System and method for reducing catheter leakage

Abstract

The invention relates to a system and method for reducing conduit leakage. Systems and methods described herein relate to an intracardiac blood pump system including a pump, an elongate multi-lumen catheter, a compartment connected to the catheter, a first lumen, a conduit, and a filter disposed within the conduit. At least one electronic component is located within the compartment. A conduit extends through an interface between the compartment and the conduit. The conduit is configured to allow gas to permeate from a first end of the conduit through the first opening of the compartment to a second end of the conduit. The second end of the conduit is in fluid communication with the central lumen of the elongate multi-lumen catheter. The filter is configured to prevent liquid from flowing from the multi-lumen conduit into the compartment after allowing gas to flow from the first end of the conduit through the second end of the conduit and into the multi-lumen conduit.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201980061053.5, titled "Systems and Methods for Reducing Leakage from a Catheter", filed on July 18, 2019.

[0002] Citation of Related Applications

[0003] This application claims the priority and benefit of U.S. Provisional Patent Application No. 62 / 700,683, titled "SYSTEMS AND METHODS FOR REDUCING LEAKS FROM A CATHETER", filed on July 19, 2018. The entire content of the above application is incorporated herein by reference. Background Art

[0004] Intracardiac heart pump assemblies can be introduced into the heart surgically or percutaneously and are used to pump blood from one location in the heart or circulatory system to another location in the heart or circulatory system. For example, when deployed in the heart, an intracardiac pump can pump blood from the left ventricle of the heart into the aorta or from the right ventricle to the pulmonary artery. The intracardiac pump can be powered by a motor located outside the patient or a motor located inside the patient. Some intracardiac blood pump systems can operate in parallel with the natural heart to supplement cardiac output and partially or fully relieve the load on the heart. Examples of such systems include the Abiomed AB5000 System (Abiomed, Inc., Danvers, MA).

[0005] A blood pump system includes a pump and a compartment. One end of a catheter is connected to the pump and the other end is connected to the compartment. The catheter typically includes a plurality of fluid lumens that transport liquid in a distal direction to the pump. The compartment can be multifunctional. In some configurations, it includes mechanical components and electronics that enable the pump to operate and be maintained. Leakage in the lumens within the catheter can reach the compartment and damage the electronics within the compartment. Leakage can cause, for example, the pump to stop operating or a drop in the pressure of the entire system. Summary of the Invention

[0006] Systems, methods, and devices for preventing leakage in an intracardiac blood pump system are described herein. Such systems are capable of preventing fluid from leaking out of the catheter into the compartment of the blood pump system that contains electronics while maintaining the function of the pump. A filter, as described herein, is advantageously placed between the catheter and the compartment of the blood pump system to differentially seal the compartment. For example, the filter allows a sterilization gas to pass through the filter to the catheter but prevents liquid from the catheter (e.g., as a result of leakage) from passing through the filter and entering the compartment.

[0007] In some embodiments, an intravascular blood pump system includes a pump, a catheter proximal to the pump, a chamber proximal to the catheter, a conduit extending through an interface between the chamber and the catheter, and a filter within the conduit. For example, the blood pump system can be a device of Abbott, or any other suitable system. In some embodiments, a controller is configured to facilitate operation of the intravascular blood pump system described herein. For example, the controller can be Abbott's Automated Impeller Controller or any other suitable controller that receives an input signal and translates it into an operating signal to operate the pump. At least one advantage of an independent controller configured to facilitate operation of an intravascular blood pump system is precise control of the system and acquisition of data related to the system.

[0008] In some embodiments, the pump includes a housing and a rotor disposed within the housing. The rotor can have at least one vane. Specifically, the rotor can include impeller vanes that are shaped to cause fluid flow when under a rotational force. In some embodiments, the rotor is driven by an implantable motor having a rotor and a stator. The proximal end of the rotor can be coupled to a drive shaft. In some embodiments, the motor is external to the patient and drives the rotor through an elongate mechanical transmission element such as a flexible drive shaft, a drive cable, or a hydraulic coupler.

[0009] In some embodiments, the catheter is an elongate multi-lumen catheter having a proximal end, a distal end, and a central lumen. The distal end of the elongate multi-lumen catheter can be adjacent to the pump housing. For example, when the blood pump system is in use, the pump housing is placed inside the patient's heart, and the elongate multi-lumen catheter can extend from the patient's heart and through the patient's vasculature such that a first portion of the catheter is within the patient and a second portion of the catheter is outside the patient. The catheter can include two, three, four, five, or any suitable number of lumens. For example, two separate tubes can pass through the central lumen of the catheter, thus defining a total of three lumens - a first central lumen, the lumen through the first tube, and the lumen through the second tube. Some lumens can extend the entire length of the catheter, while other lumens can only partially extend through the catheter.

[0010] In some embodiments, the chamber is proximal to the catheter. For example, the distal end of the chamber can be positioned adjacent to the proximal end of the catheter. At least one advantage of positioning the chamber adjacent to the proximal end of the catheter is that a tube can extend through the chamber and into the lumen of the catheter. In some examples, the catheter can extend partially within the chamber (e.g., to provide structural support at the connection point between the catheter and the chamber). In some examples, the proximal end of the catheter abuts the distal end of the chamber.

[0011] In some embodiments, the blood pump system further includes a connector at the interface between the compartment and the conduit. The first lumen and the tubing can pass through the connector. In some embodiments, the connector has an internal volume, and a filter fills at least 50% of the internal volume of the connector. In some examples, the connector extends partially into the compartment. In some examples, the conduit extends partially into the connector. At least one advantage of providing a connector between the compartment and the conduit is to provide additional structural stability at the connection point between these two elements. For example, the connector can prevent the conduit from sharply bending or kinking where it is connected to the compartment.

[0012] In some embodiments, the compartment includes a first opening and one or more side ports. The first opening of the compartment can be located at the distal end of the compartment and connected to the proximal end of the conduit. The one or more side ports of the compartment can be located proximal to the first opening of the compartment. For example, there can be one or two side ports between the distal and proximal ends of the compartment. At least one advantage of providing side ports is to allow the lumens for transporting fluid to enter the compartment and then extend into the proximal end of the conduit. Specifically, the side ports provide a connection to an external fluid source, which can supply fluid to the pump or the patient through the conduit.

[0013] In some embodiments, there is at least one electronic component within the compartment. The at least one electronic component can include a memory, a pressure transducer, and / or a pressure sensor. For example, a printed circuit board including transistors, inductors, resistors, capacitors, sensors, or any other suitable components can be disposed within the compartment. The electronic devices within the compartment also allow the pump to be connected to a pump controller. At least one advantage of including a storage element within the compartment is that if the pump is connected to multiple controllers at different time points, the blood pump system can store the operating parameters to be used. At least one advantage of including a pressure transducer and / or a pressure sensor within the compartment is that the pump system can "translate" the pressure readings (e.g., from the pressure transducer) so that the pressure signal or related parameters can be sent to the controller and displayed to the user.

[0014] In some embodiments, the first lumen of the elongate multi-lumen catheter is configured to transport fluid from an external source. The fluid can be transported through one or more side ports of the compartment and through the first opening of the compartment to the distal end of the elongate multi-lumen catheter. In some embodiments, the first lumen passes through the compartment. For example, the first lumen can be defined by a first end point external to the compartment, extend through a portion of the compartment, into the catheter, and terminate at a second end point within the catheter or at the distal end of the catheter. In some embodiments, the first lumen is within the central lumen. At least one advantage of placing the first lumen within the central lumen is to provide a single lumen that includes all other lumens extending from the compartment to prevent tangling and / or kinking of the tubes. Additionally, by placing the first lumen within the central lumen, the first lumen is protected from external forces (e.g., scratching, etc.) by an additional layer of tubing.

[0015] In some embodiments, the fluid is blood, saline, a cleansing fluid, glucose, heparin, or any other suitable material or combination thereof. For example, the fluid can include dextran and heparin. In some embodiments, the fluid includes a cleansing fluid that flows through the first lumen to the rotor to keep the pump substantially free of blood. At least one advantage of using a cleansing fluid is that the flow of the cleansing fluid can provide a barrier to prevent blood from entering the gap between the rotor and the motor stator or the pump housing, which otherwise could damage the blood (e.g., hemolysis) or damage the motor (e.g., increased friction, overheating, and / or jamming). For example, the cleansing fluid can include dextran and heparin. At least one advantage of using a combination of dextran and heparin is to prevent the formation of blood clots with an appropriate amount of active agent (e.g., via anticoagulant heparin), while maintaining biocompatibility and flow.

[0016] In some embodiments, the blood pump system further includes a second lumen of the elongate multi-lumen catheter. The second lumen can be configured to transport a second fluid. In some examples, the second lumen extends through the compartment. The second fluid can also be transported from an external source through one or more side ports of the compartment and through the first opening of the compartment to the distal end of the elongate multi-lumen catheter. In some examples, the second lumen is a pressure lumen and the second fluid is saline. The second lumen can have an opening distal to the compartment. At least one advantage of the second lumen is that the second lumen can transport a fluid different from the first lumen and can be provided via a different external source. For example, the first lumen can transport a cleansing fluid while the second lumen can transport saline, and the cleansing fluid and saline can be maintained separate from each other.

[0017] In some embodiments, a conduit extends through an interface between a compartment and a multi-lumen catheter. The conduit can include a first end proximal to a first opening of the compartment and a second end distal to the first opening of the compartment such that the conduit spans the first opening of the compartment. Positioning the conduit within both the compartment and the catheter allows a liquid or gas to be inserted from the compartment into the catheter and thus provides access to a central lumen of the catheter. The conduit is configured to transport gas from the first end of the conduit through the first opening of the compartment to the second end of the conduit. The second end of the conduit can be in fluid communication with the central lumen of the elongate multi-lumen catheter. For example, the proximal end of the conduit can extend a short distance into the compartment and the distal end of the conduit can extend a short distance into the catheter. The system can be immersed in a gas-filled environment introduced via an external gas source and the conduit can allow gas to permeate into the interior of the catheter. At least one advantage of transporting gas to the interior of the catheter is that the central lumen of the catheter is sterilized such that any fluid within the catheter (e.g., a fluid that may contact a patient) remains sterile.

[0018] In some embodiments, a filter is disposed within the conduit. The filter can be configured to prevent fluid from flowing out of the multi-lumen catheter into the compartment while allowing gas to flow from the first end of the conduit through the second end of the conduit and into the multi-lumen catheter. At least one advantage of placing the filter within the conduit is that any fluid leaking from within the central lumen of the catheter will reach the filter (via the conduit) before reaching any electronic components within the compartment.

[0019] In some embodiments, the gas transported by the conduit is a sterilizing gas. The sterilizing gas can be used to sterilize the central lumen. For example, the gas can be ethylene oxide, nitrogen dioxide, ozone, vaporized hydrogen peroxide, or any other suitable gas. At least one advantage of using a sterilizing gas is that the central lumen of the catheter is sterilized such that any fluid within the catheter (e.g., a fluid that may contact a patient) remains sterile.

[0020] In some embodiments, the filter is configured to prevent liquid leaking from the central lumen from passing through the conduit and reaching the compartment in some cases. During operation of the blood pump system, the first lumen may be damaged such that liquid leaks from the first lumen into the central lumen of the conduit. For example, the purification fluid may leak from the lumen into the central lumen of the conduit. Without a filter, the leaked liquid would flow from the conduit into the compartment, which would be problematic. However, the filter located in the conduit prevents the leaked liquid from reaching the interior of the compartment and thus prevents the fluid from reaching the at least one electronic component. To achieve a proper seal but still facilitate disinfection, the filter is configured to provide liquid filtration, so it allows the airflow to be transported through the filter before any liquid contact. At least one advantage of preventing leakage through the filter is to prevent the liquid from reaching the electronic components inside the compartment. For example, if the liquid contacts any exposed electronic components inside the compartment, the liquid may cause a short circuit or damage the electronic device, resulting in the pump stopping or changing its operation. At least one advantage of allowing gas to pass through the filter is to allow disinfection of the central lumen of the conduit.

[0021] Positioning the filter can help achieve a liquid seal. In some embodiments, the filter is located proximal to the first opening of the compartment. For example, the filter can be placed entirely within the compartment. In some embodiments, the filter is located distal to the first opening of the compartment. For example, the filter can be placed entirely outside the compartment. In some embodiments, the filter extends through the first opening of the compartment. In some embodiments, a portion of the filter extends within the compartment. For example, the filter can span the first opening of the compartment such that a first portion of the filter is within the compartment and a second portion of the filter is outside the compartment. At least one advantage of placing the filter so that it extends through or near the opening of the compartment is that the filter can prevent liquid from contacting the interior of the compartment (and the electronic components located therein).

[0022] In some embodiments, the filter includes a hydrogel adhered to the pore walls of a porous matrix. The filter can be, for example, the filter described in U.S. Patent Publication 2004 / 0052689, which is hereby incorporated by reference in its entirety. The hydrogel can be a hydrophilic polyurethane, a hydrophilic polyurea, a hydrophilic polyureamine, or any suitable material. At least one advantage of using a hydrogel (e.g., a hydrophilic polymer) is that the hydrogel swells in an aqueous solution and retains most of the aqueous solution to which it is exposed without dissolving. The porous matrix can be a metal, a ceramic, a glass, an organic, an inorganic, an organic polymer, an acrylic polymer, a polyolefin, or any suitable material or combination thereof. At least one advantage of the porous matrix is that it has channels through which gas can flow, which facilitates sterilization. At least one advantage of using a filter comprising a hydrogel and a porous matrix is that when the filter is placed between two parts of a tube and by preventing the flow of an aqueous solution between these two parts, the filter can prevent contamination between the two parts.

[0023] In some embodiments, the filter self-seals upon exposure to a liquid. For example, the filter may self-seal upon exposure to an aqueous medium. In some embodiments, the filter is breathable. In some embodiments, the self-sealing filter responds rapidly (i.e., seals) upon exposure to a liquid, contaminating the liquid solution with which it comes into contact little or not at all, and being able to withstand a high back pressure (e.g., greater than about 7 psi) before allowing gas or liquid to pass through again. In some embodiments, the filter is biocompatible. At least one advantage of the self-sealing filter is a short response time, contaminating the aqueous solution with which they come into contact little or not at all, and being able to withstand a high back pressure.

[0024] In some embodiments, the filter is in the shape of a narrow cylinder, and the size and shape of the filter are designed to fit within a conduit. In some embodiments, the conduit can be a narrow tube. The outer diameter of the filter can be equal to the inner diameter of the conduit such that the filter fits tightly within the conduit. In some embodiments, the filter is in the shape of a frustum of a cone, and the size and shape of the filter are designed to fit within a conduit. The filter can have a first outer diameter equal to the inner diameter of the conduit such that the filter fits tightly within the conduit at a first end and then tapers to follow the shape of the conduit. At least one advantage of designing the shape and size of the filter to fit tightly within the conduit is that any gas or liquid passing through the conduit will contact the filter, and thus the filter can prevent liquid from flowing from one end of the conduit to the other (e.g., from the central lumen of a catheter to the interior of a compartment). The filter can have any other shape that conforms to the shape of the conduit (e.g., disc-shaped, prismatic, etc.).

[0025] In some embodiments, manufacturing a filter for a blood pump system (such as the systems described herein) includes coating a support material with a hydrogel for a filter medium. For example, the filter medium can be fibers, granules, powders, or any other suitable material. At least one advantage of using a filter that includes a hydrogel and a filter medium is that when placed between two portions of a conduit, the filter permits gas flow between the two portions to allow for sterilization within one of the portions, and can prevent liquid contamination if an aqueous solution attempts to flow between the two portions. The blood pump system includes a conduit that defines at least one lumen having a lumen cross-section. The coated filter medium can be assembled to form a self-sealing filter, the size and shape of which are designed to have a cross-section equal to the lumen cross-section. At least one advantage of assembling the filter in this way is to ensure that the filter fits tightly within the lumen such that it can block or prevent any gas or liquid from passing through the conduit. The self-sealing filter can be positioned at the distal end of a sealed compartment. The elongate conduit (which defines the lumen) is positioned such that the self-sealing filter extends between a portion of the elongate conduit and the sealed compartment. The filter can thus prevent liquid from flowing from one end of the conduit to the other (e.g., from the central lumen of the conduit to the interior of the compartment). A sterilization gas is delivered to the elongate conduit via a hollow tube that extends through at least a portion of the sealed compartment. At least one advantage of using the sterilization gas is to sterilize the central lumen of the conduit such that any fluid within the conduit (e.g., fluid that may contact a patient) remains sterile.

[0026] In some embodiments, gas is permitted to penetrate the conduit to sterilize the central lumen of a multi-lumen conduit. The conduit is positioned across a first opening of a compartment. The compartment is positioned adjacent to the proximal end of the conduit. Fluid travels from an external source through a first lumen to the distal end of the multi-lumen conduit. The self-sealing filter prevents fluid from flowing out of the multi-lumen conduit into the compartment while allowing gas to flow from a first end of the conduit to a second end of the conduit. At least one advantage of preventing leakage through the filter is to prevent liquid from reaching electronic components within the compartment. If liquid contacts any exposed electronic components within the compartment, the liquid may cause a short circuit or damage the electronic components, resulting in the pump ceasing to operate or its operation changing. At least one advantage of permitting gas to pass through the filter is to allow sterilization of the central lumen of the conduit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Illustrates an exemplary blood pump system in accordance with certain embodiments;

[0028] Figure 2 Illustrates a compartment having one side port in accordance with certain embodiments;

[0029] Figure 3 Illustrates a compartment having two side ports in accordance with certain embodiments;

[0030] Figures 4A to 4C Illustrates a self - sealing filter that allows a disinfection gas to pass through and a self - sealing filter that prevents liquid flow, according to certain embodiments;

[0031] Figure 5 Illustrates a lumen within a compartment, according to certain embodiments;

[0032] Figure 6 Illustrates a manufacturing flow chart of an intracardiac blood pump system with leak protection, according to certain embodiments; and

[0033] Figure 7 Illustrates a flow chart for preventing leakage from a catheter of an intravascular blood pump, according to certain embodiments. Detailed Description

[0034] To provide a general understanding of the systems, methods, and devices described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described in connection with use in a percutaneous blood pump system, it should be understood that all of the components and other features outlined below can be combined with each other in any suitable manner and can be adapted and applied to other types of cardiac therapies and cardiac assist devices, including cardiac assist devices implanted using a surgical incision, etc. Additionally, although the application of the pump element has been described herein with respect to a blood pump, it should be understood that the pump element can be applied to other pumps for which any type of fluid flow sent distally can flow proximally and damage electronic components. For example, pumps used in acidic or other corrosive environments may require a purge flow to prevent the entry of acid, which can damage pump components. Although the embodiments and features described herein are specifically described as being used in connection with an intracardiac blood pump system, it should be understood that a blood pump system according to the embodiments and features described herein can be used in any vasculature system and / or in combination with other systems. For example, the filter systems and placement described below can be used in: urethral or bladder catheterization systems; right - heart cardiac support systems; intra - aortic balloon pumps; extracorporeal membrane oxygenation devices; left - ventricular assist devices; kidney support systems, such as cardiac assist devices for regulating renal autoregulation; infusion systems; central venous catheters; or any other suitable system.

[0035] Figure 1 Illustrates an intracardiac blood pump system 150 used in conjunction with filters (e.g., filters 216 and 316), which will be described below in connection with Figure 2 and Figure 3Further description. System 150 includes an elongate catheter body (also referred to as an elongate multi-lumen catheter) 110, a pump 140, a compartment 100, a purification side arm 120, and a pressure side arm 130. The purification side arm 120 includes a fitting 122, an accumulator 124, an infusion filter 128, and a tube 126. The pressure side arm 130 includes a tube 136. The pump 140 includes a pump housing 134, a motor housing 102, an intubation tube 173, a suction head 174, and a flexible protrusion 176. The pump 140 can be inserted into a patient's body by a variety of methods.

[0036] Methods by which the pump 140 can be inserted into a patient's body include, but are not limited to, using over-wire techniques and side-rigger techniques. For example, a first guide wire is inserted into the patient's vasculature, and then a guiding catheter is screwed onto the first guide wire. Subsequently, the first guide wire is removed, thereby allowing a second guide wire to be introduced into the guiding catheter. For example, the second guide wire is stiffer than the first guide wire to facilitate backloading the pump onto the guide wire. Once the stiffer guide wire is in place, the pump can be screwed onto the wire using standard over-wire techniques or side-rigger techniques. The guide wire is removed before the pump is operated. Alternatively, the guide wire is not removed before operation. Alternatively, the pump can be backloaded onto a guide wire inserted through the free space of the pump impeller. In one embodiment, for example, the easy catheter lumen 132 described in U.S. Patent Nos. 8,814,776, 9,402,942, and 9,750,861 (the patents are incorporated herein by reference in their entirety) can be used in conjunction with the guide wire to more easily pass the guide wire through the free space of the impeller to backload the pump without damaging the impeller. The easy catheter lumen 132 is removed before operating the pump, just like the guide wire. In another embodiment, the pump is backloaded onto the guide wire without using the easy catheter lumen.

[0037] In some embodiments, a purification fluid is delivered to the rotor in the pump 140 to keep the pump substantially free of blood. As detailed below, at least one advantage of using a purification fluid is that the flow of the purification fluid can provide a barrier to prevent blood from entering the gap between the rotor and the motor stator or the pump housing, which would otherwise damage the blood (e.g., hemolysis) or damage the motor (e.g., increased friction, overheating, and / or jamming). The purification fluid can be delivered to the proximal end of the intubation tube 173 through the first lumen of the elongate catheter body 110 (e.g., defined by Figure 5 tube 512) through the motor housing 102. The first lumen of the elongate catheter body 110 supplies the purification fluid from a fluid reservoir (not shown) to the pump 140 via the purification side arm 120. The tube 126 partially defines the first lumen of the elongate catheter body 110. The first lumen passes through the compartment 100 (e.g., respectively at Figure 2 , Figure 3 and Figure 5into compartments 200, 300, and 500) and into the elongated catheter body 110, and may include connectors or fittings.

[0038] In some embodiments, the motor is "onboard", as Figure 1 shown, and it can be located within the patient's body during operation of the pump and is configured with electrical leads that transmit electrical power to the motor for driving the pump. As previously described, the motor can alternatively be located outside the patient's body and can actuate the rotor via a drive shaft, drive cable, or drive train. For example, the motor can be located within the handle of the pump system (e.g., connected to compartment 100). In some examples, the drive cable can extend through the elongated catheter body 110 to the rotor located near the proximal end of the cannula 173. In some embodiments, the drive shaft, drive cable, or drive train operates in conjunction with the purified fluid delivery described herein (e.g., through Figure 5 the tube 512) in the

[0039] The purified fluid flows through the pump to prevent blood cells from entering the pump. Alternatively or additionally, the purified fluid can be used as a lubricant for the bearings (not shown) of the pump or as a coolant for dissipating heat generated by the electromagnetic motor coils of the motor stator. The purified fluid can be a lubricant, coolant, drug, or any suitable blood-compatible fluid. For example, the purified fluid can be saline, Ringer's solution, glucose solution, heparin, or any other suitable fluid. The purified fluid prevents blood from entering the motor housing 102 during operation of the pump 140. The purified fluid can also prevent blood from entering the elongated catheter body 110. In some embodiments, a high-viscosity purified fluid (e.g., glucose solution) is used to lubricate the bearings inside the pump 140. In other embodiments, a drug is used as the purified fluid to purify the blood pump and perform a medical purpose. For example, the purified fluid can include heparin to prevent blood clotting. The purified fluid flows through the first lumen of the elongated catheter body 110 and exits the pump 140 at an outlet opening near the proximal portion of the pump 140. The purified fluid is safely dispersed into the patient's bloodstream.

[0040] Another lumen of the elongated catheter body 110 (e.g., formed by Figure 5The tube 516 (defined by the tube 516) can supply pressure fluid to the pump via the pressure side arm 130. The pressure side arm 130 supplies fluid to the fluid-filled pressure lumen, which has an inlet at the proximal end of the motor housing 102. The fluid-filled pressure lumen, in combination with the electronic components located in the compartment 100, can be used to determine the placement of the pump relative to the patient's aortic valve. For example, the electronic component can be a pressure transducer that "translates" the pressure from the pressure lumen into a value that can be output to an external system or display. In some embodiments, a second fluid reservoir or pressure bag (not shown) is connected to the proximal end of the pressure side arm 130 to provide pressure fluid. The pressure fluid can be the same or different from the purification fluid. For example, the pressure fluid can be saline, Ringer's solution, glucose, heparin, or any blood-compatible fluid.

[0041] In some embodiments, the blood pump system 150 includes an optical pressure sensor (e.g., a Fabry - Perot optical pressure sensor) located distal to the motor. An optical fiber extends proximally along a catheter from the optical pressure sensor. The optical pressure sensor includes a cavity terminated by a thin pressure-sensitive glass membrane. The light emitted from the optical fiber is reflected by the glass membrane and enters the optical fiber. The reflected light is transmitted along the length of the optical fiber to an electronic control element (e.g., within the compartment 100 or in a connection console), which determines the pressure signal based on the interference pattern in the reflected light.

[0042] The side ports of the compartment 100 allow fluid connection to the compartment 100, as described in more detail below with respect to Figure 5 The purification side arm 120 and the pressure side arm 130 are connected to the compartment 100 at a first side port (e.g., Figure 5 the tube 526) and a second side port (e.g., Figure 5 the tube 524), respectively. A first lumen (partially defined by the tube 126) and a second lumen (partially defined by the tube 136) extend through the compartment 100 to enter the elongate catheter body 110. In some embodiments, the tube 126 is joined to a tube (e.g., Figure 5 the tube 512) within the compartment 100 at a glued joint at or near the first side port, such that the first lumen extends through the tube 126, through the compartment 100, and through the elongate catheter body 110 to deliver the purification fluid to the pump 140. In some embodiments, the tube 136 is similarly joined to a different tube (e.g., Figure 5 the tube 516) within the compartment 100 at a glued joint at or near the second side port, such that the second lumen extends through the tube 136, through the compartment 100, and through the elongate catheter body 110 to deliver the pressure fluid to the pump 140.

[0043] In some embodiments, the first lumen and the second lumen of the elongate catheter body 110 remain separated from each other. The first lumen and the second lumen may extend through the central lumen of the elongate catheter body 110 and are configured to transport fluid while the central lumen of the elongate catheter body 110 remains free of purge and pressure fluid. However, in the event of a leak from the first or second lumen, the central lumen of the elongate catheter body 110 may transport fluid. For example, during operation of the pump, the first lumen may kink or be accidentally damaged, causing the purge fluid to leak into the central lumen of the elongate catheter body 110. In the event that the leak reaches the central lumen of the elongate catheter body 110, two potential problem situations may occur: (1) the leaked fluid may reach the patient's body (e.g., via the inlets and outlets provided in the pump 140), and (2) the leaked fluid may reach the interior of the compartment 100.

[0044] To reduce or eliminate the chance of danger to the patient in the event of fluid leakage in the central lumen of the elongate catheter body 110, the central lumen is disinfected with a disinfectant gas. The fluids in the first lumen (purge fluid) and the second lumen (pressure fluid) are blood-compatible and thus a leak from the first or second lumen does not pose a risk to the patient by itself, unless the fluid is contaminated (e.g., via bacteria in the central lumen). Due to this potential risk, the central lumen is disinfected even though fluid typically does not flow through the central lumen to the pump 140.

[0045] To disinfect the central lumen, the disinfectant gas enters the central lumen of the elongate catheter body 110 via a conduit (e.g., Figure 2 conduit 214, Figure 3 conduit 314) that extends through an opening in the compartment 100 and into the elongate catheter body 110. The conduit includes a proximal end proximal to the first opening in the compartment 100 and a distal end distal to the first opening. Prior to final assembly of the blood pump system, the proximal end of the conduit 214 can be accessed, for example, through the interior of the compartment 100. By inserting the disinfectant gas through the proximal end of the conduit, the disinfectant gas reaches the central lumen of the elongate catheter body 110. In the event that purge fluid or pressure fluid leaks into the central lumen, the leaked fluid will remain sterile due to the disinfectant gas. At least one advantage of disinfecting the central lumen is that if any leaked fluid reaches the patient (e.g., via the distal end of the intracardiac blood pump system 150), the fluid remains sterile and does not introduce bacteria into the patient's body.

[0046] Because the proximal end of the conduit is located inside the compartment 100 and the distal end of the conduit is located within the central lumen of the elongate catheter body 110, in the event that fluid leaks into the central lumen of the elongate catheter body 110, the leaked fluid may reach the conduit. To prevent leaked fluid from reaching the interior of the compartment 100 (and the electronic components disposed therein) through the conduit, a self-sealing filter (e.g., Figure 2 filter 216 of Figure 3 and filter 316 of Figure 2 is placed within the conduit (e.g., conduit 214 of Figure 3 and conduit 314 of Figures 2 to 5 The self-sealing filter prevents fluid from flowing through the conduit in at least one direction while allowing gas to flow through the conduit. The self-sealing filter allows gas to flow through the conduit but seals when in contact with fluid, preventing fluid from flowing through the conduit in at least one direction. Thus, the sterilizing gas to which the device is exposed prior to any fluid exposure is allowed to pass through the conduit to reach the central lumen of the elongate catheter body 110, but any leaked fluid within the central lumen of the elongate catheter body 110 cannot reach the interior of the compartment 100. Various embodiments of the filter and the blood pump assembly are further described below in connection with

[0047] Figure 2 Figure 200 shows a compartment 200 having a single side port 228 according to certain embodiments. Compartment 200 is similar to Figure 1 compartment 100 but includes a single side port for the purge side arm rather than the two side arms described above. Compartment 200 is connected to catheter 210 by a self-sealing filter 216 to prevent fluid leaking from catheter 210 from reaching the interior of compartment 200. For example, the compartment may be an plug from Abiomed, Inc. A first lumen defined by tubes 226 and 212 extends from outside compartment 200 and through side port 228. Tube 226 may be, for example, similar to tube 126 described above with respect to Figure 1 and may be part of a purge side arm similar to purge side arm 120. The first lumen extends through a portion of the interior of compartment 200, through first opening 250 of the compartment, and through connector 260 to enter catheter 210. In some embodiments, tube 212 extends through first opening 250 and through the length of catheter 210. In some embodiments, connector 260 is a plastic component configured to provide support to the proximal end of catheter 210.

[0048] The conduit 214 extends through the opening 250, through the connector 260 and into the catheter 210. As described above, the conduit 214 may allow gas to penetrate the central lumen of the catheter 210. For example, the gas may be a sterilizing gas configured to sterilize the central lumen of the catheter 210. The conduit 214 is in the shape of a narrow cylinder and is relatively short in length compared to the length of the catheter 210. The proximal end of the conduit 214 is located within the compartment 200 and proximal to the opening 250. The conduit 214 is located within the catheter 210 and distal to the opening 250. In some embodiments, the conduit 214 is in fluid communication with the central lumen of the catheter 210. The conduit 214 is shown as a cylindrical tube. However, the conduit 214 may be a frustum, a narrow cylinder, a curved cylinder, a right prism, or any suitable shape.

[0049] The filter 216 is located within the conduit 214. In some embodiments, the filter 216 is in the shape of a narrow cylinder. In some embodiments, the size and shape of the filter 216 are designed to completely fill the inner diameter of the conduit 214 such that gas or liquid flowing through the conduit 214 will encounter the filter 216, as described in further detail below with reference to Figure 5 The filter 216 allows gas to flow from the proximal end of the conduit 214 to the distal end of the conduit 214, but prevents liquid from the distal end of the conduit 214 from reaching the proximal end of the conduit 214. This configuration allows gas (e.g., sterilizing gas) to reach the central lumen of the catheter 210 before any exposure to liquid, but prevents liquid (e.g., the leaked purification fluid as described above) from reaching within the compartment 200. The conduit 214 and the filter 216 are positioned such that the purification fluid flowing through the first lumen defined by the tubes 226 and 212 does not pass through the conduit 214 and thus does not encounter the filter 216. Thus, the purification fluid can still reach the pump (e.g., pump 140) through the catheter 210 without being blocked by the filter 216.

[0050] At least one electronic component 240 is disposed within the compartment 200. The electronic component 240 may include a pressure sensor, a pump control circuit, a resistor, a capacitor, an inductor, a transistor, wiring, or any other suitable component. Other electronic components (e.g., components such as a printed circuit board (PCB)) may also be disposed within the compartment 200. The proximal end of the compartment 200 (opposite the opening 250) may be connected, for example, to a power source configured to supply power to the electronic component 240. If a liquid (e.g., a purified fluid that has leaked from the first lumen into the central lumen of the conduit 210) enters the interior of the compartment 200, it can short-circuit or damage the electronic component 240. For example, if the electronic component corrodes due to fluid damage, the operation and function of the pump may be damaged or completely stopped, which may be dangerous to the patient. The filter 216 prevents the fluid from reaching the electronic component. In some embodiments, the filter 216 is impermeable to liquid but permeable to gas. Because the size and shape of the filter 216 are designed to fill the inner diameter of the conduit 214, the liquid that might otherwise flow through the conduit 214 (e.g., the purified fluid that has leaked into the central lumen of the conduit 210) will be "blocked" by the filter 216. Since the filter 216 is within the conduit 214 (which extends between the conduit 210 and the compartment 200), it effectively prevents the liquid from reaching the interior of the compartment 200 (which houses the electronic component 240) via the conduit 214.

[0051] Figure 3 A compartment 300 having two side ports is shown in accordance with certain embodiments. Figure 3 Similar to the above Figure 1 and Figure 2 . Regarding Figure 1 , the pressure side arm 330 corresponds to the pressure side arm 130, the purification side arm 320 corresponds to the purification side arm 120, and the conduit 310 corresponds to the elongated conduit body 110. Regarding Figure 2 , the electronic component 340 corresponds to 240, the side port 328 corresponds to the side port 228, the conduit 314 corresponds to the conduit 214, and the filter 316 corresponds to the filter 216. Figure 3 Differing from Figure 2 is that Figure 3 has an additional side port 332. The side port 332 allows connection of the pressure side arm 330, such as the pressure side arm 130 described above with reference to Figure 1 .

[0052] Figures 4A to 4C A semi-permeable filter is shown in accordance with certain embodiments. Figure 4AA semi-permeable filter 416 is shown that allows the airflow indicated by arrow 412 to pass through the conduit 410 before any contact with the liquid. The airflow indicated by arrow 412 enters and passes through the proximal portion 414 of the conduit 410, then through the filter 416, and then through the distal portion 418 of the conduit 410. Figure 4B A filter 416 is shown that prevents the liquid flow indicated by arrow 422 from passing through the conduit 410. The liquid flow indicated by arrow 422 enters the distal portion 418 of the conduit 410 and encounters resistance at the filter 416 such that the liquid flow cannot penetrate the filter 416 and reach the proximal portion 414. Instead, the liquid flow exits the conduit 410 through the distal portion 418. The liquid flow indicated by arrow 422 does not reach the proximal portion 414 of the conduit 410 because the material properties of the filter 416 cause the elements of the filter 416 to swell such that the liquid cannot pass through the entire length of the filter. Figure 4C A filter 416 is shown that allows the airflow indicated by arrow 412 to pass through the conduit 410 while preventing the liquid flow indicated by arrow 422 from passing through the conduit 410. As Figure 4C shown, in some embodiments, the filter 416 can allow gas flow while preventing liquid from flowing through the conduit 410. In some embodiments, the filter 416 self-seals when exposed to liquid. In some embodiments, when the filter 416 has sealed in response to encountering liquid, the filter 416 is also sealed completely or partially to prevent gas flow. For example, if the filter medium of the filter 416 swells to prevent liquid from flowing through the conduit 410, the swollen filter medium can also prevent gas from flowing through the conduit 410. In some embodiments, the filter 416 is permeable to gas but not to liquid.

[0053] In some embodiments, the filter 416 can include a hydrogel that can adhere to the pore walls of a porous matrix. The hydrogel can be a hydrophilic polyurethane, a hydrophilic polyurea, a hydrophilic polyureamine, or any suitable material. A hydrogel is a material that swells in water and retains a large portion of the water without dissolving in water. The porous matrix can be a metal, a ceramic, a glass, an organic, an inorganic, an organic polymer, an acrylic polymer, a polyolefin, or any suitable material or combination thereof. The porous matrix from which the filter 416 can be made is insoluble in water and contains one or more channels or pores through which gas or liquid molecules can pass. This allows gas to pass through the channels. The hydrogel adheres to the porous matrix. When in contact with liquid, the hydrogel swells such that the liquid cannot pass through the channels. Once in contact with liquid, the filter becomes impermeable.

[0054] The mechanical, physical, and chemical properties of the filter 416 can be adjusted by appropriately selecting the matrix and hydrogel materials and the processes used to fabricate the filter material. For example, when rapid self-sealing is desired, pores or channels with a small diameter can be used. When a smaller pressure gradient across the self-sealing filter is desired, pores or channels with a large diameter can be used. The hydrogel can be selected to account for the porosity and composition of the porous matrix. The porous matrix and hydrogel materials can also affect the physical properties of the filter 416 (e.g., strength, flexibility, durability, corrosion resistance, or any other suitable property), and can be selected for the necessary physical properties in a particular application. For example, the material of the filter 416 can be selected to match the flexibility of the conduit 410. In some embodiments, the material of the filter 416 can be selected to be easily implemented in a small geometry (e.g., within the conduit 410). In some embodiments, the material of the filter 416 can be selected to easily form a complete seal with the conduit 410 during the manufacture of the system.

[0055] In some embodiments, the filter 416 is selectively permeable. Due to selectively attracting different types of molecules or bonds, the filter 416 may swell and, in some cases, seal to the particular material when encountering the particular material. For example, the filter 416 can block the flow of dextran by attracting sugar molecules while allowing the flow of water or gas (e.g., a sterilizing gas). In some embodiments, the filter 416 can separate a mixture by chromatography (i.e., by allowing one component of the mixture to flow through the filter while preventing or at least greatly delaying the flow of another component of the mixture).

[0056] Figure 5 The lumen within the compartment 500 is shown in accordance with certain embodiments. Figure 5 Similar to Figure 3 , but additional details of the tube within the compartment 300 as described below are shown. The compartment 500 corresponds to the compartment 300, the conduit 520 corresponds to the conduit 314, and the catheter 510 corresponds to the catheter 310. In some embodiments, the side fitting 502 attaches the pressure side arm (e.g., the pressure side arm 330) to the compartment 500 through the side port 524, and the side fitting 504 attaches the purification side arm (e.g., the purification side arm 320) to the compartment 500 through the side port 526.

[0057] The compartment 500 can contain sensitive electronic devices. The PCB 540 holds the electronic components (e.g., the electronic components 340) inside the compartment 500. Wiring extends from the PCB 540 to the electronic device cable 514. In some embodiments, the electronic device cable 514 is an insulated cable that includes a configuration to supply power to a pump (e.g., Figure 1The drive system of the pump 140) provides at least one wire for electrical power and electronic signals. The electronic device cable 514 extends into the proximal end of the central lumen of the elongate multi-lumen catheter 510. In some embodiments, the electronic device cable 514 extends through the central lumen of the catheter 510 to the distal end of the catheter 510.

[0058] Figure 5 The system includes a series of side connectors and lumens connected to the compartment 500, each of the side connectors and lumens facilitating direct or indirect connection to the catheter 510. The first lumen extends through the side connector 504, the side port 526, a portion of the compartment 500, and into the proximal end of the central lumen of the catheter 510. A portion of the first lumen is defined by the tube 512. The tube 512 exits the compartment 500 through the opening 508 and extends through the connector 560 (when within the catheter 510). In some embodiments, the tube 512 extends from the proximal end of the catheter 510 to the distal end of the catheter 510. For example, the tube 512 may terminate at a pump housing (e.g., Figure 1 the pump housing 134), such that fluid is delivered to a rotor within the pump housing, as described below with respect to Figure 1 described. In some embodiments, the tube 512 terminates at an opening proximal to the distal end of the catheter 510. In some embodiments, the tube 512 extends beyond the distal end of the catheter 510. In some embodiments, the first lumen (partially defined by the tube 512) transports a cleansing fluid. For example, the first lumen may transport glucose, saline, heparin, or any other suitable fluid.

[0059] The second lumen extends through the side connector 502, the side port 524, a portion of the compartment 500, and into the proximal end of the central lumen of the catheter 510. A portion of the first lumen is defined by the tube 516. The tube 516 exits the compartment 500 through the opening 508 and extends through the connector 560 (when within the catheter 510). In some embodiments, the tube 516 extends from the proximal end of the catheter 510 to the distal end of the catheter 510. For example, the tube 516 may terminate at a motor housing (e.g., Figure 1 the motor housing 102), such that fluid is delivered to a motor within the motor housing, as described below with respect to Figure 1 described. In some embodiments, the tube 516 terminates at an opening proximal to the distal end of the catheter 510. In some embodiments, the tube 516 extends beyond the distal end of the catheter 510. In some embodiments, the second lumen (partially defined by the tube 516) transports a pressurized fluid, as described below with respect to Figure 1 described. For example, the first lumen may transport glucose, saline, heparin, or any other suitable fluid.

[0060] The proximal end of the conduit 520 is located within the compartment 500. The conduit 520 is a hollow tube that extends within the central lumen of the catheter 510 and is in fluid communication with the central lumen of the catheter 510. The cross-section of the proximal end of the catheter 510 will show a central lumen surrounding a first lumen defined by the tube 512, a second lumen defined by the tube 516, the electronic device cable 514, and a third lumen defined by the conduit 520. In some embodiments, the conduit 520 is significantly shorter than the catheter 510. For example, the conduit 520 may extend through one percent, two percent, five percent, ten percent, twenty percent, or any other suitable amount of the length of the catheter 510. In some embodiments, the conduit 520 allows for the delivery of a gas to the central lumen of the catheter 510, the gas being configured to disinfect the central lumen. For example, the proximal end of the conduit 520 may be exposed to an external source of disinfecting gas, such as ethylene oxide, nitrogen dioxide, ozone, vaporized hydrogen peroxide, or any other suitable gas.

[0061] As shown in the enlarged portion 506 of the compartment 500, the third lumen defined by the conduit 520 holds a filter 528 (e.g., similar to the filters 416 and 426 of FIG. 4). In some embodiments, the filter 528 is breathable and / or self-sealing when in contact with a liquid. The filter allows the disinfecting gas to pass from the proximal end of the conduit 520 to the distal end. The filter prevents liquid from the central lumen of the catheter 510 from reaching the interior of the compartment 500 and the electronic components located therein. For example, if the tube 512 or the tube 516 is damaged and a purifying fluid or a pressurized fluid leaks into the central lumen of the catheter 510, the filter 528 will prevent the leaked liquid from reaching the compartment via the conduit 520.

[0062] Figure 6 A flowchart is shown for manufacturing an intracardiac blood pump system with leak protection according to certain embodiments. The process 600 begins at step 602, in which a matrix of a support material is coated with a hydrogel. The hydrogel may be a hydrophilic polyurethane, a hydrophilic polyurea, a hydrophilic polyureamine, or any suitable material. The support material may be a porous matrix, such as a metal, a ceramic, a glass, an organic, an inorganic, an organic polymer, an acrylic polymer, a polyolefin, or any suitable material or combination thereof.

[0063] The process 600 continues to step 604, in which the coated filter media are assembled to form a self-sealing filter. In some embodiments, the coated filter media may be assembled into a narrow cylindrical shape. For example, the coated filter media may be assembled to fit tightly within a hollow tube (e.g., Figure 5 the conduit 520). In some embodiments, the coated filter media may be assembled in the shape of a frustum of a cone. For example, a filter made of the coated filter media may plug a hollow tube (e.g.,Figure 5 One end of the pipe 520). In some embodiments, the size and shape of the filter are selected to match the size and shape of the following hollow tube. At least one advantage of adapting the filter to the size of the hollow tube is that the liquid or gas flowing through the hollow tube will pass through the filter. In some embodiments, the filter may fill 20%, 30%, 40%, 50%, 75%, 100% or any other suitable percentage of the length of the hollow tube. In some embodiments, the outer perimeter of the cross-section of the filter may be selected to match the inner perimeter of the cross-section of the hollow tube. For example, the filter can be effectively inserted into the hollow tube and form an aqueous liquid seal between one end of the hollow tube and the other end of the hollow tube. In some embodiments, the cross-section of the filter matches the cross-section of the hollow tube throughout the entire length of the filter. In some embodiments, the cross-section of the filter may match the cross-section of the hollow tube at a first position and be different from the cross-section of the hollow tube at a second position.

[0064] Process 600 continues to step 606, in which the self-sealing filter is positioned at the distal end of a sealed compartment (e.g., Figure 1 Compartment 100). Process 600 continues to step 608, in which the elongate catheter is positioned such that the self-sealing filter extends between a portion of the elongate catheter (e.g., Figure 1 Elongate catheter body 110) and a sealed compartment (e.g., Figure 1 Compartment 100).

[0065] Process 600 continues to step 610, in which the sterilizing gas is delivered to the elongate catheter via the hollow tube (e.g., Figure 5 Pipe 520). In some embodiments, the hollow tube is a narrow hollow cylinder that is relatively short in length compared to the length of the catheter. In some embodiments, the hollow tube is in the shape of a frustum of a cone. Due to the placement of the self-sealing filter (as described in steps 606 and 608) and the hollow tube, when the sterilizing gas flows through the hollow tube, the gas passes from the distal end of the sealed compartment through the filter to the elongate catheter, enabling fluid communication between the compartment and the catheter. However, the filter prevents liquid from passing through the hollow tube while allowing gas to pass through the hollow tube, as described above with respect to Figures 1 to 5 Described.

[0066] Although the steps of process 600 are recited in a particular order, these steps can be completed in any order.

[0067] Figure 7A flowchart for preventing leakage from a catheter of an intracardiac blood pump according to certain embodiments is shown. Process 700 begins at step 702, in which a conduit is positioned across a first opening of a compartment. The compartment is positioned adjacent to the proximal end of a multi-lumen catheter. In some embodiments, the conduit extends from the interior of the compartment into the central lumen of the catheter. The conduit may have a proximal end and a distal end. For example, the compartment and the catheter may be connected with a conduit extending within and between the two such that the proximal end of the conduit is within the compartment and the distal end of the conduit is within the catheter.

[0068] Process 700 continues to step 704, in which a sterilizing gas is allowed to pass through the conduit. The sterilizing gas sterilizes the central lumen of the multi-lumen catheter. In some embodiments, the multi-lumen catheter is a main tube having a first diameter and defining a central lumen, wherein at least one secondary tube extends through the length of the main tube within the central lumen, and the secondary tube has a second diameter smaller than the first diameter. The sterilizing gas may be supplied through the conduit such that it enters the central lumen of the catheter (defined by the main tube). In some embodiments, the pump is exposed to the sterilizing gas by immersion in a gas-saturated environment. Then, the gas may penetrate the proximal end of the conduit that may be within the compartment. Thus, the sterilizing gas is delivered to the interior of the catheter to sterilize the central lumen.

[0069] Process 700 continues to step 706, in which a fluid is caused to flow through a first lumen. The fluid may enter the first lumen from an external source. The first lumen extends through the compartment and reaches the distal end of the multi-lumen catheter. For example, the fluid may pass through the first lumen from an external source to the distal end of the multi-lumen catheter.

[0070] Process 700 continues to step 708, in which a filter prevents liquid from flowing out of the multi-lumen catheter into the compartment while allowing gas to flow from a first end of the conduit to a second end of the conduit. For example, the filter may allow the sterilizing gas to reach the central lumen of the catheter, but may prevent any liquid within the central lumen from reaching the compartment after sterilization.

[0071] Although the steps of process 700 are recited in a particular order, these steps may be completed in any order. In some embodiments, gas permeation must occur before the filter comes into contact with the liquid.

[0072] The foregoing is merely illustrative of the principles of the present disclosure, and these devices may be practiced by other aspects in addition to the aspects described, which are presented for purposes of illustration and not limitation. It should be understood that the devices disclosed herein, although shown for percutaneous insertion of a blood pump, may be applied to devices in other applications that require hemostasis.

[0073] Those skilled in the art will envision variations and modifications after reviewing this disclosure. The disclosed features may be implemented in any combination and sub-combination (including multiple dependent combinations and sub-combinations) with one or more other features described herein. The various features described or shown above, including any of its components, may be combined or integrated in other systems. Additionally, certain features may be omitted or not implemented.

[0074] Examples of variations, substitutions, and alterations may be determined by those skilled in the art and may be made without departing from the scope of the information disclosed herein. All references cited herein are hereby incorporated by reference in their entirety and become a part of this application.

Claims

1. A heart blood pump system, comprising: A pump, comprising a housing and a rotor disposed within the housing; An elongate multi-lumen catheter having a proximal end, a distal end, and a central lumen, wherein the distal end is adjacent to the pump housing; A compartment including a first opening and one or more side ports, the first opening of the compartment being connected to the proximal end of the elongate multi-lumen catheter, the one or more side ports of the compartment being proximal to the first opening of the compartment; At least one electronic component within the compartment; A first lumen of the elongate multi-lumen catheter configured to transport liquid from an external source through the one or more side ports of the compartment and through the first opening of the compartment to the distal end of the elongate multi-lumen catheter; A conduit extending through an interface between the compartment and the multi-lumen catheter, the conduit including a first end proximal to the first opening and a second end distal to the first opening, the conduit being configured to transport gas from the first end of the conduit through the first opening of the compartment to the second end of the conduit, the second end of the conduit being in fluid communication with the central lumen of the elongate multi-lumen catheter; and A filter disposed within the conduit, wherein the filter is configured to prevent liquid from flowing out of the multi-lumen catheter into the compartment.

2. The system according to claim 1, wherein the filter is configured to allow the gas to flow from the first end of the pipe through the second end of the pipe and into the multi-lumen catheter, while preventing the liquid from flowing out of the multi-lumen catheter into the compartment.

3. The system according to any one of the preceding claims, wherein the first lumen passes through the compartment, and wherein the filter is configured to prevent the liquid leaking from the central lumen from passing through the pipe and reaching the compartment.

4. The system according to any one of the preceding claims, wherein the filter is proximal to the first opening of the compartment.

5. The system according to any one of the preceding claims, wherein the filter is distal to the first opening of the compartment.

6. The system according to any one of the preceding claims, wherein the filter extends through the first opening of the compartment.

7. The system according to any one of the preceding claims, wherein a portion of the filter extends within the compartment.

8. The system according to any one of the preceding claims, wherein the liquid comprises at least one of the following: blood, saline, purification fluid, heparin, and glucose.

9. The system according to any one of the preceding claims, wherein the liquid comprises a purification fluid, and the purification fluid flows through the first lumen to the rotor to keep the pump substantially free of blood.

10. The system according to any one of the preceding claims, wherein the filter self-seals when exposed to liquid.

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