Invented by Kulwinder S. Plahey, Jie Zhu, Tri Ly, Robert Matthew Ohline, William Scott Crawford, Fresenius Medical Care Holdings Inc

The market for medical fluid cassette leak detection devices and methods has been steadily growing in recent years. These devices and methods play a crucial role in ensuring the safety and efficacy of medical fluid delivery systems, such as infusion pumps and dialysis machines. Medical fluid cassettes are commonly used in healthcare settings to deliver fluids, such as medications, blood products, and intravenous solutions, to patients. However, leaks in these cassettes can lead to serious consequences, including medication errors, contamination, and patient harm. Therefore, it is essential to have reliable leak detection devices and methods in place to identify and prevent such incidents. The global market for medical fluid cassette leak detection devices and methods is expected to witness significant growth in the coming years. Factors driving this growth include the increasing prevalence of chronic diseases, the rising demand for advanced medical devices, and the growing emphasis on patient safety and quality of care. One of the key trends in this market is the development of innovative technologies for leak detection. Traditional methods, such as visual inspection and manual pressure testing, have limitations in terms of accuracy and efficiency. As a result, manufacturers are investing in research and development to introduce more advanced and automated solutions. For instance, some companies are incorporating sensors and electronic monitoring systems into medical fluid cassettes to detect leaks in real-time. These sensors can detect even the smallest leaks and trigger an alarm or alert healthcare providers, allowing for immediate intervention. This not only reduces the risk of patient harm but also improves workflow efficiency by minimizing the need for manual checks. Another trend in the market is the integration of leak detection devices with infusion pumps and other medical devices. This integration allows for seamless monitoring and control of fluid delivery, ensuring that any leaks are detected and addressed promptly. It also provides healthcare providers with valuable data on fluid usage and potential issues, enabling them to optimize treatment plans and improve patient outcomes. In terms of geography, North America is expected to dominate the market due to the presence of well-established healthcare infrastructure, stringent regulatory standards, and high adoption of advanced medical technologies. However, the Asia Pacific region is projected to witness the highest growth rate, driven by the increasing healthcare expenditure, expanding patient population, and growing awareness about patient safety. In conclusion, the market for medical fluid cassette leak detection devices and methods is witnessing significant growth due to the rising demand for patient safety and quality of care. The development of innovative technologies and the integration of leak detection devices with medical devices are driving this growth. As healthcare providers continue to prioritize patient safety, the demand for these devices and methods is expected to further increase in the coming years.

The Fresenius Medical Care Holdings Inc invention works as follows

The method includes applying a first force to the flexible membrane, measuring a first physical property of a system that includes the medical fluid cassette and a medical fluid pumping machine, removing the applied force from the flexible membrane and then applying a second pressure to the flexible membrane. This is followed by determining whether the medical fluid cassette leaks based on a comparison between the measured properties. The method involves applying a force to a flexible membrane and measuring the physical properties of a system including the medical cassette and a fluid pumping device. It then removes the force and applies a second force.

Background for Medical fluid cassette leak detection devices and methods

Dialysis is used to treat a patient who has insufficient kidney function. “The two main dialysis methods include peritoneal and hemodialysis.

During hemodialysis, (?HD?) the patient’s blood is passed through a dialyzer of a dialysis machine while also passing dialysate through the dialyzer. Dialysis machines pass the blood of the patient through a dialyzer while also passing the dialysate. Dialyzers have a semi-permeable dialysate membrane that separates blood from dialysate. This membrane allows for diffusion and osmosis to occur between the dialysate, and blood. The exchanges that occur across the membrane remove waste products from the blood, such as urea, creatinine and other solutes. These exchanges regulate other substances in the blood, like sodium and water. The dialysis machine works as a kidney to cleanse the blood.

During peritoneal dialysate (?PD? Dialysate is periodically infused into the peritoneal cavity of a patient. The peritoneal membrane acts as a semi-permeable natural membrane, allowing diffusion and osmosis to occur between the solution and blood. The exchanges that take place across the peritoneum of the patient, similar to the exchanges that occur across the dialyzer of HD, remove waste products from the blood such as urea, creatinine and other solutes. They also regulate other substances in the blood like sodium and water.

Many PD machines are designed for automatic infusion, dwell and drainage dialysate into and out of the patient’s peritoneal cavities. The treatment usually lasts several hours and begins with a drain cycle that empties the peritoneal cavities of dialysate. The sequence continues through successive phases of fill, dwell and drain. “Each phase is called a ‘cycle.’

In some aspects, it is possible to detect leaks within a disposable fluid cassette. The medical fluid cassette comprises a base, and a flexible layer attached to the base so that they cooperate to form at least a partial fluid passageway. The method involves applying a force to a flexible membrane, measuring the first physical properties of a system including the medical cassette and a pumping system while the force is being applied to flexible membrane. Removing the force from flexible membrane and applying a force to a flexible membrane again.

In some aspects, a method for detecting leaks within a disposable medical liquid cassette is provided. The medical cassette comprises a base, and a flexible flexible membrane that is attached to the base so that they cooperate to form at least a fluid passageway with fluid inlet and fluid outlet port that allow communication between the fluid passageway to an exterior of a medical fluid cassette. The method involves applying a force to a base, a force to a membrane and closing fluid inlet and fluid outlet ports. It also includes measuring the physical properties of a system including the medical cassette and a pumping machine.

The methods can include one or more additional features or steps: The first physical characteristic is a first internal pressure of the medical cassette, and the second physical characteristic is a second internal pressure. If the second pressur is higher than the first, then the medical fluid cassette has a leak. The difference between the two is at least the given difference value. A medical fluid cassette has a leak when the second press is lower than the first, and the difference between the first and second pressures is greater than a certain value. The medical fluid pumping device comprises a piston that can be advanced and withdrawn from a flexible membrane. Applying the first pressure to the membrane consists of advancing and withdrawing the piston until a certain pressure is reached within the cassette. Applying the second pressure to the membrane consists of advancing and withdrawing the piston until the desired pressure is reached within the cassette. Calculating a difference between first and second positions is part of comparing the first and second physical properties. The first force and the second force are the same.

The methods can also include additional steps or features, such as: the medical fluid cartridge has fluid inlet and fluid outlet ports that allow communication between the fluid path and the exterior of the cassette. The first force is applied with both the fluid inlet and fluid output ports open. Fluid inlet and fluid outlet port are closed before the first force is removed from the flexible membrane. Fluid inlet and fluid outlet ports are provided on the medical fluid cartridge to allow communication between the fluid path and the exterior of the cassette. The first force is applied with these ports closed. The method also includes waiting a certain period of time between the removal of the first force and the application the second force on the flexible membrane. The period of time can range from 15 seconds to 60. The period of time given is between 20 seconds and 30 seconds. The medical fluid cartridge includes fluid inlet and fluid outlet ports that allow fluid to flow between the fluid passageway of the cassette and the exterior. Between applying the first force on the flexible membrane and determining the first physical characteristic of the system, a method is performed that involves closing the fluid ports in order to trap fluid within the cassette. The method involves applying a vacuum on the outer surface of the membrane between the removal of the first force and the application the second force. The fluid cassette has fluid inlet and fluid outlet ports which communicate between the fluid passageway of the cassette and its exterior. Before applying the first pressure to the flexible membrane the method closes the fluid inlet and fluid output ports so that fluid is trapped in the cassette. Fluid within the cassette will be redistributed between closing the fluid inlet and fluid outlet port so that fluid is trapped inside the medical fluid cassette, and applying the force to the flexible surface. The first force is applied to the flexible surface until at least some of the membrane touches the base. The medical fluid pumping device comprises a piston. Applying the first force on the flexible membrane involves advancing the piston towards the cassette in a way that ensures the space between flexible membrane and base is predetermined. The second force is applied to the flexible membrane by advancing the piston in a direction that corresponds to the first property. “The method involves applying a vacuum on an outer surface to the flexible membrane in between removing the force and applying the force.

In certain aspects, a fluid pumping device for medical purposes is configured to accept a disposable fluid cassette. The medical fluid cartridge includes a base, and a flexible layer attached to the base so that they cooperate to form at least a partial fluid passageway. The medical liquid pumping machine has a compartment for the medical cassette, and a pressure application device configured to apply force to the cassette when it is in the compartment. The medical liquid pumping device also includes a processor that is configured to “control the pressure application in such way that a force is first applied to a flexible membrane while the medical cassette is within the compartiment; measure the first physical properties of a system including the pumping system with the fluid cassette within the chamber while the force is first applied; control pressure applicator so that the force first is removed from flexible membrane while the fluid cassette within the chamber; control pressure applicator such that the force first is removed when the fluid cassette within the disposed in the compartment,

The The The

The medical liquid pumping machines” may include any or all of the following: the machine has a vacuum controllable by a processor, which is disposed in the compartment so that, when activated, while the medical cassette is inside the compartment, it can apply a pressure to the flexible surface. The processor is also configured to alter the spacing between the flexible base and flexible membrane by activating this vacuum source. The processor can change the spacing by activating the vacuum source after the pressure is removed from flexible membrane, and before the pressure is applied. The vacuum source may apply a force on the outer surface of flexible membrane. The machine includes a compartment door configured to selectively shut the compartment and retain a medical fluid cartridge within the compartment. An inflatable bladder disposed at the inside of the door is also included. It is configured so that, when inflated, while the cassette is inside the compartment the inflatable is configured compress the cassette. When deflated, while the cassette is inside the compartment the inflatable is configured contract against the interior surface of door to create a space. The processer can deflate the bladder by controlling the pressure application in a manner that removes the first force from the flexible surface and then controlling the pressure application in a manner that applies the second force to the flexible surface. The pressure applicator is controlled in a manner that applies the first force to the flexible layer. This is done by compressing the flexible membrane against the base. The pressure applicator consists of a piston that can be advanced and retracted into the compartment. Fluid inlet and fluid outlet ports are provided on the medical fluid casette to allow communication between a fluid passageway and the exterior of the cassette. The fluid inlet and fluid output ports must be open in order for the pressure applicator to apply the first force. The medical fluid cartridge includes fluid inlet and fluid outlet ports that communicate between the fluid passageway of the medical cassette and its exterior. The processer is configured so that it closes the fluid inlet and fluid output ports after the pressure applicator has been controlled to apply the first force to the flexible membrane, but before measuring the first internal pressure. The medical fluid cartridge includes fluid inlet and fluid outlet ports that allow communication between the fluid path and the exterior of the cassette. Controlling the pressure applicator so that the first force applied to the membrane is done with the fluid ports and outlet ports closed.

The following benefits can be included in the implementation.

In some implementations, a way to determine whether a medical cassette (e.g. a PD cassette) leaks includes applying a pressure to the medical cassette, measuring a measurement of the first pressure, and then removing the force applied from the medical cassette. A force is applied to a medical fluid cartridge after a predetermined time period. The second pressure is then measured. A comparison between the first and the second pressure measurements can determine if there is a leak within the flexible membrane. This method has an advantage over other leak detection methods because the force applied to the medical fluid cassette is removed between pressure measurements. For example, when the force is applied using pistons from a medical liquid pumping machine (e.g. The pistons of a PD-cycler may obstruct a leak in the membrane of a medical fluid cassette in the vicinity or the pump chambers. This can lead to false confidence when tests are performed with a continuous force. The accuracy of leak detection is improved by removing the applied pressure (for instance, by retracting pistons) in between pressure measurements. Membrane leaks near the applied force are not blocked, allowing detection of leaks around the applied forces (for example in the membrane above the pump chambers).

In some implementations, there is a “dry” method of detecting leaks in a disposable medical fluid cassette. A method for detecting leaks within a disposable medical cassette is described. The method can be used, for example, to test a PD cassette before performing peritoneal dialysate, using air as a fluid instead of dialysate. The method tests the PD cassette in a PD Cycler before treatment. This allows leaks to be detected and remedied more easily than if they were detected during a cycle. The dialysis machine will not be damaged by leaks because air is used to test the cassette. There is no need for dialysate to be thrown away or disinfected if a leak in the cassette is detected. Moreover, if a liquid leak is detected, it is prevented from entering into the mechanical and pneumatic system of the PD Cycler.

In some cases, the dialysis device can alert the user if it detects a leak and prompt them to take corrective action, such as changing the cassette for a new one, before the machine is permanently damaged or certain components are permanently damaged.

The description, drawings and claims will reveal other aspects, features and advantages.

DESCRIPTION of Drawings

FIG. “FIG. The PD system includes a PD biker positioned atop a mobile cart.

FIG. “FIG. The PD system of FIG. 1 is shown with the door of the PD Cycler open to reveal the surfaces on the PD Cycler that interact with the PD Cassette during use.

FIG. “FIG. 1.

FIG. The assembled PD cassette in FIG. 3. The base of the cassette can be seen through the clear membrane attached to the base.

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