A,236B. In one embodiment, the stepper motors drive lead screws, which move nuts inward and outward along the lead screws. The nuts, in turn, are connected to the pistons233A,233B and thus cause the pistons233A,233B to move inward and outward as the stepper motors rotate the lead screws. Stepper motor controllers provide the necessary current to be driven through the windings of the stepper motors to move the pistons233A,233B. The polarity of the current determines whether the pistons233A,233B are advanced or retracted.

The PD machine200may also include encoders (e.g., optical encoders) that measure the rotational movement of the lead screws. The axial positions of the pistons233A,233B can be determined based on the rotational movement of the lead screws, as determined by the encoders. Thus, the measurements of the encoders can be used to accurately position the pump heads241A,241B of the pistons233A,233B.

In use, when the cassette202is properly positioned within the cassette compartment214of the PD machine200with the door226closed, the pump heads241A,241B of the PD machine200align with pump chambers239A,239B of the cassette202such that the pump heads241A,241B can be mechanically connected to dome-shaped fastening members of the cassette202overlying the pump chambers239A,239B. As a result of this arrangement, movement of the pump heads241A,241B toward the cassette202during treatment can decrease the volume of the pump chambers239A,239B and force dialysate out of the pump chambers239A,239B, while retraction of the pump heads241A,241B away from the cassette202can increase the volume of the pump chambers239A,239B and cause dialysate to be drawn into the pump chambers239A,239B.

As shown inFIG.3B, the cassette interface210may also include pressure sensors251A,251B that align with pressure sensing chambers263A,263B of the cassette202when the cassette202is positioned within the cassette compartment214. When included, portions of a membrane of the cassette202that overlie the pressure sensing chambers263A,263B adhere to the pressure sensors251A,251B using vacuum pressure. Specifically, clearance around the pressure sensors251A,251B communicates vacuum to the portions of the cassette membrane overlying the pressure sensing chambers263A,263B to hold those portions of the cassette membrane tightly against the pressure sensors251A,251B. The pressure of fluid within the pressure sensing chambers263A,263B causes the portions of the cassette membrane overlying the pressure sensing chambers263A,263B to contact and apply pressure to the pressure sensors251A,251B. The pressure sensors251A,251B can be any sensors that are capable of sensing the fluid pressure in the sensing chambers263A,263B.

The PD machine200may also include inflatable members (not shown) positioned within inflatable member ports (not shown) in the cassette interface210. The inflatable members align with depressible dome regions of the cassette202when the cassette202is positioned within the cassette compartment214of the PD machine200. The inflatable members act as valves to direct dialysate through the cassette202in a desired manner during use. In particular, the inflatable members bulge outward beyond the surface of the cassette interface210and into contact with the depressible dome regions of the cassette202when inflated, and retract into the inflatable member ports and out of contact with the cassette202when deflated. By inflating certain inflatable members to depress their associated dome regions on the cassette202, certain fluid flow paths within the cassette202can be occluded. Thus, dialysate can be pumped through the cassette202by actuating the pump heads241A,241B, and can be guided along desired flow paths within the cassette202by selectively inflating and deflating the various inflatable members.

The PD machine200may also include locating pins249(FIG.4) extending from the cassette interface210. When the door226is in the open position, the cassette202can be loaded onto the cassette interface210by positioning the top portion of the cassette202under the locating pins249and pushing the bottom portion of the cassette202toward the cassette interface210. The cassette202is dimensioned to remain securely positioned between the locating pins249and a spring loaded latch extending from the cassette interface210to allow the door226to be closed over the cassette202. The locating pins249help to ensure that proper alignment of the cassette202within the cassette compartment214is maintained during use.

As shown, the door226may include cylindrical recesses252A,252B that substantially align with the pistons233A,233B when the door226is in the closed position. When the cassette202is positioned within the cassette compartment214, hollow projections (not shown) of the cassette202, inner surfaces of which partially define the pump chambers239A,239B, fit within the recesses252A,252B. The door226may further include a pad that is inflated during use to compress the cassette202between the door226and the cassette interface210. With the pad inflated, the portions of the door226forming the recesses252A,252B support the projections of the cassette202and the planar surface of the door226supports the other regions of the cassette202. The door226can counteract the forces applied by the inflatable members and thus allows the inflatable members to actuate the depressible dome regions on the cassette202. The engagement between the door226and the hollow projections of the cassette202can also help to hold the cassette202in a desired fixed position within the cassette compartment214to further ensure that the pistons233A,233B align with the fluid pump chambers239A,239B of the cassette202.

In use, the controller is connected to the pressure sensors251A,251B, to the stepper motors (e.g., the drivers of the stepper motors) that drive the pistons233A,233B, and to the encoders that monitor rotation of the lead screws of the stepper motors such that the controller can receive signals from and transmit signals to those components of the system. In use, the controller monitors the components to which it is connected to determine whether any complications exists within the PD system100. In the event of complications, the controller can trigger one or more alarms and initiates communication (e.g., wirelessly) to activate one or more of the peripheral devices. The peripheral devices can, for example, be activated in a manner to get the attention of the patient and/or to draw the attention of the patient to a region of the PD system100determined to be experiencing the complication. Additional information and details on the operation of the PD machine including the pumps is disclosed in United States Published Patent Application No. 2015/0025449, filed on Jul. 22, 2013, entitled Activating Peripheral Devices in a Dialysis System, the entire contents of which are incorporated by reference herein.

In accordance with one or more aspects of the present disclosure, the dialysis machine, such as PD machine150,200, includes one or more sensors associated with the cassette interface210to detect proper loading, insertion, positioning, alignment, etc. of the cassette202into the cassette compartment214. Referring toFIG.4, in accordance with one aspect of the present disclosure, the dialysis machine200may include one or more sensors300to detect proper loading of the cassette202within the PD machine200. For example, the PD machine200may include one or more sensors300associated with the cassette interface210in the PD machine200. The one or more sensors300being arranged and configured to detect proper loading of the cassette202within the cassette compartment214of the PD machine200. The one or more sensors300may be any suitable sensor now known or hereafter developed to detect proper loading of the cassette202within the cassette compartment214of the PD machine200. In use, the one or more sensors300may be arranged and configured to transmit an input, a signal, etc. to, for example, a controller (e.g., controller155), which upon receiving the input or signal that the cassette202is not properly positioned transmits an alarm and/or prevents the dialysis machine200from starting a treatment cycle. For example, the controller may prevent the pump heads241A,241B from extending if the cassette202is misaligned within the PD machine200(e.g., actuation of the dialysis machine200is prevented if proper alignment of the cassette202within the dialysis machine200is not detected). In addition, and/or alternatively, the dialysis machine200can issue an alarm, an alert, etc. (e.g., a visual alert such as, for example, a flashing LED, an audio alert, etc.) to indicate that the cassette202is not properly aligned within the cassette interface214of the dialysis machine200so that the patient or care giver can take appropriate corrective measures.

For example, in one embodiment and as illustrated inFIG.4, the one or more sensors300may be a limit switch (e.g., a mechanical limit switch). The limit switch may extend, protrude, or the like from the surface of the cassette interface210. For example, as illustrated, the PD machine200may include first and second limit switches300A,300B built into the first and second locating pins249located on the surface of the PD machine200. In use, proper positioning of the cassette202within the cassette compartment214of the PD machine200will cause the cassette202to contact the limit switches300A,300B. Contacting the limit switches300A,300B will cause the limit switches to transition from a first stage or configuration to a second stage or configuration indicating that the cassette202is properly positioned.

Alternatively, as previously mentioned, the one or more sensors300may take on other forms. For example, the one or more sensors may be in the form of optical sensors. In use, the one or more optical sensors may be arranged and configured to detect the location of the various edges (e.g., perimeter) of the cassette202within the cassette compartment214of the dialysis machine200to detect proper alignment of the cassette202within the cassette compartment214of the dialysis machine200. Alternatively, and/or in addition, the cassette202may include one or more registration marks printed on an outer surface of the cassette202. In use, the dialysis machine200may include one or more image sensors. In use, the image sensors can be arranged and configured to determine alignment of the cassette202based on imaging of the registration marks on the cassette202. Alternatively, the one or more sensors may be in the form of one or more capacitive sensors arranged and configured to detect proper positioning of the cassette202within the cassette compartment214. For example, in one embodiment, the one or more capacitive sensors may be arranged and configured to detect whether the cassette202is properly seated within the cassette compartment214such as, for example, the capacitive sensors may be arranged and configured to detect if the cassette202is sitting flush with the surface of the cassette compartment214indicating that the cassette202is properly positioned within the cassette compartment214of the dialysis machine200. It should be appreciated that any combination of sensors may be utilized to detect proper positioning, alignment, etc. of the cassette202within the cassette compartment214.

In addition, and/or alternatively, referring toFIG.5, in accordance with one or more aspects of the present disclosure, the dialysis machine200may include one or more sensors320to detect a leak within the PD machine200. In use, the one or more sensors for detecting a leak within the PD machine200may be used in combination with the one or more sensors to detect proper loading, insertion, positioning, alignment, etc. of the cassette202into the cassette compartment214, or separately therefrom. For example, the PD machine200may include one or more sensors320associated with the pumps or pistons233A,233B in the PD machine200. In one embodiment, as shown inFIG.5, the pump heads241A,241B may include one or more capacitive sensors320arranged and configured to detect a presence of a liquid on the surface of the pump heads241A,241B or on the surface of the cassette interface surrounding the pump heads241A,241B. In addition, and/or alternatively, the surface of the cassette202may include one or more capacitive sensors arranged and configured to detect a presence of a liquid on the surface of the pump heads241A,241B or on the surface of the cassette interface surrounding the pump heads241A,241B. During use, if a leak is detected (e.g., if the capacitive sensor320detects liquid on the surface of the pump heads241A,241B or on the surface of the cassette202), a signal can be transmitted by the capacitive sensors320to the controller resulting in an alarm and/or stopping the dialysis treatment. Additional information on this embodiment can be found in U.S. patent application Ser. No. 16/680,778, filed on Nov. 12, 2019, entitled “Piston Assembly Including Leak Detection in a Dialysis Machine”, the entire contents of which are hereby incorporated by reference in its entirety.

In addition, and/or alternatively, in accordance with one or more aspects of the present disclosure, the dialysis machine, such as PD machine150,200, includes one or more sensors associated with the cassette interface to detect proper operation of the pumps (e.g., pistons) of the dialysis machine200. In use, the one or more sensors for detecting proper operation of the pumps (e.g., pistons) may be used in combination with the one or more sensors to detect proper loading, insertion, positioning, alignment, etc. of the cassette202into the cassette compartment214, with the one or more sensors to detect a leak within the PD machine, or separately therefrom. That is, for example, the PD machine200may include one or more sensors arranged and configured to aid with detecting proper operation of the pumps (e.g., pistons). In one embodiment, in addition to the encoders used to detect a position of the pump heads241A,241B via, for example, indirect measurements of the rotation of the lead screw (as previously described), the dialysis machine200may include one or more additional sensors positioned in the dialysis machine adjacent to, for example, the pump heads241A,241B to monitor proper operation of the pumps (e.g., pistons).

In use, the one or more sensors are arranged and configured to detect proper operation of the pumps (e.g., pistons) within the PD machine. For example, as previously mentioned, during manufacturing of the dialysis machines, problems may arise such as, for example, using parts that are bent, etc. that may cause the pump heads241A,241B to be misaligned in the dialysis machine. As a result, engagement of the pump heads241A,241B in the dialysis machine200with the pump chambers239A,239B of the cassette202positioned within the dialysis machine200may be inaccurate, which may cause problems resulting in leaks in the cassette202or prevent proper positioning, alignment, etc. of the pump heads241A,241B with the pump chambers239A,239B, respectively, of the cassette202.

The one or more sensors may be any suitable sensor now known or hereafter developed to detect proper operation of the pumps (e.g., pistons) within the PD machine200. In use, the one or more sensors may be arranged and configured to transmit an input, a signal, etc. to, for example, a controller (e.g., controller155), which upon receiving the input or signal that the pumps (e.g., pistons) are not properly operating, transmits an alarm and/or prevents the dialysis machine200from starting a treatment cycle. For example, the controller prevents the pump heads241A,241B from extending if the pistons are determined to be improperly operating (e.g., prevents actuation of the dialysis machine if proper operation of the pistons within the dialysis machine is not detected). In addition, and/or alternatively, the dialysis machine can issue an alarm, an alert, etc. (e.g., a visual alert such as, for example, a flashing LED, an audio alert, etc.) to indicate that the pumps (e.g., pistons) are not properly operating so that the patient or care giver can take appropriate corrective measures.

For example, in one example of an embodiment, referring toFIG.6, one or more sensors340can be positioned about the pumps (e.g., pistons). In use, the sensors340, which may be in the form of proximity sensors, are arranged and configured to monitor axial alignment of the pump assemblies. For example, as illustrated, in one embodiment, a plurality of proximity sensors340(e.g. such as, for example, six to eight proximity sensors) may be positioned radially around an axis of travel of the pumps (e.g., pistons). Thereafter, in use, as the pumps (e.g., pistons) move, the proximity sensors340can detect alignment of the pumps (e.g., pistons). For example, the proximity sensors340can detect misalignment based on the relative signal strength of the different proximity sensors. A detected misalignment may cause a signal to be transmitted to the controller, which may cause an alarm and/or stopping treatment cycle thus indicating to the patient and/or care giver that the dialysis machine may need to be serviced to repair or replace the pump assembly. In use, the plurality of proximity sensors340may also detect proper operation of the pumps (e.g., pistons) such that the sensors340can detect if the pump heads241A,241B are actually being extended or retracted. For example, if the pump heads241A,241B are removed from the pump assembly and/or the lead screw threads are stripped, the pump heads241A,241B may not move with rotation of the lead screw. This can be detected by the proximity sensors.

Thus arranged, during normal operation of the dialysis machine150,200, fluid (e.g., dialysate) is properly contained within its respective fluid bags and/or fluid lines. The sensors300,320,340may be configured to monitor the dialysis machine to ensure proper operation and/or patient safety. In the event that the sensor detects misalignment of the cassette202within the cassette compartment214, detects fluid on the outer surface of the cassette202or pumps, and/or detects improper operation of the pumps, the dialysis machine150,200may be configured to react to the detection in any number of ways, including initiating alarms and/or causing one or more operational conditions. For example, once a condition has been detected, a signal may be sent from the sensor300,320,340to, for example, the controller of the dialysis machine to: activate an alarm, halt operations, or a combination thereof. For example, the dialysis machine150,200may be arranged and configured to generate an alarm condition, such as a visual and/or audible notifier. For example, a signal may be sent to the user interface portion of the dialysis machine to indicate the condition, and/or an audio or a light indicator may be triggered. In some embodiments, the dialysis machine150,200may transmit (e.g., via a wireless connection) the alarm condition to a remote location, including but not limited to a doctor's office, hospital, call center, and technical support. For example, the dialysis machine150,200may provide real time remote monitoring of machine operation. The dialysis machine150,200may include a memory for storing data, or may transmit data to a local or remote server at scheduled intervals. In addition, and/or alternatively, the dialysis machine150,200may be arranged and configured to automatically shut off operation, or allow the user to monitor, pause, and/or cease the dialysis operation based on the detection. In this manner, the dialysis treatment can be halted and/or the condition corrected.

Referring toFIG.7, a flow diagram500of a method of detecting improper alignment of the cassette within the cassette compartment, a leak during a dialysis operation, and/or improper operation of the pumps (e.g., pistons) according to one or more embodiments of the present disclosure is shown. At step505, components of the dialysis machine150,200are inserted, for example, a cassette202may inserted into a cassette compartment of a housing of the dialysis machine. At step510, the dialysis machine is operated by pumping dialysate fluid via the cassette. As described above, in a peritoneal dialysis operation, fresh dialysate may be pumped into an abdomen of a patient, and spent dialysate, including waste and excess fluid, may flow out of the patient's abdomen. At step515, a condition of the dialysis machine such as, for example, alignment of the cassette within the cassette compartment, a leak during a dialysis operation, and/or improper operation of the pumps (e.g., pistons) is monitored by one or more sensors300,320,340. At step520, when a condition is detected in the dialysis machine, a signal is transmitted from the sensor to the processor of the machine. As described above, the machine may send an audible or a visual indication of the condition, and alternatively, or additionally, automatically stop dialysis operation.

The system described herein has been explained in connection dialysis machines having a particular configuration. It is contemplated that the system described herein may be used with dialysis machines having other configurations, for example, different types of dialysis machines and/or dialysis machines having cassettes positionable in other configurations and having other features. The system described herein may be used with any appropriate dialysis machine and/or other medical devices utilizing disposable cassettes that would benefit from leak detection.

Some embodiments of the disclosed system may be implemented, for example, using a storage medium, a computer-readable medium or an article of manufacture which may store an instruction or a set of instructions that, if executed by a machine (i.e., processor or microcontroller), may cause the machine to perform a method and/or operations in accordance with embodiments of the disclosure. In addition, a server or database server may include machine readable media configured to store machine executable program instructions. Such a machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware, software, firmware, or a combination thereof and utilized in systems, subsystems, components, or sub-components thereof. The computer-readable medium or article may include, for example, any suitable type of memory unit, memory device, memory article, memory medium, storage device, storage article, storage medium and/or storage unit, for example, memory (including non-transitory memory), removable or non-removable media, erasable or non-erasable media, writeable or re-writeable media, digital or analog media, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or disks, various types of Digital Versatile Disk (DVD), a tape, a cassette, or the like. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, encrypted code, and the like, implemented using any suitable high-level, low-level, object-oriented, visual, compiled and/or interpreted programming language.

While the systems and techniques described herein for detecting leaks have been largely explained with reference to a dialysis machine, in particular, a peritoneal dialysis machine, the systems and techniques described for detecting leaks may be used in connection with other types of medical treatment systems and/or machines, such as a hemodialysis machine or other medical treatment device involving medical fluids. In some implementations, the dialysis machine may be configured for use in a patient's home (e.g., a home dialysis machine). The home dialysis machine can take the form of a peritoneal dialysis machine or a home hemodialysis machine.